Virtual Journal of Ultrafast Science

Three dimensional laser microfabrication in diamond using a dual adaptive optics system

Richard D. Simmonds, Patrick S. Salter, Alexander Jesacher, and Martin J. Booth
Femtosecond laser fabrication of controlled three dimensional structures deep in the bulk of diamond is facilitated by a dual adaptive optics system. A deformable mirror is used in parallel with a liquid crystal spatial light modulator to compensate the extreme aberrations caused by the refractive i ... [Opt. Express 19, 24122 (2011)] published Thu Dec 1, 2011.

Low-loss channel optical waveguide fabrication in Nd-doped silicate glasses by femtosecond laser direct writing

Shi-Ling Li, Peigao Han, Meng Shi, Yicun Yao, Bing Hu et al.
Optical waveguides were fabricated in neodymium-doped silicate glass by using a low-repetition-rate (1 kHz) femtosecond laser inscription. Two different types of waveguide structure are fabricated. In the first, guiding occurs in the focal spot. In the second, guiding occurs in the region between th ... [Opt. Express 19, 23958 (2011)] published Thu Dec 1, 2011.

All-optical 1st and 2nd order integration on a chip

Marcello Ferrera, Yongwoo Park, Luca Razzari, Brent E. Little, Sai T. Chu et al.
We demonstrate all-optical temporal integration of arbitrary optical waveforms with temporal features as short as ~1.9ps. By using a four-port micro-ring resonator based on CMOS compatible doped glass technology we perform the 1st- and 2nd-order cumulative time integral of optical signals over a ban ... [Opt. Express 19, 23153 (2011)] published Thu Dec 1, 2011.

Nonlinear-optical brain anatomy by harmonic-generation and coherent Raman microscopy on a compact femtosecond laser platform

Lyubov V. Doronina-Amitonova, Aleksandr A. Lanin, Olga I. Ivashkina, Marina A. Zots, Andrei B. Fedotov et al.
An extended-cavity Cr:forsterite laser is integrated with a photonic-crystal fiber soliton frequency shifter and a periodically poled lithium niobate spectrum compressor for simultaneous harmonic-generation and coherent Raman brain imaging. Adapting the laser beam focusing geometry to the tissue mor ... [Appl. Phys. Lett. 99, 231109 (2011)] published Thu Dec 8, 2011.

Attoclock reveals natural coordinates of the laser-induced tunnelling current flow in atoms

Adrian N. Pfeiffer, Claudio Cirelli, Mathias Smolarski, Darko Dimitrovski, Mahmoud Abu-samha et al.
In the research area of strong-laser-field interactions and attosecond science, tunnelling of an electron through the barrier formed by the electric field of the laser and the atomic potential is typically assumed to be the initial key process that triggers subsequent dynamics. Here we use the atto ... [Nature Phys. 8, 76 (2011)] published Thu Dec 22, 2011.

Probing dielectric-response effects with attosecond time-resolved streaked photoelectron spectroscopy of metal surfaces

C.-H. Zhang and U. Thumm
The release of conduction-band electrons from a metal surface by a subfemtosecond extreme ultraviolet (XUV) pulse and their propagation through the solid provoke a dielectric response in the solid that acts back on the photoelectron wave packet. We calculated the (wake) potential associated with thi ... [Phys. Rev. A 84, 063403 ] published .

Optimization of three-color laser field for the generation of single ultrashort attosecond pulse

Peng-Cheng Li, I-Lin Liu, and Shih-I Chu
We present an efficient and realizable scheme for the generation of an ultrashort single attosecond (as) pulse. The feasibility of such a scheme is demonstrated by solving accurately the time-dependent Schrodinger equation using the time-dependent generalized pseudospectral (TDGPS) method. This sche ... [Opt. Express 19, 23857 (2011)] published Thu Dec 1, 2011.

Theory of ac Stark splitting in core-resonant Auger decay in strong x-ray fields

L. A. A. Nikolopoulos, T. J. Kelly, and J. T. Costello
In this work we report the modification of the normal Auger line shape under the action of an intense x-ray radiation. Under strong Rabi-type coupling of the core, the Auger line profile develops into a doublet structure with an energy separation mainly determined by the relative strength of the Rab ... [Phys. Rev. A 84, 063419 ] published .

Attosecond control of dissociative ionization of O molecules

W. Siu, F. Kelkensberg, G. Gademann, A. Rouzee, P. Johnsson et al.
We demonstrate that dissociative ionization of O can be controlled by the relative delay between an attosecond pulse train (APT) and a copropagating infrared (IR) field. Our experiments reveal a dependence of both the branching ratios between a range of electronic states and the fragment angular dis ... [Phys. Rev. A 84, 063412 ] published .

Time delay between photoemission from the 2p and 2s subshells of neon

L. R. Moore, M. A. Lysaght, J. S. Parker, H. W. van der Hart, and K. T. Taylor
The R-matrix incorporating time (RMT) method is a method developed recently for solving the time-dependent Schrodinger equation for multielectron atomic systems exposed to intense short-pulse laser light. We have employed the RMT method to investigate the time delay in the photoemission of an electr ... [Phys. Rev. A 84, 061404 ] published .

Compression methods for XUV attosecond pulses

Mark Mero, Fabio Frassetto, Paolo Villoresi, Luca Poletto, and Katalin Varju
Attosecond extreme-ultraviolet (XUV) pulses generated in gases via high-order harmonic generation typically carry an intrinsic positive chirp. Compression of such pulses has been demonstrated using metallic transmission filters, a method with very limited tunability. We compare here the compression ... [Opt. Express 19, 23420 (2011)] published Thu Dec 1, 2011.

Optimizing intracavity high harmonic generation for XUV fs frequency combs

Jane Lee, David R. Carlson, and R. Jason Jones
Previous work has shown that use of a passive enhancement cavity designed for ultrashort pulses can enable the up-conversion of the fs frequency comb into the extreme ultraviolet (XUV) spectral region utilizing the highly nonlinear process of high harmonic generation. This promising approach for an ... [Opt. Express 19, 23315 (2011)] published Thu Dec 1, 2011.

Precise evaluation of polarization mode dispersion by separation of even- and odd-order effects in quantum interferometry

A. Fraine, D. S. Simon, O. Minaeva, R. Egorov, and A. V. Sergienko
The use of quantum correlations between photons to separate measure even- and odd-order components of polarization mode dispersion (PMD) and chromatic dispersion in discrete optical elements is investigated. Two types of apparatus are discussed which use coincidence counting of entangled photon pair ... [Opt. Express 19, 22820 (2011)] published Thu Dec 1, 2011.

The influence of plasma defocusing in high harmonic generation

Chien-Jen Lai and Franz X. Kartner
We numerically investigate the influence of plasma defocusing in high harmonic generation (HHG) by solving the first-order wave equation in an ionized medium and defining an enhancement factor to quantitatively analyze the influence of plasma defocusing. While degrading the driver pulse intensity, p ... [Opt. Express 19, 22377 (2011)] published Thu Dec 1, 2011.

Time-and-energy-resolved measurement of Auger cascades following Kr 3d excitation by attosecond pulses

A Verhoef, A Mitrofanov, X Nguyen, M Krikunova, S Fritzsche et al.
We show that attosecond metrology has evolved from proof-of-principle experiments to a level where complex processes can be resolved in time that cannot be accessed using any other existing technique. The cascaded Auger decay following ionization and excitation of the 3d-subshell in Kr with subfemto ... [New J. Phys. 13, 113003 (2011)] published Thu Dec 1, 2011.

Efficient control of quantum paths via dual-gas high harmonic generation

A Willner, F Tavella, M Yeung, T Dzelzainis, C Kamperidis et al.
The accurate control of the relative phase of multiple distinct sources of radiation produced by high harmonic generation is of central importance in the continued development of coherent extreme UV (XUV) and attosecond sources. Here, we present a novel approach which allows extremely accurate phase ... [New J. Phys. 13, 113001 (2011)] published Thu Dec 1, 2011.

Ultrafast nonlinear optics in gas-filled hollow-core photonic crystal fibers [Invited]

John C. Travers, Wonkeun Chang, Johannes Nold, Nicolas Y. Joly, and Philip St. J. Russell
We review the use of hollow-core photonic crystal fibers (PCFs) in the field of ultrafast gas-based nonlinear optics, including recent experiments, numerical modeling, and a discussion of future prospects. Concentrating on broadband guiding kagome-style h ... [J. Opt. Soc. Am. B 28, A11 (2011)] published Fri Dec 23, 2011.

Control of high-order harmonics for attoscience using a static-electric-field pattern

Carles Serrat
Quantum control in high-order-harmonic generation is considered theoretically by using a spatial distribution of static electric fields along the propagation direction of the driving field. It is shown that the trajectories of the electrons during its acceleration by the laser field in the high-harm ... [Phys. Rev. A 84, 061803 ] published .

High-order-harmonic generation in gas with a flat-top laser beam

W. Boutu, T. Auguste, O. Boyko, I. Sola, Ph. Balcou et al.
We present experimental and numerical results on high-order-harmonic generation with a flat-top laser beam. We show that a simple binary tunable phase plate, made of two concentric glass plates, can produce a flat-top profile at the focus of a Gaussian infrared beam. Both experiments and numerical c ... [Phys. Rev. A 84, 063406 ] published .

Conical emission from laser filaments and higher-order Kerr effect in air

P. Bejot and J. Kasparian
We numerically investigate the conical emission (CE) from ultrashort laser filaments, both considering and disregarding the higher-order Kerr effect (HOKE). While the consideration of HOKE has almost no influence on the predicted CE from collimated beams, differences arise for tightly focused beams. ... [Opt. Lett. 36, 4812 (2011)] published Tue Dec 20, 2011.

Kadomtsev-Petviashvili solitons propagation in a plasma system with superthermal and weakly relativistic effects

Hafeez-Ur-Rehman, Asif Shah, S. Mahmood, and Q. Haque
Two dimensional (2D) solitons are studied in a plasma system comprising of relativistically streaming ions, kappa distributed electrons, and positrons. Kadomtsev-Petviashvili (KP) equation is derived through the reductive perturbation technique. Analytical solution of the KP equation has been studie ... [Phys. Plasmas 18, 122302 (2011)] published Tue Dec 13, 2011.

Molecular dynamic studies on anisotropy of atomic cluster explosions driven by few-cycle intense lasers

Gaurav Mishra and N. Gupta
The dynamical processes following the irradiation of various argon clusters (1658) with high-intensity lasers (510W/cm310W/cm) of femtosecond pulse durations (5100fs) are modelled using a three-dimensional relativistic time-dependent molecular dynamic approach. Various parameters governing the clust ... [EPL 96, 63001 (2011)] published Thu Dec 22, 2011.

Enhanced thermal self-focusing of a Gaussian laser beam in a collisionless plasma

Devki Nandan Gupta and Hyyong Suk
Theory given by Wang-Zhou [Phys. Plasmas 18, 043101 (2011)] for the thermal self-focusing of a Gaussian laser beam in a collisionless plasma is revisited by including the effect of a localized upward plasma-density ramp. As the equilibrium electron density is an increasing function of the distance o ... [Phys. Plasmas 18, 124501 (2011)] published Wed Dec 7, 2011.

Equation of motion with radiation reaction in ultrarelativistic laser-electron interactions

Keita Seto, Hideo Nagatomo, James Koga, and Kunioki Mima
The intensity of the ultra-short pulse lasers has reached 10 W/cm owing to the advancements of laser technology. When the motion of an electron becomes relativistic, bremsstrahlung accompanies it. The energy from this bremsstrahlung corresponds to the energy loss of the electron; therefore, the moti ... [Phys. Plasmas 18, 123101 (2011)] published Fri Dec 2, 2011.

Measurements and simulations of shock wave generated plasma-vacuum interface

D. Kaganovich, M. H. Helle, D. F. Gordon, and A. Ting
A controlled gradient gas jet was designed, constructed, and tested at the Naval Research Laboratory for the generation of high density and sharp gradient plasma regions. The gas jet uses a laser-generated shock wave to control the density gradient at the vacuum and neutral gas interface. The length ... [Phys. Plasmas 18, 120701 (2011)] published Wed Dec 21, 2011.

Study of self-generated magnetic fields in laser produced plasmas using a three-channel polaro-interferometer

Y. B. S. R. Prasad, S. Barnwal, E. A. Bolkhovitinov, P. A. Naik, M. P. Kamath et al.
Self-generated magnetic fields produced in laser plasmas at moderate laser intensities have been measured using a three-channel polaro-interferometer. The main elements of this device are two birefringent calcite wedges placed between two crossed polarizers. Using this device, the spatial profiles o ... [Rev. Sci. Instrum. 82, 123506 (2011)] published Fri Dec 23, 2011.

A novel zirconium Kalpha imager for high energy density physics research

K. U. Akli, M. Sanchez del Rio, S. Jiang, M. S. Storm, A. Krygier et al.
We report on the development and characterization of a zirconium Kalpha imager for high energy density physics research. The imager consists of a spherically bent quartz crystal operating at 15.7 keV photon energy. We compare the performance of the imager in terms of integrated reflectivity (R) and ... [Rev. Sci. Instrum. 82, 123503 (2011)] published Mon Dec 12, 2011.

Energetics and energy scaling of quasi-monoenergetic protons in laser radiation pressure acceleration

Tung-Chang Liu, Xi Shao, Chuan-Sheng Liu, Jao-Jang Su, Bengt Eliasson et al.
Theoretical and computational studies of the ion energy scaling of the radiation pressure acceleration of an ultra-thin foil by short pulse intense laser irradiation are presented. To obtain a quasi-monoenergetic ion beam with an energy spread of less than 20%, two-dimensional particle-in-cell simul ... [Phys. Plasmas 18, 123105 (2011)] published Thu Dec 29, 2011.

Modeling of 10 GeV-1 TeV laser-plasma accelerators using Lorentz boosted simulations

J.-L. Vay, C. G. R. Geddes, E. Esarey, C. B. Schroeder, W. P. Leemans et al.
Modeling of laser-plasma wakefield accelerators in an optimal frame of reference [J.-L. Vay, Phys. Rev. Lett. 98, 130405 (2007)] allows direct and efficient full-scale modeling of deeply depleted and beam loaded laser-plasma stages of 10 GeV-1 TeV (parameters not computationally accessible otherwise ... [Phys. Plasmas 18, 123103 (2011)] published Tue Dec 13, 2011.

Hollow-core photonic band gap fibers for particle acceleration

Robert J. Noble, James E. Spencer, and Boris T. Kuhlmey
Photonic band gap (PBG) dielectric fibers with hollow cores are being studied both theoretically and experimentally for use as laser driven accelerator structures. The hollow core functions as both a longitudinal waveguide for the transverse-magnetic (TM) accelerating fields and a channel for the ch ... [Phys. Rev. ST Accel. Beams 14, 121303 ] published .

Laser accelerated protons captured and transported by a pulse power solenoid

T. Burris-Mog, K. Harres, F. Nurnberg, S. Busold, M. Bussmann et al.
Using a pulse power solenoid, we demonstrate efficient capture of laser accelerated proton beams and the ability to control their large divergence angles and broad energy range. Simulations using measured data for the input parameters give inference into the phase-space and transport efficiencies of ... [Phys. Rev. ST Accel. Beams 14, 121301 ] published .

Harmonic radiation of a relativistic nonlinear inverse Compton scattering using two laser wavelengths

Y. Sakai, O. Williams, G. Andonian, A. Fukasawa, E. Hemsing et al.
The use of two different wavelength lasers in the nonlinear regime of the inverse Compton scattering interaction is proposed in order to provide a new strategy for controlling scattered photon energy distributions in the x-ray to gamma-ray spectral region. In this nonlinear interaction, the componen ... [Phys. Rev. ST Accel. Beams 14, 120702 ] published .

Tunable Radiation Source by Coupling Laser-Plasma-Generated Electrons to a Periodic Structure

Z. Jin (金展), Z. L. Chen (陈正林), H. B. Zhuo (卓红斌), A. Kon (今亮), M. Nakatsutsumi (中堤基彰) et al.
Near-infrared radiation around 1000 nm generated from the interaction of a high-density MeV electron beam, obtained by impinging an intense ultrashort laser pulse on a solid target, with a metal grating is observed experimentally. Theoretical modeling and particle-in-cell simulation suggest that the ... [Phys. Rev. Lett. 107, 265003 ] published .

Laser Shaping of a Relativistic Intense, Short Gaussian Pulse by a Plasma Lens

H. Y. Wang, C. Lin, Z. M. Sheng, B. Liu, S. Zhao et al.
By 3D particle-in-cell simulation and analysis, we propose a plasma lens to make high intensity, high contrast laser pulses with a steep front. When an intense, short Gaussian laser pulse of circular polarization propagates in near-critical plasma, it drives strong currents of relativistic electrons ... [Phys. Rev. Lett. 107, 265002 ] published .

Symmetry breaking from radiation reaction in ultra-intense laser fields

Chris Harvey, Thomas Heinzl, and Mattias Marklund
We discuss radiation reaction effects on charges propagating in ultraintense laser fields. Our analysis is based on an analytic solution of the Landau-Lifshitz equation. We suggest quantifying radiation reaction in terms of a symmetry breaking parameter associated with the violation of null translat ... [Phys. Rev. D 84, 116005 ] published .

Radiative polarization of electrons in a strong laser wave

Dmitry V. Karlovets
We reanalyze the problem of radiative polarization of electrons brought into collision with a circularly polarized strong plane wave. We present an independent analytical verification of formulas for the cross section given by Ivanov et al. [Eur. Phys. J. C 36, 127 (2004)]. By choosing the exact ele ... [Phys. Rev. A 84, 062116 ] published .

Comparison of the electron density measurements using Thomson scattering and emission spectroscopy for laser induced breakdown in one atmosphere of helium

E. Nedanovska, G. Nersisyan, T. J. Morgan, L. Huwel, C. L. S. Lewis et al.
Thomson scattering from laser-induced plasma in atmospheric helium was used to obtain temporally and spatially resolved electron temperature and density profiles. Electron density measurements at 5 [mu]s after breakdown are compared with those derived from the separation of the allowed and forbidden ... [Appl. Phys. Lett. 99, 261504 (2011)] published Wed Dec 28, 2011.

Intense terahertz emission from atomic cluster plasma produced by intense femtosecond laser pulses

Fazel Jahangiri, Masaki Hashida, Takeshi Nagashima, Shigeki Tokita, Masanori Hangyo et al.
Terahertz (THz) emission from argon cluster plasma, generated by intense femtosecond laser pulses in the energy range of 1070 mJ, has been investigated. THz polarization, energy dependence, and angular distribution were measured to provide an initial discussion on the mechanisms of THz emission. THz ... [Appl. Phys. Lett. 99, 261503 (2011)] published Wed Dec 28, 2011.

Laser guiding plasma channel formation criterion in highly relativistic regime

Y. J. Gu, Z. Zhu, Q. Kong, Y. Y. Li, X. F. Li et al.
Self-formed plasma channels induced by ultra-intense and ultra-short laser pulses have been investigated with 2.5-dimensional particle-in-cell simulations. A criterion of channel formation under the highly relativistic regime is proposed and tested by simulation results. Good matches between criteri ... [Appl. Phys. Lett. 99, 241501 (2011)] published Wed Dec 14, 2011.

Effect of air breakdown with a focusing lens on ultrashort laser ablation

Wenqian Hu, Yung C. Shin, and Galen King
The effect of air breakdown on ultrashort laser ablation is investigated in this letter using an integrated simulation method on atomistic level. The generation of air breakdown with different laser peak power densities in the range from 10 to 10 W/cm and various focusing conditions is analyzed. Air ... [Appl. Phys. Lett. 99, 234104 (2011)] published Tue Dec 6, 2011.

Dynamic behavior of postfilamentation Raman pulses

Jean-Francois Daigle, Tie-Jun Wang, Sima Hosseini, Shuai Yuan, Gilles Roy et al.
We report on the postfilamentation behavior of a Stokes pulse created from intense and collimated ultrashort pulses propagating in air. A systematic analysis of the pulse propagation revealed that the redshifted Raman pulse produced during filamentation had a larger divergence than the postfilamenta ... [Appl. Opt. 50, 6234 (2011)] published Wed Dec 7, 2011.

Ultrafast laser ablation of gold thin film targets

S. Amoruso, N. N. Nedyalkov, X. Wang, G. Ausanio, R. Bruzzese et al.
Ultrafast laser ablation of a gold thin film is studied and compared with that of a bulk target, with particular emphasis given to the process of nanoparticles generation. The process is carried out in a condition where a single laser shot removes all the irradiated film spot. The experimental resul ... [J. Appl. Phys. 110, 124303 (2011)] published Mon Dec 19, 2011.

Femtosecond laser tuning of silicon microring resonators

Daniel Bachman, Zhijiang Chen, Ashok M. Prabhu, Robert Fedosejevs, Ying Y. Tsui et al.
Femtosecond laser modification is demonstrated as a possible method for postfabrication tuning of silicon microring resonators. Single 400 nm femtosecond laser pulses were used to modify the effective index of crystalline silicon microring waveguides by either amorphization or surface nanomilling de ... [Opt. Lett. 36, 4695 (2011)] published Mon Dec 5, 2011.

Full-band quantum-dynamical theory of saturation and four-wave mixing in graphene

Zheshen Zhang and Paul L. Voss
The linear and nonlinear optical response of graphene are studied within a quantum-mechanical, full-band, steady-state density-matrix model. This nonpurtabative method predicts the saturatable absorption and saturable four-wave mixing of graphene. The model includes tau and tau time constants that d ... [Opt. Lett. 36, 4569 (2011)] published Mon Dec 5, 2011.

Strain field manipulation in ultrafast laser inscribed BiBO optical waveguides for nonlinear applications

S. J. Beecher, R. R. Thomson, D. T. Reid, N. D. Psaila, M. Ebrahim-Zadeh et al.
A novel technique was used to control the spatial overlap of the orthogonal linearly polarized waveguide modes in ultrafast laser inscribed BiBO waveguides. We report that the strain fields induced by the expansion of material in the laser focus can be considered independently in the design of type ... [Opt. Lett. 36, 4548 (2011)] published Mon Dec 5, 2011.

Impact of dispersion profiles of silicon waveguides on optical parametric amplification in the femtosecond regime

Zhaolu Wang, Hongjun Liu, Nan Huang, Qibing Sun, and Jin Wen
The impact of dispersion profiles of silicon waveguides on femtosecond optical parametric amplification (OPA) is theoretically investigated. It is found that flat quasi-phase-matching, smooth temporal profiles and separable spectra for 200 fs pulses can be obtained by tailoring the cross-section of ... [Opt. Express 19, 24730 (2011)] published Thu Dec 1, 2011.

10Gbit/s all-optical NRZ-OOK to RZ-OOK format conversion in an ultra-small III-V-on-silicon microdisk fabricated in a CMOS pilot line

Rajesh Kumar, Thijs Spuesens, Pauline Mechet, Nicolas Olivier, Jean-Marc Fedeli et al.
We report the demonstration of an all-optical, bias free and error-free (bit-error-rate ~10), 10Gbit/s non-return-to-zero (NRZ) to return-to-zero (RZ) data format conversion using a 7.5[mu]m diameter III-V-on-silicon microdisk resonator. The device is completely processed in a 200mm CMOS pilot line. ... [Opt. Express 19, 24647 (2011)] published Thu Dec 1, 2011.

Ultrafast all-optical switching in a silicon-based plasmonic nanoring resonator

S. Sederberg, D. Driedger, M. Nielsen, and A.Y. Elezzabi
A silicon-based plasmonic nanoring resonator is proposed for ultrafast, all-optical switching applications. Full-wave numerical simulations demonstrate that the photogeneration of free carriers enables ultrafast switching of the device by shifting the transmission minimum of the resonator with a swi ... [Opt. Express 19, 23494 (2011)] published Thu Dec 1, 2011.

Extremely nondegenerate two-photon absorption in direct-gap semiconductors [Invited]

Claudiu M. Cirloganu, Lazaro A. Padilha, Dmitry A. Fishman, Scott Webster, David J. Hagan et al.
Two-photon absorption (2PA) spectra with pairs of extremely nondegenerate photons are measured in several direct-gap semiconductors (GaAs, CdTe, ZnO, ZnS and ZnSe) using picosecond or femtosecond pulses. In ZnSe, using photons with a ratio of energies of ~12, we obtain a 270-fold enhancement of 2PA ... [Opt. Express 19, 22951 (2011)] published Thu Dec 1, 2011.

Reducing multi-photon rates in pulsed down-conversion by temporal multiplexing

M. A. Broome, M. P. Almeida, A. Fedrizzi, and A. G. White
We present a simple technique to reduce the emission rate of higher-order photon events from pulsed spontaneous parametric down-conversion. The technique uses extra-cavity control over a mode locked ultrafast laser to simultaneously increase repetition rate and reduce the energy of each pulse from t ... [Opt. Express 19, 22698 (2011)] published Thu Dec 1, 2011.

Laser mode feeding by shaking quantum dots in a planar microcavity

C. Brggemann, A. V. Akimov, A. V. Scherbakov, M. Bombeck, C. Schneider et al.
Semiconductor light emission can be changed considerably in an optical resonator. Prerequisite is that the electronic transitions involved in light generation are in resonance with a cavity mode. Although resonance can be arranged through dedicated fabrication, there are cases where this is virtuall ... [Nat. Photonics 6, 30 (2011)] published Thu Dec 22, 2011.

Bistability and instability of dark-antidark solitons in the cubic-quintic nonlinear Schrodinger equation

M. Crosta, A. Fratalocchi, and S. Trillo
We characterize the full family of soliton solutions sitting over a background plane wave and ruled by the cubic-quintic nonlinear Schrodinger equation in the regime where a quintic focusing term represents a saturation of the cubic defocusing nonlinearity. We discuss the existence and properties of ... [Phys. Rev. A 84, 063809 ] published .

Supercontinuum Generation with Femtosecond Self-Healing Airy Pulses

Craig Ament, Pavel Polynkin, and Jerome V. Moloney
We report experiments and numerical simulations on supercontinuum generation with femtosecond Airy pulses in a highly nonlinear optical fiber. The ability of the Airy waveform to regenerate its dominant intensity peak results in the generation of distinct spectral features. Airy pulses and other sel ... [Phys. Rev. Lett. 107, 243901 ] published .

Terahertz generation from laser filaments in the presence of a static electric field in a plasma

Lalita Bhasin and V. K. Tripathi
Two femtosecond laser pulses with frequencies omega and omega that undergo filamentation in a plasma couple nonlinearly in the presence of a transverse, static electric field to generate terahertz wave at the frequency omega-omega. The coupling is enhanced in the presence of the static electric fiel ... [Phys. Plasmas 18, 123106 (2011)] published Thu Dec 29, 2011.

Higher-Order Modulation Instability in Nonlinear Fiber Optics

Miro Erkintalo, Kamal Hammani, Bertrand Kibler, Christophe Finot, Nail Akhmediev et al.
We report theoretical, numerical, and experimental studies of higher-order modulation instability in the focusing nonlinear Schrodinger equation. This higher-order instability arises from the nonlinear superposition of elementary instabilities, associated with initial single breather evolution follo ... [Phys. Rev. Lett. 107, 253901 ] published .

Two-photon indirect optical injection and two-color coherent control in bulk silicon

J. L. Cheng, J. Rioux, and J. E. Sipe
Using an empirical pseudopotential description of electron states and an adiabatic bond charge model for phonon states in bulk silicon, we theoretically investigate two-photon indirect optical injection of carriers and spins and two-color coherent control of the motion of the injected carriers and s ... [Phys. Rev. B 84, 235204 ] published .

Effect of wave-function localization on the time delay in photoemission from surfaces

C.-H. Zhang and U. Thumm
We investigate streaking time delays in the photoemission from a solid model surface as a function of the degree of localization of the initial-state wave functions. We consider a one-dimensional slab with lattice constant a of attractive Gaussian-shaped core potentials of width sigma. The parameter ... [Phys. Rev. A 84, 065403 ] published .

Nonponderomotive electron acceleration in ultrashort surface-plasmon fields

Peter Racz and Peter Dombi
We investigate the nonponderomotive nature of ultrafast plasmonic electron acceleration in strongly decaying electromagnetic fields generated by few-cycle and single-cycle femtosecond laser pulses. We clearly identify the conditions contributing to nonponderomotive acceleration and establish fundame ... [Phys. Rev. A 84, 063844 ] published .

Quantum complementarity of cavity photons coupled to a three-level system

R. Vilardi, A. Ridolfo, S. Portolan, S. Savasta, and O. Di Stefano
Recently a device enabling the ultrafast all-optical control of the wave-particle duality of light was proposed [Ridolfo et al., Phys. Rev. Lett. 106, 013601 (2011)]. It is constituted by a three-level quantum emitter strongly coupled to a microcavity and can be realized by exploiting a great variet ... [Phys. Rev. A 84, 063842 ] published .

Broadband colored-crescent generation in a single beta-barium-borate crystal by intense femtosecond pulses

L. Wang, Y. X. Fan, H. Zhu, Z. D. Yan, H. Zeng et al.
A visible colored crescent with a bandwidth broader than 220 nm is observed experimentally by loosely focused femtosecond pulses in a bulk quadratic nonlinear crystal (beta-BBO crystal) at certain incident angles. Through the analysis based on a simple collinear phase-matching model, we suggest that ... [Phys. Rev. A 84, 063831 ] published .

Chirped femtosecond solitons and double-kink solitons in the cubic-quintic nonlinear Schrodinger equation with self-steepening and self-frequency shift

Alka, Amit Goyal, Rama Gupta, C. N. Kumar, and Thokala Soloman Raju
We demonstrate that the competing cubic-quintic nonlinearity induces propagating solitonlike dark(bright) solitons and double-kink solitons in the nonlinear Schrodinger equation with self-steepening and self-frequency shift. Parameter domains are delineated in which these optical solitons exist. Als ... [Phys. Rev. A 84, 063830 ] published .

Conservation of the photon number in the generalized nonlinear Schrodinger equation in axially varying optical fibers

O. Vanvincq, J. C. Travers, and A. Kudlinski
We reexamine the derivation of the generalized nonlinear Schrodinger equation in the case of nonaxially uniform optical fibers, taking into account the longitudinal and spectral evolutions of all pertinent linear parameters. Our theory leads to an improved form of this equation that highlights an ad ... [Phys. Rev. A 84, 063820 ] published .

Enhancement of peak intensity in a filament core with spatiotemporally focused femtosecond laser pulses

Bin Zeng, Wei Chu, Hui Gao, Weiwei Liu, Guihua Li et al.
We demonstrate that the peak intensity in the filament core, which is inherently limited by the intensity clamping effect during femtosecond laser filamentation, can be significantly enhanced using spatiotemporally focused femtosecond laser pulses. In addition, the filament length obtained by spatio ... [Phys. Rev. A 84, 063819 ] published .

Time-resolved femtosecond optical characterization of multi-photon absorption in high-pressure-grown AlGaN single crystals

Jie Zhang, Andrey Belousov, Janusz Karpinski, Bertram Batlogg, Gary Wicks et al.
We report our experimental studies on time-resolved pumpprobe spectroscopy in high-quality AlGaN single crystals, grown using a solution technique in a high-nitrogen-gas-pressure system. Our optical measurements were performed using a non-traditional, two-beam [one ultraviolet (UV) and one infrared ... [J. Appl. Phys. 110, 113112 (2011)] published Mon Dec 12, 2011.

Ultrafast two-bit all-optical analog-to-digital conversion based on femtosecond soliton sequence sampling

Aida Esmaeilian-Marnani, Ahmad Fauzi Abas, Mohd Adzir Mahdi, and Khairulmizam Samsudin
Realization of two-bit all-optical analog-to-digital conversion for an analog signal sampled by a femtosecond soliton sequence is investigated. Two approaches are suggested. The first one is based on filtering the broadened soliton spectrum after evolution over half of the soliton period in a standa ... [Opt. Eng. 50, 125001 (2011)] published Thu Nov 17, 2011.

Photoluminescence and ultrafast intersubband relaxation in Ge/SiGe multiple quantum wells

E. Gatti, E. Grilli, M. Guzzi, D. Chrastina, G. Isella et al.
The intricate relaxation dynamics in compressively strained Ge quantum wells with Ge-rich SiGe barriers is investigated systematically for various excitation conditions. Evidence of efficient ultrafast intersubband relaxation in competition with the intrasubband electron cooling is found in continuo ... [Phys. Rev. B 84, 245319 ] published .

Quantum control of a Landau-quantized two-dimensional electron gas in a GaAs quantum well using coherent terahertz pulses

T. Arikawa, X. Wang, D. J. Hilton, J. L. Reno, W. Pan et al.
We demonstrate coherent control of cyclotron resonance in a two-dimensional electron gas (2DEG). We use a sequence of terahertz (THz) pulses to control the amplitude of coherent cyclotron resonance oscillations in an arbitrary fashion via phase-dependent coherent interactions. We observe a self-inte ... [Phys. Rev. B 84, 241307 ] published .

Sub-100 fs charge transfer in a novel donoracceptordonor triad organized in a smectic film

T. Roland, J. Leonard, G. Hernandez Ramirez, S. Mery, O. Yurchenko et al.
Ultrafast transient absorption spectroscopy is performed on a novel donoracceptordonor triad made of two identical bisthiophene derivatives as electron donors and a central perylenediimide moiety as electron acceptor. The triad is extended at both ends by covalently bound siloxane chains that confer ... [Phys. Chem. Chem. Phys. 14, 273 (2011)] published Mon Dec 5, 2011.

Observing the Multiexciton State in Singlet Fission and Ensuing Ultrafast Multielectron Transfer

Wai-Lun Chan, Manuel Ligges, Askat Jailaubekov, Loren Kaake, Luis Miaja-Avila et al.
Multiple exciton generation (MEG) refers to the creation of two or more electron-hole pairs from the absorption of one photon. Although MEG holds great promise, it has proven challenging to implement, and questions remain about the underlying photo-physical dynamics in nanocrystalline as well as mol ... [Science 334, 1541 (2011)] published Wed Dec 14, 2011.

Ultrafast electrical measurements of polarization dynamics in ferroelectric thin-film capacitors

Alexei Grigoriev, Mandana Meisami Azad, and John McCampbell
We have developed a new approach to measure fast electrical signals during polarization switching in ferroelectric thin-film capacitors. This article describes a simple method for probing transient currents and voltages in a broad range of time scales from microseconds to hundreds of picoseconds. In ... [Rev. Sci. Instrum. 82, 124704 (2011)] published Wed Dec 14, 2011.

Ultrafast energy transfer of one-dimensional excitons between carbon nanotubes: a femtosecond time-resolved luminescence study

Takeshi Koyama, Yasumitsu Miyata, Koji Asaka, Hisanori Shinohara, Yahachi Saito et al.
Excitation energy transfer has long been an intriguing subject in the fields of photoscience and materials science. Along with the recent progress of photovoltaics, photocatalysis, and photosensors using nanoscale materials, excitation energy transfer between a donor and an acceptor at a short dista ... [Phys. Chem. Chem. Phys. 14, 1070 (2011)] published Fri Dec 16, 2011.

Characteristics of laser absorption and welding in FOTURAN glass by ultrashort laser pulses

Isamu Miyamoto, Kristian Cvecek, Yasuhiro Okamoto, Michael Schmidt, and Henry Helvajian
The nonlinear absorptivity of FOTURAN glass to ultrashort laser pulses is evaluated by experimental measurement and thermal conduction model at different parameters including energy and repetition rate of the laser pulse, translation speed and thermal properties of the sample. The mechanical strengt ... [Opt. Express 19, 22961 (2011)] published Thu Dec 1, 2011.

Characterization of Femtosecond laser-irradiation crystallization and structure of multiple periodic Si/SbTe nanocomposite films by coherent phonon spectroscopy

Weiling Zhu, Changzhou Wang, Mingcheng Sun, Simian Li, Jiwei Zhai et al.
Multiple parameters of nanocomposite Si/SbTe multilayer films are possibly optimized simultaneously to satisfy the development of ideal phase-change memory devices by adjusting chemical composition and physical structure of multilayer films. The crystallization and structure of the films are studied ... [Opt. Express 19, 22684 (2011)] published Thu Dec 1, 2011.

Driving force of ultrafast magnetization dynamics

B Mueller, T Roth, M Cinchetti, M Aeschlimann, and B Rethfeld
Irradiating a ferromagnetic material with an ultrashort laser pulse leads to demagnetization on the femtosecond timescale. We implement ElliottYafet-type spin-flip scattering, mediated by electronelectron and electronphonon collisions, in the framework of a spin-resolved Boltzmann equation. Consider ... [New J. Phys. 13, 123010 (2011)] published Thu Dec 29, 2011.

Coherent control of three-spin states in a triple quantum dot

L. Gaudreau, G. Granger, A. Kam, G. C. Aers, S. A. Studenikin et al.
Spin qubits involving individual spins in single quantum dots or coupled spins in double quantum dots have emerged as potential building blocks for quantum information processing applications. It has been suggested that triple quantum dots may provide additional tools and functionalities. These inc ... [Nature Phys. 8, 54 (2011)] published Thu Dec 22, 2011.

Induction of coherent magnetization switching in a few atomic layers of FeCo using voltage pulses

Yoichi Shiota, Takayuki Nozaki, Frdric Bonell, Shinichi Murakami, Teruya Shinjo et al.
The magnetization direction of a metallic magnet has generally been controlled by a magnetic field or by spin-current injection into nanosized magnetic cells. Both these methods use an electric current to control the magnetization direction; therefore, they are energy consuming. Magnetization contr ... [Nature Mater. 11, 39 (2011)] published Thu Dec 15, 2011.

Ultrafast Transparent Ceramic Scintillators Using the Yb Charge Transfer Luminescence in REO Host

Takayuki Yanagida, Yutaka Fujimoto, Shunsuke Kurosawa, Kenichi Watanabe, Hideki Yagi et al.
We report a new discovery of Yb-doped ultrafast scintillators based on the Yb charge transfer luminescence. Transparent ceramic Yb-doped YO, ScO, LuO, and YbO were prepared by sintering. When irradiated by \gamma- and X-rays, they showed a well detectable photoabsorption peak in the pulse height spe ... [Appl. Phys. Express 4, 126402 (2011)] published Tue Dec 13, 2011.

Superior local conductivity in self-organized nanodots on indium-tin-oxide films induced by femtosecond laser pulses

Chih Wang, Hsuan-I Wang, Wei-Tsung Tang, Chih-Wei Luo, Takayoshi Kobayashi et al.
Large-area surface ripple structures of indium-tin-oxide films, composed of self-organized nanodots, were induced by femtosecond laser pulses, without scanning. The multi-periodic spacing (?800 nm, ?400 nm and ?200 nm) was observed in the laser-induced ripple of ITO films. The local conductivity of ... [Opt. Express 19, 24286 (2011)] published Thu Dec 1, 2011.

Electric field-induced coherent control in GaAs: polarization dependence and electrical measurement [Invited]

J. K. Wahlstrand, H. Zhang, S. B. Choi, J. E. Sipe, and S. T. Cundiff
A static electric field enables coherent control of the photoexcited carrier density in a semiconductor through the interference of one- and two-photon absorption. An experiment using optical detection is described. The polarization dependence of the signal is consistent with a calculation using a 1 ... [Opt. Express 19, 22563 (2011)] published Thu Dec 1, 2011.

Harmonic generation and energy transport in dielectric and semiconductors at visible and UV wavelengths: the case of GaP

V. Roppo, N. Akozbek, D. de Ceglia, M. A. Vincenti, and M. Scalora
We study the propagation and momentum transport of the inhomogeneous component of second and third harmonic pulses in dielectrics and semiconductors, at visible and UV wavelengths, focusing on materials like GaP. In these spectral regions GaP is characterized by large absorption, metallic behavior o ... [J. Opt. Soc. Am. B 28, 2888 (2011)] published Fri Dec 23, 2011.

Ultrafast recombination for NiO sensitized with a series of perylene imide sensitizers exhibiting Marcus normal behaviour

Amanda L. Smeigh, Loic Le Pleux, Jerome Fortage, Yann Pellegrin, Errol Blart et al.
Ultrafast recombination observed from several perylene imide sensitizers bound to NiO appears to align with Marcus normal region behaviour; this indicates recombination to intra-bandgap states. ... [Chem. Commun. 48, 678 (2011)] published Mon Dec 12, 2011.

Enhanced rectifying response from metal-insulator-insulator-metal junctions

P. Maraghechi, A. Foroughi-Abari, K. Cadien, and A. Y. Elezzabi
We present on a metal-insulator-insulator-metal quantum electronic tunneling devices suitable for high speed rectifiers. Through the introduction of double oxide layer between similar metallic electrodes, a cascaded potential barrier is formed which alters the electron tunneling mechanism at forward ... [Appl. Phys. Lett. 99, 253503 (2011)] published Tue Dec 20, 2011.

Unraveling the Solid-Liquid-Vapor Phase Transition Dynamics at the Atomic Level with Ultrafast X-Ray Absorption Near-Edge Spectroscopy

F. Dorchies, A. Levy, C. Goyon, P. Combis, D. Descamps et al.
X-ray absorption near-edge spectroscopy (XANES) is a powerful probe of electronic and atomic structures in various media, ranging from molecules to condensed matter. We show how ultrafast time resolution opens new possibilities to investigate highly nonequilibrium states of matter including phase tr ... [Phys. Rev. Lett. 107, 245006 ] published .

Hole spin relaxation and intervalley electron scattering in germanium

Eric J. Loren, J. Rioux, C. Lange, J. E. Sipe, H. M. van Driel et al.
Hole spin relaxation and intervalley electron scattering in bulk Ge at 300 K are distinguished and selectively investigated using a spectrally, temporally, and polarization-resolved pump-probe differential transmission technique that takes advantage of the indirect band gap nature of Ge and of the d ... [Phys. Rev. B 84, 214307 ] published .

Theory of the inverse Faraday effect in view of ultrafast magnetization experiments

Daria Popova, Andreas Bringer, and Stefan Blugel
We supplement the theory of the inverse Faraday effect, which was developed in the 1960s, to the conditions used today in ultrafast magnetization experiments. We show that assumptions used to derive the effective Hamiltonian and magnetization are not valid under these conditions. We extended the app ... [Phys. Rev. B 84, 214421 ] published .

Linear and nonlinear Fano resonance on two-dimensional magnetic metamaterials

H. Liu, G. X. Li, K. F. Li, S. M. Chen, S. N. Zhu et al.
We demonstrate that both linear and nonlinear Fano resonances can be realized on two dimensional magnetic metamaterials. The Fano resonance comes from the interference between localized magnetic plasmon resonance and propagating surface plasmon polaritons. When studying the linear optical response o ... [Phys. Rev. B 84, 235437 ] published .

Publisher's Note: Observation of Size-Dependent Thermalization in CdSe Nanocrystals Using Time-Resolved Photoluminescence Spectroscopy [Phys. Rev. Lett. 107, 177403 (2011)]

Daniel C. Hannah, Nicholas J. Dunn, Sandrine Ithurria, Dmitri V. Talapin, Lin X. Chen et al.
Abstract not available. [Phys. Rev. Lett. 107, 259901 ] published .

Nonlinear optical properties of lanthanum-modified lead zirconate titanate investigated by the femtosecond Z-scan technique

Tsong-Ru Tsai and Chih-Hsiung Yu
We used a closed-aperture Z-scan technique to study the nonlinear optical refractive index of lanthanum-modified lead zirconate titanate (PLZT) (9/65/35) ceramics. Our laser light source was a mode-locked titanium-sapphire laser, the output pulse width was approximately 100 femtoseconds at a wavelen ... [Appl. Phys. Lett. 99, 241101 (2011)] published Mon Dec 12, 2011.

Imaging of surface plasmon polariton fields excited at a nanometer-scale slit

Lingxiao Zhang, Atsushi Kubo, Leiming Wang, Hrvoje Petek, and Tamar Seideman
Nonlinear two-photon photoemission electron microscopy is used to image surface plasmon polariton (SPP) wave packets excited by an obliquely incident laser pulse (~10 fs) at a single slit fabricated in a thin silver film. We image the forward propagating polarization grating formed by the coherent s ... [Phys. Rev. B 84, 245442 ] published .

Temperature-insensitive optical alignment of the exciton in nanowire-embedded GaN quantum dots

A. Balocchi, J. Renard, C. T. Nguyen, B. Gayral, T. Amand et al.
We report on the exciton spin dynamics of nanowire-embedded GaN/AlN quantum dots (QDs) investigated by time-resolved photoluminescence spectroscopy. Under a linearly polarized quasiresonant excitation, we evidence the quenching of the exciton spin relaxation and a temperature-insensitive degree of t ... [Phys. Rev. B 84, 235310 ] published .

Direct observation of two-phonon bound states in ZnTe

Jianbo Hu, Oleg V. Misochko, and Kazutaka G. Nakamura
A coherent two-phonon bound state has been impulsively generated in ZnTe(110) via second-order Raman scattering in the time domain. The two-phonon bound state, composed of two acoustic phonons anticorrelated in a wave vector, exhibits full Gamma symmetry and has energy higher than the corresponding ... [Phys. Rev. B 84, 224304 ] published .

Ultrashort-pulse laser ablation of nanocrystalline aluminum

Maxime Gill-Comeau and Laurent J. Lewis
Molecular-dynamics simulations of the ablation of nanocrystalline Al films by ultrashort laser pulses in the low-fluence (no-ionization) regime (02.5 times the ablation threshold, F) are reported. The simulations employ an embedded-atom method potential for the dynamics of the ions and a realistic t ... [Phys. Rev. B 84, 224110 ] published .

Dynamics of photoinduced phenomena in AVO (A = Ba, Sr)

A. Nogami, K. Takubo, T. Kajita, M. Hoshino, and T. Katsufuji
We studied the dynamics of photoinduced phenomena in AVO (A = Ba, Sr), where the ground state changes from an insulating state with V trimerization (Ba) to another insulating state with no structural anomaly (Sr). We found that the time dependence of photoinduced reflectivity change is similar up to ... [Phys. Rev. B 84, 214442 ] published .

Influence of temperature on dynamics of birefringence switching in photochromic nematic phase

Jaroslaw Mysliwiec, Maciej Czajkowski, Stanislaw Bartkiewicz, Krystian Zygadlo, Zbigniew Galewski et al.
We present results of dynamic and fast switching of birefringence in a photochromic liquid-crystalline system as a function of the sample temperature. The system consists of photochromic molecules of 4-heptyl-4[prime]-methoxyazobenzene showing a liquid-crystalline nematic state close to room tempera ... [J. Appl. Phys. 110, 113104 (2011)] published Mon Dec 5, 2011.

Evidence for Confined Tamm Plasmon Modes under Metallic Microdisks and Application to the Control of Spontaneous Optical Emission

O. Gazzano, S. Michaelis de Vasconcellos, K. Gauthron, C. Symonds, J. Bloch et al.
We demonstrate strong confinement of the optical field by depositing a micron sized metallic disk on a planar distributed Bragg reflector. Confined Tamm plasmon modes are evidenced both experimentally and theoretically, with a lateral confinement limited to the disk area and strong coupling to TE po ... [Phys. Rev. Lett. 107, 247402 ] published .

Coherent Longitudinal-Optical Ground-State Phonon in CdSe Quantum Dots Triggered by Ultrafast Charge Migration

L. Dworak, V. V. Matylitsky, M. Braun, and J. Wachtveitl
We observe the CdSe longitudinal-optical ground-state phonon in the electron transfer system composed of CdSe quantum dots and methylviologen directly by femtosecond absorption spectroscopy. A significant phase shift indicates that the coherent oscillations are triggered by an ultrafast charge migra ... [Phys. Rev. Lett. 107, 247401 ] published .

Synthesis of submicron metastable phase of silicon using femtosecond laser-driven shock wave

Masashi Tsujino (辻野雅之), Tomokazu Sano (佐野智一), Osami Sakata (坂田修身), Norimasa Ozaki (尾崎典雅), Shigeru Kimura (木村滋) et al.
We measured the grain size of metastable phase of Si synthesized by shock compression. We analyzed the crystalline structures of the femtosecond laser-driven shock compressed silicon with x-ray diffraction measurements. We found that submicron grains of metastable Si-VIII exist in the silicon. We su ... [J. Appl. Phys. 110, 126103 (2011)] published Thu Dec 29, 2011.

Optical properties and thermal response of copper films induced by ultrashort-pulsed lasers

Yunpeng Ren, J. K. Chen, and Yuwen Zhang
A critical point model with three Lorentzian terms for interband transition was proposed to describe temperature-dependent reflectivity (R) and absorption coefficient (alpha) for copper irradiated by ultrashort-pulsed lasers of wavelength 2001000 nm. After validated with experimental data at room te ... [J. Appl. Phys. 110, 113102 (2011)] published Thu Dec 1, 2011.

Carrier dynamics and activation energy of CdTe quantum dots in a CdZnTe quantum well

W. I. Han, J. H. Lee, J. S. Yu, J. C. Choi, and H. S. Lee
We investigate the optical properties of CdTe quantum dots (QDs) in a CdZnTe quantum well (QW) grown on GaAs (100) substrates. Carrier dynamics of CdTe/ZnTe QDs and quantum dots-in-a-well (DWELL) structure is studied using time-resolved photoluminescence (PL) measurements, which show the longer exci ... [Appl. Phys. Lett. 99, 231908 (2011)] published Thu Dec 8, 2011.

Energy relaxation of intermolecular motions in supercooled water and ice: A molecular dynamics study

Takuma Yagasaki and Shinji Saito
We investigate the energy relaxation of intermolecular motions in liquid water at temperatures ranging from 220 K to 300 K and in ice at 220 K using molecular dynamics simulations. We employ the recently developed frequency resolved transient kinetic energy analysis, which provides detailed informat ... [J. Chem. Phys. 135, 244511 (2011)] published Thu Dec 29, 2011.

High-Field Transport in an Electron-Hole Plasma: Transition from Ballistic to Drift Motion

P. Bowlan, W. Kuehn, K. Reimann, M. Woerner, T. Elsaesser et al.
The time evolution of high-field carrier transport in bulk GaAs is studied with intense femtosecond THz pulses. While ballistic transport of electrons occurs in an n-type sample, a transition from ballistic to driftlike motion is observed in an electron-hole plasma. This onset of friction is due to ... [Phys. Rev. Lett. 107, 256602 ] published .

Non-Markovian effects in time-resolved fluorescence spectrum of molecular aggregates: Tracing polaron formation

Andrius Gelzinis, Darius Abramavicius, and Leonas Valkunas
Time-resolved fluorescence spectroscopy of molecular aggregates is described using the response function theory, which incorporates exciton dynamics through nonequilibrium Green's functions. The dynamics are simulated using nonperturbative density matrix theory, which allows us to describe spectral ... [Phys. Rev. B 84, 245430 ] published .

Shot noise and conductivity at high bias in bilayer graphene: Signatures of electron-optical phonon coupling

A. Fay, R. Danneau, J. K. Viljas, F. Wu, M. Y. Tomi et al.
We have studied electronic conductivity and shot noise of bilayer graphene (BLG) sheets at high bias voltages and low bath temperature T=4.2 K. As a function of bias, we find initially an increase of the differential conductivity, which we attribute to self-heating. At higher bias, the conductivity ... [Phys. Rev. B 84, 245427 ] published .

Quantum-beat spectroscopy of image-potential resonances

M. Marks, C. H. Schwalb, K. Schubert, J. Gudde, and U. Hofer
The dynamics of electrons in image-potential resonances on the Ag(111) surface, i.e., image-potential states that are resonant with bulk bands, have been studied by time-resolved two-photon photoemission in combination with quantum-beat spectroscopy. Energies and lifetimes of these resonances were d ... [Phys. Rev. B 84, 245402 ] published .

Real-time approach to the optical properties of solids and nanostructures: Time-dependent Bethe-Salpeter equation

C. Attaccalite, M. Gruning, and A. Marini
Many-body effects are known to play a crucial role in the electronic and optical properties of solids and nanostructures. Nevertheless, the majority of theoretical and numerical approaches able to capture the influence of Coulomb correlations are restricted to the linear response regime. In this wor ... [Phys. Rev. B 84, 245110 ] published .

Driving magnetic order in a manganite by ultrafast lattice excitation

M. Forst, R. I. Tobey, S. Wall, H. Bromberger, V. Khanna et al.
Femtosecond midinfrared pulses are used to directly excite the lattice of the single-layer manganite LaSrMnO. Magnetic and orbital orders, as measured by femtosecond resonant soft x-ray diffraction with an x-ray free-electron laser, are reduced within a few picoseconds. This effect is interpreted as ... [Phys. Rev. B 84, 241104 ] published .

Ultrafast relaxation of highly excited hot electrons in Si: Roles of the LX intervalley scattering

T. Ichibayashi, S. Tanaka, J. Kanasaki, K. Tanimura, and Thomas Fauster
Two-photon photoemission (2PPE) spectroscopy is used to reveal dynamic relaxation of highly excited electrons generated by 3 eV photons in Si. Monochromatic 2PPE at probe-photon energies ranging from 3.2 to 3.5 eV reveals a coherent 2PPE peak from the valence band maximum, and a transiently populate ... [Phys. Rev. B 84, 235210 ] published .

Allowed and forbidden Raman scattering mechanisms for detection of coherent LO phonon and plasmon-coupled modes in GaAs

Kunie Ishioka, Amlan Kumar Basak, and Hrvoje Petek
Detection mechanisms of coherent phonons in variously doped GaAs are investigated by transient reflectivity method with photoexcitation near the E gap and probe near either the E or E gaps. By varying the probe light polarization angle, the coherent amplitudes of both the LO phonon and the LO phonon ... [Phys. Rev. B 84, 235202 ] published .

All-optical magnetization recording by tailoring optical excitation parameters

Daniel Steil, Sabine Alebrand, Alexander Hassdenteufel, Mirko Cinchetti, and Martin Aeschlimann
We investigate the dependency of all-optical magnetization switching on the properties of the exciting laser pulse by specifically tailoring all accessible laser parameterspulse duration, wavelength, chirp, and bandwidthover a wide range. Our results show that all-optical switching can be achieved w ... [Phys. Rev. B 84, 224408 ] published .

Electron-phonon scattering dynamics in ferromagnetic metals and their influence on ultrafast demagnetization processes

Sven Essert and Hans Christian Schneider
We theoretically investigate spin-dependent carrier dynamics due to the electron-phonon interaction after ultrafast optical excitation in ferromagnetic metals. We calculate the electron-phonon matrix elements including the spin-orbit interaction in the electronic wave functions and the interaction p ... [Phys. Rev. B 84, 224405 ] published .

Resonant generation of coherent phonons in a superconductor by ultrafast optical pump pulses

Andreas P. Schnyder, Dirk Manske, and Adolfo Avella
We study the generation of coherent phonons in a superconductor by ultrafast optical pump pulses. The nonequilibrium dynamics of the coupled Bogoliubov quasiparticle-phonon system after excitation with the pump pulse is analyzed by means of the density-matrix formalism with the phonons treated at a ... [Phys. Rev. B 84, 214513 ] published .

Theory of magnetization precession induced by a picosecond strain pulse in ferromagnetic semiconductor (Ga,Mn)As

T. L. Linnik, A. V. Scherbakov, D. R. Yakovlev, X. Liu, J. K. Furdyna et al.
A theoretical model of the coherent precession of magnetization excited by a picosecond acoustic pulse in a ferromagnetic semiconductor layer of (Ga,Mn)As is developed. The short strain pulse injected into the ferromagnetic layer modifies the magnetocrystalline anisotropy resulting in a tilt of the ... [Phys. Rev. B 84, 214432 ] published .

Energy dissipation in dielectrics after swift heavy-ion impact: A hybrid model

O. Osmani, N. Medvedev, M. Schleberger, and B. Rethfeld
The energy dissipation after irradiation of dielectrics with swift heavy ions is studied applying a combination of the Monte Carlo (MC) method and the two-temperature model (TTM). Within the MC calculation the transient dynamics of the electrons in the excited dielectric is described: the primary ex ... [Phys. Rev. B 84, 214105 ] published .

Depth-profiling of elastic and optical inhomogeneities in transparent materials by picosecond ultrasonic interferometry: Theory

V. Gusev, A. M. Lomonosov, P. Ruello, A. Ayouch, and G. Vaudel
The theoretical backgrounds for the depth-profiling of the optically transparent materials by picosecond ultrasonic interferometry are developed. The mathematical description of the light reflection from inhomogeneous transparent films or coatings is proposed. The inhomogeneity can be caused both by ... [J. Appl. Phys. 110, 124908 (2011)] published Tue Dec 20, 2011.

Generation of inhomogeneous plane shear acoustic modes by laser-induced thermoelastic gratings at the interface of transparent and opaque solids

Mansour Kouyate, Thomas Pezeril, Denis Mounier, and Vitalyi Gusev
The detailed theoretical description of how picosecond plane shear acoustic fronts can be excited by ultrafast lasers at the interface of two isotropic media, a transparent medium and an opaque medium, is presented. The processes leading to the emission of inhomogeneous plane bulk shear acoustic mod ... [J. Appl. Phys. 110, 123526 (2011)] published Wed Dec 28, 2011.

Hot carriers relaxation in highly excited polar semiconductors: Hot phonons versus phononplasmon coupling

Eric Tea, Hani Hamzeh, and Frederic Aniel
We present a study of the photo-excited charge carriers relaxation dynamics in polar semiconductors comparing calculations to pump probe experiments. Hot carrier densities in the 10cm range can easily be photo-generated using moderately intense optical excitations. This can lead to known phenomena, ... [J. Appl. Phys. 110, 113108 (2011)] published Thu Dec 8, 2011.

Fast switching of magnetization in the ferromagnetic semiconductor (Ga,Mn)(As,P) using nonequilibrium phonon pulses

A. Casiraghi, P. Walker, A. V. Akimov, K. W. Edmonds, A. W. Rushforth et al.
We use short acoustic pulses to induce a fast irreversible switching of the magnetization orientation in a layer of (Ga,Mn)(As,P). The pulses are generated by femtosecond optical excitation of a metal transducer film and travel ballistically through the sample. We show that the switching is triggere ... [Appl. Phys. Lett. 99, 262503 (2011)] published Wed Dec 28, 2011.

Observations of laser induced magnetization dynamics in Co/Pd multilayers with coherent x-ray scattering

B. Wu, D. Zhu, Y. Acremann, T. A. Miller, A. M. Lindenberg et al.
We report on time-resolved coherent x-ray scattering experiments of laser induced magnetization dynamics in Co/Pd multilayers with a high repetition rate optical pump x-ray probe setup. Starting from a multi-domain ground state, the magnetization is uniformly reduced after excitation by an intense 5 ... [Appl. Phys. Lett. 99, 252505 (2011)] published Thu Dec 22, 2011.

Temperature and size dependence of time-resolved exciton recombination in ZnO quantum dots

I. Musa, F. Massuyeau, L. Cario, J. L. Duvail, S. Jobic et al.
ZnO nanocrystals with various sizes were prepared and characterized. Their photoluminescence dynamics has been investigated at low temperatures. For the smallest particles (3 nm), a defect-induced long-lived photoluminescence occurs around 2.5 eV which is slowed down at decay times longer than 3 ns ... [Appl. Phys. Lett. 99, 243107 (2011)] published Wed Dec 14, 2011.

Incoherence induced by phonon excitations in domain-growth dynamics: Role of the domain center-of-gravity motion

K. Iwano
An ultrafast growth dynamics of a quantum domain after visible or near-infrared photoexcitation is discussed in a one-dimensional system that resides on the first-order phase boundary. Special emphasis is placed on the effects of phonon excitations that are expected to occur in the course of the dyn ... [Phys. Rev. B 84, 235139 ] published .

Saturation effects in femtosecond laser ablation of silicon-on-insulator

Hao Zhang, D. van Oosten, D. M. Krol, and J. I. Dijkhuis
We report a surface morphology study on single-shot submicron features fabricated on silicon on insulator by tightly focused femtosecond laser pulses. In the regime just below single-shot ablation threshold nano-tips are formed, whereas in the regime just above single-shot ablation threshold, a satu ... [Appl. Phys. Lett. 99, 231108 (2011)] published Thu Dec 8, 2011.

The influence of charged InAs quantum dots on the conductance of a two-dimensional electron gas: Mobility vs. carrier concentration

B. Marquardt, A. Beckel, A. Lorke, A. D. Wieck, D. Reuter et al.
Using time-resolved transport spectroscopy, we investigate the influence of charge-tunable InAs quantum dots (QDs) on the conductance of a nearby two-dimensional electron gas (2DEG). Loading successively electrons into the self-assembled QDs decreases the carrier concentration and mobility in the 2D ... [Appl. Phys. Lett. 99, 223510 (2011)] published Wed Nov 30, 2011.

Ultrafast decay of high frequency optical phonon mode in KTiOPO

Shan Yang (杨山), Sanjay Adhikari, Manoj Dobbala, and Feruz Ganikhanov
Decay of the strongest optical phonon mode in KTiOPO was directly traced using femtosecond coherent anti-Stokes Raman scattering spectroscopy. Dephasing of the Raman active mode at ~700 cm proceeds with the nonlinear polarization dephasing time of 495 10 fs. The dephasing is solely due to the phono ... [Appl. Phys. Lett. 99, 221903 (2011)] published Mon Nov 28, 2011.

Carrier Relaxation in Epitaxial Graphene Photoexcited Near the Dirac Point

S. Winnerl, M. Orlita, P. Plochocka, P. Kossacki, M. Potemski et al.
We study the carrier dynamics in epitaxially grown graphene in the range of photon energies from 10 to 250 meV. The experiments complemented by microscopic modeling reveal that the carrier relaxation is significantly slowed down as the photon energy is tuned to values below the optical-phonon freque ... [Phys. Rev. Lett. 107, 237401 ] published .

Dependence of Resonance Energy Transfer on Exciton Dimensionality

Jan Junis Rindermann, Galia Pozina, Bo Monemar, Lars Hultman, Hiroshi Amano et al.
We investigate the dependence of resonance energy transfer from Wannier-Mott excitons to an organic overlayer on exciton dimensionality. We exploit the excitonic potential disorder in a single quantum well to tune the balance between localized and free excitons by scaling the Boltzmann distribution ... [Phys. Rev. Lett. 107, 236805 ] published .

Micromagnetic study of current-pulse-induced magnetization switching in magnetic tunnel junctions with antiferromagnetically and ferromagnetically coupled synthetic free layers

Chikako Yoshida, Young Min Lee, Takao Ochiai, Yuji Uehara, and Toshihiro Sugii
We investigated the dynamics of current-pulse-induced magnetization switching in magnetic tunnel junctions (MTJs) with antiferromagnetically and ferromagnetically coupled synthetic free layers through micromagnetic simulations. We found that a magnetic vortex is formed in thick upper ferromagnetic l ... [Appl. Phys. Lett. 99, 222505 (2011)] published Mon Nov 28, 2011.

Quantum Dynamics of a Driven Correlated System Coupled to Phonons

L. Vidmar, J. BonCa, T. Tohyama, and S. Maekawa
Nonequilibrium interplay between charge, spin, and lattice degrees of freedom on a square lattice is studied for a single charge carrier doped in the t-J-Holstein model. In the presence of a static electric field we calculate the quasistationary state. With increasing electron-phonon (e-ph) coupling ... [Phys. Rev. Lett. 107, 246404 ] published .

Time-resolved plasma measurements in Ge-doped silica exposed to infrared femtosecond laser

M. Lancry, N. Groothoff, B. Poumellec, S. Guizard, N. Fedorov et al.
Using a time-resolved interferometric technique, we study the laser-induced carrier-trapping dynamics in SiO and Ge-doped SiO. The fast trapping of electrons in the band gap is associated with the formation of self-trapped excitons (STE). The STE trapping is doping dependent in SiO. The mean trappin ... [Phys. Rev. B 84, 245103 ] published .

State-resolved observation in real time of the structural dynamics of multiexcitons in semiconductor nanocrystals

Samuel L. Sewall, Ryan R. Cooney, Eva A. Dias, Pooja Tyagi, and Patanjali Kambhampati
Biexciton processes in semiconductor nanocrystals, e.g. optical gain, are widely treated as arising from structureless biexcitons. We challenge this view by observing the binding energies of hot biexcitons in CdSe nanocrystals. These experiments reveal a previously unobserved spectrum in the biexcit ... [Phys. Rev. B 84, 235304 ] published .

Redshift in the Optical Absorption of ZnO Single Crystals in the Presence of an Intense Midinfrared Laser Field

Shambhu Ghimire, Anthony D. DiChiara, Emily Sistrunk, Urszula B. Szafruga, Pierre Agostini et al.
We report time-resolved electroabsorption of a weak probe in a 500 [mu]m thick zinc-oxide crystal in the presence of a strong midinfrared pump in the tunneling limit. We observe a substantial redshift in the absorption edge that scales with the cube root of intensity up to 1 TW/cm (0.38 eV cm TW) ... [Phys. Rev. Lett. 107, 167407 ] published .

Detailed calculation of hydroxyl (OH) radical two-photon absorption via broadband ultrafast excitation

Hans U. Stauffer, Sukesh Roy, Waruna D. Kulatilaka, and James R. Gord
The theoretical framework for calculation of two-photon absorption cross sections for intermediate Hund's cases (a) and (b) diatomic species is described in detail and applied toward the hydroxyl (OH) radical. Analytical expressions are derived for the 20 rotational branches that are present in the ... [J. Opt. Soc. Am. B 29, 40 (2011)] published Tue Dec 27, 2011.

Tailoring terahertz radiation by controlling tunnel photoionization events in gases

I Babushkin, S Skupin, A Husakou, C Khler, E Cabrera-Granado et al.
Various applications ranging from nonlinear terahertz (THz) spectroscopy to remote sensing require broadband and intense THz radiation, which can be generated by focusing two-color laser pulses into a gas. In this setup, THz radiation originates from the buildup of electron density in sharp steps of ... [New J. Phys. 13, 123029 (2011)] published Thu Dec 29, 2011.

Exploring Interatomic Coulombic Decay by Free Electron Lasers

Philipp V. Demekhin, Spas D. Stoychev, Alexander I. Kuleff, and Lorenz S. Cederbaum
To exploit the high intensity of laser radiation, we propose to select frequencies at which single-photon absorption is of too low energy and two or more photons are needed to produce states of an atom that can undergo interatomic Coulombic decay (ICD) with its neighbors. For Ne it is explicitly dem ... [Phys. Rev. Lett. 107, 273002 ] published .

Evolution of superpositions of quantum states through a level crossing

B. T. Torosov and N. V. Vitanov
The Landau-Zener-Stuckelberg-Majorana (LZSM) model is widely used for estimating transition probabilities in the presence of crossing energy levels in quantum physics. This model, however, makes the unphysical assumption of an infinitely long constant interaction, which introduces a divergent phase ... [Phys. Rev. A 84, 063411 ] published .

Generating Molecular Rovibrational Coherence by Two-Photon Femtosecond Photoassociation of Thermally Hot Atoms

Leonid Rybak, Saieswari Amaran, Liat Levin, Michal Tomza, Robert Moszynski et al.
The formation of diatomic molecules with rotational and vibrational coherence is demonstrated experimentally in free-to-bound two-photon femtosecond photoassociation of hot atoms. In a thermal gas at a temperature of 1000 K, pairs of magnesium atoms, colliding in their electronic ground state, are e ... [Phys. Rev. Lett. 107, 273001 ] published .

Control of Molecular Rotation with a Chiral Train of Ultrashort Pulses

S. Zhdanovich, A. A. Milner, C. Bloomquist, J. Floss, I. Sh. Averbukh et al.
Trains of ultrashort laser pulses separated by the time of rotational revival (typically, tens of picoseconds) have been exploited for creating ensembles of aligned molecules. In this work we introduce a chiral pulse traina sequence of linearly polarized pulses with the polarization direction rotati ... [Phys. Rev. Lett. 107, 243004 ] published .

Differential study on molecular suppressed ionization in intense linearly and circularly polarized laser fields

Yongkai Deng, Yunquan Liu, Xianrong Liu, Hong Liu, Yudong Yang et al.
We present a differential study on above-threshold ionization of the O (N) molecule as well as the companion atom Xe (Ar) (with close ionization potential) produced by linearly and circularly polarized laser fields (25 fs, 795 nm). The photoelectron angular distributions of the companion target are ... [Phys. Rev. A 84, 065405 ] published .

Comparative investigation of third- and fifth-harmonic generation in atomic and molecular gases driven by midinfrared ultrafast laser pulses

Jielei Ni, Jinping Yao, Bin Zeng, Wei Chu, Guihua Li et al.
We report on the comparative experimental investigation on third- and fifth-harmonic generation (THG and FHG) in atomic and molecular gases driven by midinfrared ultrafast laser pulses at a wavelength of ~1500 nm. We observe that the conversion efficiencies of both the THG and FHG processes saturate ... [Phys. Rev. A 84, 063846 ] published .

Phase-dependent coherent population trapping and optical switching

J. Kou, R. G. Wan, Z. H. Kang, L. Jiang, L. Wang et al.
We propose a scheme for achieving phase-dependent coherent population trapping, showing that both the dark state of the atoms and light propagation dynamics depend on the relative phase of the fields. The atomic coherence prepared via adiabatic process plays a key role in the interaction of light wi ... [Phys. Rev. A 84, 063807 ] published .

Optimized control of multistate quantum systems by composite pulse sequences

G. T. Genov, B. T. Torosov, and N. V. Vitanov
We introduce a technique for derivation of high-fidelity composite pulse sequences for two types of multistate quantum systems: systems with the SU(2) and Morris-Shore dynamic symmetries. For the former type, we use the Majorana decomposition to reduce the dynamics to an effective two-state system, ... [Phys. Rev. A 84, 063413 ] published .

Competition between two-photon-resonant three-photon ionization and four-wave mixing in Xe

Hidekazu Nagai and Taisuke Nakanaga
Competitive inhibition of a resonance enhanced multiphoton ionization process by a resonant four-wave mixing has been observed in Xe atoms. When an intense IR (1064 nm) laser was applied to a sample of Xe which was also being irradiated by a UV laser tuned to the two-photon absorption line of Xe, th ... [Phys. Rev. A 84, 063408 ] published .

Field-free molecular alignment control by phase-shaped femtosecond laser pulse

Shian Zhang, Chenhui Lu, Tianqing Jia, Zhenrong Sun, and Jianrong Qiu
In this paper, we theoretically show that the field-free molecular alignment can be controlled by shaping the femtosecond laser pulse with a periodic phase step modulation, involving the maximum degree and temporal structure of the molecular alignment. We show that the molecular alignment can be com ... [J. Chem. Phys. 135, 224308 (2011)] published Wed Dec 14, 2011.

Circular Dichroism in Laser-Assisted Short-Pulse Photoionization

A. K. Kazansky, A. V. Grigorieva, and N. M. Kabachnik
A remarkable effect of circular dichroism, i.e., a difference in photoelectron spectra produced by right and left circularly polarized light in two-color multiphoton ionization of atoms, is predicted for the case when the atom is ionized by an extreme ultraviolet or x-ray femtosecond pulse in the fi ... [Phys. Rev. Lett. 107, 253002 ] published .

Enhanced Nonlinear Double Excitation of He in Intense Extreme Ultraviolet Laser Fields

A. Hishikawa, M. Fushitani, Y. Hikosaka, A. Matsuda, C.-N. Liu et al.
Nonlinear, three-photon double excitation of He in intense extreme ultraviolet free-electron laser fields (~24.1 eV, ~5 TW/cm) is presented. Resonances to the doubly excited states converging to the He N=3 level are revealed by the shot-by-shot photoelectron spectroscopy and identified by theoreti ... [Phys. Rev. Lett. 107, 243003 ] published .

Effects of pulse shape on strongly driven two-level systems

C. W. S. Conover
We present an experimental study of the dynamics of a two-level system driven by strong nonresonant electromagnetic pulses as a function of pulse intensity and detuning. We have explored the qualitative and quantitative behavior of the transition probability as a function of pulse area for five diff ... [Phys. Rev. A 84, 063416 ] published .

Rotational coherence imaging and control for CN molecules through time-frequency resolved coherent anti-Stokes Raman scattering

Johan Lindgren, Eero Hulkko, Mika Pettersson, and Toni Kiljunen
Numerical wave packet simulations are performed for studying coherent anti-Stokes Raman scattering (CARS) for CN radicals. Electronic coherence is created by femtosecond laser pulses between the X Sigma and B Sigma states. Due to the large energy separation of vibrational states, the wave packets ar ... [J. Chem. Phys. 135, 224514 (2011)] published Tue Dec 13, 2011.

Selective nonlinear response preparation using femtosecond spectrally resolved four-wave-mixing

Jan Philip Kraack, Marcus Motzkus, and Tiago Buckup
A novel method is presented to assist the assignment of vibrational coherence in the homodyne degenerate four-wave-mixing technique. The dependence of vibrational coherence dynamics on the interaction sequence of chirped pump and Stokes excitation pulses is exploited to distinguish quantum beating f ... [J. Chem. Phys. 135, 224505 (2011)] published Fri Dec 9, 2011.

Coherent control of molecular torsion

Shane M. Parker, Mark A. Ratner, and Tamar Seideman
We propose a coherent, strong-field approach to control the torsional modes of biphenyl derivatives, and develop a numerical scheme to simulate the torsional dynamics. By choice of the field parameters, the method can be applied either to drive the torsion angle to an arbitrary configuration or to i ... [J. Chem. Phys. 135, 224301 (2011)] published Thu Dec 8, 2011.

The electronic spectrum of SiH: Jahn-Teller Rydberg series

A. M. Velasco, C. Lavin, A. M. J. Sanchez de Meras, and J. Sanchez Marin
The aim of the present theoretical work is to provide data necessary for a better understanding of the electronic spectrum of the silane molecule, which is affected by the Jahn-Teller effect. By selecting an adequate distorted C geometry of SiH, the three lower Koopmans ionization potentials are eva ... [J. Chem. Phys. 135, 214304 (2011)] published Fri Dec 2, 2011.

Apparatus for laser-assisted electron scattering in femtosecond intense laser fields

Reika Kanya, Yuya Morimoto, and Kaoru Yamanouchi
An apparatus for observation of laser-assisted electron scattering (LAES) in femtosecond intense laser fields was developed. The unique apparatus has three essential components, i.e., a photocathode-type ultrashort pulsed-electron gun, a toroidal-type electron energy analyzer enabling simultaneous d ... [Rev. Sci. Instrum. 82, 123105 (2011)] published Tue Dec 13, 2011.

GHz Rabi Flopping to Rydberg States in Hot Atomic Vapor Cells

B. Huber, T. Baluktsian, M. Schlagmuller, A. Kolle, H. Kubler et al.
We report on the observation of Rabi oscillations to a Rydberg state on a time scale below 1 ns in thermal rubidium vapor. We use a bandwidth-limited pulsed excitation and observe up to 6 full Rabi cycles within a pulse duration of ~4 ns. We find good agreement between the experiment and numerical ... [Phys. Rev. Lett. 107, 243001 ] published .

Temporal analysis of nonresonant two-photon coherent control involving bound and dissociative molecular states

Jing Su, Shaohao Chen, Agnieszka Jaron-Becker, and Andreas Becker
We theoretically study the control of two-photon excitation to bound and dissociative states in a molecule induced by trains of laser pulses, which are equivalent to certain sets of spectral phase modulated pulses. To this end, we solve the time-dependent Schrodinger equation for the interaction of ... [Phys. Rev. A 84, 065402 ] published .

Exactly solvable model for nonlinear light-matter interaction in an arbitrary time-dependent field

J. M. Brown, A. Lotti, A. Teleki, and M. Kolesik
Exact analytic expressions are derived for the dipole moment and nonlinear current of a one-dimensional quantum particle subject to a short-range attractive potential and an arbitrary time-dependent electric field. An efficient algorithm for the current evaluation is described and a robust implement ... [Phys. Rev. A 84, 063424 ] published .

Dressed-bound-state molecular strong-field approximation: Application to above-threshold ionization of heteronuclear diatomic molecules

E. Hasovic, M. Busuladzic, W. Becker, and D. B. Milosevic
The molecular strong-field approximation (MSFA), which includes dressing of the molecular bound state, is introduced and applied to above-threshold ionization of heteronuclear diatomic molecules. Expressions for the laser-induced molecular dipole and polarizability as functions of the laser paramete ... [Phys. Rev. A 84, 063418 ] published .

Nonadiabatic tunneling in circularly polarized laser fields: Physical picture and calculations

Ingo Barth and Olga Smirnova
We consider selectivity of strong-field ionization in circularly polarized laser fields to the sense of electron rotation in the laser polarization plane in the initial state. We show that, in contrast to the textbook examples of one-photon ionization and bound-state excitations with increase in the ... [Phys. Rev. A 84, 063415 ] published .

Intensity-resolved ionization yields of aniline with femtosecond laser pulses

J. Strohaber, T. Mohamed, N. Hart, F. Zhu, R. Nava et al.
We present experimental results for the ionization of aniline and benzene molecules subjected to intense ultrashort laser pulses. Measured parent molecular ions yields were obtained using a recently developed technique capable of three-dimensional imaging of ion distributions within the focus of a l ... [Phys. Rev. A 84, 063414 ] published .

Unveiling and Driving Hidden Resonances with High-Fluence, High-Intensity X-Ray Pulses

E. P. Kanter, B. Krassig, Y. Li, A. M. March, P. Ho et al.
We show that high fluence, high-intensity x-ray pulses from the world's first hard x-ray free-electron laser produce nonlinear phenomena that differ dramatically from the linear x-raymatter interaction processes that are encountered at synchrotron x-ray sources. We use intense x-ray pulses of sub-10 ... [Phys. Rev. Lett. 107, 233001 ] published .

Parity-selective enhancement of field-free molecular orientation in an intense two-color laser field

Hyeok Yun, Hyung Taek Kim, Chul Min Kim, Chang Hee Nam, and Jongmin Lee
We investigated the characteristics of molecular orientation induced by a nonresonant two-color femtosecond laser field. By analyzing the rotational dynamics of asymmetric linear molecules, we revealed that the critical parameter in characterizing the molecular orientation was the hyperpolarizabilit ... [Phys. Rev. A 84, 065401 ] published .

Enhancing photoassociation efficiency by using a picosecond laser pulse with cubic-phase modulation

Wei Zhang (张为), Ting Xie (谢廷), Yin Huang (黄寅), and Shu-Lin Cong (丛书林)
The photoassociation (PA) dynamics of ultracold cesium atoms steered by the picosecond laser pulse with cubic-phase modulation has been investigated theoretically by solving numerically the time-dependent Schrodinger equation using the mapped Fourier grid method. The temporal duration of the pulse i ... [Phys. Rev. A 84, 065406 ] published .

Vibrational dynamics of the bending mode of water interacting with ions

L. Piatkowski and H. J. Bakker
We studied the vibrational relaxation dynamics of the bending mode (nu) of the HO water molecules in the presence of different salts (LiCl, LiBr, LiI, NaI, CsI, NaClO, and NaBF). The linear and nonlinear spectra of the bending mode show distinct responses of water molecules hydrating the anions. We ... [J. Chem. Phys. 135, 214509 (2011)] published Wed Dec 7, 2011.

Spectroscopic characterization of the first ultrafast catalytic intermediate in protochlorophyllide oxidoreductase

Olga A. Sytina, Ivo H. M. van Stokkum, Derren J. Heyes, C. Neil Hunter, and Marie Louise Groot
The enzyme NADPH:protochlorophyllide oxidoreductase (POR) catalyses the reduction of protochlorophyllide into chlorophyllide, a precursor of chlorophyll a in photosynthetic organisms. The enzyme binds the substrate and the cofactor in the dark and catalysis is initiated by the absorption of light by ... [Phys. Chem. Chem. Phys. 14, 616 (2011)] published Fri Dec 9, 2011.

On the nature and signatures of the solvated electron in water

B. Abel, U. Buck, A. L. Sobolewski, and W. Domcke
The hydrated electron is one of the simplest chemical transients and has been the subject of intense investigation and speculation since its discovery in 1962 by Hart and Boag. Although extensive kinetic and spectroscopic research on this species has been reported for many decades, its structure, i. ... [Phys. Chem. Chem. Phys. 14, 22 (2011)] published Mon Dec 5, 2011.

Initiation and control of catalytic surface reactions with shaped femtosecond laser pulses

Patrick Nuernberger, Daniel Wolpert, Horst Weiss, and Gustav Gerber
We report on femtosecond laser-induced catalytic reactions of carbon monoxide and hydrogen on single crystal surfaces under high vacuum conditions. Several product molecules are synthesized, among them also species for whose formation at least three reactants are required. By applying closed-loop op ... [Phys. Chem. Chem. Phys. 14, 1185 (2011)] published Fri Dec 16, 2011.

Complexes of tetracyclines with divalent metal cations investigated by stationary and femtosecond-pulsed techniques

Benedetta Carlotti, Alessio Cesaretti, and Fausto Elisei
Spectroscopic techniques both in steady-state (in absorption and emission) and pulsed (absorption of excited states with femtosecond resolution) conditions were used to study the complexation process between six molecules belonging to the tetracycline family and Mg; in the case of TC the study was e ... [Phys. Chem. Chem. Phys. 14, 823 (2011)] published Fri Dec 9, 2011.

Excited-state dynamics of phenolpyridinium biaryl

Jean-Pierre Malval, Helene Chaumeil, Wolfgang Rettig, Vladimir Kharlanov, Vincent Diemer et al.
The excited-state dynamics of a donoracceptor phenolpyridinium biaryl cation was investigated in various solvents by femtosecond transient absorption spectroscopy and temperature dependent steady-state emission measurements. After excitation to a near-planar FranckCondon delocalized excited S(DE) st ... [Phys. Chem. Chem. Phys. 14, 562 (2011)] published Fri Dec 9, 2011.

Probing structural evolution along multidimensional reaction coordinates with femtosecond stimulated Raman spectroscopy

Renee R. Frontiera, Chong Fang, Jyotishman Dasgupta, and Richard A. Mathies
Mapping out multidimensional potential energy surfaces has been a goal of physical chemistry for decades in the quest to both predict and control chemical reactivity. Recently a new spectroscopic approach called Femtosecond Stimulated Raman Spectroscopy or FSRS was introduced that can structurally i ... [Phys. Chem. Chem. Phys. 14, 405 (2011)] published Fri Dec 9, 2011.

Transient infrared spectroscopy: a new approach to investigate valence tautomerism

Touron Touceda Patricia, Mosquera Vazquez Sandra, Lima Manuela, Lapini Andrea, Foggi Paolo et al.
In this work we present, to our knowledge for the first time, the results of a transient infrared spectroscopic study of the photoinduced valence tautomerism process in cobaltdioxolene complexes with sub-picosecond time resolution. The molecular systems investigated were [Co(tpa)(diox)]PF (1) and [C ... [Phys. Chem. Chem. Phys. 14, 1038 (2011)] published Fri Dec 9, 2011.

Using shaped ultrafast laser pulses to detect enzyme binding

Chien-hung Tseng, Thomas C. Weinacht, Anna E. Rhoades, Matthew Murray, and Brett J. Pearson
We use multiphoton quantum-control spectroscopy to discriminate between unbound and enzyme-bound NADH (reduced nicotinamide adenine dinucleotide) molecules in solution. Shaped ultrafast laser pulses are used to illuminate both forms of NADH, and the ratio of the fluorescence from the bound and unbou ... [Opt. Express 19, 24638 (2011)] published Thu Dec 1, 2011.

Spectral modulation observed in Chl-a by ultrafast laser spectroscopy

Juan Du, Kazuaki Nakata, Yongliang Jiang, Eiji Tokunaga, and Takayoshi Kobayashi
Broadband real-time dynamic vibronic coupling in Chl-a were experimentally studied using few cycle laser pulses of 6.8fs duration and a 128-channnel lock-in amplifier. Thanks to the extreme temporal resolution benefitting from the ultrashort laser pulse, the real-time modulation of the electronic tr ... [Opt. Express 19, 22480 (2011)] published Thu Dec 1, 2011.

Photoinduced Neutral-to-Ionic Phase Transition in Tetrathiafulvalene-p-chloranil Studied by Time-Resolved Vibrational Spectroscopy

Yoshitaka Matsubara, Yoichi Okimoto, Tatsushi Yoshida, Tadahiko Ishikawa, Shin-ya Koshihara et al.
We studied the photoinduced neutral-to-ionic phase transition in tetrathiafulvalene-p-chloranil (TTF-CA) using time-resolved infrared (IR) vibrational spectroscopy with a broadband femtosecond IR laser pulse and a linear IR detector array. After photoexcitation, the strength of the TTF a_{g}\nu_{3} ... [J. Phys. Soc. Jpn. 80, 124711 (2011)] published Tue Dec 13, 2011.

Charge-Transfer State and Charge Dynamics in Poly(9,9'-dioctylfluorene-co-bithiophene) and [6,6]-Phenyl C-butyric Acid Methyl Ester Blend Film

Kouhei Yonezawa, Minato Ito, Hayato Kamioka, Takeshi Yasuda, Liyuan Han et al.
Bulk heterojunction (BHJ) based on a donor (D) polymer and acceptor (A) fullerene derivative is a promising organic photovoltaics. Here, we performed femtosecond time-resolved spectroscopy of poly(9,9'-dioctylfluorene-co-bithiophene) (F8T2)/[6,6]-phenyl C-butyric acid methyl ester (PCBM) blend film ... [Appl. Phys. Express 4, 122601 (2011)] published Tue Dec 13, 2011.

Individual bioaerosol particle discrimination by multi-photon excited fluorescence

Denis Kiselev, Luigi Bonacina, and Jean-Pierre Wolf
Femtosecond laser induced multi-photon excited fluorescence (MPEF) from individual airborne particles is tested for the first time for discriminating bioaerosols. The fluorescence spectra, analysed in 32 channels, exhibit a composite character originating from simultaneous two-photon and three-photo ... [Opt. Express 19, 24516 (2011)] published Thu Dec 1, 2011.

Self-terminating diffraction gates femtosecond X-ray nanocrystallography measurements

Anton Barty, Carl Caleman, Andrew Aquila, Nicusor Timneanu, Lukas Lomb et al.
X-ray free-electron lasers have enabled new approaches to the structural determination of protein crystals that are too small or radiation-sensitive for conventional analysis. For sufficiently short pulses, diffraction is collected before significant changes occur to the sample, and it has been pred ... [Nat. Photonics 6, 35 (2011)] published Thu Dec 22, 2011.

Multiple time scale molecular dynamics for fluids with orientational degrees of freedom. II. Canonical and isokinetic ensembles

Igor P. Omelyan and Andriy Kovalenko
We have developed several multiple time stepping techniques to overcome the limitations on efficiency of molecular dynamics simulations of complex fluids. They include the modified canonical and isokinetic schemes, as well as the extended isokinetic Nose-Hoover chain approach. The latter generalizes ... [J. Chem. Phys. 135, 234107 (2011)] published Mon Dec 19, 2011.

Structural dynamics of surfaces by ultrafast electron crystallography: Experimental and multiple scattering theory

Sascha Schafer, Wenxi Liang, and Ahmed H. Zewail
Recent studies in ultrafast electron crystallography (UEC) using a reflection diffraction geometry have enabled the investigation of a wide range of phenomena on the femtosecond and picosecond time scales. In all these studies, the analysis of the diffraction patterns and their temporal change after ... [J. Chem. Phys. 135, 214201 (2011)] published Fri Dec 2, 2011.

Theory of quantum energy transfer in spin chains: Superexchange and ballistic motion

Claire X. Yu, Lian-Ao Wu, and Dvira Segal
Quantum energy transfer in a chain of two-level (spin) units, connected at its ends to two thermal reservoirs, is analyzed in two limits: (i) in the off-resonance regime, when the characteristic subsystem excitation energy gaps are larger than the reservoirs frequencies, or the baths temperatures ar ... [J. Chem. Phys. 135, 234508 (2011)] published Mon Dec 19, 2011.

The dependence of singlet exciton relaxation on excitation density and temperature in polycrystalline tetracene thin films: Kinetic evidence for a dark intermediate state and implications for singlet fission

Jonathan J. Burdett, David Gosztola, and Christopher J. Bardeen
The excited state dynamics of polycrystalline tetracene films are studied using femtosecond transient absorption in combination with picosecond fluorescence, continuing work reported in an earlier paper [J. J. Burdett, A. M. Muller, D. Gosztola, and C. J. Bardeen, J. Chem. Phys. 133, 144506 (2010)]. ... [J. Chem. Phys. 135, 214508 (2011)] published Wed Dec 7, 2011.

Competitive ionization processes of anthracene excited with a femtosecond pulse in the multi-photon ionization regime

M. Goto and K. Hansen
To clarify the ionization mechanism of large molecules under multi-photon ionization conditions, photo-electron spectroscopic studies on anthracene have been performed with electron imaging technique. Electron kinetic energy distributions below a few eV reveal that three kinds of ionization channels ... [J. Chem. Phys. 135, 214310 (2011)] published Tue Dec 6, 2011.

Efficient electron dynamics with the planewave-based real-time time-dependent density functional theory: Absorption spectra, vibronic electronic spectra, and coupled electron-nucleus dynamics

Seung Kyu Min, Yeonchoo Cho, and Kwang S. Kim
The electron dynamics with complex third-order Suzuki-Trotter propagator (ST) has been implemented into a planewave (PW) based density functional theory program, and several applications including linear absorption spectra and coupled electron-nucleus dynamics have been calculated. Since the ST redu ... [J. Chem. Phys. 135, 244112 (2011)] published Fri Dec 30, 2011.

Ultrafast Dynamics of Photoionized Acetylene

Mohamed El-Amine Madjet, Oriol Vendrell, and Robin Santra
Acetylene cations [HCCH] produced in the ASigma state by extreme ultraviolet (XUV) photoionization are investigated theoretically, based on a mixed quantum-classical approach. We show that the decay of the ASigma state occurs via both ultrafast isomerization and nonradiative electronic relaxation. W ... [Phys. Rev. Lett. 107, 263002 ] published .

Chasing charge localization and chemical reactivity following photoionization in liquid water

Ondrej Marsalek, Christopher G. Elles, Piotr A. Pieniazek, Eva Pluharova, Joost VandeVondele et al.
The ultrafast dynamics of the cationic hole formed in bulk liquid water following ionization is investigated by ab initio molecular dynamics simulations and an experimentally accessible signature is suggested that might be tracked by femtosecond pump-probe spectroscopy. This is one of the fastest fu ... [J. Chem. Phys. 135, 224510 (2011)] published Mon Dec 12, 2011.

Radiation damage in protein serial femtosecond crystallography using an x-ray free-electron laser

Lukas Lomb, Thomas R. M. Barends, Stephan Kassemeyer, Andrew Aquila, Sascha W. Epp et al.
X-ray free-electron lasers deliver intense femtosecond pulses that promise to yield high resolution diffraction data of nanocrystals before the destruction of the sample by radiation damage. Diffraction intensities of lysozyme nanocrystals collected at the Linac Coherent Light Source using 2 keV pho ... [Phys. Rev. B 84, 214111 ] published .

Subharmonic excitation in amplitude modulation atomic force microscopy in the presence of adsorbed water layers

Sergio Santos, Victor Barcons, Albert Verdaguer, and Matteo Chiesa
In ambient conditions, nanometric water layers form on hydrophilic surfaces covering them and significantly changing their properties and characteristics. Here we report the excitation of subharmonics in amplitude modulation atomic force microscopy induced by intermittent water contacts. Our simulat ... [J. Appl. Phys. 110, 114902 (2011)] published Fri Dec 2, 2011.

Nonequilibrium Fermi golden rule for electronic transitions through conical intersections

Artur F. Izmaylov, David MendiveTapia, Michael J. Bearpark, Michael A. Robb, John C. Tully et al.
We consider photoinduced electronic transitions through conical intersections in large molecules. Starting from the linear vibronic model Hamiltonian and treating linear diabatic couplings within the second order cumulant expansion, we have developed a simple analytical expression for the time evolu ... [J. Chem. Phys. 135, 234106 (2011)] published Mon Dec 19, 2011.

High-power 200 fs Kerr-lens mode-locked Yb:YAG thin-disk oscillator

O. Pronin, J. Brons, C. Grasse, V. Pervak, G. Boehm et al.
We demonstrate a power-scalable Kerr-lens mode-locked Yb:YAG thin-disk oscillator. It delivers 200 fs pulses at an average power of 17 W and a repetition rate of 40 MHz. At an increased (180 W) pump power level, the laser produces 270 fs 1.1 [mu]J pulses at an average power of 45 W (optical-to-optic ... [Opt. Lett. 36, 4746 (2011)] published Tue Dec 20, 2011.

1 MHz repetition rate hollow fiber pulse compression to sub-100-fs duration at 100 W average power

Jan Rothhardt, Steffen Hadrich, Henning Carstens, Nicholas Herrick, Stefan Demmler et al.
We report on nonlinear pulse compression at very high average power. A high-power fiber chirped pulse amplification system based on a novel large pitch photonic crystal fiber delivers 700 fs pulses with 200 [mu]J pulse energy at a 1 MHz repetition rate, resulting in 200 W of average power. Subsequen ... [Opt. Lett. 36, 4605 (2011)] published Mon Dec 5, 2011.

Coherently-combined two channel femtosecond fiber CPA system producing 3 mJ pulse energy

Arno Klenke, Enrico Seise, Stefan Demmler, Jan Rothhardt, Sven Breitkopf et al.
We present a fiber CPA system consisting of two coherently combined fiber amplifiers, which have been arranged in an actively stabilized Mach-Zehnder interferometer. Pulse durations as short as 470 fs and pulse energies of 3 mJ, corresponding to 5.4 GW of peak power, have been achieved at an average ... [Opt. Express 19, 24280 (2011)] published Thu Dec 1, 2011.

Femtosecond VECSEL with tunable multi-gigahertz repetition rate

Oliver D. Sieber, Valentin J. Wittwer, Mario Mangold, Martin Hoffmann, Matthias Golling et al.
We present a femtosecond vertical external cavity surface emitting laser (VECSEL) that is continuously tunable in repetition rate from 6.5 GHz up to 11.3 GHz. The use of a low-saturation fluence semiconductor saturable absorber mirror (SESAM) enables stable cw modelocking with a simple cavity design ... [Opt. Express 19, 23538 (2011)] published Thu Dec 1, 2011.

Modelocked semiconductor laser system with pulse picking for variable repetition rate

J.C. Balzer, T. Schlauch, Th. Hoffmann, A. Klehr, G. Erbert et al.
The generation of picosecond pulses from a hybrid modelocked semiconductor master oscillator power amplifier system with a repetition rate as low as 340 kHz is presented. The fundamental repetition rate of the external cavity laser was 348 MHz and is reduced by an integrated ultrafast semiconductor ... [Electron. Lett. 47, 1387 ] published .

Femtosecond high-power spontaneous mode-locked operation in vertical-external cavity surface-emitting laser with gigahertz oscillation

Y. F. Chen, Y. C. Lee, H. C. Liang, K. Y. Lin, K. W. Su et al.
We realize a femtosecond high-power spontaneous mode-locked operation with gigahertz oscillation in a vertical-external cavity surface-emitting laser under the condition of eliminating the internal and external unwanted reflection. We find that the reflectivity of the output coupler has a significan ... [Opt. Lett. 36, 4581 (2011)] published Mon Dec 5, 2011.

High-power widely tunable sub-20fs Gaussian laser pulses for ultrafast nonlinear spectroscopy

Bernd Metzger, Andy Steinmann, and Harald Giessen
We demonstrate the generation of widely tunable sub-20fs Gaussian-shaped laser pulses using a grating-based 4-f pulse shaper and a liquid crystal spatial light modulator. Our pump source is an Yb:KGW solitary mode-locked oscillator at 44MHz repetition rate which is coupled into a large mode area mic ... [Opt. Express 19, 24354 (2011)] published Thu Dec 1, 2011.

Two-color deep-ultraviolet 40-fs pulses based on parametric amplification at 100 kHz

Huan Shen, Shunsuke Adachi, Takuya Horio, and Toshinori Suzuki
We present a 100-kHz deep-ultraviolet (DUV) laser system that generates 40-fs pulses. A 520-nm pulse generated by a noncollinear optical parametric amplifier pumped by the second harmonic of a Ti:sapphire laser is converted into 226- and 260-nm DUV pulses simultaneously with pulse energies of 250 an ... [Opt. Express 19, 22637 (2011)] published Thu Dec 1, 2011.

Mid-infrared laser-driven broadband water-window supercontinuum generation from pre-excited medium

Yang Li, Weiyi Hong, Qingbin Zhang, Shaoyi Wang, and Peixiang Lu
We theoretically investigate the broadband water-window supercontinuum generation from pre-excited medium with a mid-infrared pulse. We find that the wavelength scaling of the harmonic yield from near-visible (0.8 [mu]m) to mid-infrared (1.8 [mu]m) in single-atom level is lambda. Using an intense ph ... [Opt. Express 19, 24376 (2011)] published Thu Dec 1, 2011.

Coherent single-cycle pulses with MV/cm field strengths from a relativistic transition radiation light source

Matthias C. Hoffmann, Sebastian Schulz, Stephan Wesch, Steffen Wunderlich, Andrea Cavalleri et al.
Terahertz (THz) pulses with energies up to 100 [mu]J and corresponding electric fields up to 1 MV/cm were generated by coherent transition radiation from 500 MeV electron bunches at the free-electron laser Freie-Elektronen-Laser in Hamburg (FLASH). The pulses were characterized in the time domain by ... [Opt. Lett. 36, 4473 (2011)] published Mon Dec 5, 2011.

Coherent x-ray generation from below-threshold harmonics

Ji-Cai Liu, Markus C. Kohler, Christoph H. Keitel, and Karen Z. Hatsagortsyan
The possibility of x-ray emission employing below-threshold-harmonic generation in the nontunneling regime is considered. The interaction of a tightly bound valence electron in a highly charged ion with intense extreme-ultraviolet laser radiation is investigated in the weakly relativistic regime by ... [Phys. Rev. A 84, 063817 ] published .

Tunable and collimated terahertz radiation generation by femtosecond laser pulses

Hitendra K. Malik and Anil K. Malik
A mechanism is proposed for the generation of tunable terahertz (THz) radiation under the application of two femtosecond laser pulses and an external magnetic field, where quick tunnel ionization is achieved that leads to higher plasma density evolution and large residual current for the efficient T ... [Appl. Phys. Lett. 99, 251101 (2011)] published Mon Dec 19, 2011.

Vertical cavity surface emitting lasers with the active layer position detuned from standing wave antinode for picosecond pulse generation by gain switching

Boris S. Ryvkin, Eugene A. Avrutin, and Juha T. Kostamovaara
A vertical cavity surface emitting laser with the active layer position detuned from the standing wave antinode is proposed for the purpose of high energy picosecond pulse generation by gain switching and analysed using numerical simulations and a fully analytical model. An optimum value of the conf ... [J. Appl. Phys. 110, 123101 (2011)] published Mon Dec 19, 2011.

Multiscale multimodal imaging with multiphoton microscopy and optical coherence tomography

Shuo Tang, Yifeng Zhou, Kenny K. H. Chan, and Tom Lai
A multiscale multiphoton microscopy (MPM) and optical coherence tomography (OCT) system has been developed using a sub-10 fs Ti:sapphire laser. The system performs cross-sectional OCT imaging over millimeter field-of-view and en-face high-resolution MPM imaging with submicrometer resolution from the ... [Opt. Lett. 36, 4800 (2011)] published Tue Dec 20, 2011.

Test of the all-optical control of waveparticle duality of cavity photons by ordinary photodetection

O. Di Stefano, A. Ridolfo, S. Portolan, and S. Savasta
The principle of complementarity refers to the ability of quantum entities to behave as particles or waves under different experimental conditions. We present a proposal for the experimental observation of the ultrafast all-optical control of the waveparticle duality of light. The device is constitu ... [Opt. Lett. 36, 4509 (2011)] published Mon Dec 5, 2011.

Terahertz pinch harmonics enabled by single nano rods

Hyeong-Ryeol Park, Young-Mi Bahk, Jong Ho Choe, Sanghoon Han, Seong Soo Choi et al.
A pinch harmonic (or guitar harmonic) is a musical note produced by lightly pressing the thumb of the picking hand upon the string immediately after it is picked [J. Chem. Educ. 84, 1287 (2007)]. This technique turns off the fundamental and all overtones except those with a node at that location. He ... [Opt. Express 19, 24775 (2011)] published Thu Dec 1, 2011.