Virtual Journal of Ultrafast Science

High-harmonic gyrotron with sectioned cavity

I. V. Bandurkin, Yu. K. Kalynov, and A. V. Savilov
High-harmonic large-orbit gyrotrons require long-length operating cavities because of both a weak electron-wave coupling and relatively low electron currents. Since diffraction Q factors of such cavities are very high, a large fraction of the radiated power is dissipated in Ohmic losses. A sectioned ... [Phys. Plasmas 17, 073101 (2010)] published Thu Jul 8, 2010.

Ultralong-range energy transfer by interatomic Coulombic decay in an extreme quantum system

Nicolas Sisourat, Nikolai V. Kryzhevoi, Premysl KolorenC, Simona Scheit, Till Jahnke et al.
When an atom is electronically excited, it relaxes by emitting a photon or an electron. These carry essential information on the electronic structure of their emitter. However, if an atom is embedded in a chemical environment, another ultrafast non-radiative decay process called interatomic Coulomb ... [Nature Phys. 6, 508 (2010)] published Thu Jul 1, 2010.

Multiple-laser flash shadowgraphy system for terminal studies of small-caliber projectiles

R. C. Kalonia, Gautam Mitra, G. S. Singh, R. K. Varma, Manpreet Singh et al.
A multiple-laser flash shadowgraphy system has been innovatively designed and developed to study the terminal effects of projectiles. The system has been designed based on modulated laser diodes operated at low voltage and current. In order to study the ballistics effects of small arms, an exposure ... [Opt. Eng. 49, 064303 (2010)] published Thu Jul 1, 2010.

Laser-induced water condensation in air

Philipp Rohwetter, Jerome Kasparian, Kamil Stelmaszczyk, Zuoqiang Hao, Stefano Henin et al.
Triggering rain on demand is an old dream of mankind, with a huge potential socio-economical benefit. To date, efforts have mainly focused on cloud-seeding using silver salt particles. We demonstrate that self-guided ionized filaments generated by ultrashort laser pulses are also able to induce wate ... [Nat. Photonics 4, 451 (2010)] published Tue Jul 6, 2010.

Organic photonics for communications

Jenny Clark and Guglielmo Lanzani
Photons as information carriers have the potential to meet the ever-increasing demands on bandwidth and information density in fields such as information and communication technology, biomedicine and computing. Organic semiconductors may be well-suited to such applications, thanks to their ability t ... [Nat. Photonics 4, 438 (2010)] published Tue Jul 6, 2010.

Embellishment of microfluidic devices via femtosecond laser micronanofabrication for chip functionalization

Juan Wang, Yan He, Hong Xia, Li-Gang Niu, Ran Zhang et al.
This paper demonstrates the embellishment of existing microfluidic devices with integrated three dimensional (3D) micronanostructures via femtosecond laser micronanofabrication, which, for the first time, proves two-photon photopolymerization (TPP) to be a powerful technology for chip functionalizat ... [Lab Chip 10, 1993 (2010)] published Thu Jul 15, 2010.

Efficient laser-ion acceleration from closely stacked ultrathin foils

T. Kluge, W. Enghardt, S. D. Kraft, U. Schramm, Y. Sentoku et al.
A new scheme to efficiently accelerate protons by a single linear polarized high-intensity ultrashort laser pulse using multiple ultrathin foils is proposed. The foils are stacked at a spacing comparable to their thickness and subsequently irradiated by the same laser pulse. The foil thicknesses are ... [Phys. Rev. E 82, 016405 ] published .

Proton radiography of a shock-compressed target

A. Ravasio, L. Romagnani, S. Le Pape, A. Benuzzi-Mounaix, C. Cecchetti et al.
In this paper we report on the radiography of a shock-compressed target using laser produced proton beams. A low-density carbon foam target was shock compressed by long pulse high-energy laser beams. The shock front was transversally probed with a proton beam produced in the interaction of a high in ... [Phys. Rev. E 82, 016407 ] published .

Direct particle acceleration by two identical crossed radially polarized laser beams

Yousef I. Salamin
Electrons and alpha particles injected midway between two ultrahigh intensity crossed laser beams of radial polarization are shown to be accelerated in vacuum to several gigaelectron volts and to have average energy gradients in excess of 150 GeV/m. A unique model of the crossing beams is suggested, ... [Phys. Rev. A 82, 013823 ] published .

Spectral tunneling of lattice nonlocal solitons

Yaroslav V. Kartashov, Victor A. Vysloukh, and Lluis Torner
We address spectral tunneling of walking spatial solitons in photorefractive media with nonlocal diffusion component of the nonlinear response and an imprinted shallow optical lattice. In contrast to materials with local nonlinearities, where solitons traveling across the lattice close to the Bragg ... [Phys. Rev. A 82, 013806 ] published .

Radiation generated by bunched electron beams in corrugated plasma channels

Thomas M. Antonsen, Jr.
The excitation of radiation by bunched electron beams propagating in miniature corrugated plasma channels is considered. It is shown that the rate at which power is radiated by a beam is characterized by impedance that depends on the properties of the channel. For experimentally obtainable parameter ... [Phys. Plasmas 17, 073112 (2010)] published Fri Jul 30, 2010.

A computational study of x-ray emission from laser-irradiated Ge-doped foams

Jeffrey D. Colvin, Kevin B. Fournier, Mark J. May, and Howard A. Scott
New advances in fabrication of low-density high-Z-doped foams have opened new windows on understanding how materials that are not in local thermodynamic equilibrium (LTE) are heated and radiate. Simulations are discussed in this paper of the x-ray spectral emissions from laser-irradiated very low-de ... [Phys. Plasmas 17, 073111 (2010)] published Thu Jul 29, 2010.

Correlation between laser accelerated MeV proton and electron beams using simple fluid model for target normal sheath acceleration

M. Tampo, S. Awano, P. R. Bolton, K. Kondo, K. Mima et al.
High density energetic electrons that are created by intense laser plasma interactions drive MeV proton acceleration. The correlation between accelerated MeV protons and escaped electrons is experimentally investigated at laser intensities in the range of 1010 W/cm with S-polarization. Observed pro ... [Phys. Plasmas 17, 073110 (2010)] published Thu Jul 29, 2010.

Quasitransient backward Raman amplification of powerful laser pulses in dense plasmas with multicharged ions

V. M. Malkin and N. J. Fisch
The range of plasma parameters, where the efficient quasitransient backward Raman amplification (QBRA) of powerful laser pulses is possible, is determined for dense plasmas with multicharged ions. Approximate scalings that portray in a simple way the efficient QBRA range in multidimensional paramete ... [Phys. Plasmas 17, 073109 (2010)] published Tue Jul 27, 2010.

Ionization heating in rare-gas clusters under intense XUV laser pulses

Mathias Arbeiter and Thomas Fennel
The interaction of intense extreme ultraviolet (XUV) laser pulses (lambda=32 nm, I=1010 W/cm) with small rare-gas clusters (Ar) is studied by quasiclassical molecular dynamics simulations. Our analysis supports a very general picture of the charging and heating dynamics in finite samples under shor ... [Phys. Rev. A 82, 013201 ] published .

Modulated vortex solitons of four-wave mixing

Yanpeng Zhang, Zhiqiang Nie, Yan Zhao, Changbiao Li, Ruimin Wang et al.
We experimentally demonstrate the vortex solitons of four-wave mixing (FWM) in multi-level atomic media created by the interference patterns with superposing three or more waves. The modulation effect of the vortex solitons is induced by the cross-Kerr nonlinear dispersion due to atomic coherence in ... [Opt. Express 18, 10963 (2010)] published Wed Jul 7, 2010.

Effect of self-generated magnetic fields on fast-electron beam divergence in solid targets

X Yuan, A Robinson, M Quinn, D Carroll, M Borghesi et al.
The collimating effect of self-generated magnetic fields on fast-electron transport in solid aluminium targets irradiated by ultra-intense, picosecond laser pulses is investigated in this study. As the target thickness is varied in the range of 25 [mu]m to 1.4 mm, the maximum energies of protons acc ... [New J. Phys. 12, 063018 (2010)] published Thu Jul 1, 2010.

Femtosecond electronic response of atoms to ultra-intense X-rays

L. Young, E. P. Kanter, B. Krssig, Y. Li, A. M. March et al.
An era of exploring the interactions of high-intensity, hard X-rays with matter has begun with the start-up of a hard-X-ray free-electron laser, the Linac Coherent Light Source (LCLS). Understanding how electrons in matter respond to ultra-intense X-ray radiation is essential for all applications. H ... [Nature 466, 56 (2010)] published Thu Jul 1, 2010.

Recombination effects during expansion into vacuum in laser produced Sn plasma

Russell A. Burdt, Yoshifumi Ueno, Yezheng Tao, Sam Yuspeh, Mark S. Tillack et al.
The distance over which the charge state distribution evolves during the expansion of laser produced Sn plasma in vacuum is investigated experimentally. This distance is found to be less than 6 cm with a planar target irradiated by a 1.064 [mu]m laser at 8.3 x 10 W/cm but greater than 60 cm when a ... [Appl. Phys. Lett. 97, 041502 (2010)] published Fri Jul 30, 2010.

Controlling the Pointing Angle of a Relativistic Electron Beam in a Weakly-Nonlinear Laser Wakefield Accelerator

Nasr A. M. Hafz, Tae Jun Yu, Seong Ku Lee, Tae Moon Jeong, Jae Hee Sung et al.
Advanced laser wakefield accelerators offer electron beams which could be useful for many applications. However, the problem of stabilizing the electron beam parameters has not been resolved yet. Here, we report the generation of a relativistic electron beam with a stabilized pointing angle of 2 mra ... [Appl. Phys. Express 3, 076401 (2010)] published Mon Jul 26, 2010.

A high resolution, broad energy acceptance spectrometer for laser wakefield acceleration experiments

Christopher M. S. Sears, Sofia Benavides Cuevas, Ulrich Schramm, Karl Schmid, Alexander Buck et al.
Laser wakefield experiments present a unique challenge in measuring the resulting electron energy properties due to the large energy range of interest, typically several 100 MeV, and the large electron beam divergence and pointing jitter >1 mrad. In many experiments the energy resolution and accura ... [Rev. Sci. Instrum. 81, 073304 (2010)] published Wed Jul 21, 2010.

Modeling of laser induced plasma expansion in the presence of non-Maxwellian electrons

D. Bennaceur-Doumaz and M. Djebli
The one-dimensional expansion into vacuum of ion-electron plasma produced by laser ablation is investigated. The ions considered as an ideal fluid are governed by a fluid model where charge quasineutrality is assumed to prevail, while electron density follows a non-Maxwellian distribution. Showing t ... [Phys. Plasmas 17, 074501 (2010)] published Thu Jul 8, 2010.

Ultraintense ion beams driven by a short-wavelength short-pulse laser

J. Badziak and S. Jablonski
The results of particle-in-cell simulations are reported which demonstrate that a short-wavelength (lambda<=0.5 [mu]m) short-pulse laser driver can produce much more intense ion beams than the commonly used long-wavelength (lambda~1 [mu]m) ones. In particular, such a driver allows for efficient ge ... [Phys. Plasmas 17, 073106 (2010)] published Thu Jul 22, 2010.

Relativistic Quasimonoenergetic Positron Jets from Intense Laser-Solid Interactions

Hui Chen, S. C. Wilks, D. D. Meyerhofer, J. Bonlie, C. D. Chen et al.
Detailed angle and energy resolved measurements of positrons ejected from the back of a gold target that was irradiated with an intense picosecond duration laser pulse reveal that the positrons are ejected in a collimated relativistic jet. The laser-positron energy conversion efficiency is ~2 x 10. ... [Phys. Rev. Lett. 105, 015003 ] published .

Observations of low-aberration plasma lens focusing of relativistic electron beams at the underdense threshold

M. C. Thompson, H. Badakov, J. B. Rosenzweig, G. Travish, N. Barov et al.
Focusing of a 15 MeV electron bunch by a plasma lens operated at the threshold of the underdense regime has been demonstrated. The strong, 1.7 cm focal length, plasma lens focused both transverse directions simultaneously and reduced the minimum area of the beam spot by a factor of 23. It is shown t ... [Phys. Plasmas 17, 073105 (2010)] published Wed Jul 21, 2010.

Quantum electrodynamics vacuum polarization modification of photon acceleration in plasma

Zhigang Bu and Peiyong Ji
The modification of photon frequency shifting based on taking into account the nonlinear quantum electrodynamics vacuum properties in plasma is studied. Motion equations of a laser field propagating in a plasma are derived from the HeisenbergEuler Lagrangian density. It is found that besides the cla ... [Phys. Plasmas 17, 073103 (2010)] published Fri Jul 16, 2010.

Photon acceleration in the amplified plasma density wake of two copropagating laser pulses

G. Raj, M. R. Islam, B. Ersfeld, and D. A. Jaroszynski
Photon acceleration of a laser pulse occurs in a medium with a space and time-varying permittivity. Using Hamiltonian formulation, a theoretical study of the frequency upshift of a probe laser pulse, which is considered as a quasiphoton or test particle, propagating through an amplified plasma densi ... [Phys. Plasmas 17, 073102 (2010)] published Wed Jul 14, 2010.

Classification and stability of plasma motion in periodic linearly polarized relativistic waves

G. Lehmann and K. H. Spatschek
Based on a relativistic fluid-Maxwell model, laser-induced plasma dynamics is investigated for relativistic periodic waves. Within a one-dimensional (1D) description, the AkhiezerPolovin model is applied to the existence of periodic, nonlinearly coupled electromagnetic and electrostatic waves, and t ... [Phys. Plasmas 17, 072102 (2010)] published Thu Jul 8, 2010.

Stimulated Raman Side Scattering in Laser Wakefield Acceleration

T. Matsuoka, C. McGuffey, P. G. Cummings, Y. Horovitz, F. Dollar et al.
Stimulated Raman side scattering of an ultrashort high power laser pulse is studied in experiments on laser wakefield acceleration. Experiments and simulations reveal that stimulated Raman side scattering occurs at the beginning of the interaction, that it contributes to the evolution of the pulse p ... [Phys. Rev. Lett. 105, 034801 ] published .

Light Bullets by Synthetic Diffraction-Dispersion Matching

Valery E. Lobanov, Yaroslav V. Kartashov, and Lluis Torner
We put forward a new approach to generate stable, fully three-dimensional light bullets, which is based on the matching of the intrinsic material dispersion with a suitable effective diffraction. The matching is achieved in adequate waveguide arrays whose refractive index is periodically modulated a ... [Phys. Rev. Lett. 105, 033901 ] published .

Hot Electrons Transverse Refluxing in Ultraintense Laser-Solid Interactions

S. Buffechoux, J. Psikal, M. Nakatsutsumi, L. Romagnani, A. Andreev et al.
We have analyzed the coupling of ultraintense lasers (at ~2 x 10 W/cm) with solid foils of limited transverse extent (~10 s of [mu]m) by monitoring the electrons and ions emitted from the target. We observe that reducing the target surface area allows electrons at the target surface to be reflecte ... [Phys. Rev. Lett. 105, 015005 ] published .

Spatiotemporal evolution of high-power relativistic laser pulses in electron-positron-ion plasmas

A. Sharma, I. Kourakis, and P. K. Shukla
The spatiotemporal pulse dynamics of a high-power relativistic laser pulse interacting with an electron-positron-ion plasmas is investigated theoretically and numerically. The occurrence of pulse compression is studied. The dependence of the mechanism on the concentration of the background ions in e ... [Phys. Rev. E 82, 016402 ] published .

Near-critical phase explosion promoting breakdown plasma ignition during laser ablation of graphite

A. A. Ionin, S. I. Kudryashov, and L. V. Seleznev
Removal rate, air shock, and ablative recoil pressure parameters were measured as a function of laser intensity I during nanosecond laser ablation of graphite. Surface vaporization of molten graphite at low intensities I<0.15 GW/cm was observed to transform into its near-critical phase explosion (i ... [Phys. Rev. E 82, 016404 ] published .

Heating dynamics and extreme ultraviolet radiation emission of laser-produced Sn plasmas

S. Yuspeh, K. L. Sequoia, Y. Tao, M. S. Tillack, R. A. Burdt et al.
The impact of 1.064 [mu]m laser absorption depth on the heating and in-band (2% bandwidth) 13.5 nm extreme ultraviolet emissions in Sn plasmas is investigated experimentally and numerically. In-band emission lasting longer than the laser pulse and separation between the laser absorption and in-band ... [Appl. Phys. Lett. 96, 261501 (2010)] published Wed Jun 30, 2010.

Optical Realization of Relativistic Non-Hermitian Quantum Mechanics

Stefano Longhi
Light propagation in distributed-feedback optical structures with gain or loss regions is shown to provide an accessible laboratory tool to visualize in optics the spectral properties of the one-dimensional Dirac equation with non-Hermitian interactions. Spectral singularities and [script P][script ... [Phys. Rev. Lett. 105, 013903 ] published .

Time-Domain Coherent Anti-Stokes Raman Scattering Signal Detection for Terahertz Vibrational Spectroscopy Using Chirped Femtosecond Pulses

Masahiko Tani, Toshiyuki Koizumi, Hisashi Sumikura, Mariko Yamaguchi, Kohji Yamamoto et al.
A new scheme for low-frequency coherent anti-Stokes Raman scattering spectroscopy (CARS) using chirped femtosecond pulses is proposed and demonstrated. Two chirped broadband optical pulses created terahertz (THz) polarization in the sample and generated CARS signal. The chirped CARS signal was then ... [Appl. Phys. Express 3, 072401 (2010)] published Mon Jul 26, 2010.

High harmonic emission from a superposition of multiple unrelated frequency fields

T. Siegel, R. Torres, D. J. Hoffmann, L. Brugnera, I. Procino et al.
We report observations and analysis of high harmonic generation driven by a superposition of fields at 1290 nm and 780 nm. These fields are not commensurate in frequency and the superposition leads to an increase in the yield of the mid-plateau harmonics of more than two orders of magnitude compared ... [Opt. Express 18, 6853 (2010)] published Wed Jul 7, 2010.

Analytical description of gain depletion and recovery in quantum dot optical amplifiers

Ermin Malic, Marten Richter, Gregor Hartmann, Jordi Gomis-Bresco, Ulrike Woggon et al.
We present an analytical description of ultrashort femtosecond pumpprobe experiments and investigate the gain response of quantum dot (QD) semiconductor optical amplifiers. The calculation provides a full analytical solution of numerical studies to recent experiments in such structures (Gomis-Bresco ... [New J. Phys. 12, 063012 (2010)] published Thu Jul 1, 2010.

Ultra-fast responding and recovering CHOH sensors using SnO hollow spheres prepared and activated by Ni templates

Hae-Ryong Kim, Kwon-Il Choi, Kang-Min Kim, Il-Doo Kim, Guozhong Cao et al.
Ultra-fast responding and recovering CHOH sensors were prepared using nanoscale SnO hollow spheres with NiO-functionalized inner walls. The exceptional ultra-fast recovery characteristics were attributed to the catalytic surface reaction assisted by NiO at the inner shell. ... [Chem. Commun. 46, 5061 (2010)] published Tue Jul 6, 2010.

Bright vector solitons in cross-defocusing nonlinear media

A. I. Yakimenko, O. O. Prikhodko, and S. I. Vilchynskyi
We study two-dimensional soliton-soliton vector pairs in media with self-focusing nonlinearities and defocusing cross interactions. The general properties of the stationary states and their stability are investigated. The different scenarios of instability are observed using numerical simulations. T ... [Phys. Rev. E 82, 016605 ] published .

Erratum: Infrared Two-Color Multicycle Laser Field Synthesis for Generating an Intense Attosecond Pulse [Phys. Rev. Lett. 104, 233901 (2010)]

Eiji J. Takahashi, Pengfei Lan, Oliver D. Mucke, Yasuo Nabekawa, and Katsumi Midorikawa
Abstract not available. [Phys. Rev. Lett. 105, 049902 ] published .

Distortionless large-ratio stretcher for ultra-short pulses using photonic crystal fiber

L.-G. Li, L.-S. Yan, G.-Y. Feng, W. Pan, B. Luo et al.
A large-ratio stretcher for ultra-short pulses is proposed based on photonic crystal fiber (PCF). Through proper design of the PCF structure, we obtain over 300-nm wavelength range with flattened dispersion characteristics. Analysis indicates that 1-km of such fiber can broaden over 10,000 times for ... [Opt. Express 18, 12341 (2010)] published Wed Jul 7, 2010.

Fabrication of three-dimensional 1 x 4 splitter waveguides inside a glass substrate with spatially phase modulated laser beam

Masaaki Sakakura, Tsutomu Sawano, Yasuhiko Shimotsuma, Kiyotaka Miura, and Kazuyuki Hirao
Multiple light spots can be generated by modulating the spatial phase distribution of laser beam with a spatial light modulator (SLM). In this paper, we demonstrate the fabrication of three-dimensional 1 x 4 splitter waveguides inside a glass by focusing multiple light spots of femtosecond (fs) la ... [Opt. Express 18, 12136 (2010)] published Wed Jul 7, 2010.

Wideband spectral compression of wavelength-tunable ultrashort soliton pulse using comb-profile fiber

N. Nishizawa, K. Takahashi, Y. Ozeki, and K. Itoh
We demonstrated spectral compression of ultrashort soliton pulses in a wide wavelength region based on an adiabatic soliton spectral compression technique using a comb-profile fiber. The comb-profile fiber was carefully designed using numerical analysis and fabricated using a conventional single-mod ... [Opt. Express 18, 11700 (2010)] published Wed Jul 7, 2010.

Relativistic Single-Cycled Short-Wavelength Laser Pulse Compressed from a Chirped Pulse Induced by Laser-Foil Interaction

L. L. Ji (吉亮亮), B. F. Shen (沈百飞), D. X. Li (李冬雪), D. Wang (王丁), Y. X. Leng (冷雨欣) et al.
By particle-in-cell simulation and analysis, we propose a plasma approach to generate a relativistic chirped pulse based on a laser-foil interaction. When two counterpropagating circularly polarized pulses interact with an overdense foil, the driving pulse (with a larger laser field amplitude) will ... [Phys. Rev. Lett. 105, 025001 ] published .

Ultrafast optical imaging of the spin Hall effect of light in semiconductors

Jean-Michel Menard, Adam E. Mattacchione, Henry M. van Driel, Christine Hautmann, and Markus Betz
We experimentally demonstrate a general optical pump-probe technique to observe the spin Hall effect of light (SHEL) in an absorbing medium. In essence, a locally confined pump-induced modification of a material's absorptivity can effectively be used as an induced aperture allowing one to detect the ... [Phys. Rev. B 82, 045303 ] published .

Focal dynamics of multiple filaments: Microscopic imaging and reconstruction

P. Prem Kiran, Suman Bagchi, Siva Rama Krishnan, C. L. Arnold, G. Ravindra Kumar et al.
We observe the complete dynamics of the propagation of very intense, femtosecond laser pulses in air under tight focusing conditions via direct imaging of the entire interaction zone. The whole life history of the focused pulses is then reconstructed by means of numerical simulations. We show that b ... [Phys. Rev. A 82, 013805 ] published .

Collinear generation of ?ultrashort UV and XUV pulses

E. M. Bothschafter, A. Schiffrin, V. S. Yakovlev, A. M. Azzeer, F. Krausz et al.
We demonstrate the collinear generation of few-femtosecond ultraviolet and attosecond extreme ultraviolet pulses via a combination of third-harmonic and high harmonic generation in noble gases. The ultrashort coherent light bursts are produced by focusing a sub-1.5-cycle near-infrared/visible laser ... [Opt. Express 18, 9173 (2010)] published Wed Jul 7, 2010.

Infrared laser induced lateral photovoltaic effect observed in CuO nanoscale film

Liang Du and Hui Wang
The large infrared lateral photovoltaic effect (LPE) based on semiconductor structures has been a challenge for a long time because the light in this region is hard to be absorbed. In this study, we report an unusual infrared laser induced LPE observed in sputtered CuO thin films. The maximum open-c ... [Opt. Express 18, 9113 (2010)] published Wed Jul 7, 2010.

High accuracy polarization measurements using binary polarization rotators

X. Steve Yao, Xiaojun Chen, and Tiegen Liu
We report a novel system for the accurate measurement of all polarization related parameters, including polarization mode dispersion and polarization dependent loss, using binary magneto-optic polarization rotators. By taking advantage of the binary nature of the rotators, we achieved unprecedented ... [Opt. Express 18, 6667 (2010)] published Wed Jul 7, 2010.

Modal effects on pump-pulse propagation in an Ar-filled capillary

Richard T. Chapman, Thomas J. Butcher, Peter Horak, Francesco Poletti, Jeremy G. Frey et al.
Accurate three-dimensional modelling of nonlinear pulse propagation within a gas-filled capillary is essential for understanding and improving the XUV yield in high harmonic generation. We introduce both a new model based on a multimode generalized nonlinear Schrodinger equation and a novel spatio-s ... [Opt. Express 18, 13279 (2010)] published Wed Jul 7, 2010.

Formation of filament and plasma channel by the Bessel incident beam in Ar gas: role of the outer part of the beam

Zhenming Song and Takashi Nakajima
We theoretically investigate the formation of filament and plasma channel in Ar gas by intense femtosecond pulses in the Bessel, truncated Bessel, and combination of two Gaussian modes. Through the numerical results obtained by solving the generalized nonlinear Schrodinger equation coupled with the ... [Opt. Express 18, 12923 (2010)] published Wed Jul 7, 2010.

Measurements of nonlinear refractive index in scattering media

Prathyush Samineni, Zachary Perret, Warren S. Warren, and Martin C. Fischer
We have recently developed a spectral re-shaping technique to simultaneously measure nonlinear refractive index and nonlinear absorption. In this technique, the information about the nonlinearities is encoded in the frequency domain, rather than in the spatial domain as in the conventional Z-scan me ... [Opt. Express 18, 12727 (2010)] published Wed Jul 7, 2010.

Soliton mediated optical quantization in the transmission of one-dimensional photonic crystals

Falk Eilenberger, C. Martijn de Sterke, and Benjamin J. Eggleton
We report the experimental and numerical observation of step-like behavior of the high-intensity transmission deep inside the bandgap of a 1D photonic crystal. We show this to be a novel manifestation of the quantization of the soliton area, and derive an upper limit for the energy of the transmissi ... [Opt. Express 18, 12708 (2010)] published Wed Jul 7, 2010.

Hybrid metamaterial design and fabrication for terahertz resonance response enhancement

C. S. Lim, M. H. Hong, Z. C. Chen, N. R. Han, B. Luk'yanchuk et al.
Planar hybrid metamaterial with different split ring resonators (SRR) structure dimensions are fabricated on silicon substrates by femtosecond (fs) laser micro-lens array (MLA) lithography and lift-off process. The fabricated metamaterial structures consist of: (a) uniform metamaterial with 4 SRRs a ... [Opt. Express 18, 12421 (2010)] published Wed Jul 7, 2010.

Fourier domain pump-probe optical coherence tomography imaging of Melanin

Desmond Jacob, Ryan L. Shelton, and Brian E. Applegate
We report the development of a two-color Fourier domain Pump-Probe Optical Coherence Tomography (PPOCT) system. Tissue phantom experiments to characterize the system performance demonstrated imaging depths in excess of 725 [mu]m, nearly comparable to the base Optical Coherence Tomography system. PPO ... [Opt. Express 18, 12399 (2010)] published Wed Jul 7, 2010.

Simultaneous demodulation and demultiplexing of multi-rate WDM DPSK signals using a programmable wavelength-selective switch

Pegah Seddighian, Victor Torres-Company, and Lawrence R. Chen
We show demodulation and demultiplexing of multi-channel WDM differential phase-shift-keying (DPSK) signals operating simultaneously at 10 Gb/s and 40 Gb/s using a 1 x 4 wavelength selective switch. We achieve error-free performance for four channels equally spaced by 100 GHz propagated over an 85 k ... [Opt. Express 18, 11657 (2010)] published Wed Jul 7, 2010.

Ultrafast optical switching based on nonlinear polarization rotation in silicon waveguides

Jonathan Y. Lee, Lianghong Yin, Govind P. Agrawal, and Philippe M. Fauchet
We experimentally realize ultrafast all-optical switching in the 1.5-[mu]m spectral region using cross-phase modulation inside a 5-mm long silicon waveguide. Modulation depths of up to 90% and switching window durations ~1 ps are achieved using 500-fs pump pulses with energies below 10 pJ. ... [Opt. Express 18, 11514 (2010)] published Wed Jul 7, 2010.

Vibrational sum frequency generation spectroscopy using inverted visible pulses

Champika Weeraman, Steven A. Mitchell, Rune Lausten, Linda J. Johnston, and Albert Stolow
We present a broadband vibrational sum frequency generation (BB-VSFG) scheme using a novel ps visible pulse shape. We generate the fs IR pulse via standard procedures and simultaneously generate an `inverted' time-asymmetric narrowband ps visible pulse via second harmonic generation in the pump depl ... [Opt. Express 18, 11483 (2010)] published Wed Jul 7, 2010.

Mid-infrared modulated polarization gating for ultra-broadband supercontinuum generation

Weiyi Hong, Pengfei Wei, Qingbin Zhang, Shaoyi Wang, and Peixiang Lu
We propose a method to control the harmonic process by a mid-IR modulated polarization gating for the effective generation of an ultra-broadband supercontinuum in the neutral rare-gas media. Using a mid-IR polarization gating pulse modulated by a weaker 800-nm linearly polarized pulse, the ionizatio ... [Opt. Express 18, 11308 (2010)] published Wed Jul 7, 2010.

Passive mode-locked lasing by injecting a carbon nanotube-solution in the core of an optical fiber

Amos Martinez, Kaiming Zhou, Ian Bennion, and Shinji Yamashita
In this paper, we propose a saturable absorber (SA) device consisting on an in-fiber micro-slot inscribed by femtosecond laser micro fabrication, filled by a dispersion of Carbon Nanotubes (CNT). Due to the flexibility of the fabrication method, efficient and simple integration of the mode-locking d ... [Opt. Express 18, 11008 (2010)] published Wed Jul 7, 2010.

Defect solitons in two-dimensional optical lattices

W. H. Chen, X. Zhu, T. W. Wu, and R. H. Li
We report on the existence and stability of solitons in a defect embedded in a square optical lattice based on a photorefractive crystal with focusing saturable nonlinearity. These solitons exist in different bandgaps due to the change of defect intensity. For a positive defect, the solitons only ex ... [Opt. Express 18, 10956 (2010)] published Wed Jul 7, 2010.

High-repetition-rate pulse generation using dual-mode self-injection locking in a Fabry-Perot laser diode

Xiaohui Fang, P. K. A. Wai, Chao Lu, H. Y. Tam, and Xinyong Dong
A novel and simple method is presented to generate a tunable high-repetition-rate pulse train based on dual-mode self-injection locking of a Fabry-Perot laser diode (FP-LD). Two fiber Bragg gratings (FBGs) are used in the experiment as feedback components. The two self-injection-locked modes evolve ... [Opt. Eng. 49, 074201 (2010)] published Thu Jul 8, 2010.

Supercontinuum conical emission accompanying filamentation of a femtosecond laser pulse in fused quartz

E. O. Smetanina, A. E. Dormidonov, and V. O. Kompanets
The frequency-angular spectrum of the supercontinuum accompanying the filamentation of femtosecond laser pulses in KU-1 fused quartz at various wavelengths has been experimentally and numerically investigated. The splitting effect of divergent conical-emission radiation of the supercontinuum into di ... [J. Opt. Technol. 77, 463 (2010)] published Wed Jul 28, 2010.

Transmission of femtosecond laser pulses through an optical fiber

L. N. Asnis, Ya. V. Grachev, I. Yu. Denisyuk, and O. A. Smolyanskaya
This article discusses questions of how the pulse width of a femtosecond fiber laser, its spectrum, and the envelope of its spectrum vary when the pulse passes through single-mode and multimode quartz optical fibers about 1 m long. ... [J. Opt. Technol. 77, 297 (2010)] published Wed Jul 28, 2010.

Experimental aspects of multiharmonic-order coherent diffractive imaging

Sven Teichmann, Bo Chen, Ruben A. Dilanian, Peter Hannaford, and Lap Van Dao
We describe some experimental aspects required for the implementation of a few-order high-harmonic source for coherent diffractive imaging in the extreme-ultraviolet region. Polychromatic high-angle diffractive images have been successfully processed for both periodic and aperiodic inorganic samples ... [J. Appl. Phys. 108, 023106 (2010)] published Mon Jul 26, 2010.

Ultrabroadband terahertz generation using 4-N,N-dimethylamino-4-N-methyl-stilbazolium tosylate single crystals

I. Katayama, R. Akai, M. Bito, H. Shimosato, K. Miyamoto et al.
Ultrabroadband terahertz generation up to 200 THz has been demonstrated using a 5 fs Ti:sapphire laser and a 4-N,N-dimethylamino-4-N-methyl-stilbazolium tosylate (DAST) crystal. The high-frequency components beyond 100 THz are much stronger than those generated using conventional electro-optic cryst ... [Appl. Phys. Lett. 97, 021105 (2010)] published Wed Jul 14, 2010.

Generation of isolated sub-100-as pulses with 30-fs lasers

Songsong Tang and Xianfeng Chen
We propose a scheme to generate isolated sub-100-as pulses with 30-fs lasers. Our model is based on high-order harmonic generation from a helium atom irradiated by a two-color femtosecond laser field, in which the driving and the control fields are linearly polarized and the polarization angle betwe ... [Phys. Rev. A 82, 013827 ] published .

Wideband amplification using orthogonally polarized pulse trapping in birefringent fibers

Eiji Shiraki and Norihiko Nishizawa
We analyzed the amplification effect of orthogonally polarized pulse trapping in birefringent fibers both experimentally and numerically. Trapped pulses were amplified over a wide wavelength range of 1650-1800 nm accompanying the red-shift. The maximum effective gain was 26 dB for a 140 m-long low b ... [Opt. Express 18, 7323 (2010)] published Wed Jul 7, 2010.

Testing ultrafast two-photon spectral amplitudes via optical fibres

G. Brida, V. Caricato, M. V. Chekhova, M. Genovese, M. Gramegna et al.
We test two-dimensional TPSA of biphoton light emitted via ultrafast spontaneous parametric down-conversion (SPDC) using the effect of group-velocity dispersion in optical fibres. Further, we apply this technique to demonstrate the engineering of biphoton spectral properties by acting on the pump pu ... [Opt. Express 18, 12915 (2010)] published Wed Jul 7, 2010.

Mechanism of depolarization of white light generated by femtosecond laser pulse in water

Jing Yu, Hongbing Jiang, Jing Wen, Hong Yang, and Qihuang Gong
The polarization state of the white light produced by a femtosecond laser pulse through a water cell is investigated. The depolarization of the white light was found to be induced by magnification of the polarization perturbation in the incident light which is caused by the focus lens. Cross-phase m ... [Opt. Express 18, 12581 (2010)] published Wed Jul 7, 2010.

Study on the time-varying and propagating characteristics of ultrashort pulse Laguerre-Gaussian beams

Yi-Dong Liu and Chunqing Gao
This work proposes a simple model of pulse Laguerre-Gaussian Beams (LGBs) by chopping the incident continuous wave LGB into ultrashort pulse. The pulse LGBs are expanded into a series of LGBs with the same angular quantum number (AQN), whose expansion coefficients show the time-varying and propagati ... [Opt. Express 18, 12104 (2010)] published Wed Jul 7, 2010.

Research on Cherenkov second-harmonic generation in periodically poled lithium niobate by femtosecond pulses

Xuewei Deng, Huaijin Ren, Huiying Lao, and Xianfeng Chen
We systematically study the characteristics of the Cherenkov second-harmonic generation in periodically poled lithium niobate by femtosecond pulses. A relatively high conversion efficiency is obtained and what we believe to be a new different explanation is proposed that nonlinearities in the domain ... [J. Opt. Soc. Am. B 27, 1475 (2010)] published Thu Jul 15, 2010.

Energy Exchange between Femtosecond Laser Filaments in Air

Y. Liu, M. Durand, S. Chen, A. Houard, B. Prade et al.
We report on the energy exchange between femtosecond laser filaments in air. A traveling plasma grating formed at the intersection of the filaments is proposed to explain the energy transfer. In this moving plasma grating mediated mechanism the laser energy transfers from the lower frequency pulse t ... [Phys. Rev. Lett. 105, 055003 ] published .

Modulational-instability-induced supercontinuum generation with saturable nonlinear response

R. Vasantha Jayakantha Raja, K. Porsezian, and K. Nithyanandan
We theoretically investigate the supercontinuum generation (SCG) on the basis of modulational instability (MI) in liquid-core photonic crystal fibers (LCPCF) with CS-filled central core. The effect of saturable nonlinearity of LCPCF on SCG in the femtosecond regime is studied using an appropriately ... [Phys. Rev. A 82, 013825 ] published .

Ultrafast double-quantum-coherence spectroscopy of excitons with entangled photons

Marten Richter and Shaul Mukamel
We calculate the four-wave-mixing signal of excitons generated at k=k+k-k by two pulsed entangled photon pairs (k, k) and (k, k), where all four modes are chronologically ordered. Entangled photons offer an unusual combination of bandwidths and temporal resolution not possible by classical beams. Co ... [Phys. Rev. A 82, 013820 ] published .

Gains without inversion in quantum systems with broken parities

W. Z. Jia and L. F. Wei
For a quantum system with broken parity symmetry, selection rules cannot hold and cyclic transition structures are generated. With these loop transitions we discuss how to achieve inversionless gain of the probe field by properly setting the control and auxiliary fields. Possible implementations of ... [Phys. Rev. A 82, 013808 ] published .

Temporal compression of quantum-information-carrying photons using a photon-echo quantum memory approach

S. A. Moiseev and W. Tittel
We study quantum compression and decompression of light pulses that carry quantum information using a photon-echo quantum memory technique with controllable inhomogeneous broadening of an isolated atomic absorption line. We investigate media with differently broadened absorption profiles, transverse ... [Phys. Rev. A 82, 012309 ] published .

Continuous-wave light modulation at molecular frequencies

J. T. Green, J. J. Weber, and D. D. Yavuz
By using continuous-wave (CW)stimulated Raman scattering inside a high-finesse cavity, we generate three CW spectral components covering about one octave of optical bandwidth. We investigate the mutual coherence of these three beams by studying phase-dependent second harmonic generation. From the hi ... [Phys. Rev. A 82, 011805 ] published .

Observation of cooperative Mie scattering from an ultracold atomic cloud

H. Bender, C. Stehle, S. Slama, R. Kaiser, N. Piovella et al.
Scattering of light at a distribution of scatterers is an intrinsically cooperative process, which means that the scattering rate and the angular distribution of the scattered light are essentially governed by bulk properties of the distribution, such as its size, shape, and density, although local ... [Phys. Rev. A 82, 011404 ] published .

Analysis of time-multiplexed optical line-by-line pulse shaping: application for radio-frequency and microwave photonics

Chen-Bin Huang and Andrew M. Weiner
Time-multiplexed optical line-by-line pulse shaping with specific application to rapid update radio-frequency (RF) waveform generation is modeled. The effects of fundamental pulse shaping parameters on generated RF waveforms are numerically analyzed. Experimental and theoretical results are compared ... [Opt. Express 18, 9366 (2010)] published Wed Jul 7, 2010.

A suspended core nanofiber with unprecedented large diameter ratio of holey region to core

Meisong Liao, Chitrarekha Chaudhari, Xin Yan, Guanshi Qin, Chihiro Kito et al.
For a suspended core nanofiber, the holey region is expected to be as large as possible to propagate the light at wavelengths as long as possible. Additionally, a large holey region is significant for its applications in sensors. However, the fabrication of nanofiber with large holey region is still ... [Opt. Express 18, 9088 (2010)] published Wed Jul 7, 2010.

Compact all-fiber high-energy fiber laser with sub-300-fs duration

X. M. Liu and D. Mao
We report a compact all-fiber high-energy fiber laser that consists of a laser oscillator and a compression section. The laser oscillator generates the pulses with high energy and large chirp. The compression section is made of a piece of standard single-mode fiber that dechirps the chirped pulses. ... [Opt. Express 18, 8847 (2010)] published Wed Jul 7, 2010.

Effect of pulse temporal shape on optical trapping and impulse transfer using ultrashort pulsed lasers

Janelle C. Shane, Michael Mazilu, Woei Ming Lee, and Kishan Dholakia
We investigate the effects of pulse duration on optical trappingwith high repetition rate ultrashort pulsed lasers, through Lorentz-Mietheory, numerical simulation, and experiment. Optical trapping experimentsuse a 12 femtosecond duration infrared pulsed laser, with the trappingmicroscope's temporal ... [Opt. Express 18, 7554 (2010)] published Wed Jul 7, 2010.

A dissipative attractor in the spatiotemporal collapse of ultrashort light pulses

Miguel A. Porras
Spatiotemporal self-focusing in nonlinear lossy media pushes ultrashort pulses towards a universal, non-solitary and non-conical light bullet wave state defined by the medium solely, and characterized by maximum energy losses. Its stationary propagation relies on a balance between nonlinear losses a ... [Opt. Express 18, 7376 (2010)] published Wed Jul 7, 2010.

Experimental investigations on nonlinear dynamics in supercontinuum generation with feedback

Nicoletta Brauckmann, Michael Kues, Till Walbaum, Petra Gross, and Carsten Fallnich
A system for supercontinuum generation by using a photonic crystal fiber within a synchronously pumped ring cavity is presented. The feedback led to an interaction of the generated supercontinuum with the following femtosecond laser pulses and thus to the formation of a nonlinear oscillator. The non ... [Opt. Express 18, 7190 (2010)] published Wed Jul 7, 2010.

Tunable narrow band THz wave generation from laser induced gas plasma

Jayashis Das and Masashi Yamaguchi
Tunable narrowband THz waveforms were generated from laser induced gas plasma using shaped optical pulses. Square wave phase patterns were fed to a spatial light modulator. The frequency and amplitude of the square wave phase were used as parameters to tailor the terahertz waveforms. The dependence ... [Opt. Express 18, 7038 (2010)] published Wed Jul 7, 2010.

Nanogratings and nanoholes fabricated by direct femtosecond laser writing in chalcogenide glasses

Qiming Zhang, Han Lin, Baohua Jia, Lei Xu, and Min Gu
We report on the fabrication of sub-wavelength nanostructures on the surface of AsS chalcogenide glasses by appropriately controlling the irradiation condition of single-beam direct femtosecond laser writing. Nanogratings with a period of 180 nm were realized by multipulse irradiation. More importan ... [Opt. Express 18, 6885 (2010)] published Wed Jul 7, 2010.

Generalized Miller Formulae

W. Ettoumi, Y. Petit, J. Kasparian, and J.-P. Wolf
We derive the spectral dependence of the non-linear susceptibility of any order, generalizing the common form of Sellmeier equations. This dependence is fully defined by the knowledge of the linear dispersion of the medium. This finding generalizes the Miller formula to any order of non-linearity. I ... [Opt. Express 18, 6613 (2010)] published Wed Jul 7, 2010.

High speed all optical logic gates based on quantum dot semiconductor optical amplifiers

Shaozhen Ma, Zhe Chen, Hongzhi Sun, and Niloy K. Dutta
A scheme to realize all-optical Boolean logic functions AND, XOR and NOT using semiconductor optical amplifiers with quantum-dot active layers is studied. nonlinear dynamics including carrier heating and spectral hole-burning are taken into account together with the rate equations scheme. Results sh ... [Opt. Express 18, 6417 (2010)] published Wed Jul 7, 2010.

Modulation response of nanoLEDs and nanolasers exploiting Purcell enhanced spontaneous emission

T. Suhr, N. Gregersen, K. Yvind, and J. Mork
The modulation bandwidth of quantum well nanoLED and nanolaser devices is calculated from the laser rate equations using a detailed model for the Purcell enhanced spontaneous emission. It is found that the Purcell enhancement saturates when the cavity quality-factor is increased, which limits the ma ... [Opt. Express 18, 11230 (2010)] published Wed Jul 7, 2010.

Probing and modeling of interfacial carrier motion in organic devices by optical second harmonic generation

Mitsumasa Iwamoto, Takaaki Manaka, Martin Weis, and Dai Taguchi
Here the authors report a novel optical second harmonic generation (SHG) measurement that allows carrier motion in solids to be probed directly. By catching nonlinear polarization induced in the solids by coupling with incident electromagnetic waves (laser beam) and dc electric field from moving car ... [J. Vac. Sci. Technol. B 28, C5F12 (2010)] published Tue Jul 27, 2010.

All-optical memory operation of 980-nm polarization bistable VCSEL for 20-Gb/s PRBS RZ and 40-Gb/s NRZ data signals

Jun Sakaguchi, Takeo Katayama, and Hitoshi Kawaguchi
The fastest known operation of all-optical flip-flop memory was experimentally demonstrated using a 980-nm polarization bistable vertical-cavity surface-emitting laser (VCSEL). Operating conditions of the input signal power and the frequency detuning to achieve the fast optical memory operation were ... [Opt. Express 18, 12362 (2010)] published Wed Jul 7, 2010.

Broad emission band of Yb in the nonlinear Nb:RbTiOPO crystal: origin and applications

J. J. Carvajal, G. Ciatto, X. Mateos, A. Schmidt, U. Griebner et al.
By means of micro-structural and optical characterization of the Yb:Nb:RbTiOPO crystal, we demonstrated that the broad emission band of Yb in these crystals is due to the large splitting of the ytterbium ground state only, and not to a complex multisite occupation by the ytterbium ions in the crysta ... [Opt. Express 18, 7228 (2010)] published Wed Jul 7, 2010.

Photonic generation of ultra-wideband signals by direct current modulation on SOA section of an SOA-integrated SGDBR laser

Hui Lv, Yonglin Yu, Tan Shu, Dexiu Huang, Shan Jiang et al.
Photonic ultra-wideband (UWB) pulses are generated by direct current modulation of a semiconductor optical amplifier (SOA) section of an SOA-integrated sampled grating distributed Bragg reflector (SGDBR) laser. Modulation responses of the SOA section of the laser are first simulated with a microwave ... [Opt. Express 18, 7219 (2010)] published Wed Jul 7, 2010.

Spatially resolved ultrafast transport current in GaAs photoswitches

L. Prechtel, S. Manus, D. Schuh, W. Wegscheider, and A. W. Holleitner
We apply a pump- and probe-scheme to coplanar stripline circuits to investigate the photocurrent response of GaAs photoswitches in time and space. We find a displacement current pulse, as reported earlier. We interpret a time-delayed second pulse as a transport current. In a time-of-flight analysis ... [Appl. Phys. Lett. 96, 261110 (2010)] published Thu Jul 1, 2010.

Tailoring lightmatterspin interactions in colloidal hetero-nanostructures

Jiatao Zhang, Yun Tang, Kwan Lee, and Min Ouyang
The interplay between light and matter is the basis of many fundamental processes and various applications. Harnessing lightmatter interactions in principle allows operation of solid state devices under new physical principles: for example, the a.c. optical Stark effect (OSE) has enabled coherent q ... [Nature 466, 91 (2010)] published Thu Jul 1, 2010.

Multicarrier Recombination and Energy Transfer in Mn-Doped CdS Nanocrystals Studied by Femtosecond PumpProbe Spectroscopy

Seiji Taguchi, Atsushi Ishizumi, and Yoshihiko Kanemitsu
We studied the photocarrier decay dynamics of Mn-doped CdS nanocrystals (NCs) coated with a ZnS shell layer by femtosecond pumpprobe transient absorption spectroscopy. At low excitation intensities, the decay dynamics of photocarriers is determined by energy transfer from electronhole pairs in C ... [J. Phys. Soc. Jpn. 79, 063710 (2010)] published Thu Jul 1, 2010.

Nonlinear spectra of ZnO: reverse saturable, two- and three-photon absorption

M.G. Vivas, T. Shih, T. Voss, E. Mazur, and C. R. Mendonca
We present a broadband (460 - 980 nm) analysis of the nonlinear absorption processes in bulk ZnO, a large-bandgap material with potential blue-to-UV photonic device applications. Using an optical parametric amplifier we generated tunable 1-kHz repetition rate laser pulses and employed the Z-scan tec ... [Opt. Express 18, 9628 (2010)] published Wed Jul 7, 2010.

Ultrafast amorphization in GeSbTe thin film induced by single femtosecond laser pulse

Mitsutaka Konishi, Hisashi Santo, Yuki Hongo, Kazuyuki Tajima, Masaharu Hosoi et al.
We demonstrate amorphization in a GeSbTe (GST) thin film through a nonthermal process by femtosecond electronic excitation. Amorphous recording marks were formed by irradiation with a single femtosecond pulse, and were confirmed to be recrystallized by laser thermal annealing. Scanning electron micr ... [Appl. Opt. 49, 3470 (2010)] published Wed Jul 7, 2010.

High pressure effect on the ultrafast energy relaxation rate of LDS698 (CHNOCl) in a solution

Bingguo Liu, Chunyuan He, Mingxing Jin, Qiaoqiao Wang, Sheng Hsien Lin et al.
Effects of high pressure in a range of up to 1.7 GPa on ultrafast energy relaxation of LDS698 (CHNOCl) molecules in solution have experimentally been illustrated by a method of femtosecond time-resolved absorption spectroscopy. The rates of the intramolecular and intermolecular energy relaxations sh ... [Opt. Express 18, 6863 (2010)] published Wed Jul 7, 2010.

Laser turns silicon superwicking

A. Y. Vorobyev and Chunlei Guo
Using high-intensity femtosecond laser pulses, we create a novel surface pattern that transforms regular silicon to superwicking. Due to the created surface structure, water sprints vertically uphill in a gravity defying way. Our study of the liquid motion shows that the fast self-propelling motion ... [Opt. Express 18, 6455 (2010)] published Wed Jul 7, 2010.

Optical fiber link for transmission of 1-nJ femtosecond laser pulses at 1550 nm

Finn Eichhorn, Rasmus Kjelsmark Olsson, Jonas C. D. Buron, Lars Gruner-Nielsen, Jens Engholm Pedersen et al.
We report on numerical and experimental characterization of the performance of a fiber link optimized for the delivery of sub-100-fs laser pulses at 1550 nm over several meters of fiber. We investigate the power handling capacity of the link, and demonstrate all-fiber delivery of 1-nJ pulses over a ... [Opt. Express 18, 6978 (2010)] published Wed Jul 7, 2010.

Two-photon spectral hole burning spectroscopy of InAs/GaAs quantum dots

T. Moldaschl, W. Parz, T. Muller, S. Golka, G. Strasser et al.
Femtosecond spectral hole burning experiments were performed on InAs/GaAs quantum dots to investigate the influence of high excitation intensities. The observation of additional spectral holes, as well as distinct absorption line broadening are both attributed to two-photon absorption processes. The ... [Appl. Phys. Lett. 97, 011903 (2010)] published Wed Jul 7, 2010.

Probing valence band structure in wurtzite InP nanowires using excitation spectroscopy

S. Perera, K. Pemasiri, M. A. Fickenscher, H. E. Jackson, L. M. Smith et al.
We use time-resolved photoluminescence spectroscopy and photoluminescence excitation spectroscopy to measure the valence band parameters of hexagonal wurtzite InP nanowires. The A exciton emission and excitation energy is observed at 1.504 eV as expected. Excitation spectra show that the B and C hol ... [Appl. Phys. Lett. 97, 023106 (2010)] published Wed Jul 14, 2010.

Electron-Hole Overlap Dictates the Hole Spin Relaxation Rate in Nanocrystal Heterostructures

Jun He, Haizheng Zhong, and Gregory D. Scholes
Hole spin relaxation dynamics in CdTe/CdSe core-shell nanocrystals are measured by an ultrafast polarization transient grating technique. Photoexcited charge separation in type II structures suppresses the electron-hole exchange interaction and the hole spin relaxation time constant is found to incr ... [Phys. Rev. Lett. 105, 046601 ] published .

Superdiffusive Spin Transport as a Mechanism of Ultrafast Demagnetization

M. Battiato, K. Carva, and P. M. Oppeneer
We propose a semiclassical model for femtosecond laser-induced demagnetization due to spin-polarized excited electron diffusion in the superdiffusive regime. Our approach treats the finite elapsed time and transport in space between multiple electronic collisions exactly, as well as the presence of ... [Phys. Rev. Lett. 105, 027203 ] published .

Band-dependent Quasiparticle Dynamics in Single Crystals of the BaKFeAs Superconductor Revealed by Pump-Probe Spectroscopy

Darius H. Torchinsky, G. F. Chen, J. L. Luo, N. L. Wang, and Nuh Gedik
We report on band-dependent quasiparticle dynamics in BaKFeAs (T=37 K) measured using ultrafast pump-probe spectroscopy. In the superconducting state, we observe two distinct relaxation processes: a fast component whose decay rate increases linearly with excitation density and a slow component with ... [Phys. Rev. Lett. 105, 027005 ] published .

Optical detection of folded mini-zone-edge coherent acoustic modes in a doped GaAs/AlAs superlattice

R. Beardsley, A. V. Akimov, B. A. Glavin, W. Maryam, M. Henini et al.
A coherent phonon mode with frequency corresponding to the first mini Brillouin-zone edge stop gap is observed in ultrafast pump-probe measurements on a doped semiconductor superlattice structure. It is proposed that the optical detection of the mode is facilitated by interactions with the free carr ... [Phys. Rev. B 82, 041302 ] published .

Optical emission and nanoparticle generation in Al plasmas using ultrashort laser pulses temporally optimized by real-time spectroscopic feedback

M. Guillermin, J. P. Colombier, S. Valette, E. Audouard, F. Garrelie et al.
With an interest in pulsed laser deposition and remote spectroscopy techniques, we explore here the potential of laser pulses temporally tailored on ultrafast time scales to control the expansion and the excitation degree of various ablation products including atomic species and nanoparticulates. Ta ... [Phys. Rev. B 82, 035430 ] published .

Coherent control of metallic nanoparticles near fields: Nanopulse controllers and functional nanoamplifiers

S. M. Sadeghi
When a hybrid system consisting of a metallic nanoparticle and a semiconductor quantum dot interacts with a coherent light source (laser beam) the coherence generated in the quantum dot can significantly renormalize the plasmonic field. In this paper we study the impacts of such coherent-plasmonic p ... [Phys. Rev. B 82, 035413 ] published .

Optically induced anisotropy of surface plasmons in spherical metal nanoparticles

Igor Dmitruk, Ivan Blonskiy, Ihor Pavlov, Oleg Yeshchenko, Alexandr Alexeenko et al.
Red shift and splitting of surface plasmon band in absorption spectra of copper nanoparticles incorporated in silica matrix have been observed under irradiation by intense femtosecond laser pulse with power density 1010 W/cm. These phenomena are interpreted as a result of change of dielectric const ... [Phys. Rev. B 82, 033401 ] published .

Stochastic heating of a molecular nanomagnet

L. Chotorlishvili, P. Schwab, Z. Toklikishvili, and J. Berakdar
We study the excitation dynamics of a single molecular nanomagnet by static and pulsed magnetic fields. Based on a stability analysis of the classical magnetization dynamics we identify analytically the fields parameters for which the energy is stochastically pumped into the system in which case the ... [Phys. Rev. B 82, 014418 ] published .

Room temperature terahertz electro-optic modulation by excitons in carbon nanotubes

T. Ogawa, S. Watanabe, N. Minami, and R. Shimano
We have investigated the electroabsorption of aligned micelle-wrapped single-walled carbon nanotubes induced by intense terahertz (THz) pulses by using THz-pump and optical-probe spectroscopy at room temperature. The electroabsorption signal is enhanced at exciton resonances near the optical communi ... [Appl. Phys. Lett. 97, 041111 (2010)] published Tue Jul 27, 2010.

Strong spin-lattice coupling in multiferroic hexagonal manganite YMnO probed by ultrafast optical spectroscopy

Kyeong-Jin Jang, Han-gyoel Lee, Sangkyung Lee, Jaewook Ahn, Jai Seok Ahn et al.
We report the observation of spin-lattice coupling in multiferroic YMnO by femtosecond near-infrared pump and probe spectroscopy. A coherent 31 GHz acoustic phonon was detected above the magnetic ordering temperature, and a higher frequency coherent mode was observed in the antiferromagnetic phase. ... [Appl. Phys. Lett. 97, 031914 (2010)] published Thu Jul 22, 2010.

Intrinsic geometric scattering probed by picosecond optoacoustics in a cylindrical cavity: Application to acoustic and optical characterizations of a single micron carbon fiber

D. Segur, Y. Guillet, and B. Audoin
A picosecond pump-probe technique is used to reveal the optoacoustic response of a single micrometric carbon fiber. The signature of the intrinsic geometric scattering resulting from acoustic reflections at free surface of the cylindrical cavity is contained in the signals. The fiber transverse elas ... [Appl. Phys. Lett. 97, 031901 (2010)] published Mon Jul 19, 2010.

Nonreciprocal emission of spin-wave packet in FeNi film

K. Sekiguchi, K. Yamada, S. M. Seo, K. J. Lee, D. Chiba et al.
We report a time-resolved propagating spin wave spectroscopy for FeNi film. We show that the amplitude of the spin-wave packet depends on the direction of magnetization and that its phase can be controlled by the polarity of pulsed magnetic field for the excitation. The nonreciprocal emission of spi ... [Appl. Phys. Lett. 97, 022508 (2010)] published Thu Jul 15, 2010.

Long exciton spin relaxation in coupled quantum wells

K. Kowalik-Seidl, X. P. Vogele, B. N. Rimpfl, S. Manus, J. P. Kotthaus et al.
Spatially indirect excitons in a coupled quantum well structure were studied by means of polarization and time-resolved photoluminescence. A strong degree of circular polarization (>50%) in emission was achieved when the excitation energy was tuned into resonance with the direct exciton state. The i ... [Appl. Phys. Lett. 97, 011104 (2010)] published Thu Jul 8, 2010.

Direct observation of low frequency confined acoustic phonons in silver nanoparticles: Terahertz time domain spectroscopy

Sunil Kumar, N. Kamaraju, B. Karthikeyan, M. Tondusson, E. Freysz et al.
Terahertz time domain spectroscopy has been used to study low frequency confined acoustic phonons of silver nanoparticles embedded in poly(vinyl alcohol) matrix in the spectral range of 0.12.5 THz. The real and imaginary parts of the dielectric function show two bands at 0.60 and 2.12 THz attributed ... [J. Chem. Phys. 133, 014502 (2010)] published Fri Jul 2, 2010.

Electron-phonon coupling and the charge gap of spin-density wave iron-pnictide materials from quasiparticle relaxation dynamics

L. Stojchevska, P. Kusar, T. Mertelj, V. V. Kabanov, X. Lin et al.
We investigate the quasiparticle relaxation and low-energy electronic structure in undoped SrFeAs exhibiting spin-density wave (SDW) ordering using optical pump-probe femtosecond spectroscopy. A remarkable critical slowing down of the quasiparticle relaxation dynamics at the SDW transition temperatu ... [Phys. Rev. B 82, 012505 ] published .

Fidelity susceptibility approach to quantum phase transitions in the XY spin chain with multisite interactions

W. W. Cheng and J.-M. Liu
We study the quantum critical behavior of the XY spin chain with multisite interaction by means of a fidelity susceptibility (FS) calculation. The key ingredients (e.g., finite-size scaling behavior, universality principle) of the quantum criticality near the critical point are investigated carefull ... [Phys. Rev. A 82, 012308 ] published .

Terahertz generation based on an optically pumped ballistic electron wave swing device

D. Dragoman, M. Dragoman, and H. Hartnagel
Terahertz (THz) signals can be generated by the periodic motion of ballistic electron bunches inside a quantum well cavity surrounded by two asymmetric resonant tunneling structure implemented in an InAlAs/InGaAs heterostructure. The electron bunches are produced in an adjacent active quantum well b ... [J. Appl. Phys. 108, 026103 (2010)] published Tue Jul 27, 2010.

Field-dependent ultrafast dynamics and mechanism of magnetization reversal across ferrimagnetic compensation points in GdFeCo amorphous alloy films

Zhifeng Chen, Ruixin Gao, Zixin Wang, Chudong Xu, Daxin Chen et al.
Ultrafast dynamics of genuine magneto-optical recording across ferrimagnetic compensation points is demonstrated in GdFeCo films using time-resolved polar Kerr spectroscopy combined with a laser-synchronized sinusoidal alternating magnetic field which can reinitialize irreversible initial magnetizat ... [J. Appl. Phys. 108, 023902 (2010)] published Fri Jul 16, 2010.

Fast and slow carrier recombination transients in highly excited 4H and 3CSiC crystals at room temperature

P. SCajev, V. Gudelis, K. Jarasiunas, and P. B. Klein
Nonequilibrium carrier recombination in highly excited epitaxial layers of 4HSiC and free standing 3CSiC was analyzed numerically and studied experimentally by the time-resolved free carrier absorption (FCA) technique. The measurement setup combined interband carrier excitation by a picosecond laser ... [J. Appl. Phys. 108, 023705 (2010)] published Tue Jul 27, 2010.

Ultrafast observation of shocked states in a precompressed material

Michael R. Armstrong, Jonathan C. Crowhurst, Sorin Bastea, and Joseph M. Zaug
We apply ultrafast single shot interferometry to determine the pressure and density of argon shocked from up to 7.8 GPa static initial pressure in a diamond anvil cell. This method enables the observation of thermodynamic states distinct from those observed in either single shock or isothermal compr ... [J. Appl. Phys. 108, 023511 (2010)] published Tue Jul 27, 2010.

Dynamics of polarized photoluminescence in m-plane InGaN/GaN quantum wells

Vytautas Liuolia, Saulius MarcinkeviCius, You-Da Lin, Hiroaki Ohta, Steven P. DenBaars et al.
Spectrally-, polarization-, and time-resolved photoluminescence (PL) experiments have been performed on 2.5 nm thick m-plane single InGaN quantum wells. It has been found that PL decay is mainly determined by nonradiative recombination through several types of recombination centers, while PL rise is ... [J. Appl. Phys. 108, 023101 (2010)] published Fri Jul 16, 2010.

Radiation efficiency of heavily doped bulk n-InP semiconductor

Oleg Semyonov, Arsen Subashiev, Zhichao Chen, and Serge Luryi
Recombination of minority carriers in heavily doped n-InP wafers has been investigated using spectral and time-resolved photoluminescence at different temperatures. Studies of the transmitted luminescence were enabled by the partial transparency of the samples due to the MossBurstein effect. Tempora ... [J. Appl. Phys. 108, 013101 (2010)] published Thu Jul 1, 2010.

Carrier dynamics in isoelectronic ZnSeO semiconductors

Y. C. Lin, H. L. Chung, W. C. Chou, W. K. Chen, W. H. Chang et al.
This study explores the effects of both Oxygen and temperature on the carrier dynamics of isoelectronic ZnSeO (x=0.027 and 0.053) semiconductors using photoluminescence (PL) and time-resolved PL spectroscopy. We find that the Kohlrausch law is highly consistent with the complex decay traces induced ... [Appl. Phys. Lett. 97, 041909 (2010)] published Thu Jul 29, 2010.

Controllable chirality switching of a moving domain wall by oblique magnetic field

Soo-Man Seo, Kyung-Jin Lee, Soon-Wook Jung, and Hyun-Woo Lee
A full micromagnetic model and a simplified one-dimensional analytical model are used to investigate the domain wall dynamics driven by an oblique magnetic field. Both models show that the Walker breakdown [N. L. Schryer and L. R. Walker, J. Appl. Phys. 45, 5406 (1974)] can occur at two distinct fie ... [Appl. Phys. Lett. 97, 032507 (2010)] published Fri Jul 23, 2010.

Femtosecond laser near-field nanoablation patterning using Mie resonance high dielectric constant particle with small size parameter

Yuto Tanaka, Go Obara, Akira Zenidaka, Mitsuhiro Terakawa, and Minoru Obara
We demonstrate near-field nanohole patterning using a Mie resonance, small size parameter particle for nanofabrication technology regardless of substrate's refractive index. Maximal enhancement factor and nearly smallest spot diameter among the same size dielectric particles are simultaneously obtai ... [Appl. Phys. Lett. 96, 261103 (2010)] published Tue Jun 29, 2010.

Ultrafast All-Optical Coupling of Light to Surface Plasmon Polaritons on Plain Metal Surfaces

Nir Rotenberg, Markus Betz, and Henry M. van Driel
We propose and demonstrate an ultrafast all-optical method to couple light to surface plasmon polaritons on planar gold films. By interfering two 150 fs, 810 nm pulses we excite a transient grating in the temperature of the free electrons of the metal, resulting in a grating in the dielectric functi ... [Phys. Rev. Lett. 105, 017402 ] published .

On femtosecond micromachining of HPHT single-crystal diamond with direct laser writing using tight focusing

Othman H. Y. Zalloum, Matthew Parrish, Alexander Terekhov, and William Hofmeister
We investigate the formation of diversiform micro-/nano-structures in High-Pressure High-Temperature (HPHT) synthetic single-crystal diamond by tight-focusing 200 fs regeneratively amplified Ti: Sapphire laser pulses centered at lambda = 800 nm. Ablated samples of synthetic single crystal nanodiamon ... [Opt. Express 18, 13122 (2010)] published Wed Jul 7, 2010.

Geometrical Resonance Conditions for THz Radiation from the Intrinsic Josephson Junctions in BiSrCaCuO

Manabu Tsujimoto, Kazuhiro Yamaki, Kota Deguchi, Takashi Yamamoto, Takanari Kashiwagi et al.
Subterahertz radiation emitted from a variety of short rectangular-, square-, and disk-shaped mesas of intrinsic Josephson junctions fabricated from a BiSrCaCuO single crystal was studied from the observed I-V characteristics, far-infrared spectra, and spatial radiation patterns. In all cases, the r ... [Phys. Rev. Lett. 105, 037005 ] published .

Thermoelastic analysis of a silicon surface under x-ray free-electron-laser irradiation

A. R. B. de Castro, Aurea R. Vasconcellos, and Roberto Luzzi
We present an analysis of the time evolution of a highly excited silicon substrate after partial absorption of a femtosecond soft x-ray pulse. The detailed time-dependent thermoelastic behavior of the substrate in terms of the displacements u(r,t) is derived for time delays for which the usual local ... [Rev. Sci. Instrum. 81, 073102 (2010)] published Thu Jul 8, 2010.

Following a chemical reaction using high-harmonic interferometry

H. J. Wrner, J. B. Bertrand, D. V. Kartashov, P. B. Corkum, and D. M. Villeneuve
The study of chemical reactions on the molecular (femtosecond) timescale typically uses pump laser pulses to excite molecules and subsequent probe pulses to interrogate them. The ultrashort pump pulse can excite only a small fraction of molecules, and the probe wavelength must be carefully chosen t ... [Nature 466, 604 (2010)] published Thu Jul 29, 2010.

Control of ionization and dissociation by optical pulse trains

A. Kirrander, Ch. Jungen, and H. H. Fielding
Ever since the first lasers were built over 40 years ago, chemists and physicists have been attempting to exploit them as tools for controlling the outcome of chemical reactions. Over the last decade this dream has become a reality. The most successful approaches have employed learning algorithms to ... [Phys. Chem. Chem. Phys. 12, 8948 (2010)] published Thu Jul 29, 2010.

Doppler effect in fragment autoionization following core-to-Rydberg excitations of N

Eiji Shigemasa, Tatsuo Kaneyasu, Tomohiro Matsushita, Yusuke Tamenori, and Yasumasa Hikosaka
The autoionization of atomic fragments after core-to-Rydberg excitations in N has been studied using high-resolution electron spectroscopy. Doppler profiles are clearly observed on atomic autoionization peaks and show dependence on the symmetries of the excited states. It is demonstrated that inform ... [New J. Phys. 12, 063030 (2010)] published Thu Jul 1, 2010.

Momentum space analysis of multiphoton double ionization of helium by intense attosecond xuv pulses

Zheng Zhang, Liang-You Peng, Qihuang Gong, and Toru Morishita
We investigate the momentum and energy distributions of the two electrons in multiphoton double ionization of He by intense attosecond xuv pulses, based on a two-dimensional model. Two different patterns of the momentum distributions are identified, corresponding to the uncorrelated and correlated c ... [Opt. Express 18, 8976 (2010)] published Wed Jul 7, 2010.

Molecular high harmonic generation in a two-color field

Pengfei Wei, Candong Liu, Chunmei Zhang, Yansui Huang, Yuxin Leng et al.
We experimentally investigate the high harmonic generation (HHG) from CH molecules and Xe atoms in a two-color field (using the 800nm laser and the tunable laser with the longer wavelength from 1500nm to 1900nm), and observe that the longer wavelength component can destructively suppress the HHG fro ... [Opt. Express 18, 11664 (2010)] published Wed Jul 7, 2010.

Mapping Molecular Orbital Symmetry on High-Order Harmonic Generation Spectrum Using Two-Color Laser Fields

Hiromichi Niikura, Nirit Dudovich, D. M. Villeneuve, and P. B. Corkum
We have measured high-order harmonic generation spectra of D, N, and CO by mixing orthogonally polarized 800 and 400 nm laser fields. The intensity of the high-harmonic spectrum is modulated as we change the relative phase of the two pulses. For randomly orientated molecules, the phase of the intens ... [Phys. Rev. Lett. 105, 053003 ] published .

Attosecond Electron Spectroscopy Using a Novel Interferometric Pump-Probe Technique

J. Mauritsson, T. Remetter, M. Swoboda, K. Klunder, A. L'Huillier et al.
We present an interferometric pump-probe technique for the characterization of attosecond electron wave packets (WPs) that uses a free WP as a reference to measure a bound WP. We demonstrate our method by exciting helium atoms using an attosecond pulse (AP) with a bandwidth centered near the ionizat ... [Phys. Rev. Lett. 105, 053001 ] published .

Tracking Autoionizing-Wave-Packet Dynamics at the 1-fs Temporal Scale

E. Skantzakis, P. Tzallas, J. E. Kruse, C. Kalpouzos, O. Faucher et al.
We present time-resolved studies and Fourier transform spectroscopy of inner-shell excited states undergoing Auger decay and doubly excited autoionizing states, utilizing coherent extreme-ultraviolet (XUV) radiation continua. Series of states spanning a range of ~4 eV are excited simultaneously. An ... [Phys. Rev. Lett. 105, 043902 ] published .

Isotope effects in the harmonic response from hydrogenlike muonic atoms in strong laser fields

Atif Shahbaz, Thomas J. Burvenich, and Carsten Muller
High-order harmonic generation from hydrogenlike muonic atoms exposed to ultraintense high-frequency laser fields is studied. Systems of low nuclear-charge number Z are considered where a nonrelativistic description applies. By comparing the radiative response for different isotopes, we demonstrate ... [Phys. Rev. A 82, 013418 ] published .

Theory of probing attosecond electron wave packets via two-path interference of angle-resolved photoelectrons

N. N. Choi, T. F. Jiang, T. Morishita, M.-H. Lee, and C. D. Lin
We study theoretically the electron wave packet generated by an attosecond pulse train (APT) which is probed with a time-delayed infrared (IR) laser pulse. The APT creates an excited state and a continuum electron wave packet. By ionizing the excited state with an IR, a delayed new continuum electro ... [Phys. Rev. A 82, 013409 ] published .

Designing of transparency windows by quantum interference of wave packets

Krishna Rai Dastidar and Anindita Bhattacharjee
It has been shown that control over the design of single- or multimode-transparency windows can be achieved by control-probe quantum interferometry using two delayed phase-locked ultrashort pulses. We have investigated how single- or multimode-transparency windows can be designed by eliminating the ... [Phys. Rev. A 82, 013404 ] published .

Mechanisms underlying strong-field double ionization of argon dimers

B. Manschwetus, H. Rottke, G. Steinmeyer, L. Foucar, A. Czasch et al.
We investigate double ionization of argon dimers in high-intensity ultrashort Ti:sapphire laser pulses. We are able to identify several strong-field excitation pathways of the dimer that terminate in atomic ion pairs from a Coulomb explosion. The explosion starts from two-site double-ionized dimers ... [Phys. Rev. A 82, 013413 ] published .

Photodissociation dynamics of acetylene via the C-tilde Pi electronic state

Yongwei Zhang, Kaijun Yuan, Shengrui Yu, David H. Parker, and Xueming Yang
Photodissociation of acetylene has been studied using the H-atom Rydberg tagging time-of-flight technique at two excitation wavelengths (148.35 and 151.82 nm) in the vacuum ultraviolet region. Product translational energy distributions have been obtained from the H-atom time-of-flight spectra. Exper ... [J. Chem. Phys. 133, 014307 (2010)] published Wed Jul 7, 2010.

Real-time dissociation dynamics of the NeBr van der Waals complex

Jordan M. Pio, Molly A. Taylor, Wytze E. van der Veer, Craig R. Bieler, Jose A. Cabrera et al.
We have characterized the vibrational predissociation (VP) of the NeBr van der Waals complex using time- and frequency-resolved pump-probe spectroscopy. After exciting Br within the complex to a vibrational level 16<=nu<=23 in the B state, we follow the flow of halogen vibrational energy to the van ... [J. Chem. Phys. 133, 014305 (2010)] published Wed Jul 7, 2010.

Steplike Intensity Threshold Behavior of Extreme Ionization in Laser-Driven Xenon Clusters

T. Doppner, J. P. Muller, A. Przystawik, S. Gode, J. Tiggesbaumker et al.
The generation of highly charged Xe ions up to q=24 is observed in Xe clusters embedded in helium nanodroplets and exposed to intense femtosecond laser pulses (lambda=800 nm). Laser intensity resolved measurements show that the high-q ion generation starts at an unexpectedly low threshold intensity ... [Phys. Rev. Lett. 105, 053401 ] published .

Newton's Cradle and Entanglement Transport in a Flexible Rydberg Chain

S. Wuster, C. Ates, A. Eisfeld, and J. M. Rost
In a regular, flexible chain of Rydberg atoms, a single electronic excitation localizes on two atoms that are in closer mutual proximity than all others. We show how the interplay between excitonic and atomic motion causes electronic excitation and diatomic proximity to propagate through the Rydberg ... [Phys. Rev. Lett. 105, 053004 ] published .

Ionization Branching Ratio Control with a Resonance Attosecond Clock

Luca Argenti and Eva Lindroth
We investigate the possibility to monitor the dynamics of autoionizing states in real-time and control the yields of different ionization channels in helium by simulating extreme ultraviolet (XUV) pump IR-probe experiments focused on the N=2 threshold. The XUV pulse creates a coherent superposition ... [Phys. Rev. Lett. 105, 053002 ] published .

Simulation of the above-threshold-ionization experiment using the molecular strong-field approximation: The choice of gauge

M. Busuladzic and D. B. Milosevic
We investigate how various versions of the molecular strong-field approximation (MSFA) agree with the experiment by Grasbon et al. [Phys. Rev. A 63, 041402(R) (2001)], in which the suppression of the ionization yield in the low-energy spectrum of the O molecule, compared to the spectrum of its compa ... [Phys. Rev. A 82, 015401 ] published .

Recoil effects in multiphoton electron-positron pair creation

K. Krajewska and J. Z. Kaminski
Triply differential probability rates for electron-positron pair creation in laser-nucleus collisions, calculated within the S-matrix approach, are investigated as functions of the nuclear recoil. Pronounced enhancements of differential probability rates of multiphoton pair production are found for ... [Phys. Rev. A 82, 013420 ] published .

Time-dependent analysis of few-photon coherent control schemes

Shaohao Chen, Agnieszka Jaron-Becker, and Andreas Becker
We investigate the coherent control of nonresonant two-photon excitation and (2+1) photon ionization processes from the time-dependent perspective. To this end, we have solved the time-dependent Schrodinger equation for a hydrogen atom interacting with an ultraviolet laser field. Results are obtaine ... [Phys. Rev. A 82, 013414 ] published .

Implementation of a single femtosecond optical frequency comb for rovibrational cooling

W. Shi and S. Malinovskaya
We show that a single femtosecond optical frequency comb may be used to induce two-photon transitions between molecular vibrational levels to form ultracold molecules (e.g., KRb). The phase across an individual pulse in the pulse train is sinusoidally modulated with a carefully chosen modulation amp ... [Phys. Rev. A 82, 013407 ] published .

Unified understanding of tunneling ionization and stabilization of atomic hydrogen in circularly and linearly polarized intense laser fields

Haruhide Miyagi and Kiyohiko Someda
On the basis of the Floquet formalism, the ionization mechanisms of atomic hydrogen in circularly and linearly polarized intense laser fields are discussed. By using the complex scaling method in the velocity gauge, the pole positions of the scattering-matrix on the complex quasienergy Riemann surfa ... [Phys. Rev. A 82, 013402 ] published .

Interpretation of the Si Kalpha x-ray spectra accompanying the stopping of swift Ca ions in low-density SiO aerogel

J. Rzadkiewicz, A. Gojska, O. Rosmej, M. Polasik, and K. Slabkowska
This article presents a detailed analysis of the Kalpha x-ray spectra of Si induced by 11.4 MeV/u Ca projectiles penetrating a low-density SiO aerogel target measured with high spectral and spatial resolution at the UNILAC accelerator at GSI-Darmstadt. The low-density material used in the experiment ... [Phys. Rev. A 82, 012703 ] published .

Internuclear-distance dependence of electron correlation in nonsequential double ionization of H

Aihong Tong, Qing Liao, Yueming Zhou, and Peixiang Lu
Using three-dimensional classical ensembles, we have investigated the internuclear distance dependence of nonsequential double ionization (NSDI) of H molecules by an 800 nm, 1 x 10 W/cm laser pulse. For the internuclear distance R ranging from 2 to 12 a.u., the NSDI of H provides rich correlation pa ... [Opt. Express 18, 9064 (2010)] published Wed Jul 7, 2010.

Effect of pure dephasing on the Jaynes-Cummings nonlinearities

A. Gonzalez-Tudela, E. del Valle, E. Cancellieri, C. Tejedor, D. Sanvitto et al.
We study the effect of pure dephasing on a two-level system in strong coupling in the nonlinear regime with the single mode of a cavity. The photoluminescence spectrum of the cavity has a robust tendency to display triplet structures, instead of the expected Jaynes-Cummings pairs of doublets at the ... [Opt. Express 18, 7002 (2010)] published Wed Jul 7, 2010.

Ultrafast Interatomic Electronic Decay in Multiply Excited Clusters

Alexander I. Kuleff, Kirill Gokhberg, Soren Kopelke, and Lorenz S. Cederbaum
An ultrafast mechanism belonging to the family of interatomic Coulombic decay (ICD) phenomena is proposed. When two excited species are present, an ultrafast energy transfer can take place bringing one of them to its ground state and ionizing the other one. It is shown that if large homoatomic clust ... [Phys. Rev. Lett. 105, 043004 ] published .

Alignment-dependent ionization of molecular hydrogen in intense laser fields

Yulian V. Vanne and Alejandro Saenz
The alignment dependence of the ionization behavior of H exposed to intense ultrashort laser pulses is investigated on the basis of solutions of the full time-dependent Schrodinger equation within the fixed-nuclei and dipole approximation. The total ionization yields as well as the energy-resolved e ... [Phys. Rev. A 82, 011403 ] published .

Double-ionization mechanisms of the argon dimer in intense laser fields

B. Ulrich, A. Vredenborg, A. Malakzadeh, M. Meckel, K. Cole et al.
We have measured the two-site double ionization of argon dimers by ultrashort laser pulses leading to fragmentation into two singly charged argon ions. Contrary to the expectations from a pure Coulomb explosion following rapid removal of one electron from each of the atoms, we find three distinct pe ... [Phys. Rev. A 82, 013412 ] published .

Two-Photon Inner-Shell Ionization in the Extreme Ultraviolet

V. Richardson, J. T. Costello, D. Cubaynes, S. Dusterer, J. Feldhaus et al.
We have observed the simultaneous inner-shell absorption of two extreme-ultraviolet photons by a Xe atom in an experiment performed at the short-wavelength free electron laser facility FLASH. Photoelectron spectroscopy permitted us to unambiguously identify a feature resulting from the ionization of ... [Phys. Rev. Lett. 105, 013001 ] published .

Nonlinear Fourier-transform spectroscopy of D using high-order harmonic radiation

Yusuke Furukawa, Yasuo Nabekawa, Tomoya Okino, Sebastien Saugout, Kaoru Yamanouchi et al.
We have determined the multiphoton ionization and dissociation pathways of D with the simultaneous irradiation of the high-order harmonic fields and the low-order harmonic fields of Ti:sapphire laser pulses in the visible-vacuum ultraviolet region with the aid of a nonlinear Fourier-transform spectr ... [Phys. Rev. A 82, 013421 ] published .

Creation of multihole molecular wave packets via strong-field ionization

Dominik Geissler, Tamas Rozgonyi, Jesus Gonzalez-Vazquez, Leticia Gonzalez, Sarah Nichols et al.
We demonstrate the creation of vibrational wave packets on multiple electronic states of a molecule via strong-field ionization. Furthermore, we show that the relative contribution of the different electronic states depends on the shape of the laser pulse which launches the wave packets. ... [Phys. Rev. A 82, 011402 ] published .

Long-lived quantum coherence in photosynthetic complexes at physiological temperature

Gitt Panitchayangkoon, Dugan Hayes, Kelly A. Fransted, Justin R. Caram, Elad Harel et al.
Photosynthetic antenna complexes capture and concentrate solar radiation by transferring the excitation to the reaction center that stores energy from the photon in chemical bonds. This process occurs with near-perfect quantum efficiency. Recent experiments at cryogenic temperatures have revealed t ... [Proc. Natl. Acad. Sci. U.S.A. 107, 12766 (2010)] published Mon Jul 26, 2010.

Ultrafast reversible ligand isomerisation in Na[Fe(CN)NO]2HO single crystals

Dominik Schaniel, Matthieu Nicoul, and Theo Woike
We present a time-resolved absorption study on the light-induced generation of reversible linkage NO isomers in single crystals of Na[Fe(CN)NO]2HO using laser pulses of 160 fs width. Using the pump wavelength lambda = 500 nm the singletsinglet A-->E excitation induces the NO rotation by about 90 deg ... [Phys. Chem. Chem. Phys. 12, 9029 (2010)] published Thu Jul 29, 2010.

Ring-puckering motion in cyclopentene studied by time-resolved rotational coherence spectroscopy and ab initio calculations

Maksim Kunitski, Stefan Knippenberg, Maxim Gelin, Christoph Riehn, Andreas Dreuw et al.
The ring-puckering vibration in cyclopentene was studied by rotational time-resolved femtosecond degenerate four-wave mixing (fs DFWM) spectroscopy. The fs DFWM spectra of cyclopentene were measured both in a supersonic expansion and in a gas cell at room temperature. The room temperature fs DFWM sp ... [Phys. Chem. Chem. Phys. 12, 8190 (2010)] published Thu Jul 15, 2010.

Interrogating the ultrafast dynamics of an efficient dye for sunlight conversion

Marcin Ziolek, Xichuan Yang, Licheng Sun, and Abderrazzak Douhal
We report on studies of the recently synthesized compound (TPC1) with a promising potential use in dye-sensitized solar cells. We used steady-state as well as femtosecond (fs) to nanosecond (ns) time-resolved emission techniques to understand its behaviour under different conditions of solvation and ... [Phys. Chem. Chem. Phys. 12, 8098 ] published .

Photophysics of aromatic thiourea derivatives and their complexes with anions. Fast and ultrafast spectroscopic investigations

Tiziana Del Giacco, Benedetta Carlotti, Stefano De Solis, Arianna Barbafina, and Fausto Elisei
In order to collect detailed information on the interaction mechanism between fluorescent thiourea derivatives and anions, 9-[4-(trifluoromethyl)phenylthioureidomethyl]anthracene (1) and the corresponding 10-cyanoanthracene derivative (2) were synthesized and investigated in DMSO and MeCN by using a ... [Phys. Chem. Chem. Phys. 12, 8062 ] published .

Femtosecond time-resolved photophysics and photodissociation dynamics of 1-iodonaphthalene

Raul Montero, Alvaro Peralta Conde, Asier Longarte, Fernando Castano, Maria E. Corrales et al.
The ultrafast relaxation of 1-iodonaphthalene, with particular attention to the dissociation channels, has been studied by time-resolved femtosecond pumpprobe mass spectrometry following excitation at 267 and 317 nm. The measured transients for the parent ion and the isobaric fragments, iodine and n ... [Phys. Chem. Chem. Phys. 12, 7988 ] published .

Observation and control of coherent torsional dynamics in a quinquethiophene molecule

Giovanni Cirmi, Daniele Brida, Alessio Gambetta, Manuel Piacenza, Fabio Della Sala et al.
By applying femtosecond pumpprobe spectroscopy to a substituted quinquethiophene molecule in solution, we observe in the time domain the coherent torsional dynamics that drives planarization of the excited state. Our interpretation is based on numerical modeling of the ground and excited state poten ... [Phys. Chem. Chem. Phys. 12, 7917 ] published .

Spectroscopic study of the authentic emitter of AMPPD chemiluminescence in alkaline aqueous solution

Langping Tu, Yu Wang, Yifei Yang, Bert H. Bakker, Xianggui Kong et al.
To design more effective CIEEL (chemically initiated electron exchange luminescence) systems demands a complete picture of the dynamics of the chemiluminescence, which is often a challenge. In this work, photoluminescence of the methyl m-oxybenzoate anion the authentic emitter of AMPPD (3-[2-spiroa ... [Phys. Chem. Chem. Phys. 12, 6789 (2010)] published Fri Jul 2, 2010.

Exciton dynamics in photosynthetic complexes: excitation by coherent and incoherent light

Tomas ManCal and Leonas Valkunas
In this paper, we consider the dynamics of a molecular system subjected to external pumping by a light source. Within a completely quantum mechanical treatment, we derive a general formula, which enables us to assess the effects of different light properties on the photo-induced dynamics of excitati ... [New J. Phys. 12, 065044 (2010)] published Thu Jul 1, 2010.

Dynamics of electronic dephasing in the FennaMatthewsOlson complex

Dugan Hayes, Gitt Panitchayangkoon, Kelly Fransted, Justin Caram, Jianzhong Wen et al.
Electronic coherence has been shown to persist in the FennaMatthewsOlson (FMO) antenna complex from green sulfur bacteria at 77 K for at least 660 fs, several times longer than the typical lifetime of a coherence in a dynamic environment at this temperature. Such long-lived coherence was proposed to ... [New J. Phys. 12, 065042 (2010)] published Thu Jul 1, 2010.

Limits of quantum speedup in photosynthetic light harvesting

Stephan Hoyer, Mohan Sarovar, and K Birgitta Whaley
It has been suggested that excitation transport in photosynthetic light-harvesting complexes features speedups analogous to those found in quantum algorithms. Here we compare the dynamics in these light-harvesting systems to the dynamics of quantum walks, in order to elucidate the limits of such qua ... [New J. Phys. 12, 065041 (2010)] published Thu Jul 1, 2010.

Intrinsic lifetimes of the Soret bands of the free-base tetraphenylporphine (HTPP) and Cu(ii)TPP in the condensed phase

Ki Young Yeon, Dahyi Jeong, and Sang Kyu Kim
Soret band lifetimes of the free-base tetraphenylporphine (HTPP) and Cu(ii) tetraphenylporphine (CuTPP) at 408 nm have been directly measured with femtosecond (fs) resolution using the fluorescence-upconversion technique for the first time, giving tau = 68 15 and 63 15 fs, respectively, in benzene ... [Chem. Commun. 46, 5572 (2010)] published Mon Jul 26, 2010.

Fiber-optic multiphoton flow cytometry in whole blood and in vivo

Yu-Chung Chang, Jing Yong Ye, Thommey P. Thomas, Zhengyi Cao, Alina Kotlyar et al.
Circulating tumor cells in the bloodstream are sensitive indicators for metastasis and disease prognosis. Circulating cells have usually been monitored via extraction from blood, and more recently in vivo using free-space optics; however, long-term intravital monitoring of rare circulating cells rem ... [J. Biomed. Opt. 15, 047004 (2010)] published Mon Jul 26, 2010.

Combined multiphoton imaging and automated functional enucleation of porcine oocytes using femtosecond laser pulses

Kai Kuetemeyer, Andrea Lucas-Hahn, Bjoern Petersen, Erika Lemme, Petra Hassel et al.
Since the birth of Dolly as the first mammal cloned from a differentiated cell, somatic cell cloning has been successful in several mammalian species, albeit at low success rates. The highly invasive mechanical enucleation step of a cloning protocol requires sophisticated, expensive equipment and co ... [J. Biomed. Opt. 15, 046006 (2010)] published Wed Jul 21, 2010.

A computational study of ultrafast acid dissociation and acid-base neutralization reactions. I. The model

Patrick Maurer, Vibin Thomas, Ugo Rivard, and Radu Iftimie
Ultrafast, time-resolved investigations of acid-base neutralization reactions have recently been performed using systems containing the photoacid 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS) and various Bronsted bases. Two conflicting neutralization mechanisms have been formulated by ... [J. Chem. Phys. 133, 044108 (2010)] published Fri Jul 23, 2010.

Infrared signatures of the peptide dynamical transition: A molecular dynamics simulation study

Maja Kobus, Phuong H. Nguyen, and Gerhard Stock
Recent two-dimensional infrared (2D-IR) experiments on a short peptide 3-helix in chloroform solvent [E. H. G. Backus et al., J. Phys. Chem. B 113, 13405 (2009)] revealed an intriguing temperature dependence of the homogeneous line width, which was interpreted in terms of a dynamical transition of t ... [J. Chem. Phys. 133, 034512 (2010)] published Tue Jul 20, 2010.

Toward the origin of exciton electronic structure in phycobiliproteins

Jordan M. Womick, Stephen A. Miller, and Andrew M. Moran
Femtosecond laser spectroscopies are used to examine the electronic structures of two proteins found in the phycobilisome antenna of cyanobacteria, allophycocyanin (APC) and C-phycocyanin (CPC). The wave function composition involving the pairs of phycocyanobilin pigments (i.e., dimers) found in bot ... [J. Chem. Phys. 133, 024507 (2010)] published Wed Jul 14, 2010.

Anharmonicity and mode-mode coupling effects analyzed by four-wave-mixing photon-echo spectroscopy

K. K. Liang and A. A. Villaeys
The present work is devoted to the description of a nonperturbative treatment of anharmonic effect and mode-mode coupling taking place in molecular vibrational systems. The information is obtained from the four-wave-mixing signal detected in the usual photon-echo phase-matched direction, termed 4WM ... [Phys. Rev. A 82, 013423 ] published .

Phototransfection of mammalian cells using femtosecond laser pulses: optimization and applicability to stem cell differentiation

Patience Mthunzi, Kishan Dholakia, and Frank Gunn-Moore
Recently, femtosecond laser pulses have been utilized for the targeted introduction of genetic matter into mammalian cells. This rapidly expanding and developing novel optical technique using a tightly focused laser light beam is called phototransfection. Extending previous studies [Stevenson et al. ... [J. Biomed. Opt. 15, 041507 (2010)] published Tue Jul 6, 2010.

Photoacoustic lifetime imaging of dissolved oxygen using methylene blue

Shai Ashkenazi
Measuring distribution of dissolved oxygen in biological tissue is of prime interest for cancer diagnosis, prognosis, and therapy optimization. Tumor hypoxia indicates poor prognosis and resistance to radiotherapy. Despite its major clinical significance, no current imaging modality provides direct ... [J. Biomed. Opt. 15, 040501 (2010)] published Wed Jul 21, 2010.

Indirect activation of porphyrin by semiconductor quantum dots with two-photon excitation

Yanan Wen, Yuqiang Liu, Yanqiang Yang, Limin An, Weisi Song et al.
Steady-state and nanosecond time-resolved spectroscopies are performed to investigate the interaction between CdSe quantum dots (QDs) and mesotetraphenylporphyrin (TPP) photosensitizers under two-photon excitation with 800-nm femtosecond laser pulses. The luminescent intensity and lifetime of the QD ... [J. Micro/Nanolith. MEMS MOEMS 9, 031003 (2010)] published Fri Jul 2, 2010.

Exciton coherence length fluctuations in chromophore aggregates probed by multidimensional optical spectroscopy

Frantisek Sanda, Vaclav Perlik, and Shaul Mukamel
The coherent third order optical response of molecular aggregates with fluctuating frequencies, couplings, and transition dipole moments is studied. We derived stochastic nonlinear exciton equations (SNEEs) by combining the quasiparticle picture of excitons with the path integral over stochastic bat ... [J. Chem. Phys. 133, 014102 (2010)] published Fri Jul 2, 2010.

Metrology of Wide Field of View Nano-Thickness Foils' Homogeneity by Conventional and Phase Contrast Soft X-ray Imaging

Anatoly Faenov, Tatiana Pikuz, Yuji Fukuda, Masaki Kando, Hideyuki Kotaki et al.
A tabletop ultra-bright, debris-free femtosecond-laser-driven cluster-based plasma soft X-ray source, which emits more than $10^{12}$ photons/(sr$\cdot$pulse) in the spectral range 110 nm within a $4\pi$ sr solid angle was developed. Using such source in combination with a high dynamic range LiF ... [Jpn. J. Appl. Phys. 49, 06GK03 (2010)] published Thu Jul 1, 2010.

Direct frequency comb synthesis with arbitrary offset and shot-noise-limited phase noise

Sebastian Koke, Christian Grebing, Harald Frei, Alexandria Anderson, Andreas Assion et al.
Carrier-envelope phase stabilization has opened an avenue towards achieving frequency metrology with unprecedented precision and optical pulse generation on the previously inaccessible attosecond timescale. Recently, sub-100-as pulse generation has been demonstrated, approaching the timescale of the ... [Nat. Photonics 4, 462 (2010)] published Tue Jul 6, 2010.

Control of the high-order harmonics cutoff and attosecond pulse generation through the combination of a chirped fundamental laser and a subharmonic laser field

Jie Wu, Gang-Tai Zhang, Chang-Long Xia, and Xue-Shen Liu
We propose a method to generate an isolated attosecond (as) pulse in combination with a chirped fundamental laser field (5 fs, 800 nm) and a subharmonic laser field (12 fs, 1600 nm). It is shown that, for the case of the chirped parameter beta=0.25, not only is the efficiency of the extended harmoni ... [Phys. Rev. A 82, 013411 ] published .

Ultrafast Spatiotemporal Dynamics of Terahertz Generation by Ionizing Two-Color Femtosecond Pulses in Gases

I. Babushkin, W. Kuehn, C. Kohler, S. Skupin, L. Berge et al.
We present a combined theoretical and experimental study of spatiotemporal propagation effects in terahertz (THz) generation in gases using two-color ionizing laser pulses. The observed strong broadening of the THz spectra with increasing gas pressure reveals the prominent role of spatiotemporal res ... [Phys. Rev. Lett. 105, 053903 ] published .

InGaN/GaN self-organized quantum dot green light emitting diodes with reduced efficiency droop

Meng Zhang, Pallab Bhattacharya, and Wei Guo
High density (25 x 10 cm) self-organized InGaN/GaN quantum dots were grown by plasma-assisted molecular beam epitaxy. Room temperature photoluminescence shows that the quantum dots have strong emission ranging from 430 to 524 nm. The internal quantum efficiency of dots emitting at 500 nm was determ ... [Appl. Phys. Lett. 97, 011103 (2010)] published Wed Jul 7, 2010.

Short-wavelength soft-x-ray laser pumped in double-pulse single-beam non-normal incidence

D. Zimmer, D. Ros, O. Guilbaud, J. Habib, S. Kazamias et al.
We demonstrated a 7.36 nm Ni-like samarium soft-x-ray laser, pumped by 36 J of a neodymium:glass chirped-pulse amplification laser. Double-pulse single-beam non-normal-incidence pumping was applied for efficient soft-x-ray laser generation. In this case, the applied technique included a single-optic ... [Phys. Rev. A 82, 013803 ] published .

A 113 fs fiber laser operating at 1.56 [mu]m using a cascadable film-type saturable absorber with P3HT-incorporated single-wall carbon nanotubes coated on polyamide

Fumio Shohda, Masataka Nakazawa, Junji Mata, and Jun Tsukamoto
We successfully fabricated a cascadable film-type single-wall carbon nanotube (SWNT) saturable absorber coated on aromatic polyamide film, in which the saturable absorption effect can be controlled with the number of films. A conductive polymer P3HT (poly-3-hexylthiophene) was adopted to obtain a un ... [Opt. Express 18, 9712 (2010)] published Wed Jul 7, 2010.

131 fs, 33 MHz all-fiber soliton laser at 1.07 [mu]m with a film-type SWNT saturable absorber coated on polyimide

Fumio Shohda, Yuichiro Hori, Masataka Nakazawa, Junji Mata, and Jun Tsukamoto
We present a 1.07 [mu]m all-fiber femtosecond soliton laser employing a film-type saturable absorber with a P3HT (poly-3-hexylthiophene) incorporated SWNT coated on polyimide film. We optimized the laser cavity as a dispersion-managed soliton laser with photonic crystal fiber (PCF) as an anomalous d ... [Opt. Express 18, 11223 (2010)] published Wed Jul 7, 2010.

Fiber-comb-stabilized light source at 556 nm for magneto-optical trapping of ytterbium

Masami Yasuda, Takuya Kohno, Hajime Inaba, Yoshiaki Nakajima, Kazumoto Hosaka et al.
A frequency-stabilized light source emitting at 556 nm is realized by frequency doubling a 1112 nm laser, which is phase locked to a fiber-based optical frequency comb. The 1112 nm laser is either an ytterbium (Yb)-doped distributed feedback fiber laser or a master-slave laser system that uses an ex ... [J. Opt. Soc. Am. B 27, 1388 (2010)] published Thu Jul 15, 2010.

Optically induced fast wavelength modulation in a quantum cascade laser

Gang Chen, Rainer Martini, Seong-wook Park, Clyde G. Bethea, I.-Chun A. Chen et al.
An optically induced fast wavelength shift is demonstrated in a standard middle infrared (MIR) quantum cascade laser (QCL) by illuminating the front facet with a femtosecond (fs) near infrared (NIR) laser, allowing fast optical frequency modulation (FM) for free space optical communication (FSOC) an ... [Appl. Phys. Lett. 97, 011102 (2010)] published Wed Jul 7, 2010.

Kilohertz dye laser system for high resolution laser spectroscopy

J. H. Gurian, H. Maeda, and T. F. Gallagher
We have electro-optically sliced the output light of a commercial Coherent Evolution Nd:YLF laser to pump a kilohertz repetition rate nanosecond dye laser system. Simple and highly adjustable, this laser system can easily be used for initial state preparation for ultrafast systems as well as high re ... [Rev. Sci. Instrum. 81, 073111 (2010)] published Wed Jul 28, 2010.

100 W peak-power 1 GHz repetition picoseconds optical pulse generation using blue-violet GaInN diode laser mode-locked oscillator and optical amplifier

Rintaro Koda, Tomoyuki Oki, Takao Miyajima, Hideki Watanabe, Masaru Kuramoto et al.
We have generated single-transverse-mode optical pulses with 100 W peak power and 3 ps duration at 1 GHz repetition from a blue-violet GaInN mode-locked laser diode (MLLD) and a semiconductor optical amplifier (SOA) without the use of any pulse compression. The generation of clean optical pulses wit ... [Appl. Phys. Lett. 97, 021101 (2010)] published Mon Jul 12, 2010.

Design of high-energy terahertz sources based on optical rectification

J. A. Fulop, L. Palfalvi, G. Almasi, and J. Hebling
Detailed analysis of the tilted-pulse-front pumping scheme used for ultrashort THz pulse generation by optical rectification of femtosecond laser pulses is presented. It is shown that imaging errors in a pulse-front-tilting setup consisting of a grating and a lens can lead to a THz ... [Opt. Express 18, 12311 (2010)] published Wed Jul 7, 2010.