Virtual Journal of Laser is a web tool to help laser researchers follow new publications from major academic journals, discover and promote interesting works by voting, commenting and simply visiting. Subscribe Virtual Journal of Laser to take the advantage! Read more...
If you find VJLaser helpful, please consider donation for covering the host costage. Many thanks!
Tunable microwave generation based on a dual-wavelength single-longitudinal-mode fiber laser using a phase-shifted grating on a triangular cantilever
Sun, 2011-05-01 02:00 — GuestMeng Jiang, Bo Lin, Perry Ping Shum, Swee Chuan Tjin, Xinyong Dong, Qizhen Sun
Frequency tunable microwave signal generation, based on a dual-wavelength single-longitudinal-mode (SLM) erbium-doped fiber (EDF) laser, incorporating a phase-shifted fiber Bragg grating (PS-FBG) with two π-phase shifts, is demonstrated. In the proposed configuration, the PS-FBG with two ... [Appl. Opt. 50, 1900-1904 (2011)]
Reversal of Coherently Controlled Ultrafast Photocurrents by Band Mixing in Undoped GaAs Quantum Wells
Fri, 2010-05-28 02:00 — GuestAuthor(s): S. Priyadarshi, A. M. Racu, K. Pierz, U. Siegner, M. Bieler, H. T. Duc, J. Förstner, and T. Meier
It is demonstrated that valence-band mixing in GaAs quantum wells tremendously modifies electronic transport. A coherent control scheme in which ultrafast currents are optically injected into undoped GaAs quantum wells upon excitation with femtosecond laser pulses is employed. An oscillatory depende...
[Phys. Rev. Lett. 104, 217401] Published Fri May 28, 2010
MHz-rate nitric oxide planar laser-induced fluorescence imaging in a Mach 10 hypersonic wind tunnel
Tue, 2011-02-01 02:00 — GuestNaibo Jiang, Matthew Webster, Walter R. Lempert, Joseph D. Miller, Terrence R. Meyer, Christopher B. Ivey, Paul M. Danehy
Nitric oxide planar laser-induced fluorescence (NO PLIF) imaging at repetition rates as high as 1MHz is demonstrated in the NASA Langley 31 in. Mach 10 hypersonic wind tunnel. Approximately 200 time-correlated image sequences of between 10 and 20 individual frames were obtained over eight days of ... [Appl. Opt. 50, A20-A28 (2011)]
Influence of the parameters of the Er:YAG laser on the apical sealing of apicectomized teeth
Mon, 2010-06-07 19:10 — Guest
The Er:YAG laser has been proposed as an alternative for the use of rotator instruments in surgical endodontics due to its
precision, lack of vibration, less post-operative discomfort, bacterial reduction, and less stress for patients and professionals.
Following approval by the ethics committee, 12 extracted human canines without previous endodontic treatment with anatomically
normal roots and free from apical lesions were washed in running tap water and disinfected. The teeth were sectioned axially
at the crown-root junction and submitted to routine endodontic treatment. The apical limit was set at 1 mm before the apical
foramen. The root canals were routinely filled with Gutta-Percha points and Sealer 26 and were randomly distributed into two
groups (n = 6).
Continuous-wave subwavelength microdisk lasers at λ = 1.53 µm
Mon, 2010-08-30 02:00 — GuestZhijun Liu, Jeffrey M. Shainline, Gustavo E. Fernandes, Jimmy Xu, Jianxin Chen, Claire F. Gmachl
Subwavelength InGaAs/AlInAs microdisk lasers are demonstrated under continuous-wave optical pumping at a heat-sink temperature of 45 K. A 1.49 µm diameter, 209 nm thick microdisk lases in single-mode at a wavelength of 1.53 µm, which is identified as the whispering-gallery mode with the ... [Opt. Express 18, 19242-19248 (2010)]
- Add new comment
- Feed: Optics Express
- Original article
- 2631 reads
Ferroelectric Q-phase in a NaNbO epitaxial thin film
Thu, 2010-06-03 21:01 — GuestYu. I. Yuzyuk, R. A. Shakhovoy, S. I. Raevskaya, I. P. Raevski, M. El Marssi et al.
Epitaxial NaNbO thin films have been grown by pulsed laser deposition on cubic (00l) MgO substrate with epitaxial (LaSr)CoO buffer layer. Micro-Raman spectroscopy studies revealed that the ferroelectric Q phase (Pmc2, Z=4) is stable in a 250-nm-thick film in contrast to the antiferroelectric phase P ... [Appl. Phys. Lett. 96, 222904 (2010)] published Thu Jun 3, 2010.
Comparison of effects of diode laser and CO2 laser on human teeth and their usefulness in topical fluoridation
Tue, 2010-04-27 08:57 — Guest
conventional topical fluoridation. Besides the beneficial effect of lasers in reducing the acid solubility of an enamel surface,
they can also increase the uptake of fluoride. The study objectives were to compare the action of CO2 and GaAlAs diode lasers on dental enamel and their effects on pulp temperature and enamel fluoride uptake. Different groups
of selected enamel surfaces were treated with amine fluoride and irradiated with CO2 laser at an energy power of 1 or 2 W or with diode laser at 5 or 7 W for 15 s each and compared to enamel surfaces without
treatment or topical fluoridated. Samples were examined by means of environmental scanning electron microscopy (ESEM). Surfaces
of all enamel samples were then acid-etched, measuring the amount of fluoride deposited on the enamel by using a selective
ion electrode.
Linear terrestrial laser scanning using array avalanche photodiodes as detectors for rapid three-dimensional imaging
Wed, 2010-12-01 02:00 — GuestYinqiao Cai, Xiaohua Tong, Peng Tong, Hongyi Bu, Rong Shu
As an active remote sensor technology, the terrestrial laser scanner is widely used for direct generation of a three-dimensional (3D) image of an object in the fields of geodesy, surveying, and photogrammetry. In this article, a new laser scanner using array avalanche photodiodes, as designed by ... [Appl. Opt. 49, H11-H19 (2010)]
- 1 comment
- Feed: Applied Optics
- Original article
- 828 reads
Pulse characteristics of a passively mode-locked thulium fiber laser with positive and negative cavity dispersion
Mon, 2010-08-30 02:00 — GuestFrithjof Haxsen, Dieter Wandt, Uwe Morgner, Joerg Neumann, Dietmar Kracht
We investigated of the output characteristics of a spectrally filtered stretched-pulse thulium fiber laser in dependence of cavity dispersion and pump power. The experimental results together with corresponding theoretical modeling allow for a deeper insight into the pulse shaping mechanisms. [Opt. Express 18, 18981-18988 (2010)]
Simple analytical derivations of thermal lensing in longitudinally Q-CW pumped Yb:YAG
Sun, 2010-08-01 02:00 — GuestGilbert L. Bourdet, Claude Gouédard
In this paper, we introduce analytical derivations for the thermal lensing of an end-pumped laser disk. These derivations are done for pump beam shapes from Gaussian to top hat, assuming that the thermal conductivity is either constant with the temperature or not. We give examples in two ... [Appl. Opt. 49, 4160-4167 (2010)]
Chirped pulse shadowgraphy for single shot time resolved plasma expansion measurements
Thu, 2010-06-03 00:00 — GuestY. B. S. R. Prasad, S. Barnwal, P. A. Naik, J. A. Chakera, R. A. Khan et al.
The dynamics of ultrashort laser plasmas demand single shot temporal measurements on fast time scales. We describe a method to record the plasma expansion on picosecond (ps) timescales continuously over hundreds of ps, in single shot. The method uses the chirp of a Ti:sapphire laser as a time-resolv ... [Appl. Phys. Lett. 96, 221503 (2010)] published Wed Jun 2, 2010.
Application of the extended Jones matrix formalism for higher-order transverse modes to laser resonators
Mon, 2010-10-11 02:00 — GuestAndreas Voss, Marwan Abdou-Ahmed, Thomas Graf
The extension of the Jones matrix formalism to higher-order transverse modes using N x N matrices presented in a previous paper [8] is applied to laser resonators. The resonator discussed in detail has a TEM_01* Hermite-Gaussian mode, an axially symmetric polarizer combined with an axially ... [Opt. Express 18, 21540-21550 (2010)]
Carrier generation and IF signal up-conversion using optical injection locking and stimulated Brillouin scattering
Fri, 2010-08-06 21:37 — GuestPublication year: 2010
Source: Optics Communications, In Press, Uncorrected Proof, Available online 6 August 2010
Wei, Li , Ning Hua, Zhu , Li Xian, Wang , Jian Guo, Liu , Xiao Qiong, Qi , ...
We theoretically investigate the intermediate frequency (IF) signal up-conversion with dual modes modulation (DMM) and single-mode modulation (SMM) of two single sideband (SSB) modulation modes for radio-over-fiber (RoF) systems. The simulation results indicate that the SMM can overcome the dispersion-induced power penalties of the generated carrier and up-converted IF signals. Then, we experimentally demonstrate an approach for RF carrier generation with SSB modulation and IF signal up-conversion with SMM using a combination of direct modulation in an injection-locked distributed feedback (DFB) laser and stimulated Brillouin scattering (SBS). The experimental results are compared with the predictions of the numerical simulation in...
Effect of Intense, Ultrashort Laser Pulses on DNA Plasmids in their Native State: Strand Breakages Induced by In Situ Electrons and Radicals
Mon, 2011-03-14 06:00 — GuestAuthor(s): J. S. D’Souza, J. A. Dharmadhikari, A. K. Dharmadhikari, B. J. Rao, and D. Mathur
Single strand breaks are induced in DNA plasmids, pBR322 and pUC19, in aqueous media exposed to strong fields generated using ultrashort laser pulses (820 nm wavelength, 45 fs pulse duration, 1 kHz repetition rate) at intensities of 1–12 TW cm^{-2} . The strong fields generate, in situ,...
[Phys. Rev. Lett. 106, 118101] Published Mon Mar 14, 2011
Characterization of high-intensity sub-4-fs laser pulses using spatially encoded spectral shearing interferometry
Sun, 2011-05-01 02:00 — GuestTobias Witting, Felix Frank, Christopher A. Arrell, William A. Okell, Jonathan P. Marangos, John W. G. Tisch
We report on the full amplitude and phase characterization of high-intensity few-cycle laser pulses generated in a single-stage hollow core fiber system with subsequent compression by ultrabroadband chirped mirrors. We use a spatially-encoded arrangement (SEA) spectral phase interferometry for ... [Opt. Lett. 36, 1680-1682 (2011)]
High-power Q-switched laser with high-order Laguerre–Gaussian modes: application for extra-cavity harmonic generations
Fri, 2011-04-15 07:47 — Guest
p,0 modes in a diode-pumped actively Q-switched Nd:YVO4 laser. The resonator is composed of two plane mirrors with an intracavity concave lens to expand the cavity mode size for
generating a high-power Laguerre–Gaussian TEM5,0 mode. We further confirm that the TEM5,0 mode is noticeably superior to the TEM0,0 mode in the processes of second and third harmonic generations.
Optimization of displacement-measuring quadrature interferometers considering the real properties of optical components
Sun, 2011-03-20 02:00 — GuestTomaž Požar, Peter Gregorčič, Janez Možina
We present the influence of alignment and the real properties of optical components on the performance of a two-detector homodyne displacement-measuring quadrature laser interferometer. An experimental method, based on the optimization of visibility and sensitivity, was established and ... [Appl. Opt. 50, 1210-1219 (2011)]
Pair Creation in QED-Strong Pulsed Laser Fields Interacting with Electron Beams
Thu, 2010-11-04 06:00 — GuestAuthor(s): Igor V. Sokolov, Natalia M. Naumova, John A. Nees, and Gérard A. Mourou
QED effects are known to occur in a strong laser pulse interaction with a counterpropagating electron beam, among these effects being electron-positron pair creation. We discuss the range of laser pulse intensities of J≥5×10^{22} W/cm^{2} combined with electron beam energies of tens of GeV....
[Phys. Rev. Lett. 105, 195005] Published Thu Nov 04, 2010
Broadband, rapidly tunable Ti:sapphire-pumped BiB_3O_6 femtosecond optical parametric oscillator
Sun, 2011-05-01 02:00 — GuestA. Esteban-Martin, V. Ramaiah-Badarla, V. Petrov, M. Ebrahim-Zadeh
We report a femtosecond optical parametric oscillator (OPO) based on the nonlinear material BiB_3O_6 (BIBO) pumped directly by a Kerr lens mode-locked Ti:sapphire laser. Using a 1.5?mm long BIBO crystal cut at θ=11.4° for collinear type I (e?o+o) phase matching in the xz optical plane, ... [Opt. Lett. 36, 1671-1673 (2011)]
- Add new comment
- Feed: Optics Letters
- Original article
- 1478 reads
Femtosecond laser filament-fringes in fused silica
Mon, 2011-04-11 02:00 — GuestZuoqiang Hao, Kamil Stelmaszczyk, Philipp Rohwetter, Walter M. Nakaema, Ludger Woeste
Linear diffraction was used to modulate intensity distribution across the femtosecond laser beam to create quasi regular arrays of filaments in fused silica. A fringe type of filament distributions (filament-fringe) were formed that could be controlled and observed over a distance of several ... [Opt. Express 19, 7799-7806 (2011)]
