共查询到20条相似文献,搜索用时 46 毫秒
1.
We present a double-pass non-collinear optical parametric amplifier (NOPA) that delivers 4-fs visible–near-infrared pulses.
The paper discusses geometrical and temporal properties of the NOPA configuration, which allow us to broaden the gain band
of simultaneous parametric amplification in excess of 250 THz. The key elements of the bandwidth enhancement include (i) the
use of a broadband second-harmonic pump, (ii) optimization of the incidence angle of all monochromatic spectral components
of the pump in order to produce a favorable offset of the corresponding phase-matching curves, and (iii) selection of the
chirp rate and time delay between the stretched pump and seed pulses. We next devise a two-stage compressor that incorporates
a flexible mirror for adaptive pulse shaping and develop a simple and trustworthy feedback loop based on a one-dimensional
spectral measurement. Our rapid numerical algorithm for adaptive control of the flexible membrane is found superior to more
complex search routines that are less resistant to the fluctuations of the laser intensity. The automated optimization procedure
results in the generation of two-cycle pulses with a carrier wavelength at ∼600 nm. The absence of deep modulation on the
parametrically amplified spectrum in combination with the adaptive phase correction lead to a high quality of the temporal
profile and allow concentrating 90% of the pulse energy within only a 7.5-fs time window.
Received: 8 April 2002 / Revised version: 26 June 2002 / Published online: 25 September 2002
RID="*"
ID="*"Present address: Institut für Photonik, Technische Universit?t Wien, Gusshausstrasse 27, 1040 Vienna, Austria
RID="**"
ID="**"Corresponding author. Fax: +81-3/5841-4165, E-mail: kobayashi@phys.s.u-tokyo.ac.jp 相似文献
2.
A. Porzio C. Altucci P. Aniello C. de Lisio S. Solimeno 《Applied physics. B, Lasers and optics》2002,75(6-7):655-665
Twin-beam fluctuations are analyzed for detuned and mismatched OPO configurations. Resonances and frequency responses to the
quantum noise sources (quantum and pump amplitude/phase fluctuations) are examined as functions of cavity decay rates, excitation
parameters and detuning. The dependence of self- and mutual correlations of beam amplitudes and phases on detuning, mismatch
and damping parameters is discussed.
Received: 25 January 2002 / Revised version: 28 May 2002 / Published online: 15 November 2002
RID="*"
ID="*"Corresponding author. Fax: +39-81/676-346, E-mail: alberto.porzio@na.infn.it 相似文献
3.
C. Dölle C. Reinhardt P. Simon B. Wellegehausen 《Applied physics. B, Lasers and optics》2002,75(6-7):629-634
. Investigations of the efficient generation of powerful coherent radiation at 82.8 nm by frequency tripling of short-pulse
KrF laser radiation are presented. Argon gas is selected as nonlinear medium due to the resonantly enhanced 3rd-order susceptibility
χ(3)(-3ω,ω,ω,ω). Pulse energies of 100 μJ at 82.8 nm have been measured for a pump pulse energy of 14 mJ. An upscaling to more
than 500 μJ is expected with available more powerful pump lasers. Features of this XUV source and possible applications are
discussed.
Received: 26 July 2002 / Published online: 15 November 2002
RID="*"
ID="*"Corresponding author. Fax: +49-511/7622211, E-mail: reinhardt@iqo.uni-hannover.de 相似文献
4.
Soliton-like pulse-shaping mechanism in passively mode-locked surface-emitting semiconductor lasers 总被引:1,自引:0,他引:1
R. Paschotta R. Häring A. Garnache S. Hoogland A.C. Tropper U. Keller 《Applied physics. B, Lasers and optics》2002,75(4-5):445-451
We discuss a mechanism that allows the formation of nearly transform-limited soliton-like pulses in passively mode-locked
optically pumped external-cavity surface-emitting semiconductor lasers. It involves the interplay of positive dispersion and
the nonlinear index changes in gain medium and saturable absorber, while ordinary solitons are based on dispersion and the
Kerr effect. The obtained quasi-soliton pulses share some of the properties of ordinary solitons (in particular, their stability
and near bandwidth-limited nature), while other properties are different. In particular, the pulse duration scales with the
square root of the cavity dispersion, and an excessive drift of the laser wavelength must be avoided by proper design.
Received: 23 April 2002 / Published online: 25 September 2002
RID="*"
ID="*"Corresponding author. Fax: +41-1/633-1059, E-mail: Paschotta@iqe.phys.ethz.ch 相似文献
5.
G. Zhang H. Wang Y. Yu F. Xiong G. Tang W. Chen 《Applied physics. B, Lasers and optics》2003,76(6):677-681
All-optical switching and beam deflection of 2-(2′-hydroxyphenyl) benzoxazole (HBO) in three species of solvent (cyclohexane, ethanol and dimethyl sulfoxide) have been investigated
by using third-harmonic generation (355 nm) of a mode-locked Nd:YAG laser as a pump beam and a continuous-wave He-Ne laser
(632.8 nm) as a probe beam. The nonlinear refractive indices of HBO in different solvents are determined by using the Z-scan
technique. The optical switching and beam-deflection effects are due to the change of the refractive index of HBO under the
pump beam. Through the study of the absorption spectra and the fluorescence spectra of HBO in different solvents, we conclude
that the principal reason for the change of the refractive index of HBO is not the thermal effect because of absorption of
the pump beam, but the excited-state intramolecular proton-transfer (ESIPT) effect of HBO under the pump beam. As the ESIPT
process is very fast, HBO might be an excellent material for high-speed optical switching.
Received: 28 October 2002 / Revised version: 18 March 2003 / Published online: 2 June 2003
RID="*"
ID="*"Corresponding author. Fax: +86-22/2350-1242, E-mail: zhanggl@nankai.edu.cn 相似文献
6.
K.P. Unnikrishnan J. Thomas V.P.N. Nampoori C.P.G. Vallabhan 《Applied physics. B, Lasers and optics》2002,75(8):871-874
The wavelength dependence of the nonlinear absorption of a bis-phthalocyanine, Nd(Pc)2, dissolved in dimethyl formamide was studied in the rising part of the Q-band using the open aperture Z-scan technique, to
determine the wavelength region over which the nonlinear absorption changes from reverse saturable absorption to saturable
absorption. It was found that the sample could be used as a reverse saturable absorber, and hence as an optical limiter, up
to a wavelength of about 604 nm. The imaginary part of the third order susceptibility was also calculated for these wavelengths.
Resonant enhancement of the imaginary part of the third order susceptibility was clearly observed.
Received: 26 April 2002 / Revised version: 30 June 2002 / Published online: 20 December 2002
RID="*"
ID="*"Corresponding author. Fax: +91-484/576-714, E-mail: kpu@cusat.ac.in
RID="**"
ID="**"Present address: Optical Sciences Center, University of Arizona, Tucson, USA 相似文献
7.
This paper reports on an experimental investigation of the spatial beam quality of a pulsed nanosecond optical parametric
oscillator (OPO). The OPO is a 355 nm pumped type-I BBO-OPO. The spatial quality of the OPO output is characterized by the
M2-parameter in dependence of other experimental parameters such as resonator length, pump-beam diameter, pump-pulse duration
and pump energy. The results obtained indicate, that an appropriate choice of these parameters substantially improves the
spatial beam quality of the OPO output.
Received: 19 November 2002 / Revised version: 3 February 2003 / Published online: 5 May 2003
RID="*"
ID="*"Corresponding author. Fax: +49-631/205-3906, E-mail: anstett@rhrk.uni-kl.de 相似文献
8.
We demonstrate, for the first time to our knowledge, operation of a self-adaptive holographic laser with wavelength selection,
which uses Nd:YLF as the gain medium. The holographic laser was self-starting and, by virtue of the temporal dynamics in writing
the gain grating, passively Q-switched the cavity to produce pulses with 20–50 ns duration. A pulse energy of 184 mJ was obtained
from the system with beams having a TEM00 spatial profile. Single-longitudinal-mode operation was observed with near-transform-limited bandwidth.
Received: 30 July 2002 / Revised version: 1 October 2002 / Published online: 26 February 2003
RID="*"
ID="*"Corresponding author. Fax: +44-20/7594-7744, E-mail: s.y.lam@ic.ac.uk 相似文献
9.
T. Andres P. Haag S. Zelt J.-P. Meyn A. Borsutzky R. Beigang R. Wallenstein 《Applied physics. B, Lasers and optics》2003,76(3):241-244
A synchronously pumped femtosecond optical parametric oscillator based on congruent MgO-doped periodically poled lithium niobate
(c-MgO:PPLN) is reported. The system, operating at room temperature, was pumped by a mode-locked Ti:sapphire laser. The wavelengths
of the signal and idler waves were tuned from 870 nm to 1.54 μm and 1.58 to 5.67 μm, respectively, by changing the pump wavelength,
the grating period or the cavity length. Pumped by 1.1 W of 755 nm laser radiation, the OPO generated 310 mW of 1080 nm radiation.
This signal output corresponds to a total conversion efficiency of 50%. Without dispersion compensation the OPO generated
phase-modulated signal pulses of 200 fs duration. Besides the OPO of c-MgO:PPLN, an OPO of stoichiometric (s) MgO:PPLN was
investigated. Because of the reduced sensitivity to photorefractive damage, both crystals allowed efficient OPO operation
at room temperature.
Received: 19 August 2002 / Revised version: 11 December 2002 / Published online: 19 March 2003
RID="*"
ID="*"Corresponding author. Fax: +49-631/205-3906, E-mail: andres@physik.uni-kl.de 相似文献
10.
An improved model for pure rotational coherent anti-Stokes Raman scattering (CARS) has been developed for the dual-broadband
approach. This model takes into account the fact that coherent anti-Stokes as well as Stokes radiation are generated simultaneously,
and these two branches overlap and interact at high pressures giving rise to an inter-branch interference effect. In combustion
studies, the anti-Stokes branch is used to determine temperature and concentrations of key species, of which nitrogen is the
most widely used, and we have found that the interference effect on the anti-Stokes side is of such magnitude that it clearly
needs to be taken into account at pressures of a few MPa. The necessary modifications to the total third-order susceptibility
are presented and a derivation of the convolution integral for a finite-bandwidth pump source is given.
Received: 18 February 2002 / Revised version: 9 July 2002 / Published online: 22 November 2002
RID="*"
ID="*"Corresponding author. Fax: +46-46/2224542, E-mail: mikael.afzelius@forbrf.lth.se 相似文献
11.
M. Nisoli G. Sansone S. Stagira C. Vozzi S. De Silvestri O. Svelto 《Applied physics. B, Lasers and optics》2002,75(6-7):601-604
A novel spectral broadening technique, based on hollow-fiber cascading, is reported, which allows the generation of a supercontinuum
extending to a bandwidth exceeding 510 THz with excellent spatial beam quality. High-peak-power, sub-7-fs light pulses tunable
from the visible to the near infrared have been generated by compression of portions of the supercontinuum, employing different
sets of chirped mirrors.
Received: 11 July 2002 / Revised version: 3 September 2002 / Published online: 15 November 2002
RID="*"
ID="*"Corresponding author. Fax: +39-02/2399-6126, E-mail: mauro.nisoli@fisi.polimi.it 相似文献
12.
A.B. Fedotov P. Zhou A.N. Naumov V.V. Temnov V.I. Beloglazov N.B. Skibina L.A. Mel’nikov A.V. Shcherbakov A.P. Tarasevitch D. von der Linde A.M. Zheltikov 《Applied physics. B, Lasers and optics》2002,75(6-7):621-627
Photonic-molecule modes of a cobweb-microstructure fiber allow efficient nonlinear optical spectral broadening of nanojoule
femtosecond light pulses. Spectral widths of approximately 200 nm are achieved at the output of a 6-cm sample of such a fiber
for 40-fs Ti:sapphire laser pulses with an energy of a few nanojoules coupled into photonic-molecule modes. Higher values
of the group index and a lower group-velocity dispersion, attainable with higher-order photonic-molecule modes, allow the
efficiency of spectral broadening of femtosecond laser pulses to be increased relative to the efficiency of spectral broadening
in the fundamental photonic-molecule mode.
Received: 9 June 2002 / Revised version: 29 June 2002 / Published online: 22 November 2002
RID="*"
ID="*"Corresponding author. Fax: +7-095/939-3959, E-mail: zheltikov@top.phys.msu.su 相似文献
13.
T. Omatsu Y. Ojima B.A. Thompson A. Minassian M.J. Damzen 《Applied physics. B, Lasers and optics》2002,75(4-5):493-495
The high phase-conjugate reflectivity of 150, by four-wave mixing in a diode-pumped Nd:YVO4, has been demonstrated. The phase-conjugate mirror was capable of correcting the phase aberration of a probe beam. The experimental
diffraction efficiency of the transmission gratings was 60.
Received: 8 April 2002 / Revised version: 10 June 2002 / Published online: 25 September 2002
RID="*"
ID="*"Corresponding author. Fax: +81/43-290-3490, E-mail: omatsu@image.tp.chiba-u.ac.jp 相似文献
14.
G. Stobrawa M. Hacker R. Netz M. Bischoff R. Sauerbrey 《Applied physics. B, Lasers and optics》2003,76(3):333-336
We present a novel method for measuring the linear and nonlinear dispersion properties of conventional and micro-structured
fibers. It is based on the automated compensation of phase modulations using a high-resolution pulse-shaping device. No tunable
laser source is required.
Received: 20 December 2002 / Published online: 19 March 2003
RID="*"
ID="*"Corresponding author. Fax: +49-3641/947202, E-mail: stobrawa@ioq.uni-jena.de
RID="**"
ID="**"Present address: Carl Zeiss Meditec AG, G?schwitzer Strasse 51–52, 07745 Jena, Germany 相似文献
15.
We report the observation of light filaments produced by a picosecond laser pulse in the visible. The pulse trapped in the
filamentary mode experiences large-scale self-phase modulation, with almost 100-fold spectral broadening along with apparent
shortening of the leading edge. Spatial-temporal properties of the light filament reveal rather complex propagation dynamics.
Received: 7 August 2002 / Revised version: 12 September 2002 / Published online: 11 December 2002
RID="*"
ID="*"Corresponding author. Fax: +370-2/3660-06, E-mail: audrius.dubietis@ff.vu.lt 相似文献
16.
R.A. Ganeev R.I. Tugushev A.A. Ishchenko N.A. Derevyanko A.I. Ryasnyansky T. Usmanov 《Applied physics. B, Lasers and optics》2003,76(6):683-686
We investigated nonlinear refraction, nonlinear absorption, and saturable absorption of polymethine dyes by the Z-scan technique
(λ=1064 nm). The analysis of simultaneous appearance of several nonlinear optical processes in dye solutions excited by picosecond
pulses was carried out. The saturable absorption was analyzed taking into account various models. Nonlinear refractive indices,
nonlinear absorption coefficients, and saturation intensities of various polymethine dyes were measured.
Received: 27 December 2002 / Revised version: 6 March 2003 / Published online: 5 May 2003
RID="*"
ID="*"Corresponding author. Fax: +81-471/363-366, E-mail: r_ganeev@issp.u-tokyo.ac.jp
RID="**"
ID="**"Present address: The Institute for Solid State Physics, The Tokyo University, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581,
Japan 相似文献
17.
We have developed a novel interferometric autocorrelator composed of only reflective elements, which functions as a beam splitter
and an optical delay line. Analytical expressions are derived to give second-order autocorrelation functions and deconvolution
factors for various conditions. The measurement of femtosecond laser pulses by interferometric autocorrelation is demonstrated
in the visible region. The results are compared with those by calculation.
Received: 9 December 2002
Revised version: 18 February 2003 / Published online: 5 May 2003
RID="*"
ID="*"Present address: Department of Physics, Tokai University, 1117 Kitakaname, Hiratsuka, Kanagawa 259-1207, Japan
RID="**"
ID="**"Corresponding author. Fax: +81-48/462-4682, E-mail: asuda@postman.riken.go.jp 相似文献
18.
Intracavity optical parametric oscillator at 1572-nm wavelength pumped by passively Q-switched diode-pumped Nd:YAG laser 总被引:4,自引:0,他引:4
W. Zendzian J.K. Jabczyński J. Kwiatkowski 《Applied physics. B, Lasers and optics》2003,76(4):355-358
An intracavity optical parametric oscillator (IOPO) based on bulk KTP crystal was constructed with a Nd:YAG slab as an active
medium pumped by a 300-W diode array and Cr:YAG as a passive Q-switch. A signal pulse of 1.9-mJ energy at 1572-nm wavelength
was demonstrated. In the cavity, optimized with respect to single-pulse energy, a five-fold shortening of signal-pulse duration
with respect to 1064-nm pump radiation was observed. A twice as large level of signal peak power of 650 kW, compared to the
pump laser in the same cavity without the IOPO, was achieved. A conversion efficiency of 44% with respect to the 1064-nm pump
beam and 3.8% with respect to diode pump energy was demonstrated.
Received: 15 October 2002 / Revised version: 19 February 2003 / Published online: 16 April 2003
RID="*"
ID="*"Corresponding author. Fax: +48-22/666-8950, E-mail: wzendzian@wat.edu.pl 相似文献
19.
Bulk heating of transparent materials using a high-repetition-rate femtosecond laser 总被引:7,自引:0,他引:7
C.B. Schaffer J.F. García E. Mazur 《Applied Physics A: Materials Science & Processing》2003,76(3):351-354
Femtosecond laser pulses can locally induce structural and chemical changes in the bulk of transparent materials, opening
the door to the three-dimensional fabrication of optical devices. We review the laser and focusing parameters that have been
applied to induce these changes and discuss the different physical mechanisms that play a role in forming them. We then describe
a new technique for inducing refractive-index changes in bulk material using a high-repetition-rate femtosecond oscillator.
The changes are caused by a localized melting of the material, which results from an accumulation of thermal energy due to
nonlinear absorption of the high-repetition-rate train of laser pulses.
Received: 21 November 2001 / Accepted: 9 July 2002 / Published online: 25 October 2002
RID="*"
ID="*"Corresponding author. Fax: +1-858/534-7697, E-mail: cschaffer@ucsd.edu
RID="**"
ID="**"Current address: University of California, San Diego, Department of Physics, La Jolla, CA 92 093, USA 相似文献
20.
Tuning and stability of a continuous-wave mid-infrared high-power single resonant optical parametric oscillator 总被引:1,自引:0,他引:1
M.M.J.W. van Herpen S. Li S.E. Bisson S. te Lintel Hekkert F.J.M. Harren 《Applied physics. B, Lasers and optics》2002,75(2-3):329-333
A 2.2-W continuous-wave, continuously tunable, single-frequency OPO has been developed in the 3.0–3.8 μm wavelength range
for the detection of molecular trace gasses. The oscillation threshold, output power and stability of the single resonant
OPO were improved by optimizing pump beam waist and OPO cavity length. Both air-spaced and solid etalons were tested to frequency
stabilize and tune the OPO, from which the solid etalon gave a better performance. Temperature oscillations in the PPLN crystal
caused oscillations in the idler wavelength of less than 200 MHz over 300 s; the short-term stability was less than 3 MHz
over 1 s. The high laser power, in combination with photoacoustic spectroscopy, achieved a detection limit of 10 parts-per-trillion
for ethane in nitrogen.
Received: 9 April 2002 / Revised version: 14 June 2002 / Published online: 2 September 2002
RID="*"
ID="*"Corresponding author. Fax:+31-24/3653311, E-Mail: maartenh@sci.kun.nl 相似文献