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1.
Pulsed solid-state laser system with fiber phase conjugation and 315 W average output power 总被引:2,自引:0,他引:2
Solid-state laser sources with high average output power and high beam quality are required for numerous applications in industry
and science. To improve the beam quality, stimulated Brillouin scattering (SBS) mirrors based on optical phase conjugation
are used to compensate for phase distortions in master oscillator power amplifier (MOPA) systems. SBS phase conjugation in
commercially available silica optical fibers facilitates the construction of high-power solid-state laser systems with high
beam quality. Here we present a flash lamp-pumped, passively Q-switched Nd:YAP system which delivers an average output power
of 315 W with M2=2.6 at a wavelength of 1.08 μm.
Received: 11 July 2001 / Revised version: 28 September 2001 / Published online: 23 November 2001 相似文献
2.
C. Du Z. Wang J. Liu X. Xu B. Teng K. Fu J. Wang Y. Liu Z. Shao 《Applied physics. B, Lasers and optics》2001,73(3):215-217
We report, for the first time, efficient intracavity second-harmonic generation (SHG) at 1.06 μm in a non-linear optical crystal,
BiB3O6 (BIBO), at a type-I phase-matching direction of (θ,ϕ)=(168.9°,90°), performed with a LD end-pumped cw Nd:YVO4 laser. A cw SHG output power of 364 mW has been obtained using a 1.9-mm-thick BIBO crystal. The optical conversion efficiency
was 12.2% and the corresponding effective intracavity SHG efficiency was determined to be 32.4%. It was found that the intracavity
SHG efficiency is greater than that obtained with a type-II phase-matching KTiOPO4 (KTP) crystal with a thickness of 3 mm. The effective non-linear optical coefficient (deff) ratio of BIBO to that of KTP, determined experimentally, is 1.23:1.
Received: 7 May 2001 / Revised version: 6 July 2001 / Published online: 19 September 2001 相似文献
3.
Y.N. Korkishko V.A. Fedorov A.N. Alkaev F. Laurell 《Applied physics. B, Lasers and optics》2001,73(5-6):519-522
A detailed correlation between the fabrication conditions, crystallographic phase state of HxLi1-xTaO3 waveguides and second-order optical non-linearity has been investigated by using reflected SHG measurements from the polished
waveguide end face. The non-linearity, strongly reduced after the initial proton exchange, is found to be restored and even
increased after annealing. However, this apparent increase in the non-linearity is accompanied by a strong degradation of
the quality of the SHG reflected beam in the region of the initial as-exchanged waveguide due to beam scattering. The high
temperature proton exchange technique has been shown to produce high-quality α-phase waveguides with essentially undegraded
non-linear optical properties. There is no phase transition when the α-phase waveguides are fabricated by direct exchange.
This phase presents the same crystalline structure as that of LiTaO3 and maintains the excellent non-linear properties of the bulk material. The results obtained are important for the design,
fabrication and optimization of guided-wave non-linear optical devices in LiTaO3.
Received: 21 May 2001 / Published online: 23 October 2001 相似文献
4.
Anirban Mitra Hidetsugu Yoshida Hisanori Fujita Masahiro Nakatsuka 《Optics Communications》2006,261(2):342-348
We present the correction of the phase distortion which occurs during the second harmonic generation by non-linear crystals, such as KDP and KTP at high average power laser. This is due to the optical quality and thicknesses of the crystals which in turn influence the quality of the incident laser beam. This phase distortion is corrected by reflecting back the laser beam into the crystal using a phase conjugate mirror. It is found that the conversion efficiency of second harmonic generation without phase conjugation is more than that with phase conjugation. Far field pattern shows that the distortion of the laser beam can be corrected by using the phase conjugate mirror. Fidelity of the beam profile increases significantly with phase conjugation in the case of KDP crystal. 相似文献
5.
F. Cornacchia A. Di Lieto P. Maroni P. Minguzzi A. Toncelli M. Tonelli E. Sorokin I. Sorokina 《Applied physics. B, Lasers and optics》2001,73(3):191-194
We present the results obtained with a Ho,Tm:YLF crystal grown at a new crystal growth facility in Pisa. The optical quality
of the sample has been tested by studying its performance as the active medium of a laser operating at 2.06 μm. We employed
three different pump laser sources: a Ti:sapphire, a diode (both tuned at 793 nm) and, for the first time, a continuous-wave
Co:MgF2 laser, tuned at 1.682 μm. At room temperature the best slope efficiency was 30 % in the case of “red” pumping, and 59 % in
the case of “infrared” excitation. The typical lasing threshold is about 100 mW.
Received: 14 March 2001 / Revised version: 15 June 2001 / Published online: 19 September 2001 相似文献
6.
Recent advances in terahertz imaging 总被引:10,自引:0,他引:10
D.M. Mittleman M. Gupta R. Neelamani R.G. Baraniuk J.V. Rudd M. Koch 《Applied physics. B, Lasers and optics》1999,68(6):1085-1094
We review recent progress in the field of terahertz “T-ray” imaging. This relatively new imaging technique, based on terahertz
time-domain spectroscopy, has the potential to be the first portable far-infrared imaging spectrometer. We give several examples
which illustrate the possible applications of this technology, using both the amplitude and phase information contained in
the THz waveforms. We describe the latest results in tomographic imaging, in which waveforms reflected from an object can
be used to form a three-dimensional representation. Advanced signal processing tools are exploited for the purposes of extracting
tomographic results, including spectroscopic information about each reflecting layer of a sample. We also describe the application
of optical near-field techniques to the THz imaging system. Substantial improvements in the spatial resolution are demonstrated.
Received: 29 January 1999 / Published online: 7 April 1999 相似文献
7.
From laser-induced line narrowing to electro- magnetically induced transparency: closed system analysis 总被引:1,自引:0,他引:1
The laser-induced line-narrowing effect, discovered more than thirty years ago, can also be applied to recent studies in high
resolution spectroscopy based on electromagnetically induced transparency. In this paper we first present a general form of
the transmission width of electromagnetically induced transparency in a homogeneously broadened medium. We then analyze a
Doppler broadened medium by using a lorentzian function as the atomic velocity distribution. The dependence of the transmission
linewidth on the driving field intensity is discussed and compared to the laser-induced line-narrowing effect. This dependence
can be characterized by a parameter which can be regarded as “the degree of optical pumping.”
Received: 17 December 2001 / Published online: 15 January 2003
RID="*"
ID="*"Corresponding author. E-mail: hwang.Lee@jpl.nasa.gov
RID="**"
ID="**"Present address: Jet Propulsion Laboratory, MS 126-347, California Institute of Technology, Pasadena, CA 91109, USA 相似文献
8.
We describe a laser system that readily provides radiation tunable from 2 μm in the infra-red to 35 nm in the extreme ultraviolet
spectral range. The broad spectral range is covered through a range of non-linear processes such as Raman shifting and high-order
harmonic generation. Pulses with duration of tens of picoseconds are obtained. The relative bandwidth of the radiation is
δλ/λ=10-4, comparable with what can be achieved by using high-resolution monochromators at state-of-the-art synchrotron beamlines.
We discuss different methods for characterising the radiation in this wide wavelength regime. We also discuss the capabilities
of the system from the measured parameters.
Received: 12 December 2000 / Revised version: 8 March 2001 / Published online: 27 April 2001 相似文献
9.
S. Borri P. Cancio P. De Natale G. Giusfredi D. Mazzotti F. Tamassia 《Applied physics. B, Lasers and optics》2003,76(4):473-477
We analyzed the spectroscopic performance of a difference-frequency source that utilizes a 5-W Yb-fiber amplifier for the
“signal” radiation in order to increase the “idler” power generated around 4.3 μm. The amplifier is seeded by a monolithic-cavity
Nd:YAG laser at 1064 nm. The intensity noise spectral density of the “idler” radiation was characterized. Cavity-enhanced
saturated-absorption spectroscopy was also performed to test the frequency resolution. In particular, we observed the Lamb-dip
spectrum of the ro-vibrational (0000-0001)R(0)transition of 17O12C16O in natural abundance. To our knowledge, this is the first observation of that transition by the Lamb-dip technique.
Received: 19 December 2002 / Revised version: 3 February 2003 / Published online: 16 April 2003
RID="*"
ID="*"Corresponding author. Fax: +39-055/4572-451, E-mail: mazzotti@inoa.it 相似文献
10.
D. Neshev A. Dreischuh G.G. Paulus H. Walther 《Applied physics. B, Lasers and optics》2001,72(7):849-854
Numerical simulations on the evolution of step-screw and edge-screw optical phase dislocations in bulk saturable self-defocusing
nonlinear media are presented, with emphasis on their ability to induce steering waveguides for signal beams (pulses). Two
schemes for directional coupling of such signals, both ensuring a reasonable coupling-to-cross-talk efficiency ratio, are
investigated. The parameters useful for performance optimization of the couplers are discussed.
Received: 19 July 2000 / Revised version: 5 February 2001 / Published online: 27 April 2001 相似文献
11.
R.A. Ganeev A.I. Ryasnyansky M.K. Kodirov S.R. Kamalov V.A. Li R.I. Tugushev T. Usmanov 《Applied physics. B, Lasers and optics》2002,75(1):47-51
The results of optical limiting investigations of cobalt-doped polyvinylpyrrolidone solutions are presented. The optical limiting
studies have shown that this process is due to self-defocusing at the wavelength of 1064 nm and also due to reverse saturable
absorption and self-defocusing at the wavelength of 532 nm. The results of measurements on the non-linear optical characteristics
of organometallic complexes are presented.
Received: 10 July 2001 / Revised version: 15 October 2001 / Published online: 29 November 2001 相似文献
12.
T. Hornung R. Meier D. Zeidler K.-L. Kompa D. Proch M. Motzkus 《Applied physics. B, Lasers and optics》2000,71(3):277-284
This paper reports two pump–probe experiments in sodium where dynamically tailored ultrashort pulses from a Ti:Sapphire-pumped
optical parametric amplifier were employed. The first study focuses on the one-photon Na(3s→3p) transition to derive sensitive
criteria which judge the performance of a frequency-domain pulse shaper using a spatial light modulator. On the basis of the
interpretation, follow-up experiments are suggested to test their cogency. The second experiment uses coherent quantum control
by placing an appropriate phase distribution on the incident beam to enhance or cancel the transition probability in the nonresonant
two-photon process Na(3s→→5s). Ignorant of the “ideal” phase function, an evolutionary algorithm which uses a feedback derived
from the experiment performs the optimization and produces the desired bright or dark pulses within a few minutes. Attention
is given to the role of resonant 3s→3p transitions excited by the spectral wings of the pump pulse. Different parametrizations
of the phase distribution have been examined. Two of these produced solutions which had not previously been predicted by theory
still meet the objective of the experiment. The study represents the first successful application of a feedback-organized
self-learning algorithm to the design of dark pulses.
Received: 3 November 1999 / Published online: 5 July 2000 相似文献
13.
E.V. Becker E.A. Romanova L.A. Melnikov T.M. Benson P. Sewell 《Applied physics. B, Lasers and optics》2001,73(5-6):531-534
A slab waveguide with an embedded non-linear grating is considered as an all-optical power-limiting device. The limiting action
is based on the power losses at boundaries between grating sections, where a mode-mismatch results from the self-focusing
of the fundamental mode in each non-linear section. Time-harmonic and optical pulse propagation are both modelled numerically
by finite-difference techniques to demonstrate the behaviour of the device.
Received: 17 May 2001 / Revised version: 7 August 2001 / Published online: 23 October 2001 相似文献
14.
Maciej Horowski Anatol Odzijewicz Agnieszka Tereszkiewicz 《Czechoslovak Journal of Physics》2002,52(11):1231-1237
We show that some quantum optical systems generate quantum algebras being the natural generalization of the Heisenberg-Weyl
algebra. The importance of these algebras for the integration of the systems under consideration is discussed.
Presented at the 11th Colloquium “Quantum Groups and Integrable Systems”, Prague, 20–22 June 2002.
This work is supported in part by KBN grant 2 PO3 A 012 19. 相似文献
15.
J.-P. Meyn C. Laue R. Knappe R. Wallenstein M.M. Fejer 《Applied physics. B, Lasers and optics》2001,73(2):111-114
Fabrication of periodically poled lithium tantalate (PPLT) with periods as short as 1.3 μm for second harmonic generation
(SHG) in the UV range and for optical parametric oscillators pumped at 532 nm is reported. Both the maximum crystal size of
up to 40 mm and the minimum poling period of 1.3 μm are improvements on earlier results, achieved by optimizing the poling
conditions and by using a novel electrode design consisting of electrode structures on both surfaces of the crystal. Single-pass
SHG of a master oscillator power amplifier (MOPA) diode laser with an output power of 1.36 mW at 336 nm using a 16-mm-long
PPLT crystal with a 1.5 μm poling period is reported.
Received: 11 June 2001 / Published online: 18 July 2001 相似文献
16.
The third harmonic of 810-nm 100-fs pulses at 130 μJ is generated very efficiently when ultrashort pulses from two noncollinear
beams interfere in an optical medium to create an instantaneous transient grating via the optical Kerr effect. The grating
couples two pathways for third-harmonic generation, each taking two photons from one beam and one photon from the other beam,
respectively. The coupling enables self-phase matching in the complete process, resulting in a conversion efficiency of ≈3%.
Scattering an independent beam at the transient grating confirms a lifetime limited by the pulse duration, with a reaction
on the order of one optical cycle. Using the second harmonic of a Ti-sapphire laser at 405 nm, it is shown that the generation
of the transient Kerr grating is a general feature, requiring less than 20 μJ/pulse. By introducing a third femtosecond beam
we are able to emulate various digital logic units with femtosecond response.
Received: 16 October 2001 / Published online: 6 June 2002 相似文献
17.
Rapid temperature measurements in a low pressure, microwave assisted, diamond CVD plasma are reported. By using a “modeless”
laser as the Stokes source for H CARS, accurate single-shot and averaged temperatures were obtained which agreed with values obtained from laser induced fluorescence
measurements. The speed of data acquisition afforded by multiplex CARS allowed variations of temperature to be monitored with
changing plasma conditions induced by variations of pressure, gas composition and microwave power. The application of the
technique for “on-line” monitoring of plasma processes is briefly discussed.
Received: 13 February 1996 / Accepted: 12 June 1996 相似文献
18.
We demonstrate an optical limiter for ultra-short (∼100-fs) laser pulses. The device has a dynamic range (= damage energy/onset-of-limiting
energy) of more than 10000 and an onset-of-limiting energy of only ∼10 nJ. The output-pulse energy is kept below 1.3 μJ. The
limiting mechanism is based on two-photon absorption and refractive nonlinearities in a 20-mm piece of ZnSe. We discuss the
importance of the different nonlinearities, damage issues, and guidelines for the construction of the device.
Received: 20 December 2001 / Revised version: 25 March 2002 / Published online: 8 May 2002 相似文献
19.
The optical and non-linear optical properties of peripheral-substituted vanadium oxide phthalocyanine (VOPc) film and substituted
VOPc/polymer composite film were investigated using stationary and transient spectroscopy techniques. The absorption Q band
of the VOPc/polymer composite film shows a red shift relative to that of the peripheral-substituted VOPc film, revealing the
monomeric characteristics of VOPc molecules. Effective quenching of PL emission was observed for the VOPc/polymer composite
film and could be assigned to the efficient VOPc–polymer interaction. From pump-probe and optical Kerr effect (OKE) measurements,
two decay components were obtained by fitting the transients for both VOPc films. The fast component, in a femtosecond time
domain, originates from the electron–phonon interaction, and the difference in their slow decay is an indication of an efficient
ISC process in the VOPc/polymer composite film. The third-order non-linear optical susceptibilities of these films were determined
to be in the order of 10-11 esu.
Received: 25 October 2001 / Revised version: 8 January 2002 / Published online: 7 February 2002 相似文献
20.
Efficient and compact intracavity-frequency-doubled Nd:GdVO4/KTP laser end-pumped by a fiber-coupled laser diode 总被引:2,自引:0,他引:2
D.Y. Shen H.R. Yang J.G. Liu S.C. Tam Y.L. Lam W.J. Xie J.H. Gu K. Ueda 《Applied physics. B, Lasers and optics》2001,72(3):263-266
A compact and efficient diode-pumped intracavity-frequency-doubled Nd:GdVO4/KTP green laser is demonstrated with a flat–flat cavity design. With a 1.3 at. % Nd3+-doped GdVO4 crystal and pumped at the weak-absorption peak of 806 nm, the second-harmonic output power at 532 nm was measured to be 1.95 W
at an incident pump power of 8.4 W, corresponding to an optical conversion efficiency of 23.2%. The output characteristic
at the fundamental wavelength of 1.063 μm was investigated with two different pump wavelengths. More than 4.5-W output power
was generated when the laser was pumped at 806.2 nm.
Received: 26 July 2000 / Revised version: 18 September 2000 / Published online: 7 February 2001 相似文献