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1.
Low-threshold mid-infrared optical parametric oscillation in periodically poled LiNbO3 synchronously pumped by a Ti:sapphire laser 总被引:1,自引:0,他引:1
We report the generation of tunable high-repetition-rate optical pulses in the mid-infrared using synchronously pumped parametric
oscillation in periodically poled LiNbO3 (PPLN). Using a Kerr-lens-mode-locked Ti:sapphire laser as the pump source and a PPLN crystal incorporating grating periods
of 21.0–22.4 μm, we have achieved wavelength conversion in the -–4 6μm spectral range in the mid-infrared. The use of a semi-monolithic
cavity design and hemispherical focusing has permitted pulse generation in the strong idler absorption region of PPLN, resulting
in a simple, compact, all-solid-state configuration with a pump power threshold as low as 17 mW and mid-infrared idler powers
of up to 64 mW at 9% extraction efficiency. Signal output powers of up to 280 mW at 35% extraction efficiency are available
over the -–1.004 1.140μm spectral range at 80.5 MHz and pulse repetition rates at harmonics of the fundamental frequency up
to 322 MHz have also been obtained.
Received: 5 December 2000 / Revised version: 23 January 2001 / Published online: 27 April 2001 相似文献
2.
The operation of a continuous-wave mode-locked silver gallium selenide (AgGaSe2) optical parametric oscillator (OPO) is reported. The OPO was synchronously excited by 120-fs-long pulses of 1.55-μm radiation
at a repetition rate of 82 MHz. The 1.55-μm radiation is generated by a noncritically phasematched cesium-titanyl-arsenate
(CTA)-OPO pumped by a mode-locked Ti:sapphire laser. The AgGaSe2-OPO generates signal and idler radiation in the range from 1.93 μm to 2.49 μm and from 4.1 μm to 7.9 μm, respectively. Up
to 67 mW of signal wave output power has been obtained. The experimentally determined pulse duration and chirp parameters
are in reasonable agreement with results from a numerical model taking into account group velocity mismatch, group velocity
dispersion, self phase modulation, and chirp enhancement.
Received: 6 August 1999 / Revised version: 4 October 1999 / Published online: 3 November 1999 相似文献
3.
Optical parametric oscillators for high pulse energy and high average power operation based on large aperture periodically poled KTP and RTA 总被引:3,自引:0,他引:3
M. Peltz U. Bäder A. Borsutzky R. Wallenstein J. Hellström H. Karlsson V. Pasiskevicius F. Laurell 《Applied physics. B, Lasers and optics》2001,73(7):663-670
We report on optical parametric oscillators (OPOs) based on large aperture periodically poled KTiOPO4 (PPKTP) and RbTiOAsO4 (PPRTA) pumped with high pulse energy and high average power Q-switched solid-state lasers. The OPOs were pumped with 1064-nm
pulses of a diode-pumped Nd:YVO4 laser at 20 kHz repetition rate. The emitted signal wavelengths were 1.72 μm and 1.58 μm and the idler wavelengths were 2.79 μm
and 3.26 μm, respectively. Pumping the PPKTP OPO with 7.2 W and the PPRTA OPO with 8 W average power, 2 W and 1.3 W total
OPO output powers were generated. Two-dimensional measurements of the total OPO output power, the signal wavelength and the
signal bandwidth in dependence on the crystal location indicated a good uniformity of the quasiphasematching structure over
the entire 3-mm-thick crystals. This allowed pumping with larger pump beams and therefore with pulse energies of tens of millijoules.
Pumping with different flash-lamp-pumped lasers, good OPO performance and high output pulse energies could be achieved for
all pump lasers. Maximum input pulse energies of 56 mJ gave output pulse energies of as much as 18 mJ. The temperature tuning
behaviors of both OPOs were measured, showing excellent agreement with calculated temperature tuning curves. New equations
for temperature dispersion in RTA are presented. These results show that large-aperture PPKTP and PPRTA crystals are well
suited for tunable nanosecond OPO operation with multi-watt average pump power and several tens of millijoules pump pulse
energies.
Received: 7 September 2001 / Published online: 7 November 2001 相似文献
4.
M. Henriksson M. Tiihonen V. Pasiskevicius F. Laurell 《Applied physics. B, Lasers and optics》2007,88(1):37-41
The total pulse energy of the signal and idler in a near-degenerate type-I periodically poled KTiOPO4 (PPKTP) optical parametrical oscillator (OPO) was spectrally confined within a 2 nm spectral bandwidth at 2.13 μm. This was
achieved by using a volume Bragg grating as the output coupler. Both the signal and the idler from the PPKTP OPO were then
simultaneously used to pump a mid-infrared ZnGeP2 (ZGP) OPO. The 2 nm bandwidth was narrower than the ZGP crystal acceptance bandwidth and, thus, made efficient conversion
in the second OPO possible. A total slope efficiency of 10% from 1.06 μm to the 3.5–5 μm region was demonstrated, generating
250 μJ in the mid-IR with only 3.6 mJ of 1.06 μm pump energy. This corresponds to a Nd:YAG pump to mid-IR conversion efficiency
of 7%.
PACS 42.65.Yj; 42.72.Ai; 42.40.Eq 相似文献
5.
A single resonator 8.30 μm ZnGeP2 (ZGP) optical parametric oscillators (OPO) was reported in the paper. The OPO was pumped by a 10.2-W Tm,Ho:GdVO4 laser at 8 kHz in a Q-switch mode, a 170-mW idler was obtained at 8.30 μm, and the output power of the idler and signal wave
was 1.0 W, corresponding to an optical-optical conversion efficiency of 10.3% and a slope efficiency of 20.9%. Tm,Ho:GdVO4 laser was pumped by a 30-W fiber-coupled laser diode (LD) at the center wavelength of 801 nm. The output wavelength of Tm,Ho:GdVO4 laser was at 2.05 μm, and the energy per pulse of 1.28 mJ in 18 ns was achieved at 8 kHz with the peak power of 71.1 kW. 相似文献
6.
Based on periodically poled lithium niobate (PPLN), a mini intracavity optical parameter oscillator (IOPO) driven by an diode-end-pumped
composite Nd3+:YAG/Cr4+:YAG laser was demonstrated. The PPLN wafer has 20 domain reversal periods from 27.8 to 31.6 μm with a step of 0.2 μm between
the neighbor periods. The output signal laser of OPO can be widely tunable in the range of 1402–1676 nm by changing the period
at a certain temperature of 50°C. Under the diode pump power of 14 W, the maximum average output power of 600 mW at 1534 nm
with pulse width of 2.0 ns and repetition rate of 16 kHz was obtained, corresponding to a peak power of 18.7 kW and a single
pulse energy of 37.5 μJ, respectively. 相似文献
7.
Parameters of eyesafe lidar at 1.54 μm for detection of small plumes of smoke from burning wood or oil have been evaluated.
It was assumed that a diode-pumped solid-state Er:glass laser at 1.54 μm or a Nd:YAG laser with a Raman cell or optical-parametric
oscillator is used as a light source and that detection of backscattered light is performed with an avalanche photodiode.
Ash and soot particle size distributions were taken from experiments. A backscattering coefficient at 1.54 μm for various
source of smoke was estimated. In computing the laser energy, range between lidar and smoke, receiver optics diameter, fuel
mass burned in unit time, fire source radius, laser pulse duration and visibility were varied. Results of the computations
enabled estimation of the required laser energy, which ranges from 0.05 to 1400 mJ depending on the parameters.
Received: 5 January 2000 / Revised version: 3 March 2000 / Published online: 11 May 2000 相似文献
8.
2 laser to 2.38 μm has been studied experimentally by using tandem AgGaSe2 and ZnGeP2 crystals. Up to 24 mJ per pulse of 2.38-μm radiation at a 10% overall conversion efficiency has been achieved with a mode-locked
pulse format. A computer model was also developed and its predictions are in reasonable agreement with our experimental data.
Received: 6 July 1997/Revised version: 8 December 1997 相似文献
9.
A. G. Rousskikh A. V. Shishlov A. S. Zhigalin V. I. Oreshkin S. A. Chaikovsky R. B. Baksht 《Technical Physics》2010,55(11):1619-1627
The results of the experiments on the formation of a plasma emitter with small spatial dimensions for pulsed radiography in
the soft X-ray spectral range are presented. Emitting hot plasma was formed as a result of compression of the plasma jet by
a current pulse with amplitude I
m
= 215 kA and rise time T
fr = 200 ns. For the jet formation, we used a plasma gun based on the arc discharge (I
m
= 8.5 kA and T
fr = 6 μs) initiated by breakdown over the surface of a dielectric in vacuum. The experiments were carried out with aluminum,
tin, copper, and iron plasma jets. A single emitter, i.e., point Z-pinch (PZ-pinch), was formed when an interelectrode gap of a high current generator of 1.3–1.5 mm was used. The smallest spatial dimensions
of the emitting region were obtained with the use of aluminum and tin. For a tin jet, the diameter of the emitting region
was 7 ± 2 μm and its height was 17 ± 2 μm. The emission pulse duration at half-height was 2–3 ns. The total emission yield
per pulse in the spectral range 1.56–1.90 keV was 30–50 mJ for the aluminum pinch and 10–30 mJ for the tin pinch. The developed
method makes it possible to carry out radiographic examination of microobjects (including biological ones) 1–1000 μm in thickness,
with spatial (10–20 μm) and time (2–3 ns) resolution. 相似文献
10.
~~A Raman laser system for multi-wavelength satellite laser ranging@K.Hamal$Czech Technical University in Prague,Czech
@I.Prochazka$Czech Technical University in Prague,Czech
@J.Blazej$Czech Technical University in Prague,Czech1. Yang Fumin, Chen Wanzhen, Zhang Zhongping et al., Satellite laser ranging experiment with sub-centimeter single-shot ranging precision at Shanghai Observatory, Science in China, Ser. A, 2002, 32(10): 935-939.
2. Degnan, J. J., Millimeter accurac… 相似文献
11.
An efficient continuous wave (CW) and Q-switched c-cut Tm:YAP laser is reported in this letter. With the dual-end-pumped convex-concave resonator, CW output power up to 13.6
W at 1.99 μm was obtained under a total incident pump power of 50 W. The corresponding slope efficiency was 34.3% and conversion
efficiency was 27.2%. The active Q-switched operation of the laser had an average output power of 12.5 W at 10 kHz pulse repetition
frequency, with a minimum pulse width of 126 ns. With 6 kHz pulse repetition frequency, the maximum pulse energy of 1.6 mJ
was obtained. In addition, using the Tm:YAP laser as a pumping source for gain-switched Cr:ZnSe laser, as much as 4 W output
power in the wavelength range of 2.5–2.6 μm was obtained. 相似文献
12.
2 ) nonlinear crystal is reported. The device uses a standing-wave dual-resonator scheme to enhance both near-infrared lasers.
For 7 mW of 778.2-nm and 275 mW of 842.5-nm input powers, 40 nW of 10.2-μm radiation is generated by a preliminary setup.
A μW-level range output power is expected after optimization of the device optical components. This compact tunable source
will allow Fabry–Pérot high-resolution Doppler-free spectroscopy of spherical molecules, such as OsO4 or SF6, in the 9–11 μm range as an alternative source to frequency-stabilized CO2 lasers.
Received: 17 March 1998 相似文献
13.
The free running and Q-switched operation of 2 μm Tm:YAG lasers side-pumped by pulse laser diodes were reported. In the free
running mode the maximum output energies were 102.5 mJ at 1 Hz and 94.6 mJ at 10 Hz, respectively. With an acousto-optic modulator
in the laser resonator, 21 mJ 2 μm Q-switched pulse was obtained, with a pulse width of about 330 ns. The dependences of the
output energy and the efficiency on the laser resonator parameters were investigated. 相似文献
14.
B. Köhler U. Bäder A. Nebel J.-P. Meyn R. Wallenstein 《Applied physics. B, Lasers and optics》2002,75(1):31-34
We report on an injection-seeded 9.5-W 82-MHz-repetition-rate picosecond optical parametric generator (OPG) based on a 55 mm
long crystal of periodically poled lithium niobate (PPLN) with a quasi-phase-matching (QPM) grating period of 29.75 μm. The
OPG is excited by a continuously diode pumped mode-locked picosecond Nd:YVO4 oscillator-amplifier system. The laser system generates 7 ps pulses with a repetition rate of 82.3 MHz and an average power
of 24 W. Without injection-seeding the total average output power of the OPG is 8.9 W, which corresponds to an internal conversion
efficiency of 50%. The wavelengths of the signal and idler waves were tuned in the range 1.57–1.64 μm and 3.03–3.3 μm, respectively,
by changing the crystal temperature from 150 °C to 250 °C. Injection seeding of the OPG at 1.58 μm with 4 mW of single frequency
continuous-wave radiation of a distributed-feedback (DFB) diode laser increases the OPG output to 9.5 W (53% conversion efficiency).
The injection seeding increases the pulse duration and reduces the spectral bandwidth. When pumped by 10 W of 1.06 μm laser
radiation, the duration of the signal pulses increased from 3.6 ps to 5.5 ps while the spectral bandwidth is reduced from
4.5 nm to 0.85 nm. Seeding thus improved the time-bandwidth product from 1.98 to a value of 0.56, much closer to the Fourier
limit.
Received: 29 April 2002 / Published online: 8 August 2002 相似文献
15.
We report a compact and viable source of high-efficiency, high-repetition-rate, temperature-tuning, mid-IR optical parametric
oscillator (OPO) based on periodically poled MgO-doped lithium niobate (PPMgOLN) pumped by a homemade high power AOM Q-switched
Nd:YVO4 laser centered at 1.064 μm. With an optimal plane-concave resonator configuration, average output power of 5.7 W at 2.73
μm was obtained when the pump power was 25 W at the repetition rate of 80 kHz. The conversion efficiency from the 1.064 μm
laser to the 2.73 μm laser was 22.8%. Temperature tuning of the OPO yielded a signal wavelength range from 1.67 to 1.75 μm
and an idler wavelength in the range of 2.72 to 2.92 μm. 相似文献
16.
Coherent terahertz radiation in a widely step-tunable range of 72.3–2706 μm (0.11–4.15 THz) has been generated in GaAs crystal
by difference-frequency generation using one CO2 laser with dual-wavelength output. The peak power of THz pulse reaches 35 W at the wavelength of 236.3 μm, which corresponds
to a pulse energy of 2.1 μJ. An average power of 10 μW has been achieved when working repetitively. This efficient terahertz
radiation source is more compact and widely tunable than other THz sources pumped by CO2 laser. 相似文献
17.
The ability of a CO2 laser to oscillate in the range of 16 (14) μm at room temperature was investigated experimentally and theoretically. The output energy per pulse was ~60 mJ at peak power of ~50 kW. It was necessary to minimize not only harmful losses but also useful ones in both channels 0001–0200 and 0200–0110 and to increase the input energy, i.e., the density of free electrons in the discharge, in order to increase the peak power and energy of 16-μm radiation. The highest values of peak power and energy of radiation were reached at different pressures of the active mixture. The rotational bottleneck effect limiting the peak power and energy of oscillation was important at rather low pressures of the active medium. Oscillation at the R12 line is more preferable than that at the P12 line for use as 9.6-μm dumping radiation. 相似文献
18.
Li D. J. Yang G. L. Chen F. Xie J. J. Zhang L. M. Guo J. Shao C. L. Peng Z. Q. Lu Q. P. 《Laser Physics》2012,22(5):937-940
Stimulated rotational Raman scattering (SRRS) at multiwavelength pumped by TEA CO2 laser was demonstrated in this paper. Raman mediums were cooled by liquid-N2 and a multiple-pass cell (MPC) with 25 passes was designed and used. When the para-H2 was pumped by single-longitudinal-mode
(SLM) circular polarized TEA CO2 laser on 10P(20), 9P(20), and 10R(20), 50 mJ 16.95 μm, 350 mJ 14.44 μm, and 536 mJ 16.9 μm radiations were obtained, corresponding
to energy conversion efficiency of 1.2, 11.7, and 13.4%, respectively. When the ortho-D2 was pumped by CO2 laser on 10R(18), 108 mJ 12.57 μm Raman laser was obtained with energy conversion efficiency of 2.9%. 相似文献
19.
M.?Silies H.?Witte S.?Linden J.?Kutzner I.?Uschmann E.?F?rster H.?Zacharias 《Applied Physics A: Materials Science & Processing》2009,96(1):59-67
The interaction of ultrashort laser pulses with solid state targets is studied concerning the production of short X-ray pulses
with photon energies up to about 10 keV. The influence of various parameters such as pulse energy, repetition rate of the
laser system, focusing conditions, the application of prepulses, and the chirp of the laser pulses on the efficiency of this
highly nonlinear process is examined. In order to increase the X-ray flux, the laser pulse energy is increased by a 2nd multipass
amplifier from 750 μJ to 5 mJ. By applying up to 4 mJ of the pulse energy a X-ray flux of 4×1010 Fe K
α
photons/s or 2.75×1010 Cu K
α
photons/s are generated. The energy conversion efficiency is therefore calculated to η
Fe≈1.4×10−5 and η
Cu≈1.0×10−5. The X-ray source size is determined to 15×25 μm2. By focusing the produced X-rays using a toroidally bent crystal a quasi-monochromatic X-ray point source with a diameter
of 56 μm×70μm is produced containing ≈104 Fe K
α1 photons/s which permits the investigation of lattice dynamics on a picosecond or even sub-picosecond time scale. The lattice
movement of a GaAs(111) crystal is shown as a typical application. 相似文献
20.
A. Majkić G. Poberaj R. Degl’Innocenti M. Döbeli P. Günter 《Applied physics. B, Lasers and optics》2007,88(2):205-209
We report on the production and fluorescence of active channel waveguides in Cr:LiSrAlF6. We have produced ∼10 μm wide and 5 μm high channel waveguides by He+ ion implantation, lithographic patterning and subsequent Ar+ ion sputtering. Diode-pumped waveguides emitted 13 μW of fluorescence light with a spectrum ranging from 760 nm to 900 nm
at a pump power of 165 mW and a pump wavelength of 660 nm. The compact and cheap optical pump source is a main advantage of
this fluorescence material. This makes Cr:LiSrAlF6 channel waveguides a suitable candidate for a broadband fluorescence source in low-coherence interferometry and other applications
in the near-infrared wavelength range.
PACS 42.70.Hj; 42.79.Gn; 42.30.Wb 相似文献