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1.
Single axial mode operation (<200 MHz optical bandwidth) of a high repetition rate periodically poled lithium niobate optical
parametric oscillator (OPO) has been obtained at signal wavelengths between 1.46 μm and 1.64 μm. OPO signal slope efficiencies
of 35% have been measured for repetition rates of 5–20 kHz. Single mode operation required spectral narrowing of both the
pump laser and the OPO. A simple technique of prelase Q-switching was implemented to reduce the optical bandwidth of the cw diode-pumped Nd:YAG pump laser to <1 GHz. A single intracavity
étalon was then sufficient to ensure single frequency oscillation of the OPO signal. The OPO output was stable with a smooth
spatial profile and an M
2 value of 1.3.
Received: 29 September 1999 / Published online: 27 January 2000 相似文献
2.
Output performances of passively Q-switched, composite Nd:YAG/Cr4+:YAG lasers that consisted of bonded, all-poly-crystalline ceramics Nd:YAG and Cr4+:YAG are reported. Laser pulses at 1.06 μm with 2.5-mJ energy and 1.9-MW peak power are obtained from a 1.1-at % Nd:YAG/Cr4+:YAG ceramics that was quasi-continuous-wave (quasi-CW) pumped with a diode laser. Single-pass frequency doubling with LiB3O5 (LBO) nonlinear crystal at room temperature yielded green laser pulses at 532 nm of 0.36-mJ energy and 0.3-MW peak power,
with a conversion efficiency of 0.27. 相似文献
3.
C. Li J. Song D. Shen N.S. Kim J. Lu K. Ueda 《Applied physics. B, Lasers and optics》2000,70(4):471-474
With a 10-W diode laser to pump Nd:GdVO4 crystal in a folded cavity, we demonstrated Cr4+:YAG passively Q-switched Nd:GdVO4 lasers at 1.06 μm. The maximum average output power of 2.1 W and the highest peak power of 625 W were, respectively, obtained
when the initial transmissions of the Cr4+:YAG crystals were 90% and 80%.
Received: 8 September 1999 / Revised version: 30 December 1999 / Published online: 8 March 2000 相似文献
4.
N. Pavel V. Lupei J. Saikawa T. Taira H. Kan 《Applied physics. B, Lasers and optics》2006,82(4):599-605
Laser emission in the 0.94-, 1.06- and 1.34-micron ranges in diluted and concentrated Nd:YAG crystals longitudinally pumped by a 885-nm diode laser on the 4
I
9/2→4
F
3/2 transition is investigated. Continuous-wave operation at watt level in all these wavelength ranges is demonstrated with a 1.0-at. % Nd:YAG crystal; however, the laser performance is impeded by the low pump absorption efficiency. Improved output power and overall efficiency were obtained with a highly doped 2.5-at. % Nd:YAG crystal: 5.5 W at 1.06 μm and 3.8 W at 1.34 μm with 0.38 and 0.26 efficiencies, respectively. Comparative results with traditional pumping at 809 nm into the highly absorbing 4
F
5/2 level are presented, showing the advantage of the direct 4
F
3/2 pumping. The influence of the lasing wavelength and of the Nd concentration on the thermal effects induced by the optical pumping in the laser material is discussed. A clear relation between the heat generated in the Nd:YAG crystals in lasing and non-lasing regimes, a function of the Nd doping, is demonstrated. PACS 42.55.Rz; 42.60.By; 42.60.Da 相似文献
5.
Z. Librant J.K. Jabczyński H. W?glarz A. Wajler H. Tomaszewski T. ?ukasiewicz W. ?endzian J. Kwiatkowski 《Opto-Electronics Review》2009,17(1):72-77
Transparent Nd:YAG ceramics were produced by solid.state reaction of high.purity (4N) nanometric oxides powders, i.e., Al2O3, Y2O3 and Nd2O3. After sintering, mean grain sizes of 2% Nd:YAG samples were about 20 μm and their transparency were a bit worse than that
of 0.9% Nd:YAG single crystal. Two types of active elements: rods and slabs were fabricated and characterized in several diode
pumping schemes. In end pumping configuration as a pump source 20.W fiber coupled laser diode operating in low duty cycle
regime (1 ms pump duration/20 Hz) was deployed. In the best case, 3.7 W of output power for 18 W of absorbed pump power, M2 < 1.4 were demonstrated for uncoated ceramics Nd:YAG rod of ϕ 4×3mm size in preliminary experiments. For the ceramics of
two times lower Nd dopant level above 30% slope efficiency was achieved. In case of Nd:YAG ceramic slab side pumped by 600.W
laser diode stack above 12 W was demonstrated with slope efficiency of 3.5%. 相似文献
6.
Diode end-pumped Q-switched high-power intracavity frequency-doubled Nd:GdVO4/KTP green laser 总被引:2,自引:0,他引:2
J. Liu C. Wang C.Q. Wang X. Meng H. Zhang L. Zhu J. Wang Z. Shao M. Jiang 《Applied physics. B, Lasers and optics》2001,72(2):171-174
A diode-laser-array end-pumped acousto-optically Q-switched intracavity frequency-doubled Nd:GdVO4/KTP green laser, formed with a three-mirror folded resonator, has been demonstrated. With 15 W of pump power incident upon
the Nd:GdVO4 crystal, a maximum average green output power of 3.75 W was obtained at 50 kHz of pulse repetition frequency, giving an optical
conversion efficiency of 25%, whereas the effective intracavity frequency-doubling efficiency was determined to be 72%. At
the incident pump power of 12.8 W, the shortest laser pulse was achieved at a pulse repetition rate of 10 kHz, the resulting
pulse width, single pulse energy, and peak power were measured to be 35 ns, 108 μJ, and 3.1 kW, respectively.
Received: 18 May 2000 / Published online: 20 September 2000 相似文献
7.
Hua Gong Jian Zhang Ding-Yuan Tang Guo-Qiang Xie Hui Huang Jan Ma 《Journal of nanoparticle research》2011,13(9):3853-3860
Well-dispersed Nd:Y2O3 powders with uniform particle size of about 60 nm were synthesized from freeze-dried precursors. Highly transparent 2 at.%
Nd:YAG ceramics were fabricated from the as-synthesized Nd:Y2O3 powders and commercial Al2O3 powders by vacuum sintering at 1,750 °C for 5 h. Phase evolution, microstructures, and spectroscopic properties of the Nd:YAG
transparent ceramics were investigated. Freeze-drying played an important role in the synthesis of high-quality Nd:Y2O3 nanosized powders, which were essential for the fabrication of highly transparent Nd:YAG ceramics. Optical transmittance
of a 3-mm thick sample reached 82% in the wavelength range of 200–900 nm. 5.23 W output power was obtained with 14.3 W diode
laser pumping, giving a slope efficiency of 36.5%. 相似文献
8.
M. Stanislawki J. Meister T. Mitra M.M. Ivanenko K. Zanger P. Hering 《Applied physics. B, Lasers and optics》2001,72(1):115-120
The Er:YAG and the CO2 laser are competitors in the field of hard tissue ablation. The use of Er:YAG lasers (2.94 μm, pulse length
L of 100 to 200 μs) show smaller areas of thermal defects then ‘‘superpulsed’’ CO2 lasers with pulse lengths of approximately 100 μs. Only the development of a Q-switched CO2 laser (9.6 μm, τL=250 ns) allowed for similar results. In this paper new results for the Er:YAG and the Q-switched CO2 laser under the influence of water spray will be presented. Several parameters are of special interest for these investigations:
the specific ablation energy, which shows a minimum for the CO2 laser at an energy density of 9 J/cm 2 and a broad shallow minimum in the range of 10 to 70 J/cm2 for the Er:YAG laser, and comparison of the cut-shape and depth. Surface effects and cutting velocity are discussed based
on SEM pictures.
Received: 19 July 2000 / Revised version: 1 November 2000 / Published online: 30 November 2000 相似文献
9.
Operation of a 1.598-μm eye-safe third-Stokes Raman laser with a Ba(NO3)2 crystal pumped by a 1.064-μm Nd:YAG laser is described. We observed a substantial decrease in the output energy during the
first 50 s of the continuous operation at 20 Hz. The energy drop is ∼76% of the initial third-Stokes output. We confirmed
negative thermal lensing and thermally induced birefringence in the crystal. With a concave cavity mirror at a matched curvature
to the thermal lensing, we obtained an output energy of 11 mJ at 20 Hz. TEM00 output was also obtained with a smaller pump-beam diameter with a highest conversion efficiency of 15.5% for a pumping power
of only 45 MW/cm2 (0.9 J/cm2).
Received: 20 November 2001 /
Revised version: 20 February 2002 / Published online: 2 May 2002 相似文献
10.
D. Mazzotti P. De Natale G. Giusfredi C. Fort J.A. Mitchell L.W. Hollberg 《Applied physics. B, Lasers and optics》2000,70(6):747-750
We report difference-frequency generation (DFG) in periodically poled lithium niobate (PPLN) around 4.25 μm using a cw Nd:YAG
and an injection-locked diode laser. This system provides a narrow linewidth source at 4.25 μm with near-shot-noise-limited
operation. A conversion efficiency close to the theoretical limit is obtained. Detection of CO2 absorption spectra is demonstrated and further improvements and applications to high sensitivity spectroscopy are discussed.
Received: 12 August 1999 / Revised version: 21 January 2000 / Published online: 24 March 2000 相似文献