Intracavity Frequency-Doubled and Frequency-Stabilized CW Ring Nd:YAP Laser

A frequency-doubled and frequency-stabilized ring Nd:YAP laser with a six-mirror cavity is demonstrated. This laser satisfies both the thermal insensitivity and optimal frequency-doubling conditions. A second-harmonic output to 1 W at 0.54 mum is achieved. The intensity fluctuation is less than ?1.5% and the frequency stability is better than ?1 MHz (5 min).     

Intracavity frequency doubling and Q switching in diode-laser-pumped Nd:YVO(4) lasers

A highly efficient and compact Nd:YVO(4) laser is proposed. In cw operation, a single-longitudinal-mode output of 95 mW and a multilongitudinal-mode output of 435 mW have been observed at 1.06 μm with a 1-W diode laser. Using a KTP crystal in the short laser cavity, a green output of 105 mW was generated. A Q-switched pulse with a peak power of 230 W and a pulse width of 8 ns was obtained with the intracavity KTP crystal, which was used as both an electro-optic Q switch and a frequency doubler.     

Efficient High-Power Green Beam Generation by Use of an Intracavity Frequency-Doubled Laser-Diode-Pumped Q-Switched Nd:YAG Laser

An intracavity frequency-doubled diode-side-pumped Nd:YAG laser has been developed. A maximum green power of 20 W was generated at 20-kHz repetition rate with 14.2% optical-to-optical conversion efficiency and 5.3% electrical-to-optical conversion efficiency.     

Periodic pulse oscillation in an intracavity-doubled Nd:YVO(4) laser

We report periodic pulse oscillation in an intracavity-doubled Nd:YVO(4) laser. The pulse oscillation is caused by alternate oscillation between two modes. We investigated improvement of green-light power with the pulse oscillation in a Nd:YVO(4) laser. The pulse oscillation gave a factor of approximately 2 higher average green-light power than that for cw oscillation at the same pumping power.     

Highly Efficient 68-W Green-Beam Generation by Use of an Intracavity Frequency-Doubled Diode Side-Pumped Q-Switched Nd:YAG Rod Laser

An intracavity frequency-doubled diode side-pumped Nd:YAG laser was developed by use of an advanced cavity configuration and a diffusive close-coupled side-pumping design. A maximum green power of 68 W was generated at a 20-kHz repetition rate with 18.4% optical-to-optical conversion efficiency and 7.1% electrical-to-optical conversion efficiency.     

LD泵浦Nd：YVO4内腔倍频激光器获得120mW绿光连续输出

利用半导体激光器（ＬＤ）端面泵浦Ｎｄ：ＹＶＯ＿４和用ＫＴＰ内腔倍频的绿激光器获得了１２０ｍＷ连续、稳定的５３２ｎｍ绿激光输出。泵浦阈值Ｐ＿（ｔｈ）＝１６０ｍＷ，光－光转换效率η＿ｓ＝８．１％。换用激光腔输出耦合镜，在不加ＫＴＰ晶体倍频时，可连续输出１．０６μｍ的红外激光，输出功率为４５０ｍＷ，光－光转换效率为３１％。     

Compact and Efficient 3.2-W Diode-Pumped Nd:YVO(4)/KTP Green Laser

We demonstrate a simple way to achieve single-frequency operation by using fiber-coupled diode-pumped Nd:YVO(4)/KTP green lasers in a short standing-wave linear cavity. A single-mode output with 3.2-W green power was generated with a 12.6-W pump power corresponding to a conversion efficiency of 25.4%. The single-mode operation was obtained through the combined action of the anisotropic emission cross section of Nd:YVO(4) and the KTP crystal acting as a birefringent filter.     

二极管近贴泵浦Nd∶YVO4/Cr∶YAG被动调Q激光器

报道了采用国产1W连续激光二极管近贴式泵浦Nd∶YVO4晶体,慢饱和吸收体Cr∶YAG 被动调Q结构的全固体、高效率、高稳定性、高重复频率1064nm红外激光器.在注入泵浦功率为600mW时,得到平均功率138mW、脉冲宽度19.8ns、重复频率170.1kHz、峰值功率40.96W的被动调Q红外激光输出.在平均功率100mW下连续运转1小时,测得脉冲峰值稳定性优于1.8%,周期稳定性优于2%.     

Efficient Operation of an Intracavity-Doubled Nd:YVO(4)/KTP Laser End Pumped by a High-Brightness Laser Diode

Using a 1-W high-brightness laser diode as the pump source, we investigated the output characteristics of an intracavity frequency-doubled Nd:YVO(4)/KTP laser. Highly efficient operation was realized based on an optimized cavity design. The second-harmonic output power at 532 nm was measured to be 286.5 mW at an incident pump power of 881.4 mW, corresponding to an optical-to-optical efficiency of 32.5%.     

Simultaneous Mode Locking in a Diode-Pumped Passively Q-Switched Nd:YVO(4) Laser with a GaAs Saturable Absorber

Simultaneous mode locking and Q switching is accomplished in a diode-pumped Nd:YVO(4)/GaAs laser. The average output power is ~2.0 W at 10.6-W absorbed pump power, and the repetition rate of the Q-switched pulse is ~120 kHz. The mode-locked pulse inside the Q-switched pulse has a repetition rate of ~148 MHz, and its average duration is estimated to be ~100 ps.     

Passively Q-switched multi-wavelength Nd:YVO4 self-Raman laser

Abstract

Multi-wavelength self-Raman laser from a passively Q-switched c-cut Nd: YVO₄ laser at 1066.8 nm to four discrete Stokes lines at 1097.2, 1129.2, 1168.3 and 1178.8 nm is demonstrated simultaneously for the first time. With a 0.27 at% c-cut Nd:YVO₄ crystal, the total output power of Stokes lines is 267 mW at a pump power of 5.0 W.     

Nd:YVO4/KTP激光碘分子超精细光谱和稳频研究

用Nd：YVO4／KTP腔内倍频环形激光器产生的532nm波长激光，探测到了波长在532．170nm至532．200nm范围的一系列碘的多普勒吸收谱线和饱和吸收谱线。理论计算出相应的波长值和超精细谱线结构参数。理论计算值与实验测量数据在较高的精度内相一致。用三次谐波锁定的稳频电路实现了该激光器在碘饱和吸收线超精细分量上的频率稳定。     

Semianalytical thermal analysis on a Nd:YVO(4) crystal

Based on analytical theory of anisotropy, distributions of thermal distortion and temperature field within a diode-end-pumped rectangular Nd:YVO(4) laser crystal are investigated. A thermal model that matches the actual working state of the laser crystal is established by analyzing the working characteristics of the Nd:YVO(4) laser crystal. A novel method, to the best of our knowledge, is adopted to solve the heat conduction equation of the anisotropic medium. General solutions of the temperature field, thermal strain field, and thermal distortion field of the Nd:YVO(4) crystal are obtained. The effect of anisotropic thermal parameters on the thermal strain field of the Nd:YVO(4) laser crystal is also analyzed quantitatively. Research results show that a maximum temperature rise of 244.9 degrees C and a maximum thermal distortion of 1.99 mum can be obtained in the center of the pump face when the Nd:YVO(4) laser crystal doped with 0.5 at. % Nd(3+) is diode end pumped in the center of the front end face with 15 W output power. This method can be applied to other thermal analyses of laser crystals and offers a theoretical basis to solve thermal problems effectively in the laser system.     

Double-end-pumped Nd:YVO4 slab laser at 1064 nm

We demonstrate a high-power laser diode stacks double-end-pumped Nd:YVO4 1064 nm slab laser with a folded stable-unstable hybrid resonator. An output power of 220 W was obtained at the pump power of 490 W with optical conversion efficiency of 44.9%. At the output power of 202 W, the M2 factors in the unstable direction and in the stable direction were 1.7 and 2.3, respectively.     

Comparison on performance of passively Q-switched laser properties of continuous-grown composite GdVO4/Nd:GdVO4 and YVO4/Nd:YVO4 crystals under direct pumping

The comparison on performance of passively Q-switched laser properties of continuous-grown composite GdVO(4)/Nd:GdVO(4) and YVO(4)/Nd:YVO(4) crystals under direct pumping to the emitting level was demonstrated. A Cr(4+):YAG crystal was used as saturable absorber. At an incident pump power of 10 W, the average output power, the pulse width, the repetition rate, the pulse energy, and the peak power for a GdVO(4)/Nd:GdVO(4) laser were 1.22 W, 48.1 ns, 121 kHz, 10.1 μJ, and 209.6 W, respectively. And for a YVO(4)/Nd:YVO(4) laser under the same conditions, these output characteristics were 1.26 W, 44.9 ns, 218 kHz, 5.8 μJ, and 128.7 W, respectively.     

High-repetition rate Q-switched Nd:YVO4 laser with a composite semiconductor absorber

A diode-pumped Nd:YVO4 laser passively Q switched by a semiconductor absorber is demonstrated. The Q-switched operation of the laser has an average output power of 135 mW with a 1.6 W incident pump power. The minimum pulse width is measured to be about 8.3 ns with a repetition rate of 2 MHz. To our knowledge, this is the first demonstration of a solid-state laser passively Q-switched by such a composite semiconductor absorber.     

Transverse-mode astigmatism in a diode-pumped unstable resonator Nd:YVO(4) laser

We have observed a sizable astigmatism in the output beam from a diode-pumped unstable resonator Nd:YVO(4) laser operating in a single polarization and a single-longitudinal and transverse mode. The anisotropic index of refraction of the vanadate crystal has been identified as the source of this astigmatism. A theoretical prediction of the eigenmode astigmatism based on this index anisotropy is consistent with our experimental measurements.     

Efficient High-Pulse-Energy Green-Beam Generation by Intracavity Frequency Doubling of a Quasi-Continuous-Wave Laser-Diode-Pumped Nd:YAG Laser

A 50-mJ green beam was generated at a 1-kHz repetition rate by intracavity frequency doubling of a quasi-cw laser-diode-pumped Nd:YAG laser. The green laser was used for 12-mJ fourth-harmonic beam generation with a CsLiB(6)O(10) crystal.     

Crystal growth and morphology of Nd:YVO4 under hydrothermal conditions

Neodymium doped yttrium orthovanadate single crystals have been obtained from hydrothermal solutions. Systematic investigations of the role of pH of the growth media, mineralizer type and experimental temperature have been carried out with reference to the growth of Nd:YVO₄ crystals. The crystal growth mechanism has been proposed for the growth of Nd:YVO₄ crystals from hydrothermal solutions. The crystals obtained have been subjected to powder X-ray diffraction, morphological, EDAX and FTIR studies.     

Compact and efficient Nd:YVO 4 laser that generates a tunable single-frequency green output

We demonstrate 250 mW of single-frequency 532-nm output from a simple intracavity-doubled Nd:YVO(4) laser, pumped with 1.2 W from a fiber-coupled diode laser. The laser can be frequency chirped smoothly over ~17 GHz while maintaining a single-frequency green output of greater than 200 mW. A short Fabry-Perot cavity is used, and single-frequency operation is enforced by means of a birefringent filter that utilizes the birefringence of both the KTP doubling crystal and the Nd:YVO(4) laser crystal with polarization-dependent loss from a glass Brewster plate combined with polarization-dependent gain from the laser crystal.