Jingliang He

Diode-pumped passively Q-switched intracavity frequency doubled Nd:GdVO4/KTP green laser

Abstract A compact diode-pumped passively Q-switched intracavity frequency-doubled Nd:GdVO4/KTP green-pulse laser was demonstrated, using Cr4+:YAG as a saturable absorber in a simple flat–flat cavity. With a 5.9 W incident pump power, a passively Q-switched green laser was obtained with an average power of 397 mW , repetition rate of 40 kHz , and pulse width of 40 ns , when the initial transmission of Cr4+:YAG was 85%. The shortest pulse width of 30 ns , the highest green peak power of 696 W and the maximum pulse energy of 21 μJ were obtained when the initial transmission of Cr4+:YAG was 70%. Under CW green operation, we obtained 440 mW output power.

Efficient diode-pumped Nd:YVO4 continuous-wave laser at 1.34 μm

Summary We report a high-power continuous-wave(cw) diode-pumped efficient 1.34 μm Nd:YVO 4 laser. The laser properties of a low Nd 3+ -doped concentration of the Nd:YVO 4 crystal operating at 1.34 μm formed with a simple plane-concave cavity have been demonstrated. With the incident pump power of 22 W, an output power of 8.24 W was obtained, giving an optical conversion efficiency of 37.5% and slope efficiency of 40%. The thermal effects of cw end-pumped solid-state lasers were studied.

Performance of diode-pumped Nd:Y x Gd 1¿x VO 4 laser

The laser properties of Nd:YxGd12xVO4 crystal are investi- gated. The continuous-wave (cw) laser performance of diode-pumped Nd:YxGd12xVO4 crystal operating at 1.06 mm and that intracavity second-harmonic generation (SHG) with a KTP crystal into the green spectral range at 532 nm are studied. Also the pulse characteristics of Nd:YxGd12xVO4 laser crystal are reported. A diode-pumped compact and efficient Cr 41 :YAG passively Q-switched Nd:YxGd12xVO4 laser formed by a simple flat-flat resonator is demonstrated. The dependence of the operational parameters on the pump power is also investigated experimentally.

Low-threshold and highly efficient diode-pumped cw passively mode-locked Nd:YVO 4 laser with a saturable Bragg reflector

We report a diode-end-pumped 1064-nm Nd:YVO4 laser passively cw mode-locked by a semiconductor saturable absorber mir- ror. We designed a long cavity with relatively small mode size in the gain medium so that stable passive mode locking without Q-switching insta- bilities became possible under low pump power. At 2.42 W of pump power a mode-locked fundamental-mode average output power of 742 mW was attained with an overall optical-optical efficiency of 31%. The pulse duration was 9.1 ps as measured at the repetition rate of 58 MHz.

Generation of UV radiation at 335.5 nm based on frequency-quadrupling of a diode-pumped Nd:YVO 4 laser

The generation of ultraviolet (UV) light at 335.5 nm based on frequency quadrupling of a diode-end-pumped Q-switched Nd:YVO4 laser at 1342 nm was demonstrated. KTP crystal was used for generation of wavelength of 671 nm by intracavity doubling and LBO (BBO) crystal was exploited for the subsequent external fourth harmonic generation (FHG). With 6.3-W absorbed pump power and 10-kHz frequency repetition rate, the UV output power of 35 and 63 mW were obtained by using LBO and BBO as frequency quadrupling nonlinear crystals, respectively. The experimental results show that the conversion efficiency (red-UV) of 6.4% for BBO crystal is higher than that of 3.5% for LBO crystal, but the UV beam quality obtained by LBO crystal is better than by BBO crystal.

Continuous transform of transverse modes and transitional status analysis in solid-state laser.

With the agility of cavity control in solid-state-laser, we report abundant experimental phenomena of relatively complete Laguerre-Gaussian (LG) transverse multimodes transformation process including both stable and transitional status in a diode pumped Nd:YVO4 microcavity laser. Cavity structure, absorber, pump power, etc, synthetically have been found to contribute such abundant generation of patterns.