Chen Weibiao

High-Efficient Nd:YLF Q-Switched Laser Operating at 523.5 nm

An intracavity frequency doubling electro-optically Q-switched Nd:YLF 523.5 nm laser is developed. An appropriate cylindrical lens is employed in the oscillator to optimize the mode size and to improve the stability of the cavity. With an incident pump pulse energy of 58 mJ at a 500 Hz repetition rate, a green pulse energy of 16.8 mJ at 523.5 nm is obtained, corresponding to an optical-optical conversion efficiency of 29%. The pulse width is less than 8 ns, and the beam quality factor is M2 ≤ 2.5.

A Q-Switched All-Solid-State Single-Longitudinal-Mode Laser with Adjustable Pulse-Width and High Repetition Rate

A single-longitudinal-mode (SLM) laser-diode pumped Nd: YAG laser with adjustable pulse width is developed by using the techniques of pre-lasing and changing polarization of birefingent crystal. The Q-switching voltage is triggered by the peak of the pre-lasing pulse to achieve the higher stability of output pulse energy. The output energy of more than 1 mJ is obtained with output energy stability of 3% (rms) at 100 Hz. The pulse-width can be adjusted from 30 ns to 300 ns by changing the Q-switching voltage. The probability of putting out single-longitudinal-mode pulses is almost 100%. The laser can be run over four hours continually without mode hopping.

A Kilowatt Diode-Pumped Solid-State Heat-Capacity Double-Slab Laser

A kilowatt diode-pumped solid state heat capacity laser is fabricated with a double-slab Nd:YAG. Using the theoretical model of heat capacity laser output laser characteristics, the relationships between the output power, temperature and time are obtained. The slab is 59×40×4.5 mm3 in size. The average pump power is 11.2 kW, the repetition rate is 1 kHz, and the duty cycle is 20%. During the running time of 1 s, the output energy of the laser has a fluctuation with the maximal output energy at 2.06 J, and the maximal output average power is 2.06 kW. At the end of the second, the output energy declines to about 50% compared to the beginning. The thermal effects can be improved with one slab cooled by water. The experimental results are consistent with the calculation data.

A 5.9-mJ 500-Hz Electro-Optic Q-Switched 1053 nm Nd:LiLuF4 Laser

An efficient and high power 1053 nm electro-optic Q-switched Nd:LiLuF4 laser, end-pumped by two fiber coupled laser diodes at wavelength 806 nm, is reported for the first time. With an incident pump power of 24.4 W, the maximum laser output power of 7.3 W is achieved in free-running mode, and the optical conversion efficiency is 29.8%. For the Q-switched operation, the shortest pulse width of 17 ns is obtained at the pulse repetition rate of 500 Hz, corresponding to the pulse energy of 5.9 mJ with the peak power of 0.35 MW.

A Compact Diode-Pumped Injection Seeded Nd:YAG Laser with Resonance-Detection Technique

A diode pumped injection seeded single-longitudinal-mode (SLM) Nd:YAG laser is achieved by using the resonance-detection technique in Q-switching operation. The pulsed oscillator laser uses a folded cavity to achieve compact construction. This system operates at 100?Hz and provides over 20?mJ/pulse of single-frequency 1064?nm output. The M2 values of horizontal and vertical axes are 1.58 and 1.41, respectively. The probability of putting out single-longitudinal-mode pulses is 100%. The 355?nm laser output produced by frequency tripling has a linewidth less than 200?MHz. The laser can run over eight hours continually without mode hopping.