激光二极管抽运声光调Q高重复频率532 nm激光器

实现了重复频率高达105kHz的紧凑的全固态声光(A-O)调Q532nm腔内倍频激光器。激光器使用Nd：YVO4作为激光晶体，Ⅱ类匹配的KTP为倍频晶体，声光器件材料为熔融石英，由自制的声光驱动器驱动，其最大射频输出功率为7．5W，重复频率1Hz～105kHz可调。使用1W的激光二极管(LD)抽运，50kHz重复频率下，得到平均功率达224mW的532nm脉冲激光稳定平均输出，总光-光转换效率高达22．4％。低重复频率下，可以实现脉宽为17．2ns，峰值功率为470W，单脉冲能量为8．1μJ的稳定运转。给出了平均功率与重复频率关系的一般公式，并提出即使是在四能级系统中，有效储能时间也并不等于上能级寿命，理论计算结果与实验结果吻合得很好。

LD-pumped Acousto-optically Q-switched 532 nm Laser with High Repetition Rate

A compact, all solid-state and high repetition rate as up to 105 kHz acousto-optic (A-O) Q-switched intracavity frequency-doubled 532 nm laser is demonstrated. A Nd∶YVO4 crystal is used as active media and a type-Ⅱ KTP (KTiPO4) as frequency doubler, The Q switcher is made by fused silica and driven by a driver whose maximal rf output power is 7.5 W and repetition rate is variable from 1 Hz to 105 kHz, which is made by our own. 224 mW of 532 nm average power at a repetition rate of 50 kHz was generated with a 1 W laser diode (LD) as pump source, and a high optical-to-optical conversion efficiency of 22.4% was obtained. Under low repetition rate, steady operation is achieved with pulse width of 17.2 ns, peak power of 470 W and single pulse energy of 8.1 μJ. A general formula of average-power as a function of pulse repetition rate is presented which has good agreement with the experiment results. Analysis and experimental verification showed that, even in four-level system, the effective storage time is not equal to the upper state lifetime.