基于周期极化铌酸锂晶体的高功率可调谐光参量振荡器

High-Power Temperature-Tunable Periodically-Poled Lithium Niobate Optical Parametric Oscillator

研究了镁掺杂周期极化铌酸锂晶体光学参量振荡(PPMgLN-OPO)产生高功率、高重复频率中红外激光的特性。采用半导体激光器(LD)抽运的声光调Q Nd:YAG激光器,1064 nm准连续激光功率最大输出为7.8 W.重复频率5～50 kHz。产生1064 nm调Q光,抽运周期为30.7μm的掺氧化镁(摩尔分数为5%)周期性极化铌酸锂晶体,温度变化范围为40～200℃,实现了短腔双谐振红外高功率激光输出。实验中近红外激光波长调谐范围为1570～1676 nm,最高输出功率613 mW;中红外输出波长范围为2942～3300 nm,中红外光平均功率也达到了百毫瓦级,信号光单脉冲能量达40μJ;光-光(LD-信号光)转换效率为3.4%。

A high rate and high-power optical parametric oscillator is experimentally demonstrated. 1064 nm Qswitched Nd： YAG laser is pumped by laser diode （LD） laser. The maximal output power is 7.8 W with the pulses repetition rate range of 5-50 kHz. Optical parametric oscillator （OPO） based on periodically-poled lithium niobate （PPMgLN） pumped by the 1064 nm Q-switched Nd： YAG laser. Periodically poled grating （A = 30.7 gm） was successfully fabricated in 1, 0 mm thick MgO： LiNbO3 （doped 5% MgO）. The output infrared wavelength will change because of the expansion coefficient of PPLN material when the operating temperatures fluctuate from 40 to 200 ℃. The tuning dimensions of the infrared wavelength are 1570-1676 nm and 2942-3300 nm with the signal maximal power of 613 roW. Several hundred milliwatt of output idler average power was obtained by using short and dual-cavity, the energy of single pulse is 40 μJ, and the conversion efficiency is 3.4 %.