基于PPMgLN晶体低阈值宽调谐红外光参量振荡研究

LOW-THRESHOLD AND WIDE TUNABLE OPTICAL PARAMETRICAL OSCILLATOR BASED ON PERIODICALLY POLED MgO:LiNbO_3 (PPMgLN) CRYSTAL

对基于多周期极化掺镁铌酸锂晶体（PPMgLN）的信号光单谐振准相位匹配光学参量振荡器（QPM—OPO）进行了实验研究．以输出波长为1．064μm的声光调Q Nd：YAG固体激光器作为基频泵浦源对周期为29—31．5μm的多周期掺镁（5mol％）铌酸锂极化光栅进行了光学参量振荡温度、周期调谐实验，光参量振荡阈值功率仅为45mW（重复频率1kHz）．通过温度调谐（20～180℃）与周期调谐（29．0—31．0μm）相结合，实现了调谐范围为1445～1685nm的信号光稳定输出。

Experimental study was presented on signal-resonated quasi-phase matched optical parametric oscillator （OPO） in multi-grating （29.0 - 31.5μm） periodically poled MgO ： LiNbO3 （PPMgLN） pumped by an acousto-optically Q-switched Nd： YAG laser. The threshold is 45mW with pulses repetition rate 1 kHz. Furthermore a tunable infrared （IR） output from 1.445 - 1. 685μm was obtained by tuning the temperature of PPMgLN from 20℃ to 180℃ and tuning the grating of PPMgLN from 29.01.Lm to 31.0μm.