腔内CdTe电光调QCO_2窄脉冲激光外差信号特性分析

较详细地研究了腔内CdTe电光调QCO2 窄脉冲激光及其外差信号的时域频域特性,发现它的激光脉冲时域波形有很长的拖尾,拖尾持续时间与CdTe晶体外触发电压开关宽度有关,触发宽度越宽拖尾越长,反之则短。进行了调QCO2 脉冲激光微弱信号检测实验,即将脉冲激光衰减到用直接探测方法无法检测的程度,此时再用外差检测方法,在脉冲包络之内及其拖尾部分观察到了较强的外差中频信号,从实验上验证了外差探测灵敏度远远高于直接探测。根据该激光脉冲拖尾持续时间部分可控的特性,从理论上讨论了CO2 连续激光本振和窄脉冲主振激光外差中频信号频率跟踪和偏频锁定的可行性

Characteristics of Q-switched CO_2 Short-pulse Heterodyne Signal with CdTe Electrooptic Modulator

In this paper, the properties of time and frequency domain of pulsed CO 2 laser difference frequency signals with CdTe electrooptic modulator are studied in detail. The long pulse trailing is found in time domain, and the trailing time bear a relation to outer trigger voltage of CdTe crystal. If it is very weak, the pulse signals can hardly be received through direct detection. In this case, the strong difference frequency signals from pulse trailing will be received if heterodyne detection is used. According to the controllability to trailing time, the possibility of intermediate frequency signals trace and frequency-offset lock between short-pulse transmitter and CW local oscillator light in pulse laser heterodyne is discussed.