用光再生式电光调Q获得稳定的激光输出,是一种简易可行的方法。但这种方法必然有前置激光脉冲;也容易导致后置激光脉冲。这种缺点限制了这一方法在激光放大和测距等方面的应用。我们提出的轴向超辐射Q开关,克服了光再生方法中的不足。它的原理是,在脉冲电光调Q激光器的光泵过程中,一定的轴向超辐射强度对应激活介质中一定的反转粒子数。只要控制接收器中超辐射的光电转换电平,就能控制打开Q开关时的反转粒子数,也就能稳定输出的巨脉冲激光。在激光阈值附近,改变氙灯电压,测得超辐射Q开关激光峰值幅度变化小于线路延迟开关变化的四分之一。在同一氙灯电压时,超辐射Q开关的激光输出重复性也有所改进。

The optically regenerative Q-switch method, by which the laser output can be stabilized, is simple and easy to operate. But the disadvantages of laser prepulses inevitable and the successive pulses easily produced severely limit the applications of this method to laser amplifiers and laser range-finders. To overcome these shortcomings we have designed a new method using axial superradiant signal to trigger the Q-switoh. The principle is as follows: The superradiant signal intensities near the axial correspond to certain population during the laser process of the optical pumping. So we can oontrol the population whioh can trigger the Q-switch by controlling the superradiant convert electrioal level in the superradiant deteotor and then the laser output can be stabilized. ISfear the laser threshold the variation of peak heights of laser pulses controlled by ■superradiant signal triggered Q-switch is reduce^ to only 1/4 of original value when we change the voltage of xenon-flash lamp near the laser threshold. The laser output reproducibility may also be improved by this method.