高稳定激光二极管抽运Nd∶YLF再生放大器

设计并实现了一种放大纳秒激光脉冲的高稳定的激光二极管(LD)抽运Nd∶YLF再生放大器。为了获得高稳定的输出,再生放大器工作在饱和状态。此时,再生放大器输出稳定性最好,而且注入激光脉冲能量波动引起的输出激光脉冲波动被抑制。由于增益饱和效应,再生放大器输出脉冲出现时域波形失真,附加后缀脉冲能够减弱时域波形失真。放大器工作波长1053nm,工作频率1Hz。输入240pJ的3ns方波激光脉冲,输出激光脉冲能量4.2mJ,总增益大于107,不稳定度小于1%(均方根),方波扭曲1.33。为3ns方波激光脉冲引入其本身幅度0.75倍的后缀脉冲,输出激光脉冲方波扭曲由1.33降至1.17。

A highly stable, laser diode (LD)-pumped. all-solid-state Nd:YLF regenerative amplifier applied to amplify a nanosecond laser pulse is designed and realized. The maximum output energy and the best stability of the regenerative amplifier can be obtained when it operates in a saturated mode for all pulse duration and temporal profiles. In addition to the excellent stability, the output laser pulse fluctuation caused by the injected pulse energy fluctuation is inhibited. Extra post-pulse can decrease the temporal pulse profile distortion caused by the gain saturation effect. When the regenerative amplifier is seeded with a 240 pJ, 3 ns optical pulse, output energy of 4.2 mJ with an overall energy gain more than 10⁷ and output energy unstability better than 1% (root-mean-square) are obtained. When an extra post-pulse with amplitude of 0.75 times of the seed pulse is added for a 3 ns optical square seed pulse, the square-pulse distortion is decreased from 1.33 to 1.17.