分光镜法激光脉冲展宽器的研制

Development of laser pulse stretcher using beam splitter

在激光分离同位素、激光化学、激光导星（人造星）技术等领域，为了提高脉冲激光的利用效率，需将激光脉冲展宽。介绍了各种光学方法展宽激光脉冲的基本原理，并对由分光镜和反射镜组成的激光脉冲展宽器进行了具体的实验研究，这种展宽器被设计成将脉宽为２０～２５ｎｓ的染料激光脉宽展宽１倍左右。它把原始脉冲分成４个独立的子脉冲，每个子脉冲的幅值是原始脉冲的１／４，但时间序列相继延迟７～１０ｎｓ，然后通过合光镜把这些子脉冲首尾相接堆积成一个脉冲。实验结果表明，脉冲持续时间可增加２０～３０ｎｓ，在波长为５７０～６００ｎｓ的染料激光能量转换效率达８０％以上，对某些波长的能量转换效率甚至超过９０％。

In those fields of Laser Isotope Separation (LIS), laser chemistry, laser guide star (man made star) technology, etc, in order to increase the utility efficiency of the pulse laser, to stretch the pulse duration is needed. Varied optical laser pulse stretchers were analyzed. A laser pulse stretcher composed of beam splitters and mirrors was studied. This stretcher has been designed to double the dye laser pulse duration of 20 to 25 ns width. It is, in fact, a pulse stacker, which breaks up the original pulse into 4 separate pulses, each 1/4 of the original amplitude, and delays each pulse by 7￣10 ns sequentially. The stretcher then stacks all the pulses head to tail, thereby, the effectively increasing the pulse duration of 20 to 30 ns. The energy transfer efficiency of the stretcher is about 80% at wavelength between 570nm and 600nm, even more than 90% in some wavelength region.