高功率准分子激光系统中的放大自发辐射(ASE)会引起主脉冲信号对比度下降，从而导致放大过程中激光脉冲信号对比度下降以及波形展宽和畸变，影响精密物理实验的开展。基于电光开关产生短脉冲的原理，对紫外波段电光开关进行了研究，建立了一种抑制准分子激光放大链ASE的方法。在对主振荡功率放大(MOPA)系统第一级预放大器的削波实验中，单电光开关和双电光开关消光比分别达到了103和104量级，削波后的激光脉冲信号对比度由原来的几十倍分别提高到105和106量级。在单路MOPA系统放大实验中，采用级联双电光开关进行了系统的ASE控制，并最终在靶面获得了良好的窄脉宽放大激光脉冲，为高功率准分子激光系统中波形放大问题提供了一个有效的解决方案。

In high power excimer laser system, the signal contrast ratio is decreased severely by the amplified spontaneous emission (ASE), which decreases the laser pulse signal contrast severely, leads to waveform broadening and distortion, and impacts on the accurate physical experiment. In this paper, based on the principle of the short pulse generation by electro-optical switch, study on ultraviolet electro-optical switch is made, and a method for ASE suppression of the laser amplifier chain is established. In the waveform clipping experiment of the first pre-amplifier in master oscillator power amplifier (MOPA) system, the extinction ratios of the single and cascaded dual electro-optical switches reach 103 and 104 level, and the laser pulse signal contrast ratios are promoted to 105 and 106 level after clipping, respectively. In the experiment of single channel MOPA system, the cascaded dual electro-optical switch is adopted to control the ASE, and an amplified narrow pulse is obtained on the target surface, providing an effective solution to the problem of waveform amplification in the high power excimer laser system.