由级联紫外电光开关控制准分子激光的自发辐射放大

第21卷第1期2013年1月Vol. 21 No. 1Jan. 2013光学精密工程Optics and Precision Engineering文章编号 1004-924X(2013)01-0013-07由级联紫外电光开关控制准分子激光的自发辐射放大胡 云*,赵学庆，薛全喜，王大辉，郑国鑫(西北核技术研究所激光与物质相互作用国家重点实验室，陕西西安710024)摘要：考虑高功率准分子激光系统的自发辐射放大(ASE)会导致上脉冲信号对比度下降引起波形展宽和畸变本文开 展了级联双电光开关的研究来抑制ASE的产生并提髙激光脉冲信号的信号对比度。探讨了电光开关的级联工作模式. 分析了影响电光开关削波对比度的因素进而提出采用级联工作方式来大幅度地提高削波对比度。在单电光开关的基 础上设计了级联电光削波的光路布局。其中曲一级电光开关的检偏器作为后一级的起偏器电路则采用分立式以避 免相互之间的串扰。采用级联双电光开关对低占空比预放大器进行了 ASE控制实验。实验结果显示，级联双电光开关 的削波对比度达到了 10°按级而预放大器的放大输出信号对比度提岛到106 fit级此结果有利于激光脉冲信号在系统 中后续放大级的进一步放大。关 键 词：高功率澈光器；准分子激光器'级联电光开关；自发辐射；对比度 中图分类号:TN248.2文献标识码；Adoi： 10. 3788/OPE. 20132101.0013Suppression of ASE from excimer laser using cascaded UVelectro-optical switchHU YunB , ZHAO Xue-qing, XUE Quan-xi, WANG Da-hui, ZHENG Guo-xin(State Key Laboratory of Laser Interaction with MatterNorthwest Institute of Nuclear Technology 9 Xian 710024 China* Corresponding author . E-mail huyunmail. ustc. edu cnAbstract： A cascaded elcctro-optical(E-O) switch was studied to suppress Amplified Spontaneous E- mission (ASE) and promote the signal contrast of the laser pulse, because the ASE could decrease the signal contrast ratio and widen the waveform and distortion in a high power excimer laser severely. The cascaded mode of the E()switch was explored, the factors that effect on signal contrast ratio of the E-O switch were analyzed, then the work mode using the E-0 switch cascaded was proposed to promote the contrast ratio of the switch. On the basis of a single switch» the cascaded E-O switch layout was designed The analyzer of the first switch was used as the polarizer of the following one, and the driving power supply was installed discretely to avoid the crosstalk An experiment on ASE suppression for the low duty cycle of a pre-amplifier was performed using a cascaded double E-O switch. The results show that the contrast ratio of the cascaded switch reaches 104 level and the signal contrast ratio of the pre-amplifier output pulse reaches 10" level > which is beneficial to the amplification of laser pulse signals in following amplifier stages of the system.Key words： high power laser； excimer laser； cascaded electro-optical switch； spontaneous emission； contrast ratio收稿日期：2012-06-08;修订日期：2012-08-29.基金项目：激光与物质相互作用国家遠点实验室基金资助项目(No. SKLLIM1307)