圆片激光器中放大的自发辐射现象  

Amplified spontaneous emission in disk lasers

作　　者：王小军[1] 苏华[1] 蔡震[2] 

机构地区：[1]北京应用物理与计算数学研究所,北京100088 [2]中国工程物理研究院应用电子学研究所,四川绵阳621900

出　　处：《强激光与粒子束》2011年第8期1998-2004,共7页High Power Laser and Particle Beams

基　　金：中国工程物理研究院基金项目(2010B0401059)

摘　　要：研究了谐振腔式圆片激光器中放大的自发辐射(ASE)和寄生振荡的物理特征及一些抑制措施的效果。使用解析方法分析了圆片介质中本征寄生模式,指出非平庸的色散关系只允许有限数目稳态纵寄生模存在,使其与主激光进行纵模竞争时处于不利地位。研发了一套数值模拟方法对ASE、寄生振荡和主激光的耦合成长特性进行理论研究,分析了它们之间横模竞争的特点,指出弛豫振荡在ASE效应中扮演重要的角色。并且从实验和理论两方面研究了ASE吸收包边导致的热加载不均匀问题。Amplified spontaneous emission（ASE） and parasitic oscillation in laser resonators exhibit distinct physical proper ties. An analytic method is employed to find eigenmodes of disk medium. These modes processes some non trivial dispersion rela tions, which allow few stable longitudinal modes only. It decreases amplifying rate of parasitic oscillation in mode competition with main laser. A numerical model is further proposed to perform （3 ＋1） dimensional simulations. Ray tracing method, together with finite-difference in time domain and Fox-Li type iteration, are used to solve a set of coupled equations. Transverse mode corn petition between ASE/parasitic oscillations and main laser increases threshold to establish laser oscillation and decreases output power as well. Time evolution of laser output exhibits a strenuous relaxation oscillation, in which ASE plays a role of strong damping. Heat generation in a Nd： YAG thin disk laser composite with an undoped anti-ASE cap and a side ASE absorber is inves tigated. Heat load unbalance among three different regions induces a large transverse temperature inhomogeneity is observed ex perimentally.

关 键 词：片状激光器 放大的自发辐射 谐振腔 寄生振荡 

分 类 号：TN248.1[电子电信—物理电子学]