【作者】 耿玉民； 徐东东； 张来明；

【Author】 Geng-yumin 1 ;Xu-dongdong 1,2 ;Zhang-laiming 1 (1 Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,State Key Laboratory of Laser Interaction with Matter,Jilin Changchun 130033,China) (2 Graduate University of Chinese Academy of Sciences,Beijing 100049,China)

【机构】 中国科学院长春光学精密机械与物理研究所激光与物质相互作用国家重点实验室； 中国科学院研究生院；

【摘要】 为了得到高质量激光光束,设计了几组非稳腔进行理论计算以及实验方面的研究。本实验激光器使用虚焦正分支非稳谐振腔,用单脉冲放电方式对各种腔镜组合以及不同腔长参数进行实验。测量激光光束参数,得到激光单脉冲能量为13.5J、远场以及近场发散角分别为1.8mrad1.9mrad和0.7mrad0.8mrad。理论上采用快速傅里叶变换方法(FFT)计算模拟谐振腔内激光光束模式,使用ansys有限元软件计算谐振腔内凸面、凹面反射镜以及输出平面镜的热变形。将变形量代入激光模式计算方程,得到激光光束模式分别对三面镜子热变形的敏感度。理论计算的结论表明,凸面反射镜热变形对谐振腔模式的影响最大,输出镜次之,凹面反射镜影响最小,据此设计了凸面反射镜冷却装置。实验结果表明,该装置能够有效减小凸面反射镜的热变形,使激光光束质量满足技术要求。更多还原

【Abstract】 In order to get laser beam of high quality,the research on theoretical calculation and experiment of several unstable resonators was introduced.Using virtual focus positive branch unstable resonator,experiments on different association of resonator mirrors and different resonator lengths were conducted by the method of single-pulse discharge.Single-pulse energy of 13.5 J,near field divergence angle of 0.7mrad 0.8mradand far field divergence angle of 1.8mrad 1.9mradwere provided.The method of fast Fourier transform (FFT) was used to simulate the laser beam mode theoretically,and the ansys finite element software was employed to calculate the thermal deformation of the convex、concave mirror and output flat mirror.Laser beam mode’s sensitiveness individual to three mirrors’ thermal deformation was achieved by substituting that thermal deformation to calculation equation about laser beam mode.The result of theoretical calculation indicated that the impact on beam mode by convex mirror was most intensive,and the output flat mirror took the second place,the concave mirror’s effect was least.,by which the cooling facility was designed.The experimental result indicated that the cooling facility could minish the thermal deformation of convex mirror and make the laser beam quality satisfy technical requirement.更多还原