【作者】 尚红波；

【导师】 李晓彤； 岑兆丰；

【作者基本信息】 浙江大学 ， 光学工程， 2011， 硕士

【摘要】 超短脉冲激光在科学研究和工业生产中具有越来越广泛的应用,这也对脉冲激光光学系统输出的光束质量提出了更多的要求。而光学系统的面形误差和装配误差对脉冲激光光束质量有很大影响。因此对超短脉冲经过光学系统后的光束质量进行仿真,并且分析误差产生的影响,对光束质量的控制具有重要意义。脉冲激光的光束质量包括时间特性和空间特性两个方面。空间特性主要包括焦斑尺寸,脉冲波前等,而时间特性主要体现在输出脉冲的时间宽度上。对脉冲时空特性的仿真主要有两种方法,一是基于菲涅尔衍射理论和麦克斯韦方程组的数值计算方法,二是基于实际光线追迹和衍射积分相结合的方法。前者无法处理光学系统的像差和各种误差对光束的影响。因此本文采用第二种方法进行仿真。在此基础上,本文进一步对面形误差、装配误差的影响进行了分析,并设计相应实验进行了验证。作为国家自然科学基金“光学系统实际误差对高能短脉冲激光输出的影响研究”的一部分,本文主要工作内容包括面形误差的Zernike多项式拟合,带误差面型的光线追迹,空间特性仿真,脉冲宽度的计算和实验验证等。更多还原

【Abstract】 There are more and more applications of ultra-short laser pulse in science research and industrial production. In many applications the output beam quality of laser pulse optical systems needs to be contraled in order to meet these requirements. The surface errors and assembly errors in real optical systems have great influence on the laser pulse beam quality. So it has an important significance to simulate the pulse beam quality through optical systems and analyse the effects of system errors.The beam quality of laser pulse beam includes spatial characteristics and temporal characteristics. Spatial characteristics include focal spot size, pulse wave front, etc. while the temporal characteristics mainly mean the time width of output laser pulse. There are two ways to simulate the spatio-temporal characteristics. One numerical calculation method bases on Fresnel diffraction theory and Maxwell equations, the other bases on the combining of real ray tracing and diffraction integral. The former can not deal with the influence on pulse beam caused by optical system aberrations and errors. So we use the later method to simulate the pulse beam qulity in the paper. On this basis, this paper further analyses the effects caused by surface errors and assembly errors. Finaly, we design an experiment to verify our simulation.As a part of the National Natural Science Foundation of China called research of the effects on output high-energy short-pulse laser beam quality caused by actual errors of optical systems, this paper principal research content includes the surface error fitting by Zernike, ray tracing for surface with errors, spatial characteristics simulation, pulse width calculation and experimental verification, etc.更多还原