Z-scan analysis of high-order nonlinear refraction effect induced by using elliptic Gaussian beam  

作　　者：郭世方 田强 

机构地区：[1]Department of Physics,Beijing Normal University

出　　处：《Chinese Physics B》2010年第6期541-547,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant No.10574011)

摘　　要：The irradiance of an elliptic Gaussian beam that is high enough to excite high-order nonlinear refraction effect is used to calculate the normalized on-axis transmittance function in the z-scan technique by introducing complex beam parameters which make the calculation simpler. The transmittance formula is applied to the first-, first two-, and first three-order nonlinearities. Numerical evaluation shows that the symmetry no longer holds when using an elliptic Gaussian beam instead of a circular Gaussian beam. A distortion is observed in the central part of the curve, which decreases as ellipticity increases. Moreover, the variation of the normalized peak-valley difference decreases as ellipticity decreases.The irradiance of an elliptic Gaussian beam that is high enough to excite high-order nonlinear refraction effect is used to calculate the normalized on-axis transmittance function in the z-scan technique by introducing complex beam parameters which make the calculation simpler. The transmittance formula is applied to the first-, first two-, and first three-order nonlinearities. Numerical evaluation shows that the symmetry no longer holds when using an elliptic Gaussian beam instead of a circular Gaussian beam. A distortion is observed in the central part of the curve, which decreases as ellipticity increases. Moreover, the variation of the normalized peak-valley difference decreases as ellipticity decreases.

关 键 词：Z-SCAN elliptic Gaussian beam complex beam parameter high order 

分 类 号：O435.1[机械工程—光学工程]