帽顶光束Z扫描特征曲线的非对称参量  

Asymmetry Parameter of the Z-Scan Traces Using Top-Hat Laser Beam

作　　者：潘雯[1] 陶红[1] 顾兵[1] 

机构地区：[1]南京师范大学物理科学与技术学院,江苏南京210097

出　　处：《南京师大学报（自然科学版）》2007年第2期42-46,共5页Journal of Nanjing Normal University(Natural Science Edition)

基　　金：江苏省高校自然科学基金(06KJB140057)资助项目

摘　　要：研究了描述帽顶光束Z扫描曲线峰谷相对大小的非对称参量A随远场光阑的线性透过率S和三阶非线性折射相移Φ1之间的变化关系.结果表明对于光克尔介质,当S=0.156时,帽顶光束Z扫描特征曲线的峰高等于谷低且与三阶非线性折射相移Φ1无关,实验中取这一特殊值S,可以很方便地对测量的结果进行归一化处理.此外,分析了高阶非线性效应对非对称参量A的影响,发现当S=0.156时,可以从单一Z扫描特征曲线来判断非线性光学介质是否具有高阶非线性效应以及高阶非线性系数的符号.The relationship of the asymmetry parameter A, which is the ratio of the relative magnitudes of the peak and valley for the Z-scan traces using top-hat spatial profile beam, with the linear transmittance of the far-field aperture S and the third-order nonlinear refractive phase shift φ1 , was investigated in detail. For the Kerr optical nonlinear medium A = 1, implying that the relative magnitude of valley is equal to the peak＇ s, is independence of φ1 at S = 0. 156. Taking this particularly value S, it is easy to normalize the Z-scan traces from the experimental viewpoint. The influence of the high order nonlinearity on A was also analyzed. A new method, which could identify whether the sample exhibits the higher-order nonlinearity or not and its sign from a single top-hat Z-scan trace, was introduced.

关 键 词：非线性光学 Z扫描 非对称参量 非线性折射 

分 类 号：O437[机械工程—光学工程]