大非线性相移下光学非线性Z扫描特性的研究  

Study on Z-scan characteristics for large optical nonlinear phase shift

作　　者：陈树琪[1] 刘智波[1] 臧维平[1] 田建国[1] 周文远[1] 张春平[1] 

机构地区：[1]南开大学物理科学学院光子学中心,天津300071

出　　处：《物理学报》2006年第3期1211-1217,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60025512);天津市自然科学基金(批准号:043601211);南开大学创新基金资助的课题.~~

摘　　要：采用高斯分解法(GD)对大非线性相移下的Z扫描特性进行了分析,通过对数值算法的优化,将GD推广到对脉冲入射激光下大非线性相移下的Z扫描理论分析.对不同条件下大非线性相移Z扫描曲线峰谷结构的比较,发现在大非线性相移的情况下,Z扫描曲线的峰和谷随透过光阑或入射光强变化表现出某些新的特性.随着透过光阑孔径的增加,Z扫描曲线峰的变化要明显快于谷的变化,而且在谷明显存在的情况下,峰很快消失.采用皮秒脉冲激光下的纯二硫化碳实验对理论结果加以验证,实验结果和理论分析相一致.我们的分析结果对大非线性相移下Z扫描测量有一定的指导性意义,避免在大非线性相移下对Z扫描结果产生错误的分析.Using Gaussian decomposition （GD） method, we studied the theory of Z-scan with large nonlinear phase shift induced by a pulsed laser. It has been verified that the GD method is still valid to deal with analysis of Z-scan measurements with large nonlinear phase shift. By comparing the peak-valley configuration of the Z-scan curves for large nonlinear phase shift induced by pulsed and CW laser, we found that some new peak-valley features of the Z-scan curves appear as the aperture size or light intensity increases in the case of large nonlinear phase shift. Meanwhile, we carried out the Z-scan experiments of pure CS2 to confirm the results of numerical simulation in the case of large nonlinear phase shift induced by a picosecond pulsed laser. The experimental results agree well with the theoretical. Our results have some significance to the measurement of Z-scan with large nonlinear phase shift induced by a pulsed laser.

关 键 词：大非线性相移 高斯分解法 Z扫描 

分 类 号：O437[机械工程—光学工程] V443.4[理学—光学]