高灵敏度表面光学非线性测量法  

High-sensitivity measurement of surface optical nonlinearities

作　　者：史敏[1] 杨俊义[1,2] 李中国[3] 聂仲泉[3] 宋瑛林[1,3] 

机构地区：[1]苏州大学物理科学与技术学院,江苏苏州215006 [2]欧贝黎新能源科技股份有限公司,江苏南通226612 [3]哈尔滨工业大学物理学院,哈尔滨150001

出　　处：《强激光与粒子束》2013年第3期583-586,共4页High Power Laser and Particle Beams

基　　金：江苏省自然科学基金青年基金项目(BK2012078);国家自然科学基金项目(90922007)

摘　　要：提出了一种测量非透明材料表面光学非线性的新方法:挡板反射4F测量法。该方法在反射4F相位相干成像系统的基础上,在4F系统的像平面放置一个与系统入射面光阑相匹配的不透明挡板,通过测量不同情况下的反射率,实现对材料光学非线性的测量。详细介绍了该方法的基本原理,并通过数值模拟计算了入射角对测量灵敏度的影响。该方法具有单脉冲测量,可同时得到材料的非线性吸收与折射系数等特点。结果表明,在相同条件下挡板反射4F测量法的灵敏度比反射Z扫描方法高2个数量级。A novel single-shot method for the investigation of surface nonlinearity in materials with limited transparency is demonstrated. When a circular disk that blocks the beam is placed in the beam path before the detector in the conventional reflec- tion 4F coherent imaging system, the surface nonlinear optical response of the sample can be determined by measuring the nor- malized reflectance under different conditions. The theoretical principle of the method is presented in detail and the influences of incidence-angle variation on lhe measurement sensitivity are analyzed using numerical simulation. This approach allows for sensi- tivity enhancement, one laser-shot detection, determination of the nonlinear absorption coefficient and nonlinear refractive index simultaneously. The results show that the measurement sensitivity of this novel technique is two orders of magnitude larger than that of the original reflection Z scan technique under the same condition.

关 键 词：表面非线性 反射 非线性折射 非线性吸收 

分 类 号：O437[机械工程—光学工程]