磁旋光增强效应与旋光增强器特性分析

根据法拉第磁光效应的非互易性，分析了旋光反射腔的光强输出特性，表明这种反射腔具有旋光增强效应.在此基础上提出了用于检测微小旋转角的旋光增强法，并对旋光增强器的特性进行了理论分析和仿真计算.给出了测量灵敏度随器件反射率、样品吸收因素及一次旋光角变化的关系，讨论了角度测量工作点、测量范围以及相对灵敏度理论极限问题.旋光增强器有望应用于微流控系统的旋光检测以及实现磁旋光仪器的小型化和微型化. 关键词： 法拉第磁光效应 磁旋光增强 微小旋光角检测 微流控系统

Enhancement effect of magneto-optical rotation (MOR) and properties of MOR enhancement device

Based on the nonreciprocal property of Faraday effect, we investigate the light output from optical reflection cavity filled with Faraday optical rotation medium. It is shown that such a reflection cavity has the enhancement effect of megneto-optical rotation （MOR）. Base on this phenomenon, a detection method for small rotation angle is proposed, and the characteristics of MOR enhancment device is analyzed. The relations between the detection sensitivity and the factors of reflection, absorption and rotation angle are discussed analytically and simulated. The problems discussed include the angular working point, the measuring range, and the theoretical limitation of detection sensitivity. Under the condition of small angle approximation, the output intensity is proportional to the square of the rotation angle, and increses with the nise of device reflectivity. The angular working point and measuring range decrease monotoniccally with the increase of reflectivity and the drop of the absorption. The limiting value of relative sensitivity is 78.49. The results indicate that the MOR enhancement device can be applied to MOR detection of microfluidic system and miniaturization of MOR instruments.