基于透镜的楔形光隔离器的设计与分析

Design and Analysis of Wedge Type Optical Isolator with Lens

设计出一种偏振无关的两极楔形光隔离器.由传统的楔形光隔离器、透镜和反射镜构成.结构采用反射型,在引入透镜和反射镜的基础上,第一级光隔离器的出射光经反射进入第二级,使得两极光隔离器共用一个法拉第旋转器,达到器件体积小,元件数目少,隔离度高的目的.同时利用矩阵光学理论对器件的隔离度和插入损耗进行了理论分析.分析结果表明,隔离度主要受器件消光比和旋转角误差的影响.消光比由10^(-3)到10^(-4),会使隔离度增加20 dB,旋转角误差为5°时,对隔离度的影响达到25dB.插入损耗主要受透射比的影响.

Designed one kind of two stage wedge-type polarization independent optical isolator is designed. It composed of conventional wedge-type optical isolator, lens and mirror. Base on lens and mirror, the output light beam of the first stage enters the second stage through reflection, the two stage optical isolators use one Faraday rotator to reduce the elements and the volume,meanwhile, to improve the isolation effect. The isolation and insertion loss have been analyzed with the matrix-optics methods. The results show that isolation depends on the extinction ratio and rotation angle error. When extinction ratio is changed from 10^-3 to 10^-4 , isolation is increased by 20 dB, when rotation angle error is 5^o, isolation is influenced by 25 dB. The insertion loss is mainly affected by transmission ratio.