双通道光环形器结构的设计及理论分析

Structure and Characteristics of a Double Function Optical Circulator with Double Fiber Tip and Lens Twice

提出了一种双通道式多功能光环形器,在结构设计中插入了双尾纤及透镜对,实现了器件功能复用,降低了制造成本与占空比。在理论上用琼斯矩阵对光环形器的插入损耗及隔离度等性能参数进行分析,探讨了影响该双通道光环形器隔离度、插入损耗特性的因素,结果表明,双通道多功能光环形器在器件镀增透膜的基础上具有与传统单通道光隔离器相同低插入损耗和高隔离度等特性。

A new type of double function optical circulator for double fibers is proposed in this paper. Two fiber tips and lens twice are employed in this kind of device. Because two fiber tips and lens twice are used, the function of optical circulator is duplicated in comparison with conventional optical circulator with single fiber tip. Thus the optical circulator has a low cost and a small volume comparatively. Typical insertion loss and isolation of the developed circulator are analyzed and discussed by using Jones Matrix in theory. The analysis results show that the above two characteristics are as good as conventional optical circulator′s characteristics. The isolation is increasing with increment of extinction ratio. The surface reflectivity and material absorption are the main source of the insertion loss. The rotator errors of the rotators have an important effect on the isolation. The higher the errors, the lower the isolation. It′s very important for using optical material with high transmission and high extinction ratio to achieve low insertion loss and high isolation. Also the rotation error of the rotators must be reduced in assembly to win low insertion loss and high isolation. Details of design and high characteristics of this circulator are presented.