平行光束经过有加工误差的Dove棱镜后,在出射面往往会发生角度倾斜和离轴偏差,从而导致利用Dove棱镜制成的光纤旋转连接器的传输耦合损耗增大。对于Dove棱镜的加工误差在耦合损耗方面的影响,本文利用光线追迹的方法对其进行了理论及模拟分析。分析结果显示,由于加工误差带来的耦合损耗随着Dove棱镜的底角误差及其锥体角误差的增加而增大。而后依据理论结果及光纤旋转连接器的需求,设计加工了5块Dove棱镜,测量了其耦合损耗,并对实验测量值进行了修正,进一步验证了理论的正确性。
When a parallel beam light incident to a Dove prism, the manufacturing errors of Dove prism result in the tilted or lateral displacement at the emergence surface of the Dove prism. As a result, the coupling losses of optical signals are induced in an optical rotary joint using a Dove prism. The influence of manufacturing errors of Dove prism on coupling loss is analyzed both in theory and simulation using the method of light ray tracing. The analytical result shows that the coupling losses due to the manufacturing errors would increase as the error in base angles and the pyramidal error increase. Afterwards, according to the theoretical results and the demands of multi-channel optical rotary joint, 5 pieces Dove prisms are designed and manufactured, and then the coupling loss is measured and corrected, which further verifies the validity of the theory.