收发共光路单模光纤耦合光学系统研究

Study of The Receiver/Transmitter Common-Path Optical System Based on Single-Mode Fiber Coupling

目标散射光至单模光纤的高效耦合是光纤相干探测激光雷达系统研制的关键技术。为获得尽可能高的单模光纤耦合效率,首先分析了Zernike初级像差对单模光纤耦合效率的影响,在此基础上针对收发共光路单模光纤耦合光学系统在真空中使用的需求设计了带有真空补偿镜的耦合光学系统,实测耦合效率为55.9%。最后对耦合系统在不同温度下的耦合效率进行了测试,在(20.4±2)℃的温度范围内耦合效率最低为45.7%,并通过基于角锥棱镜的焦面位置等效验证方案验证了真空状态下的耦合效率与地面测试状态下的耦合效率一致。

The high-efficiency coupling of scattering light in space into single-mode fiber is a key technology in the development of fiber coherent detection laser radar system.To obtain higher single-mode fiber coupling efficiency,firstly,the effect of Zernike primary aberration on single-mode fiber coupling efficiency was analyzed,then,on the basis of the requirements of single-mode fiber coupling optical system used in vacuum environment,an coupled optical system with vacuum compensating lens was designed.The coupling efficiency of the developed optical system is measured to be 55.9%.Finally,the coupling efficiency of the system under different temperature was tested,and it is shown that the lowest coupling efficiency of 45.7%was obtained in the temperature range of(20.4±2)℃.The focal plane position equivalent verification scheme based on pyramid prism was used to verify that the coupling efficiency under vacuum environment is consistent with that obtained in ground test mode.