建立了不同影响因素下空间光-少模光纤耦合效率的理论模型.以两模光纤为例分析了相对孔径对耦合效率的影响, 当相对孔径为0.17时, 耦合效率最高为82.96%.研究了倾斜、离焦、随机角抖动等因素对少模光纤耦合效率的影响.实验测得当横向偏移量为4 μm时, 两模光纤的耦合效率比单模光纤高10.23%; 当轴向偏移量为125 μm时, 两模光纤的耦合效率比单模光纤高11.24%; 当随机抖动幅度标准差为5 μm时, 两模光纤的耦合效率比单模光纤高12.1%.结果表明少模光纤对信号光接收过程中的干扰因素如倾斜、离焦和随机角抖动都有很好的抑制作用.

The coupling efficiency theory model of the spatial light into few-mode fiber in the different influence factor is established. Takes two-mode fiber for example to study the relative aperture effect on coupling efficiency. When the relative aperture is 0.17, the highest coupling efficiency is 82.96%. The coupling efficiency in the presence of tilt, defocus and random angular jitter is studied, the experiment show that when the lateral offset is 4 μm, the coupling efficiency of two-mode fiber is higher than single-mode fiber about 10.23%, when the axial offset is 125 μm, the coupling efficiency of two-mode fiber is higher than single-mode fiber about 11.24%, when the random jitter amplitude is 5 μm, the coupling efficiency of two-mode fiber is higher than single-mode fiber about 12.1%. Accordingly, the few-mode fiber can inhibit interference factor such as tilt, defocus and random angular jitter when the signal reception.