中文摘要：

设计了芯间距较小的特殊结构四芯光纤,可用于生成格子光场或用于制作光纤传感器.研究了在采用相干长度较短的LD光源的情况下,经过一段既弯曲又扭转的四芯光纤远程传输后的纤端光场干涉特性.基于叠加原理,出射光场可视为每个独立纤芯的多光源相干叠加和圆孔衍射调制共同作用的结果,推导了相应的理论公式,给出了四芯光纤远场干涉的理论与实验相一致的结果.对光纤弯曲所导致的光程差累积和偏振态衰变效应进行了分析和讨论,并给出了相应的实验结果.

英文摘要：

A special four-core fiber has been designed and demonstrated, in which the internal distance between the neighbor cores is smaller. The special designed four-core fiber can be used as optical grid pattern generator or fiber optic sensors. The effect of both bending and twisting on the far field of the four- core fiber end is discussed for low-coherence LD light source. Based on the superposition principle of point source interference and small hole diffraction of each individual single mode core of the four-core fiber,the far-field grid pattern are obtained. It is agreement with experimental results. In an addition,the theoretical model of the optical path accumulation and the polarization fading along the bending four-core fiber is also established. The related experimental result is given.