Far-field Interferometric Characteristics of Four-core Fiber
四芯光纤的远场干涉特性研究

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.