侧边抛磨光纤波导传输特性的理论分析

在建立侧边抛磨光纤D型光纤边界条件的基础上,用三维有限差分光束传输法计算和分析了侧边抛磨光纤器件的光功率衰减随光纤的侧边抛磨长度、光纤侧边抛磨后剩余包层的厚度、以及填充聚合物材料折射率三个参量变化的特性.结果表明,侧边抛磨光纤器件的光功率衰减随着抛磨长度的增加而增大;当抛磨长度等于9 mm时,光功率衰减随着剩余包层厚度的增大而单调递减.而当抛磨长度大于9 mm时,剩余包层厚度小于3 μm的范围内,光衰减随着剩余包层厚度的增加出现振荡;当聚合物折射率与纤芯折射率相同时,光功率衰减最大.

Theoretical Analysis on Optical Propagation Characteristics of Side-polished Fibers

Based on the boundary condition of D type of SPF, the attenuations of optical power in the devices of side polished fiber are calculated and analyzed with the variation of the three main factors, which include the side-polished length, residual thickness of cladding after side polishing, and the refractive index of overlaid materials on the side polished area, by use of 3D beam propagation method. The results will analysis shows that, the longer the side polished length is, the lager the attenuation of the device of SPF will be. When the side polished length is 9 mm, the optical attenuation can be decreased gradually as the residual thickness of cladding increase. When the length is longer than 9 mm, the attenuation can wave as the residual thickness increases when it is less than 3 μm. The attenuation can be maximum as the refractive index of overlaid materials is equal to that of fiber core.