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 3m. The attenuation can be maximum as the refractive index of overlaid materials is equal to that of fiber core.