Effects of Hydrostatic Pressure and Thermal Loading on Optical Fibers Coated with Multilayer Segmented Young’s Modulus Materials

In this paper, we have reported two-layer coated fiber with tightly jacketed layer of segmented Young’s modulus (YM) material. In our proposed model, we have considered six layers out of which first two layers are assumed of soft material and the next four layers consist of hard materials. In our analysis we have dealt with the effects of hydrostatic pressure and thermal loading on microbending loss and refractive index changes of the fiber in radial, tangential, and axial directions. The microbending loss due to lateral pressure was calculated by taking layer thicknesses, Young’s modulus, Poisson’s ratio, hydrostatic pressure, and thermal loading as parameters of different cases of calculations. The results have shown that increase in soft layers’ thickness reduces the fiber losses. The inclusion of successive hard-material layers causes an increase in the fiber loss. Increase of soft material layers’ thickness has caused increase in loss and reaches a minimum value at a particular thickness of the corresponding layer. As a result, it is shown that increase of the YM of soft layers increases the fiber microbending loss while the increase in case of hard layers would decrease the fiber bending loss. In addition, higher Poisson’s ratio of soft layers would increase the loss but its higher values for hard layers would decrease the loss values.