Effect of temperature rise and hydrostatic pressure on microbending loss and refractive index change in double-coated optical fiber

This paper presents an analysis of the effect of temperature rise and hydrostatic pressure on microbending loss, refractive index change, and stress components of a double-coated optical fiber by considering coating material parameters such as Young's modulus and the Poisson ratio.It is shown that, when temperature rises, the microbending loss and refractive index changes would decrease with increase of thickness of primary coating layer and will increase after passing through a minima. Increase of thickness of secondary coating layer causes the microbending loss and refractive index changes to decrease.We have shown that the temperature rise affecting the fiber makes the microbending loss and refractive index decrease, linearly. At a particular temperature, the microbending loss takes negative values, due to tensile pressure applied on the fiber.The increase of Young's modulus and the Poisson ratio of primary coating would lower the microbending loss and refractive index change whereas in the secondary coating layer, the condition reverses.