Stress calculations based on point-matching method for mechanically inhomogeneous optical fibers

A point-matching method is introduced to calculate the stress distribution in mechanically inhomogeneous fibers in which the Young´s modulus and Poisson ratio differ from region to region over the whole of the fiber cross section. Thus, it is best suited for the stress analysis in birefringent fibers such as elliptic-clad circular core fiber, bow-tie fiber, or panda fiber, all of which belong to the class of multiply connected elasticity problems. The formulation of the method is detailed, and its accuracy is compared with that of analytical calculation, where possible, and that of numerical methods, such as finite-element and boundary-element techniques. The comparisons show that the point-matching method can produce very accurate results and is very flexible in its application to fibers of different geometries