Abstract

Thermal microbending is calculated through a loss coefficient which is a function of both fiber parameters and operating conditions. We have shown earlier¹ how to control the value of this coefficient for single-mode optical fibers. The object of this paper is to generalize the previous work for multimode fibers. Because of the thermal expansion coefficient difference between the fiber material and its coatings, a fall in the temperature results in an axial contraction strain. A mechanical strain also exists through a compressive force that occurs during the temperature drop. These strains result in a fiber bending radius p_b which affects the loss coefficient.

© 1991 Optical Society of America