Mathematical model of losses in multi-mode optical fibers at guide axis bends

The peculiarity of optical-fiber data transmission systems is that it is necessary to lay fibers into optical modules with comparative reserve to eliminate fiber strain effects. It is necessary to find the parameters of fiber bend in an optical module with given fiber-loss level, construction length interval, comparative cable lengthening and primary fiber characteristics. To solve this problem it is necessary to obtain the analytical dependence of whole mode stream losses vs. bend parameters and primary optical-fiber characteristics. The analysis of mode (or mode-group) energy interchange within the bend leads to the energy diffusion equation.