Generalized parameters for tunneling ray attenuation in optical fibers

Tunneling rays in optical fibers occupy a certain domain in ray parameter space and also have associated attenuation coefficients. We show how to avoid the involved calculation of attenuation coefficients by using an effective domain in which the tunneling rays may be taken to have zero attenuation as a good approximation. This effective domain depends only on one new generalized parameter embracing all relevant fiber and light parameters. This program is carried out for step- and graded-index fibers. Examples are given of the use of the effective domain concept in power and pulse width calculations.