Features of Self-Confinement of the Linearly Polarized Waves in a Nonlinear Fiber with a Light Induced Core

Abstract

The fundamental modes of nonlinear optical weakly guiding fiber with circular cross section are studied analytically. The dielectric constant of the fiber core is assumed to be differing from the dielectric constant of the fiber cladding. The change between them occurs abruptly when the light intensity reaches a certain level. The core radius formed at a certain intensity level in dependence of the optical characteristics of the waveguide mode and fiber is specified. It is shown that the core radius can be reduced by increasing the frequency of the wave or the magnitude of the jump in the dielectric constant, and also by decreasing the propagation constant. The self-confinement core radius decreases with increasing frequency, but this increases the diameter of the light beam localization in the fiber cross section. Increasing the propagation constant has the opposite effect.