Self-focusing of laser beams in a non-circular fiber

Abstract This paper deals with self-focusing of a high-intensity laser beam in a non-circular fiber. Weak nonlinearity is assumed for the energy-dependent dielectric. It is assumed that the electric field lines form concentric loops about the longitudinal axis. Non-orthogonal cylindrical coordinates are introduced based on the assumtion that a fiber with circular cross-section has been deformed, while the cross-sectional area remained constant. Numerical examples are given for the particular case of an elliptic fiber.