Optical branching in dye-doped polymeric waveguide

Abstract

We demonstrate theoretically and experimentally that a single optical beam splits into multiple beams (branches) as a result of light induced permanent refractive index decrease in a dye-doped polymeric slab waveguide upon its upconverted photobleaching. The input Gaussian beam initially splits into two primary branches that grow in time moving out of the central axis and eventually collapse into numerous secondary branches. The proposed theoretical model is nonlocal in time and is based on a Shrö dinger-type nonlinear propagation equation complemented by a rate equation for the decrease of the refractive index.