Determining the index profile for photobleached polymer optical waveguides

We report studies on photobleaching process of polymer waveguides by means of a high pressure mercury lamp. After considering the film shrinkage and the surface index in the bleaching front, an inversed treatment based on the improved WKB method was employed to determine the index profiles of the bleached polymer film using experimentally measured mode indices. Index profiles presented in this paper are consistent with the photobleaching kinetics.