NUMERICALLY EFFICIENT MODAL DECOMPOSITION APPROACH TO SELF-WRITING PROCESSES

We develop a modal decomposition technique to describe wave propagatio n in dynamically varying waveguides such as those predicted to occur i n photosensitive materials. In particular, we use this method to exami ne the self-writing of a channel waveguide in a slab of photosensitive glass. This method is up to two orders of magnitude faster than the n umerical technique used previously, which is based on a conventional b eam-propagation treatment. Hence it is a powerful tool for exploring t he waveguides that form under a wide range of conditions. (C) 1997 Opt ical Society of America.