Thin film sol-gel derived glass

A thin film of sol-gel derived glass on a silica substrate, said film including at least one metal oxide doped silica region of Si—O-M-O—Si with adjacent regions of SiO2, where M is a metal, said film having a thickness substantially in excess of one micron and being free of cracks and lateral shrinkage, and wherein said metal oxide is photodeposited from an organometallic photosensitizer included in the sol-gel used to form said film.

A method for forming a photosensitive sol-gel film including regions of different indices of refraction, said method comprising the steps of forming a photosensitive sol-gel film including an organometallic photosensitizer on a silica substrate, exposing said film through a mask to light of a wavelength and for a time for unbinding different amounts of metal constituents and of said sensitizer in different sections along at least a first channel thereof, exposing said film to heat at a first temperature and for a time to drive off the unbound sensitizer and to bind the metal constituents of said sol-gel film, and exposing said layer to heat at a second temperature higher than said first temperature for a time to unbind and drive off the organic constituents of said sol-gel film.