Reduction of propagation loss in silica-on-silicon channel waveguides formed by electron beam irradiation

摘要

Low loss is demonstrated at infrared wavelengths in channel guides formed by electron beam irradiation of SiO/sub 2/ layers on Si substrates. By comparing materials from different PECVD processes, it is shown that substrate losses may largely be eliminated by using a suitable SiO/sub 2/ thickness, and that extrinsic absorption caused by hydrogen contamination may be reduced by annealing before irradiation. The effectiveness of annealing depends strongly on the original material composition.