PHOTOREFRACTIVE WAVE-GUIDES PRODUCED BY ION-IMPLANTATION OF FUSED-SILICA

The implantation of 5 MeV silicon and germanium ions into silica forms a 4 mu m thick optical waveguide near the substrate's surface with a refractive index change related to that of the delivered damage. These waveguides are photosensitive due to the presence of color centres cr eated during implantation which can be bleached by laser light illumin ation. We measure the optical absorption, the compaction and the refra ctive index of implanted samples as a function of dose. We compare the absorption bleaching efficiency of ArF and KrF excimer laser light on two similar samples and observe an overall efficiency two orders of m agnitude higher in the ArF case.