WAVE-GUIDING PROPERTIES OF CDS-DOPED SIO2-TIO2 FILMS PREPARED BY SOL-GEL METHOD

We report on the preparation of SiO2 (20%)-TiO2 (80%) planar waveguidi ng layers by dip-coating technique. The layers are formed from origina lly prepared sol with the added CdO and the subsequent precipitation o f CdS nanocrystals (NC) during H2S treatment. The initial sol doping u p to 92 wt.% was reached. The determination of the refractive index an d thickness of waveguiding layer by m-line spectroscopy is presented. The porosity of film is evaluated. Influence of carbon contamination o f the layer's pre-surface area on the waveguiding properties is discus sed. The possibilities of surface relief gratings as efficient input a nd output light couplers are demonstrated. (C) 1998 Elsevier Science S .A. All rights reserved.