Abstract

Thin silica-titania planar waveguides doped with lead sulphide have been prepared on fused silica substrates using the sol-gel technique. The doping was realised by separate preparation of the matrix and the colloidal sol of the dopand, and successive mixing. Sulphide particles were obtained by reaction of metal acetates with thioacetamide and control of particle size was achieved by surface capping agents. PbS-doped films with different particle size in the range 28 nm were prepared. The films were densified for 1h at 300° C in nitrogen. The particle size was estimated from XRD spectra using the Scherrer equation. The thickness of the films is typically 900 nm and their refractive index at 1.064 microns is 1.52.

© 1996 IEEE