Metal sulfide coatings for hollow glass waveguides

Metal sulfide dielectric thin films have been deposited using dynamic wet chemistry processing on silver coated hollow glass waveguides (HGWs). Metal sulfides like cadmium sulfide (CdS) and lead sulfide (PbS) possess excellent optical properties in the IR and have high refractive index contrast. A linear growth regime with deposition time has been observed for CdS and PbS thin films on Ag inside silica hollow glass waveguides. The thickness of these thin films can be tailored to minimize the attenuation of the HGW at the operating. wavelength. We have made single dielectric metal coated HGWs using CdS and PbS. This paper discusses the processing and characterization of the thin films and the resulting dielectric metal coated hollow glass waveguides.