Silver-doped germanium sulphide glass channel waveguides fabricated by chemical vapour deposition and photo-dissolution process

Germanium sulphide glass thin films have been fabricated by chemical vapour deposition directly on commercial glass substrates. Silver (Ag)-doped channel waveguide structures were then prepared in a three step process, first channels were patterned in photo-resist, next a Ag thin film was deposited on the patterned waveguide by thermal evaporation, and finally the silver ions were doped into germanium sulphide glass by a photo-dissolution process. The refractive index of germanium sulphide increased by about 0.02 through the photo-dissolution process. The loss of the channel waveguides measured at 632.8 nm was 0.63 ± 0.05 dB/cm.