Waveguiding properties of (Se,S)-based chalcogenide glass films and some applications to optical waveguide devices

Fundamental waveguiding properties of As-Se-S-Ge chalcogenide glass films and some applications to passive waveguide components are presented. The refractive index of the chalcogenide glass film annealed just below the glass transition temperature (200 degrees C) increases by light irradiation near the absorption edge. The refractive-index change amounted to 0.03 at 1.06 microm. The propagation loss of 0.4 dB/cm has been achieved at 1-microm thickness for As(40)Se(10)S(40)Ge(10) glass film. The photoinduced refractive-index change in the chalcogenide glass film was large enough to be applied to making passive waveguide components. The curved waveguide and optical directional coupler were designed as passive components.