Improved method for hot embossing As_2S_3 waveguides employing a thermally stable chalcogenide coating

We demonstrate the fabrication of As2S3 rib waveguides using hot embossing. Because of the high temperature required, a thin (50nm) Ge(11.5)As(24)Se(64.5) was thermally evaporated on top of an 870nm As(2)S(3) layer to protect against surface degradation during embossing. The waveguides propagation loss was 0.52dB/cm for the TE and 0.41dB/cm for the TM polarizations at 1550nm for a waveguide cross-section dimension of 3.8 × 1μm. The nonlinearity of a 2.2μm wide waveguide was shown to be 13500W(-1)km(-1) using four-wave mixing demonstrating that these embossed waveguides were capable of being used for all-optical processing.