Optical characterization of Ge_11.5As₂₄S_64.5 glass for an on-chip supercontinuum

An on-chip supercontinuum (SC) source spanning from 900 nm to 2000 nm has been experimentally presented and analyzed based on a Ge_11.5As₂₄S_64.5 (GeAsS) planar waveguide at telecommunication wavelength. The nonlinear response parameter (γ) of the GeAsS waveguide is estimated to be ∼12/W/m at the pump wavelength using resonant grating waveguide (RGW) nonlinear refractive index (n₂=2×10^-18m²/W), which is measured by the z-scan technique. The dispersion of the waveguide is carefully engineered based on the refractive index of the GeAsS film where the film structure is confirmed by a Raman spectrum exhibiting consistency with the corresponding glass. The results suggest that the GeAsS glass is expected to be an ideal platform for on-chip devices.