Dispersion engineered As₂S₃ planar waveguides for broadband four-wave mixing based wavelength conversion of 40 Gb/s signals

We demonstrate broadband wavelength conversion of a 40 Gb/s return-to-zero signal using four-wave-mixing (FWM) in a dispersion engineered chalcogenide glass waveguide. The 6 cm long planar rib waveguide 2 μm wide was fabricated in a 0.87 μm thick film etched 350nm deep to correspond to a design where waveguide dispersion offsets the material leading to near-zero dispersion in the C-band and broadband phase matched FWM. The reduced dimensions also enhance the nonlinear coefficient to 9800 W^-1km^-1 at 1550 nm enabling broadband conversion in a shorter device. In this work, we demonstrate 80 nm wavelength conversions with 1.65 dB of power penalty at a bit-error rate of 10^-9. Spectral measurements and simulations indicate extended broadband operation is possible.