Highly nonlinear Chalcogenide waveguide devices for ultra-fast all-optical signal processing

A review of the development and applications of compact highly nonlinear Chalcogenide waveguides for ultra-fast all-optical signal processing is presented. We demonstrate the extreme tapering of a highly nonlinear As₂S₃ fiber to further increase its nonlinearity by more than an order of magnitude thereby enabling time-division demultiplexing of a 160 Gb/s signal by four-wave mixing (FWM) with significantly lower optical powers. The tight mode confinement at such small fiber diameters also enhances the waveguiding dispersion to reduce the total dispersion for more broadband phase-matched FWM. We also present results on a low loss serpentine shaped rib waveguide of 22.5 cm length etched from a thin film of As₂S₃, that enables wavelength conversion of an 80 Gb/s signal by cross phase modulation, highlighting the potential for such high-speed signal processing to be performed in compact photonic chip circuits.