Narrow linewidth Brillouin laser based on chalcogenide photonic chip.

We present, to the best of our knowledge, the first demonstration of a narrow linewidth, waveguide-based Brillouin laser that is enabled by large Brillouin gain of a chalcogenide chip. The waveguides are equipped with vertical tapers for low-loss coupling. Due to optical feedback for the Stokes wave, the lasing threshold is reduced to 360 mW, which is five times lower than the calculated single-pass Brillouin threshold for the same waveguide. The slope efficiency of the laser is found to be 30%, and the linewidth of 100 kHz is measured using a self-heterodyne method.

Improved method for hot embossing As2S3 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.

Photonic chip-based all-optical XOR gate for 40 and 160 Gbit/s DPSK signals.

We demonstrate a photonic chip-based all-optical exclusive-OR (XOR) gate for phase-encoded optical signals via four-wave mixing in a highly nonlinear, dispersion-engineered chalcogenide (As2S3) planar waveguide. We achieve error-free, XOR operation for 40 Gbit/s differential phase shift keying (DPSK) optical signals with no power penalty. The effectiveness and broad bandwidth operation of our approach is highlighted by implementing an XOR gate for 160 Gbit/s DPSK signals.