Optical Crosspoint Matrix Using Broadband Resonant Switches

Abstract

A low loss, broadband crosspoint switch matrix using high-order resonant optical switch elements is designed, and fabricated for the first time. Multi-path routing is demonstrated for a broad range of representative paths across the circuit. Connections are assessed between eight inputs and four outputs to show losses as low as 0.9 dB per off state ring and 2.0 dB per on state ring. Analysis of the on-state and off-state transfer functions reveal switch extinction ratios exceeding 20 dB for operational bandwidths of 100 GHz for twenty-five different path combinations. Switching is implemented with thermo-optic tuning to give 100-GHz passbands and stopbands. Thermo-optic actuation with a 2-D array of on-chip microheaters allows rise and fall switching times of 17 and 4 microseconds respectively. Power penalties of less than 1.0 dB at 10 Gb/s are observed for twenty eight paths and comparable performance is observed for 40 Gb/s routing on representative paths through the switch matrix without significant signal degradation.