High-throughput silicon nanophotonic wavelength-insensitive switch for on-chip optical networks

Recent advances in silicon nanophotonics, including demonstrations of ultracompact modulators, germanium waveguide photodetectors and wavelength-division multiplexers, indicate the feasibility of on-chip optical interconnects integrated with multicore microprocessors. Studies have suggested that direct replacement of part or all of the electrical interconnect wiring with point-to-point optical links may not provide sufficient power savings to make this approach attractive to chip designers. However, if high-bandwidth optical signals can be switched and routed using an on-chip silicon nanophotonic interconnection network, significant performance gains can be expected. Here we show an ultracompact (40 × 12 νm2) wavelength-insensitive switch based on cascaded silicon microring resonators, which may bring this vision closer to reality by serving as a critical basic element for scalable on-chip optical networks. Fast (< 2 ns) error-free (bit error rate < 1 ×10 ^-12) switching of multiple (up to 9) 40-Gbit s^-1 optical channels is demonstrated in a temperature-insensitive (±15°C) device.