Low-power 2×2 silicon electro-optic switches based on double-ring assisted Mach-Zehnder interferometers

We propose and experimentally demonstrate a low-power 2×2 silicon electro-optic (EO) switch consisting of a double-ring assisted Mach-Zehnder interferometer (DR-MZI). Active tuning elements based on p-i-n diodes and silicon resistive micro-heaters are embedded in the microrings for high-speed EO switching and low-loss thermo-optic (TO) tuning, respectively. The transmission spectrum shows the device can perform switching in a 60 GHz spectral window with a crosstalk less than -20  dB. After phase error correction with 2.31 mW TO power, the EO switch power from cross to bar states is only 0.69 mW. The rise and fall times of the switch are 405 and 414 ps, respectively. The switch operation of the device is verified by high-throughput optical signal transmission up to 25 Gbps.