Nanosecond-Scale Mach–Zehnder-Based CMOS Photonic Switch Fabrics

We describe Mach-Zehnder-based silicon photonic switch fabrics monolithically integrated with a digital CMOS logic and driver circuitry. We review 2 × 2 Mach-Zehnder switches, 2 × 2 nested Mach-Zehnder switches, and strictly nonblocking 4 × 4 switch fabrics with nanosecond-scale, low-power, low-crosstalk, and low-insertion-loss performances. We also demonstrate fast dynamic reconfigurability on an 8 × 8 butterfly switch fabric. Technical challenges and future research directions of silicon photonic scaled switching systems are also discussed.