Ultralow crosstalk nanosecond-scale nested 2 × 2 Mach–Zehnder silicon photonic switch

We present the design and characterization of a novel electro-optic silicon photonic 2×2 nested Mach-Zehnder switch monolithically integrated with a CMOS driver and interface logic. The photonic device uses a variable optical attenuator in order to balance the power inside the Mach-Zehnder interferometer leading to ultralow crosstalk performance. We measured a crosstalk as low as -34.5 dB, while achieving ∼2 dB insertion loss and 4 ns transient response.