Submilliwatt Silicon Nitride Thermo-Optic Modulator Operating at 532 nm

Optical phase control is essential for optical beam steering applications. The silicon nitride thermo-optic modulator generally suffers from high electrical power consumption. Microresonator and multipass structures could reduce the electrical power consumption of silicon nitride thermo-optic modulators, with the drawback of a narrow operating bandwidth and high insertion loss. We demonstrate a single-pass silicon nitride thermo-optic phase modulator at 532 nm with low insertion loss and low power consumption, achieving a pi phase shift power consumption down to 0.63 mW in a Mach-Zehnder switch. The rise and fall time are around 1.07 ms and 0.67 ms, respectively.