Noise Performance of On-Chip Nano-Mechanical Switches for Quantum Photonics Applications

Abstract

Nano-opto-electromechanical systems provide an elegant solution for controlling light in quantum photonic integrated circuits, enabling small footprint devices for on-chip unitary transformations with low power consumption and cryogenic compatibility. In quantum applications, the noise of optical switches and routers is an important factor in establishing high-fidelity linear optical operations. In this work, the dynamical operation and noise performance of gap-variable directional couplers fabricated in Gallium Arsenide, are reported. The noise contribution stemming from mechanical modes of the devices are investigated and a low-temperature total phase noise of $\delta \varphi \simeq (4.7\pm 0.1)\mathrm{mrad}$ is observed over the 1–5 MHz bandwidth. The noise characteristic depends very weakly on the temperature, suggesting that the origin of noise stems primarily from electrostatic actuation.