Fast and sensitive THz detector based on optomechanical resonator

Abstract

We demonstrate an optomechanical THz meta-atom device consisting of a THz resonator and an oscillating mechanical nanobeam. This device efficiently interacts with THz radiation and shows mechanical responses in oscillation amplitudes with a responsivity of 4 nm/$\mu$W, and thus can be employed as sensitive THz detectors operating at room temperature. We further implement phase lock loop (PLL) measurements and show that the device can respond at high speeds, with a harmonic bandwidth on the order of 1 MHz. Moreover, in this optomechanical system, Duffing nonlinearities can be easily observed.