Ultrafast Detection of TeraHertz Radiation with Miniaturized Optomechanical Resonator Driven by Dielectric Driving Force
Jiawen Liu, Baptiste Chomet, Paolo H. Beoletto, Djamal Gacemi, Konstantinos Pantzas, G. Beaudoin, I. Sagnes, Angela Vasanelli, Carlo Sirtori, Yanko Todorov
Abstract
We report on an optomechanical terahertz (THz) meta-atom detector empowered by a dielectric driving force scheme. The meta-atom consists of a suspended half-wavelength THz antenna that sustains high quality factor mechanical modes. The THz radiation is resonantly absorbed by the meta-atom and enforces an optimized photothermal mechanism that produces mechanical oscillations, with a responsivity of 30 pm·nW–1/3 Hz·nW–1 in terms of amplitude/frequency response. Moreover, in this optomechanical system, THz-induced Duffing nonlinearities can be easily observed. The dielectric driving forces allow the implementation of a frequency phase-lock loop, with a harmonic bandwidth on the order of 1 MHz, and thus, square wave THz signals can be temporally recovered at frequencies up to 100 kHz.