Optomechanical temporal sampling of terahertz signals

Various detection schemes are currently investigated in the terahertz frequency range (< 2 THz), as an alternative to the widespread bolometers and Golay cells that feature very high sensitivity but low modulation frequencies (< 10 kHz). In this work, we report an alternative concept based on an optomechanical detector able to read out an arbitrary periodic modulation imprinted on a terahertz beam. The detector is a based on a combination of a split-ring resonator, acting as a terahertz antenna, and a high-quality mechanical resonator with typical resonant frequency omega(0)/2 pi = 1 MHz. We demonstrate two methods for Fourier sampling the envelope of the terahertz signal, in which the mechanical resonator is used as a reference oscillator. With our methods, signals with an arbitrary period T can be sampled, even those that are much faster than the oscillation period of the mechanical resonator, 1/T >> omega(0).

Automated summary

The research presents an alternative detection scheme for terahertz signals based on an optomechanical detector, combining a split-ring resonator and a mechanical resonator to read arbitrary periodic modulations on terahertz beams. Two Fourier sampling methods for the envelope of the terahertz signal are demonstrated, utilizing the mechanical resonator as a reference oscillator.