English

SOI-based micro-mechanical terahertz detector operating at room-temperature

Optics 2022-07-13 v2 Applied Physics Instrumentation and Detectors

Abstract

We present a micro-mechanical terahertz (THz) detector fabricated on a silicon on insulator (SOI) substrate and operating at room-temperature. The device is based on a U-shaped cantilever of micrometric size, on top of which two aluminum half-wave dipole antennas are deposited. This produces an absorption extending over the 23.5\sim 2-3.5THz frequency range. Due to the different thermal expansion coefficients of silicon and aluminum, the absorbed radiation induces a deformation of the cantilever, which is read out optically using a 1.5μ1.5\mum laser diode. By illuminating the detector with an amplitude modulated, 2.5 THz quantum cascade laser, we obtain, at room-temperature and atmospheric pressure, a responsivity of 1.5×108\sim 1.5 \times 10^{8}pm/W for the fundamental mechanical bending mode of the cantilever. This yields an noise-equivalent-power of 20 nW/Hz1/2^{1/2} at 2.5THz. Finally, the low mechanical quality factor of the mode grants a broad frequency response of approximately 150kHz bandwidth, with a response time of 2.5μ\sim 2.5\mus.

Keywords

Cite

@article{arxiv.2204.03970,
  title  = {SOI-based micro-mechanical terahertz detector operating at room-temperature},
  author = {K. Froberger and B. Walter and M. Lavancier and R. Peretti and G. Ducournau and J-F. Lampin and M. Faucher and S. Barbieri},
  journal= {arXiv preprint arXiv:2204.03970},
  year   = {2022}
}
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