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arXiv · 2411.09071

Enhanced sensitivity of sub-THz thermomechanical bolometers exploiting vibrational nonlinearity

L. Alborghetti·B. Bertoni·L. Vicarelli·S. Zanotto·S. Roddaro·A. Tredicucci·M. Cautero·L. Gregorat·G. Cautero·M. Cojocari·G. Fedorov·P. Kuzhir·A. Pitanti
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Abstract

A common approach to detecting weak signals or minute quantities involves leveraging the localized spectral features of resonant modes, whose sharper lines (i.e. high Q-factors) enhance transduction sensitivity. However, maximizing the Q-factor often introduces technical challenges in fabrication and design. In this work, we propose an alternative strategy to achieve sharper spectral features by using interference and nonlinearity, all while maintaining a constant dissipation rate. Using far-infrared thermomechanical detectors as a test case, we demonstrate that signal transduction along an engineered response curve slope effectively reduces the detector's noise equivalent power (NEP), achieving $\mathrm{\sim 30 \, pW/\sqrt{Hz}}$ NEP for electrical read-out, sub-THz detectors with an optimized absorbing layer.

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L. Alborghetti, B. Bertoni, L. Vicarelli, S. Zanotto, S. Roddaro, A. Tredicucci, M. Cautero, L. Gregorat, G. Cautero, M. Cojocari, G. Fedorov, P. Kuzhir, A. Pitanti. 2024-11-13. Enhanced sensitivity of sub-THz thermomechanical bolometers exploiting vibrational nonlinearity. https://arxiv.org/abs/2411.09071

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