Parametrically amplified resonant sensor with pseudo-cooling effect

In this paper, a resonating infrared (IR) sensor with the capability of deamplifying thermal noises based on mechanical parametric amplification is reported. A single-crystalline silicon resonator is formed at the edge of an IR absorber that is freely suspended by narrow beams, and the resonant frequency of the resonator is changed by both heat conduction and thermal stress in irradiating IR radiation. An electrode for electrostatically vibrating near the resonant frequency is integrated, and two electrodes for electrostatically exciting parametric amplification are also formed nearby the resonator. We propose a scheme in which the frequency fluctuation of the mechanical vibration can be reduced by noise-squeezing involved in parametric amplification under an appropriate condition, resulting in improving the noise equivalent power (NEP) and normalized detectivity (D*). In this research, the prototype of thermal resonant IR sensors is fabricated in order to verify the scheme of the noise-squeezing, and parametric resonance with the noise-squeezing in the resonator is conformed and fundamental characteristics of the prototype is reported.