In this paper, a resonating thermal sensor with the capability of de-amplifying thermal noises based on mechanical parametric amplification is presented. A single-crystalline silicon resonator is formed at the edge of an 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 near 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 improvement of the noise equivalent power and normalized detectivity. In this research, the prototype of thermal resonant IR sensors was fabricated in order to verify the scheme of the noise-squeezing, and currently parametric resonance with the noise-squeezing in the resonator is confirmed and the fundamental characteristics of the prototype are reported.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Mechanics of Materials
- Mechanical Engineering
- Electrical and Electronic Engineering