An infrared detector based on nonlinear oscillation

An infrared detector that uses nonlinear oscillation was fabricated for achieving high sensitivity. Transducer of the infrared detection was a torsional oscillator consisting bi-materials structures. When the incident infrared is absorbed by the torsional oscillator, the oscillator is bended due to the differences in thermal expansions. The bending hardens the spring constant of torsional oscillator to shift the resonant frequency. To improve the response to light incidence, the light-absorbing material of copper black film was deposited on the light-absorber. Reflectivity of the copper black film was 0.2%. Irradiating light onto the detector shifted the resonant frequency.