IR bimaterial detectors performance

Abstract

In this paper basic parameters of a bimaterial infrared thermal detector (BMD) - sensitivity, noise equivalent power, detectivity - and their dependence on relevant thermal and mechanical parameters are given. In order to find sensitivity and noise we introduce an equivalent "thermo mechanical" excitation force for microelctromechanical bimaterial oscillator and solved equation for this oscillator assuming only first mode of vibration. After the identification of all important noise mechanisms (temperature fluctuations, Brownian motion), we solved the appropriate Langevin stochastic equation and obtained the mean square deflection of the bimaterial cantilever oscillator. This enabled us to determine all of the important parameters for BMD.