Thermomechancial Characterization In A Radiant Energy Imager Using Null Switching

Thermomechanical noise for a MEMs-based infrared detector using null switching (US patent 7977635) depends on vibrational amplitude, since IR radiation is transduced to a change in the duty cycle of a repetitively closing switch. Equipartition theorem determines the maximum rms vibrational amplitude for the fabricated cantilever switch at its natural frequency. This determines the timing uncertainty, NEP, and NETD. We estimate NETD to fall in the range 0.13 -1.5 K for a device with similar to 20 mu m pitch.