Air-bridge microbolometer for far-infrared detection

A new microbolometer for far-infrared detection has been fabricated that allows an increase in sensitivity of a factor of 4 over the best previously reported bolometer. By suspending the detector in the air above its substrate, a reduction in the thermal conductance out of the device by a factor of 5 has been achieved. At a modulation frequency of 100 kHz this microbolometer has an electrical noise equivalent power 28 pW/sq rt Hz. A thermal model is also presented that accurately fits the response of the detector.