Thin metal film room-temperature IR bolometers with nanosecond response time

The experimental and theoretical investigation of thin-film metal (bismuth, antimony, chromium, nickel) bolometers on beryllium oxide substrates is described. Responsivity, sensitivity (NEP), and time response data for each type of metal bolometer are compared with the results obtained from a thermal analysis of the bolometer. Thin-film bismuth devices can have a responsivity of
2.2 \times 10^{-2}
V/W and an NEP of
5.0 \times 10^{-8}
W/Hz
^1/2
with nanosecond response time. We report measurement of 2- ns response times for bismuth-film bolometers and calculated subnanosecond response times with thinner film devices. These results show that room-temperature thin-film, metal-bolometer IR detectors should be capable of detecting nanosecond and subnanosecond rise-time IR pulses with peak power levels of the order of a few milliwatts.