Uncooled microbolometers at DRS and elsewhere through 2013

Abstract

DRS history in microbolometer and uncooled focal plane array (UFPAA) development mimics that of the entire industry. The history extends over fifteen years as array pitches moved ever-smaller from 51uum to 25um to 17um, and now something smaller than 17uum. The uncooled microbolometer makers have transitioned through smaller pitches about every six years. This has been done while maintaining a noise equivalent temperature difference (NNETD) performance of 20-50mK, and maintaining a thermal time constant (TTTC) of 10-20mmSec. Once a newer pitch is developed to a performance level matching the previous pitch, development on the next smaller pitch is already underway. In this manner, the industry has progressed through smaller pitches without a fundamental performance improvement when measured in NNETD or in TTTC, or more specifically in NNETD*TTC product. Hence, a more-encompassing metric for tracking performance through time would involve the NNETD, the TTCC, and some indicator of bolometer size. Ann NETD*TTC**Area metric, as the appropriate metric for including bolometer size, will be proposed, theoretically justified, and discussed here. A rank-ordering of bolometers which have been published through 22013 is also presented in three charts, one for NETTD, one for NEETD*TTC, and lastly one for NETD*TTC**Area.