Uncooled infrared thermal detector arrays

Abstract

Uncooled detectors of infra-red radiation exploiting the pyroelectric effect have considerable potential for thermal imaging applications when used in 1-D and 2-D arrays. This paper discusses the factors controlling the performances of such arrays. Lead scandium tantalate is a new ferroelectric ceramic which gives a very high figure-of-meriL The properties of this material are reported and compared and contrasted with those of other ferroelectric ceramics. The possibilities for direct fabrication of thin films of the materials are discussed. Linear arrays of detectors with D*'s of up to 5x108 cmHzlaW' and 2-dimensional arrays (up to lOOxlOO) with NETD's below 0.2K (25Hz,f/i) have been developed. The technologies for processing these arrays, including the use of reticulation for thermal MTF and microphony improvement, are discussed.