Design and performance of 256x256 bolometer-type uncooled infrared detector

Abstract

This paper discusses the design and performance of a 256 X 256 bolometer-type uncooled infrared detector. First, model calculations are carried out to clarify the relations of the noise equivalent temperature difference (NETD) to the electrical properties of the bolometer material. The properties are mainly resistivity, the temperature coefficient of resistance (TCR) and 1/f noise. To obtain real-time images with NETD values smaller than 0.15 K for F/1 optics, vanadium oxide thin film was developed as the bolometer material, having a sheet resistance range of 5 - 50 k(Omega) /square and a TCR value of -2%/K. This material did not exhibit thermochroism like VO<SUB>2</SUB>(A), because it was identified as VO<SUB>2</SUB>(B). The bolometer-array was statistically evaluated and put into the infrared camera. Finally, a thermal image with a NETD of 0.15 K was obtained.