Compact uncooled long-wave infrared bolometer camera

The use of uncooled bolometer focal plane arrays in long- wave infrared cameras is becoming more widespread due to reductions in price and increases in sensitivity of these devices. These improvements have made infrared cameras affordable by almost everyone and have expanded their range of usefulness to applications not previously exploited . We describe a compact, lightweight (< 500g) camera that has a 320 X 240 focal plane array with 51 micron pixel size and a 50 milli-Kelvin noise equivalent temperature difference (NETD). Research is being conducted to reduce the pixel size to 25 microns, thus quadrupling the number of pixels, and to reduce the NETD by a factor of two. Recent measurements of the spectral response of this sensor show that it has usable sensitivity out to wavelengths of 25 microns and beyond, so that it would be useful for detecting cold targets and for applications such as detecting weapons concealed beneath clothing, since the longer wavelengths have been shown to penetrate clothing more readily than the generally accepted 8 - 12 micron range of the long-wavelength infrared (LWIR) band. Examples of images obtained with this camera will be shown.