Novel low-cost uncooled infrared camera (Invited Paper)

Abstract

A novel uncooled long-wave infrared imaging technology with optical readout is proposed and developed targeted for low cost thermal imaging applications. This technology uses the thermo-optic effect in a semiconductor to detect infrared signals rather than the thermal-resistance effect used in traditional microbolometers. The key component of the imager, the focal plane array, is made up of thermally tunable thin film filter membrane pixels. Each thermal pixel acts as a wavelength translator, converting far infrared radiation signals into near infrared signals which are then detectable by off-the-shelf CCD or CMOS cameras. This approach utilizes optical filter and MEMS technologies, to build a low-cost passive long wavelength infrared focal plane array without electrical leads or active cooling. Within one year since the commencement, NETD values of 0.28K in a 160x120 array operating at 22Hz video frame rate have been achieved without temperature control.