Competition of infrared detector technologies

Performance limits of infrared photon and thermal detectors are presented. Due to fundamental different types of noise, these two classes of detectors have different dependencies of detectivities on wavelength and temperature. Special attention is put on competition of QWIPs and HgCdTe photodiodes in long wavelength infrared spectral region. Final part of the paper is devoted to uncooled two-dimensional arrays of thermal detectors. Two most important detection mechanisms, namely, resistive bolometer and pyroelectric detectors are considered. The development of outstanding technical achievements in uncooled thermal imaging is also presented.