noise reduction systems for uncooled heterostructure IR photon detectors

Abstract The performance of infrared imaging systems in the presence of 1 f noise is considered. It is found that a simple scanned linear array system in which the pixels are reset every frame can cope with 1 f knee frequencies up to about 1 kHz before performance degradation starts to occur. This technique is not suitable for the case of ambient temperature Auger-suppressed heterostructure diodes, which have large 1 f knee frequencies. Resetting every line gives some performance advantage for devices with knee frequencies above 10 kHz. A significant improvement in the performance of 1 f noise limited arrays can be achieved by optically modulating the input at a high frequency followed by synchronous detection. With this system, 1 f noise can be suppressed for devices with knee frequencies up to about the modulation frequency, and improvements in NETD of at least an order can be achieved with knee frequencies above this. The application of this technique to produce images using Auger-suppressed detectors is considered.