Abstract

First-generation forward looking IRs (FLIRs) currently in operation satisfy present requirements for a dependable night vision camera but fall far short of their potential to provide much higher thermal sensitivity and reliability as well as lower cost. Field coverage requirements call for optomechanical scanning of a focal plane containing only a few detectors. Inherent in this requirement is a complexity imposed by the need for high-speed scanners and special related considerations of pupil formation, narcissus control, and cold shield efficiency. The development of second-generation systems to overcome the limitations of current FLIRs is largely dependent on advancements in focal plane technology. Second-generation focal planes are characterized by a very large number of detectors arranged either in a linear array or in a 2-D mosaic and in both cases integrated with on-focal plane electronics. As a result, the requirement for optomechanical scanning is either reduced to a single dimension at a relatively low frame rate or eliminated entirely. To realize fully the potential for increased thermal sensitivity, reliability, stability, and lower cost, optical systems are being compactly configured to maximize cold shield efficiency over a wide angle and passively athermalized to achieve stability of focus.

© 1988 Optical Society of America