Abstract

Remote detection and monitoring of scenes, objects, and materials in selective spectral bands is an increasingly important field with many applications. A variety of optical filtering concepts have been suggested for the sensors used for this purpose, ranging from fixed dielectric filters and rotating filter wheels to more advanced techniques based on acousto-optical gratings and interferometric devices (Fabry-Perot and Michelson). These latter methods (acousto-optic and interferometric) have been demonstrated(1,2) and have shown the value provided by tunability and spectral agility in the optical filter. More recently, methods based on diffractive optics have been proposed for tunable spectral filtering. Specifically, the large degree of longitudinal dispersion in a diffractive element has been exploited both by Hinnrichs and Morris(3) and by the authors(4).

© 1996 Optical Society of America