PROGRAMMABLE LENS ASSEMBLIES AND OPTICAL SYSTEMS INCORPORATING THEM

An imaging system (10) has a fixed lens combination (22), a spatial light modulator (SLM) (20) and a linear detector array (12). A scene image is scanned across a simple array (12) in a direction perpendicular to the array (12) by the SLM (20). This is achieved by displaying a diffraction pattern on the SLM that changes to achieve the scanning. The diffraction pattern displayed typically has a linear element (40) and a quadratic element (42). By having a programmably changed combined chirp pattern (36) displayed on the SLM, and by being able to change it thousands of times a second, an army with fast read out can take the place of a 2-D imaging array.