COHERENT IMAGING WITH 2-DIMENSIONAL FOCAL-PLANE ARRAYS - DESIGN AND APPLICATIONS

Scanned, single-channel optical heterodyne detection has been used in a variety of Lidar applications from ranging and velocity measurements to differential absorption spectroscopy. We describe the design of a coherent camera system that is based on a two-dimensional staring arra y of heterodyne receivers for coherent imaging applications. Experimen tal results with a single HgCdTe detector translated in the image plan e to form a synthetic two-dimensional array demonstrate the ability to obtain passive heterodyne images of chemical vapor plumes that are in visible to normal video infrared cameras. We describe active heterodyn e imaging experiments with use of focal-plane arrays that yield hard-b ody Doppler lidar images and also demonstrate spatial averaging to red uce speckle effects in static coherent images. (C) 1997 Optical Societ y of America.