MINIATURIZED MICRO-OPTICAL SCANNERS

Optical beam scanners are critical components for airborne and space-based laser radar, on-machine-inspection systems, factory automation systems, and optical communication systems. We describe here a laser beam steering system based on dithering two complementary (positive and negative) microlens arrays. When the two microlens arrays are translated relative to one another in the plane parallel to their surfaces, the transmitted light beam is scanned in two directions. We have demonstrated scanning speeds up to 300 Hz with a pair of 6-mm-aperture microlens arrays designed for input from a HeNe laser. The output beam covers a discrete 16x16 spot scan pattern with about 3.6 mrad separation and only 400 mu rad of beam divergence, in close agreement with design predictions. This demo system is relatively compact; less than 2 in on a side. We also describe several near-term applications, some critical design trade-offs, and important fabrication and design issues.