Zero reflectance design for tilted devices

Abstract

Techniques that eliminate or otherwise reduce retroreflections associated with focal plane arrays (cooled and uncooled) and other tilted devices are disclosed. The device topology is designed so that incoming radiation is reflected outside of the incoming focusing optical cone. Planarization is used to eliminate concave geometries and angled sidewalls can be used to eliminate convex geometries, as such geometries cause retroreflection. The resultant structure is covered with reflective material (e.g., aluminum, titanium tungsten, or other standard metallization), which not only safely reflects light from the scene, but also prevents reflections from the underlying geometries of the via. Devices configured in accordance with the principles of the present invention require less tilt, thereby minimizing optical distortion.