MicroVision, Inc.
Method and Apparatus For Filtering and Filtered Light Detection

Abstract:

A non-imaging concentrator is employed in an upside down configuration in which light enters a smaller aperture and exits a larger aperture. The input angle of light rays may be as large as 180 degrees, while the maximum exit angle is limited to the acceptance angle of the non-imaging concentrator. A dichroic filter placed at the larger aperture has a maximum angle of incidence equal to the acceptance angle of the non-imaging concentrator.