Patent Number: 6,310,345

Title: Polarization-resolving infrared imager

Abstract: The polarization-resolving infrared imager employs the configurations of either first-generation (60 horizontal rows by 1 vertical column of detector elements (pixels)) or second-generation (at least 240 horizontal rows by 4 vertical columns of detector elements (pixels)) infrared imaging detector devices and polarization filters that work in conjunction with the infrared imaging detector devices to separate incoming infrared radiation into portions each having a different polarization orientation. Such polarization separation enables the production of visible images in which various aspects of the scene are differentiated. In the preferred embodiment using the second-generation infrared imaging detector device, polarization-filtering grids are integrated onto the detector. The detector elements in three of the four columns have coupled thereto polarization filtering elements to filter, respectively, horizontal, vertical and 45-degree polarizations of the incoming infrared radiation. Using a scan mirror of sufficient sweep in conjunction with the detector device and the polarization-filtering grid results in one frame of the scene with horizontal polarization, one frame with vertical polarization, one frame with 45-degree polarization and a frame with no polarization distinction, all with one sweep of the scan mirror in real-time scenario. This provides nearly simultaneous infrared scenes at different polarizations from a single cycle of the scan mirror.

Inventors: Pittman; William C. (Huntsville, AL), Westrich; Richard G. (Huntsville, AL), Anderson; Huey F. (Huntsville, AL)

Assignee: The United States of America as represented by the Secretary of the Army

International Classification: G01N 21/31 (20060101); G01J 5/58 (20060101); G02B 23/00 (20060101); G01J 4/00 (20060101); G02B 23/12 (20060101); H01L 27/146 (20060101); H04N 5/33 (20060101); G01N 21/21 (20060101); G01N 21/35 (20060101); H01L 031/00 (); G02B 026/10 (); G01J 005/00 ()

Expiration Date: 10/30/2018