The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 25, 2002
Filed:
Oct. 03, 2000
Kwong-Kit Choi, Brookeville, MD (US);
The United States of America as represented by the Secretary of the Army, Washington, DC (US);
Abstract
A polarization-sensitive infrared (IR) detector array for use in infrared cameras and other IR based instruments, is comprised of multiple corrugated quantum well infrared photodetector elements (C-QWIP) that form a unitary detector unit (cell). The array is preferably two-dimensional, which can detect polarization contrast of an observed object in a scene. Each detector unit (cell) is formed by a group of C-QWIP detector elements having different groove orientations and cross sections. Each detector unit (cell) has at least two C-QWIP detector elements with their respective corrugations orthogonally oriented. Infrared detection by these detector cells is primarily by polarization contrast, compared to intensity contrast, which is well known in the art. By measuring polarization of reflected light from the observed object, the type of material can also be identified. A first array embodiment of the invention comprises four C-QWIP elements that form a cell. The second array embodiment of the invention comprises a detector having two C-QWIPs to form a detector cell.