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:
Jul. 13, 1993
Filed:
Dec. 04, 1990
Kenneth G Leib, Wantagh, NY (US);
Benjamin J Pernick, Forest Hills, NY (US);
Grumman Aerospace Corporation, Bethpage, NY (US);
Abstract
Holographic optical elements are utilized for discriminating between monochromatic, coherent radiation and broadband, noncoherent radiation in passive coherent radiation detection systems such as aircraft warning systems and submarine laser communication systems. Coherent laser light can possess an extremely high energy density, directivity, (i.e., collimation), and a very narrow wavelength band when compared to natural or man-made, broadband white light sources. The concentration of laser light energy by a holographic optical element at the detector stage is a consequence of its special characteristics. Moreover, equally important, the diffracted light distribution in the neighborhood of the detector possesses a unique, bright geometric pattern not readily obtained with noncoherent sources. This geometric pattern is used as a laser wavelength detector for determination of the incident angular direction of the laser beam, as well as a coherent/noncoherent light discriminator. Since it is a passive component, a holographic optical element detects pulsed as well as continuous wave illumination, and some designs are basically independent of wavelength.