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:
Apr. 03, 1979
Filed:
Jan. 16, 1967
L Curtis Foster, Atherton, CA (US);
John P Lindley, Redwood City, CA (US);
Itek Corporation, Lexington, MA (US);
Abstract
A system for detecting the presence of coherent radiation comprises an interference filter having a pair of partially-reflective mirrors. The spacing between the mirrors is varied in accordance with a sine function to change the transmission wavelength of the mirrors. A reference signal is developed which represents this periodic variation in the spacing of the mirrors. A photodetector on the output side of the filter detects radiation transmitted therethrough, yielding a detection signal in the presence of coherent radiation transmitted through the filter. An indicator responds to the signal output of the photodetector and to the reference signal to produce an identifying indication of the detected radiation.