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:
Oct. 20, 1998
Filed:
Jan. 11, 1996
Applicant:
Inventors:
Charles A DiMarzio, Cambridge, MA (US);
Scott C Lindberg, Brighton, MA (US);
Assignee:
Northeastern University, Boston, MA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
2502081 ; 2502082 ; 250226 ; 356346 ;
Abstract
An optical lock-in detection technique and circuit for coherent applications employing a photo-detector having a symmetric I-V curve is presented. The detection circuit includes a photo-detector operating as an optical lock-in amplifier, and a modulation source. The technique and circuit are used for coherent detection applications such as the determination of the frequency of modulation of an optical signal or the determination of the presence of an optical signal at a specified frequency. The technique and circuit are also used with one or more charge coupled devices in imaging applications.