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:
Sep. 14, 1993
Filed:
Jan. 11, 1991
Applicant:
Inventor:
Jonathan D Cohen, Hanover, MD (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
356351 ; 356352 ; 356353 ; 356346 ; 356347 ; 2503381 ;
Abstract
An apparatus is described which detects the presence or absence of coherent light and provides an estimate of the coherent light's wavelength. The apparatus employs a common-path 'polarization interferometer' in which the two linear polarization paths act as interferometer legs. Electro-optic modulation is used to effect periodic differential path length changes in the interferometer. The apparatus performs synchronous time-integrating detection on the light emerging from the interferometer to measure coherent contributions in the presence of obscuring incoherent light.