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:
Dec. 24, 1996
Filed:
Feb. 23, 1995
Yves Champagne, Sainte-Foy, CA;
Claude Pare, Saint-Augustin-de-Desmaures, CA;
Pierre-Andre Belanger, Sainte-Foy, CA;
Universite Laval, Quebec, CA;
Abstract
The present invention relates to an apparatus and a method upon which the apparatus is based for direct optical measurement of first and second moments (variance) of two-dimensional continuous-wave optical beam irradiance distributions. The apparatus and method are based on an optical filter having a spatially-varying transmittance or reflectance profile described by a one-dimensional truncated parabolic function. The light power transmitted through or reflected by the optical filter is measured by a photodetector as the optical filter travels horizontally across the beam irradiance profile. The variance is obtained from the ratio of the peak signal given by the photodetector normalized to the signal corresponding to the total optical power of the unobstructed optical beam. The first moment in a fixed reference frame is given by the horizontal position of the region of peak transmittance/reflectance of the filter when the maximum signal is measured.