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. 02, 1984
Filed:
Dec. 28, 1981
John W Hardy, Lexington, MA (US);
Jeffrey H Everson, Reading, MA (US);
Itek Corporation, Lexington, MA (US);
Abstract
A wavefront sensor for detecting the slope of an input wavefront. A surface acoustic wave reflective diffraction grating is positioned at a focal point of the wavefront, and generates surface acoustic waves at two primary frequencies f.sub.1 and f.sub.2. The reflective diffraction grating produces a first AC shearing interferogram between two like diffraction orders generated by the f.sub.1 and f.sub.2 surface acoustic waves. A photodetector array is positioned to detect the shearing interferogram at a two dimensional array of zones, and the phase of the output signal for each zone is representative of the local slope of the wavefront in the direction of shearing, thus producing the slope in one direction. Complete two dimensional wavefront slope information is obtained by shearing the wavefront in a second orthogonal direction in substantially the same manner utilizing a second surface acoustic wave diffraction grating and a second photodetector array.