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:
Nov. 27, 1990
Filed:
Mar. 16, 1988
Hans-Erdmann Korth, Stuttgart, DE;
International Business Machines, Armonk, NY (US);
Abstract
An optical analyzer for determining changes of the polarization plane in a light beam (4) comprises a substrate (20) supporting a photodetector array (21) and a system of imaging mirrors (22-24) underneath a parallel plate (25) of high-quality optical glass. The lower surface of the glass plate is covered by a system (26) of dielectric multilayers which acts as a polarizing beam splitter over a large range of angles of incidence. The optical beam (4) enters the analyzer through the glass plate to impinge under an oblique angle of incidence on a first mirror (24) which rotates the plane of polarization in the beam by 45 degrees with respect to the polarizing beam splitter, which then generates two beams partial (202,203) to be eventually directed to photodetector array (21). The beam analyzer is used in magneto-optical storage system to extract an information signal and to generate servo control signals for the focus and track positions of the beam. The tilted first mirror may have circular or stripe geometry and be integrally formed within the substrate (20). The multilayer polarizing beam-splitter system comprises two stacks of layers separated by an intermediate layer and covered by a thick dielectric layer.