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. 08, 1998
Filed:
Mar. 31, 1997
Satoshi Nakano, Kanagawa, JP;
Teiichi Miyauchi, Kanagawa, JP;
Takeshi Yamasaki, Kanagawa, JP;
Satoshi Sasaki, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
Even when manufacturing of a waveguide is fluctuated and an optical parameter is fluctuated or a wavelength of emitted light is fluctuated, a phase difference between two intrinsic modes can be compensated (positive integral multiple of .pi.). Thus, it is possible to prevent a reproduced signal from being deteriorated by elliptically polarized light. A magneto-optical reproducing pickup includes an optical waveguide (4) for guiding light reflected on a magneto-optical recording medium to a differential photo-detecting unit (9) side and phase compensating circuitry for compensating a phase difference between light components of a TE mode an a TM mode included in reflected light. In this case, the phase compensating circuitry comprises the optical waveguide (4) composed of a substrate formed of an electrooptic crystal and a thin film having a light refractive index higher than that of the substrate formed on the substrate, phase control electrodes (21a and 21b) for applying an electric field to the optical waveguide (4) in the direction along the TM mode and a feedback circuit (11).