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.

Date of Patent:
Aug. 03, 1993

Filed:

Nov. 29, 1991
Applicant:
Inventors:

Naohiro Tanno, Yamagata, JP;

Teruo Toma, Tsurugashima, JP;

Kiyofumi Chikuma, Tsurugashima, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 4423 ; 369 4422 ; 369 4412 ; 369100 ; 372 12 ;
Abstract

Disclosed is an optical waveguide recording medium playing apparatus which has a heterodyne detection optical system and uses a waveguide light delaying/reflecting device for a reference light generating optical system. This waveguide light delaying/reflecting device is provided with a transducer which is disposed in close proximity of an optical waveguide where light is guided and which generates a surface elastic wave, so that the surface elastic wave may propagate in the light propagating direction of the optical waveguide. A laser beam is guided on the otpical waveguide, and a high-frequency drive current modulated in a burst form is applied to an electrode to generate a surface elastic wave, thereby accomplishing the shifting and phase delay of the light frequency of the reference light which ensures information reproduction with the interaction with the laser beam and the surface elastic wave. This optical waveguide is formed by diffusing Ti, Rb or the like on a substrate of GaAs, SiO.sub.2, or TeO.sub.2. This waveguide light delaying/reflecting device can impart phase shifting of several times the wavelength A .lambda. to ensure information reading from along waveguide.


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