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:
Apr. 18, 1995
Filed:
Feb. 17, 1994
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
An optical isolator comprising first through fourth plate-like birefringent substances. Each plate-like birefringent substance receives and transmits incident light, and has a corresponding optical axis which is inclined with respect to a direction of the incident light. The optical isolator also has first and second magneto-optical materials, each for rotating a plane of polarization of the incident light. The optical axis of the second plate-like birefringent substance is rotated by one of -45.degree. and 135.degree. about a first axis which is perpendicular to a surface of the first plate-like birefringent substance. The optical axis of the third plate-like birefringent substance is rotated by one of 45.degree. and 225.degree. about a second axis which is perpendicular to the surface of the first plate-like birefringent substance. The optical axis of the fourth plate-like birefringent substance is rotated by one of -90.degree. and 90.degree. about a third axis which is perpendicular to the surface of the first plate-like birefringent substance. The first and third plate-like birefringent substance have equal thicknesses. The second and fourth plate-like birefringent substances are (1+.sqroot.2) times as thick as the first plate-like birefringent substance. The first and second magneto-optical materials rotate the plane of polarization in opposite directions. Finally, the optical isolator has an element for magnetizing the first and second magneto-optical materials.