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:
Jan. 01, 1991
Filed:
Jul. 14, 1989
Charles D Brandle, Jr, Basking Ridge, NJ (US);
Vincent J Fratello, New Providence, NJ (US);
Steven J Licht, Bridgewater, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
Apparatus according to the invention comprises magneto-optic isolator means that utilize a novel temperature compensation scheme. The scheme involves the use of a composite magneto-optic member that comprises a first single crystal garnet layer that does not have a compensation temperature within the operating temperature range of the isolator, and further comprises a single crystal garnet layer (the 'compensation point layer') that has a compensation temperature within the operating temperature range of the isolator. Exemplarily, the compensation point layer has composition (Bi.sub.0.8; Tb.sub.1.1 Gd.sub.1.1)(Fe.sub.4.6 Ga.sub.0.4)O.sub.12, and is grown on an CMZ:GGG substrate, and the first garnet layer has composition (Bi.sub.1.2 Tb.sub.1.8)(Fe.sub.4.6 Ga.sub.0.4)O.sub.12 and is grown on the compensation point layer. The novel temperature compensation scheme can result in isolators having improved extinction ratio with relatively small additional path length in the magneto-optic material.