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:
Feb. 18, 1992
Filed:
Jun. 19, 1990
Yasuaki Tamura, Tokyo, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
In an optical amplifier, light incident on a first port of a port separator is emitted out of a third port, and is input into and amplified in a semiconductor laser. Amplified light receives the first amount of rotation, e.g., a 45.degree. rotation, of the direction of polarization in a Faraday rotator assembly and is emitted outward. Light emitted out of the Faraday rotator assembly is reflected by the reflector. Passed through the Faraday rotator assembly backward, receives the second amount of rotation, e.g., a further 45.degree. rotation, of the direction of polarization in the same direction as the previous rotation, and is input into the semiconductor laser. The input light is amplified again in the semiconductor laser, is input in the third port of the port separator, and is emitted outward from a second port. The direction of polarization of light passing forward and backward through the semiconductor laser are orthogonal to each other, and therefore amplification will be done at a constant degree of amplification, regardless of the direction of polarization.