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. 19, 2000
Filed:
Feb. 20, 1998
Seiji Nogiwa, Tokyo, JP;
Tatsuhiko Takatsu, Tokyo, JP;
Naoto Sato, Tokyo, JP;
Kazuo Aida, Tokyo, JP;
Hiroji Masuda, Tokyo, JP;
Ando Electric Co., Ltd., Tokyo, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
The purpose of the invention is to offer an optical-frequency-stabilized light source with high accuracy and stability of the optical frequency. An optical splitter 8 splits output light from a local light source 7 into two beams. An optical detector 2 detects beat signals formed by the superimposition of the optical frequency difference between the local light source 7 and the output light, and a rectifier 3 rectifies the beat signal. A time measuring circuit 4 measures the time at which the beat signal was obtained. A frequency measuring circuit 5 measures the beat frequency. A CPU 6 outputs the deviation between the output light from the local light source 7 and the target optical frequency. A Fabry-Perot etalon transmission detection circuit 11 outputs an electrical signal corresponding to the optical frequency of the output light from an optical splitter 9. A control circuit 12 controls the optical frequency of the local light source 7 such that the electrical signal always matches the electrical signal corresponding to the target optical frequency. A Fabry-Perot etalon control circuit 10 corrects the relationship between the output electrical signal and the optical frequency of the light input to the Fabry-Perot etalon transmission detection circuit 11.