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:
Aug. 16, 1994
Filed:
Jul. 29, 1992
Kazuhisa Kaede, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An optical timing extraction circuit is capable of extracting an optical clock signal of greater than tens of Gb/sec from a NRZ modulated signal. The light intensity level of a light signal modulated in intensity by an NRZ signal is amplified to a level sufficient to cause the optical Kerr effect, and combined with a CW light from a semiconductor laser which is modulated in frequency by the amplified light signal in an optical converting circuit by utilizing the optical Kerr effect. This frequency-modulated light is passed through a narrow band-pass optical filter to cause a signal intensity-modulated pulsed light at each intensity changing point of the modulated signal. Next, after the pulsed light is amplified up to a required optical intensity level, it is passed through another narrow band-pass optical filter, which is an optical tank for extracting the optical clock, to extract an optical clock signal.