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. 07, 2003
Filed:
Mar. 10, 1999
Ryu Yokoyama, Tokyo, JP;
Satoshi Ishii, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An optical transmission system having an optical regeneration circuit for regenerating a signal with a deteriorated signal to noise ratio. A signal light at wavelength &lgr;1 which includes a noise light is composed with a continuous light at wavelength &lgr;2 outputted from a light source to obtain a composed signal light in an optical coupler. The composed signal light is passed through a saturable absorption type optical element which transmits only the signal light having a light intensity equal to or greater than a threshold value, thereby removing the included noise light. From the signal light, only the signal at the same wavelength &lgr;2 as the wavelength of the continuous light is extracted by a wavelength divider and data signal of the incident signal light is replicated in the continuous light and outputted. Thus, a signal light having no deterioration of the signal to noise ratio at wavelength &lgr;2 can be regenerated from the signal light having the deteriorated signal to noise ratio.