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:
Nov. 25, 2003
Filed:
Jul. 16, 2001
Fredrik Lidén, Norsborg, SE;
Johan Sandell, Enskede, SE;
Sven Wingstrand, Älvsjö, SE;
Magnus Öberg, Hägersten, SE;
Telefonaktiebolaget LM Ericsson (publ), Stockholm, SE;
Abstract
An optical communication line having optical fiber amplifiers including a pump laser can be configured to suppress the transmission of optical signals by reducing the power of the pump laser. In order that the portion of the line downstream of the amplifier can be monitored for fiber breaks causing only negligible crosstalk with a parallel working line, and with the elimination of the risk of mistaking reflections from a working line for light emitted by the standby amplifier, the light emitted by the standby amplifier is modulated by a low frequency control tone. The modulated laser light causes modulation of the amplified spontaneous emission (ASE) generated in the amplifier to create a control tone. Monitoring means disposed at the end of the optical line detect this control tone and use this as the criteria for a functional connection downstream the amplifier.