EP 0941587 A1 19990915 - OPTICAL TRANSMISSION SYSTEM WITH COHERENT OPTICAL TIME DOMAIN REFLECTOMETRY
Title (en)
OPTICAL TRANSMISSION SYSTEM WITH COHERENT OPTICAL TIME DOMAIN REFLECTOMETRY
Title (de)
OPTISCHES ÜBERTRAGUNGSSYSTEM MIT KOHÄRENTER OPTISCHEN ZEITBEREICHREFLEKTOMETRIE
Title (fr)
SYSTEME DE TRANSMISSION OPTIQUE A REFLECTOMETRIE OPTIQUE TEMPORELLE COHERENTE
Publication
Application
Priority
- FR 9801869 W 19980831
- FR 9710841 A 19970901
Abstract (en)
[origin: FR2767995A1] The invention concerns a method for reducing interactions between the signal in the transmission direction (2) and the back scattered noise coming from the other transmission direction (1) in a link through non-bi-directional and amplified optical fibre, having an optical loop-back (18, 19, 21) of the amplifiers (13, 14; 15, 16) to enable COTDR (coherent optical time domain reflectometry). The method is characterised by a spectral broadening, for example by modulating the wavelength over at least one of the transmission directions. Said modulation is produced for example simply by modulating the injection current of a laser used as transmitter (3). A low frequency modulation - of the order of kHz - is suitable, thereby reducing interactions while enabling COTDR. The invention also concerns a link implementing the method.
IPC 1-7
IPC 8 full level
G01M 11/00 (2006.01); H04B 10/071 (2013.01); H04B 10/25 (2013.01); H04J 14/00 (2006.01); H04J 14/02 (2006.01)
CPC (source: EP)
G01M 11/3109 (2013.01); H04B 10/071 (2013.01); H04B 10/2589 (2020.05)
Citation (search report)
See references of WO 9912287A1
Designated contracting state (EPC)
DE GB IT
DOCDB simple family (publication)
FR 2767995 A1 19990305; FR 2767995 B1 19991015; EP 0941587 A1 19990915; JP 2001505312 A 20010417; WO 9912287 A1 19990311
DOCDB simple family (application)
FR 9710841 A 19970901; EP 98942801 A 19980831; FR 9801869 W 19980831; JP 51638199 A 19980831