Patent ID: 7085447

Claim:
An optical demultiplexer system for separating out a single band ( 321 a ) forming part of a first comb of bands ( 321 ) which is interlaced with at least one second comb of bands ( 320 ), each band of the first comb of bands being constituted by a plurality of channels having adjacent wavelengths, the system being characterized in that it comprises: a first spectral demultiplexer stage ( 210 ) for separately extracting each of the combs ( 320 , 321 ); and a second spectral demultiplexer stage ( 240 ; 360 ) for separately extracting each of the bands ( 321 a , . . . ) constituting a comb extracted by said first stage, said first stage having a first, relatively narrow passband and a first, relatively high selectivity, and said second stage having a second passband, broader than said first passband, and having a second selectivity lower than said first selectivity.