Wavelength-division multiplexed optical fiber network

An optical communication system for transmitting information signals between a central station and a multiplicity of subscriber stations RS.sub.i (i=1, 2, . . . N) connected to the central station by first optical fiber transmission means;

• characterized in that
• (a) associated with any given subscriber station RS.sub.j is at least one distinct predetermined wavelength .lambda..sub.j, with all the predetermined wavelengths being within a spectral region .DELTA..lambda.;
• (b) the central station comprises central station generating means adapted for generating electromagnetic radiation of a multiplicity of distinct wavelengths including the predetermined wavelengths within .DELTA..lambda.;
• (c) the first optical fiber transmission means comprise
• (i) a "backbone" fiber connected to the central station such that radiation comprising the predetermined wavelengths within .DELTA..lambda. can be coupled into the backbone;
• (ii) l fiber "laterals" (1<l<N), each given lateral connected to the backbone by means that comprise means for coupling radiation power from the backbone into the lateral such that radiation of a multiplicity of wavelengths within .DELTA..lambda. can be coupled into the given lateral from the backbone;
• and
• (iii) means for connecting a multiplicity of subscriber stations to a given lateral, the means comprising a multiplicity of fiber "drops" and wavelength selective first coupling means for coupling a given drop to the lateral;
• and
• (d) the given subscriber station RS.sub.j comprises radiation detection means, the wavelength selective first coupling means are selected such that only an information signal associated with the wavelength .lambda..sub.j can be received by the subscriber station RS.sub.j ;
• wherein
• (e) at least one given subscriber station RS.sub.j comprises subscriber station generating means adapted for generating electromagnetic radiation of substantially the wavelength .lambda..sub.j associated with RS.sub.j, and wherein the communications system further comprises second optical fiber transmission means, connected to the subscriber station generating means, and central station radiation detection means that are connected to the second optical fiber transmission means, such that the radiation substantially of wavelength .lambda..sub.j can be transmitted from RS.sub.j to, and be detected by, the central station detection means, with the central station radiation detection means comprising D central station radiation detectors (1.ltoreq.D<N) connected to the second optical fiber transmission means by means that comprise wavelength selective couplers adapted for insuring that any given central station radiation detector receives, at any given time, substantially only radiation from at most one of the subscriber stations.