Wavelength division multiplexed light source and passive optical network using the same

A wavelength division multiplexed light source comprising:

• a dense wavelength division multiplexer (DWDM) which spectrally divides lights having different wavelength bands, said bands being periodically disposed on a wavelength axis such that a wavelength period between a start of a current band and a start of a next band is uniform along said axis, said current band having a plurality of structural wavelengths, the spectral division being into channels corresponding to the structural wavelengths of the lights so as to generate multiple different groups whose ones of said channels are spaced apart by said wavelength period;
• a plurality of secondary coarse wavelength division multiplexers (S-CWDMs) which are connected to the DWDM and demultiplex said channels;
• and
• external light injection type light sources connected to corresponding ones of the plural S-CWDMs, so as to output optical signals in which data are modulated, said signals being generated by corresponding ones of said channels.

A passive optical network comprising:

• a central office outputting multiplexed optical signals, which includes:
• a dense wavelength division multiplexer (DWDM) which spectrally divides lights having different wavelength bands, said bands being periodically disposed on a wavelength axis such that a wavelength period between a start of a current band and a start of a next band is uniform along said axis, said current band having a plurality of structural wavelengths, the spectral division being into channels corresponding to the structural wavelengths of the lights so as to generate multiple different groups whose ones of said channels are spaced apart by said wavelength period;
• a plurality of secondary coarse wavelength division multiplexers (S-CWDMs) which are connected to the DWDM and demultiplex said channels;
• and
• external light injection type light sources connected to corresponding ones of the plural S-CWDMs, so as to output optical signals in which data are modulated, said signals being generated by corresponding ones of said channels;
• a remote node demultiplexing multiplexed optical signals that are inputted from the central office through a trunk optical fiber, and outputting the demultiplexed optical signals;
• and
• a subscriber side apparatus detecting, by electric signals, the demultiplexed optical signals, which are inputted from the remote node through distributed optical fibers of multiple ones of said groups.

A passive optical network comprising:

• a central office outputting multiplexed optical signals;
• a remote node demultiplexing the multiplexed optical signals inputted from the central office through a trunk optical fiber, which includes:
• a dense wavelength division multiplexer (DWDM) demultiplexing the multiplexed optical signals inputted from the central office into their structural optical signals, so as to output optical signals of a plurality of different groups whose respective ones of the outputted optical signals are spaced at the free spectral range;
• and
• a plurality of secondary coarse wavelength division multiplexers (S-CWDMs) that are connected to the DWDM and demultiplex the optical signals of the corresponding group inputted from the DWDM so as to output demultiplexed optical signals;
• a subscriber side apparatus detecting, by electric signals, demultiplexed optical signals inputted from the remote node through distributed optical fibers of the plural groups.

A passive optical network comprising:

• a central office multiplexing lights of different wavelength bands which are periodically arranged on a wavelength axis and respectively have a plurality of structural wavelengths, so as to output the multiplexed lights;
• a remote node spectrally dividing the multiplexed lights, which are inputted from the central office through a trunk optical fiber, into channels corresponding to structural wavelengths of the light, so as to output the channels of multiple different groups having corresponding pluralities of channels spaced at a wavelength period common between consecutive pairs of the channels;
• and
• a subscriber side apparatus including external light injection type light sources of respective ones of the groups, said sources outputting optical signals of the corresponding group, data being modulated in said optical signals, said signals being generated by channels of the corresponding group injected from the remote node.