Patent ID: 7254332

Claim:
A wavelength division multiplexing passive optical network (WDM PON) system comprising: a central office for generating optical signals of different wavelengths, multiplexing the generated optical signals, and outputting the resultant multiplexed optical signal to an optical communication line, the central office receiving an optical signal having the same wavelengths as those of the generated optical signals, and demultiplexing the received optical signal; a remote node for demultiplexing the optical signal transmitted from the central office via the optical communication line, and outputting the resultant demultiplexed optical signals to distributed optical communication lines, respectively, the remote node multiplexing optical signals respectively transmitted from the distributed optical communication lines, and outputting the resultant multiplexed optical signal to the optical communication line; and a plurality of optical network units for receiving the optical signals transmitted from the remote node via the distributed optical communication lines, respectively, each of the optical network units generating an optical signal having the same wavelength as that of the optical signal received thereto, and transmitting the generated optical signal to the remote node through an associated one of the distributed optical communication lines, wherein the central office comprises: a plurality of first transmitters for generating and outputting optical signals of different wavelengths, respectively; a plurality of first receivers for receiving optical signals having the same wavelengths as those of the optical signals outputted from the first transmitters, respectively; a first multiplexer/demultiplexer for multiplexing the optical signals respectively outputted from the first transmitters, and outputting the resultant multiplexed optical signal, the first multiplexer/demultiplexer demultiplexing the multiplexed optical signal transmitted from the remote node, and outputting the resultant demultiplexed optical signals; and a plurality of first optical splitters for distributing the demultiplexed optical signals outputted from the first multiplexer/demultiplexer to respective first transmitters and respective second transmitters, wherein each of the first transmitters is injection-locked by the optical signal distributed by an associated one of the first optical splitters.