Patent ID: 8233808

Claim:
An optical transmission system based on four-wave mixing, comprising: an optical line terminal, a plurality of optical network units connected to the optical line terminal through an optical fiber, and a WDM (wavelength division multiplexer) which multiplexes and demultiplexes signal lights between the optical line terminal and the optical network units in a WDM-PON (passive optical network) topology, wherein the optical line terminal comprises: a downlink signal transmitter which transmits downlink signal lights from the optical line terminal to the optical network units; and a pumping light source which supplies to the optical network units pumping lights having wavelengths which have a predetermined wavelength difference from wavelengths of the downlink signal lights, and wherein each of the optical network units comprises: an optical receiver which receives a portion of the downlink signal lights transmitted from the optical line terminal; an FWM (Four Wave Mixing) generator which also receives said portion of the downlink signal lights transmitted from the optical line terminal, said FWM generator generates an uplink signal light and transmits the uplink signal light from the optical network unit to the optical line terminal based on the four-wave mixing of said portion of the downlink signal lights and the pumping light; and a modulator which modulates the uplink signal light transmitted from the FWM generator and outputs the modulated uplink signal light to the optical line terminal.