摘要 |
In a bidirectional optical transmission system between an optical subscriber unit (10; OSU) in a central office and a plurality of optical network units (20Ai; ONU) in customer premises each coupled with the subscriber unit (10) through an optical fiber cable, the optical subscriber unit (10) has a laser oscillator (11), a device (12) for splitting an output beam of the laser oscillator into n number of beams, a plurality of optical modulators (13-1 through 13-n), coupled with each of the n number of beams, for modulating a related optical beam with a transmission signal S for a respective optical network unit, a plurality of optical detectors (14-1 through 14-n) coupled with each of the optical network units to provide a receive signal R by converting the receive optical signal into electrical form. Each pair of one of the optical modulators and one of the optical detectors are coupled with a respective optical network unit through an optical fiber cable (5-1, 5-2). Each of the optical network units (20-1 through 20-n) has a device for receiving the optical signal from the ONU, to convert the receive optical beam into the electrical signal and for transmitting the optical signal modulated with the transmission signal to the ONU.
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