Bidirectional optical transmission over one single-mode fiber

Bidirectional transmission over one fiber, using two power splitter fiber couplers, is discussed. It is shown to be a simple and inexpensive method for doubling the transmission system capacity, which can be applied wherever 7 db on the power budget is available. Experimental results are reported of bidirectional transmission over up to 60 km fiber at 140 Mbit/s and over 50 km fiber at 565 Mbit/s. Experiments have been carried out over short fiber distances (< 10 km), showing the possibility to apply this technique in the subscriber network. Patch panel connectors are applied between the fiber and the fiber couplers. The observed penalties, caused by interference between the two systems, are analysed.