Optical full-duplex transmission with diode laser amplifiers

Error-free, simultaneous bidirectional optical transmission at 50 Mb/s over 5.5 km of fiber using only a single antireflection coated Fabry-Perot laser transmitter/detector at each end is demonstrated. A baseband digital signal is transmitted in one direction, while a digitally modulated subcarrier signal is transmitted in the opposite direction. At the 1.5-μm operating wavelength, the system length is dispersion limited due to the wide spectral widths of the signals. Therefore, it is expected that a system operating at the 1.3-μm low-dispersion window will show an improved capacity. The additional device capability of optical gain makes this scheme attractive in multiport-full-duplex applications