Abstract
Bidirectional transmission at 90Mbit/s over 30 km of fibre using a single laser source is demonstrated. At the subscriber end, a narrowband resonant optical amplifier serves not only as amplifier, but also as detector, modulator and optical filter. The coherent Rayleigh noise, encountered in previous single-laser bidirectional systems, is eliminated by using a subcarrier modulation scheme. The demonstrated capacity is more than an order of magnitude improvement over similar systems.