An optical multiaccess star network using subcarrier multiplexing

A fibre-optic multiaccess star network using subcarrier multiplexing and coherent detection is proposed. The network uses only one transmitter laser and is free of beat noise. The laser power is distributed among the users at different locations through the star network itself and provides the light sources for the users. Each user modulates the optical signal with a microwave subcarrier using a Mach-Zehnder intensity modulator and can select any of the subcarrier channels using an optical heterodyne receiver. the power requirement for the laser is moderate (6 dBm for a 63-user network) and the network throughput is mainly limited by the bandwidth of the intensity modulators.>