Analysis of optical bus networks using doped-fiber amplifiers

The number of stations that can be supported in a unidirectional single-channel bus using amplifiers with identical directional-coupler taps is determined. Saturation and noise limits are considered together. Doped-fiber amplifiers with the optical pump power and fiber length optimized for a given value of unsaturated gain are considered. Perfect isolation, gain, and saturation uniform with wavelength and identical for signal and spontaneous emission are assumed. It is shown that a bus network with amplifiers can support thousands of stations with reasonable requirements on amplifier gain and saturation power. For example, over 5000 stations can be supported with 10-dB amplifiers between every two stations, even with a large combined loss of 4 dB per station and no spectral filtering.