Experimental and theoretical performance of ring-shaped passive-bus optical networks

In a ring-shaped passive bus, power-splitting losses of fiber-optic passive taps are exploited so that wavelengths can be reused in different portions of the network. This spatial reuse greatly reduces the number of wavelengths that need to be multiplexed on an optical fiber to yield a large, high-capacity, multichannel network with many concurrent transmissions. Bounds on the power penalty due to interference caused by wavelength reuse (including the self-interference on a ring-shaped passive bus) are presented, and it is experimentally shown that the penalty falls within these bounds for various cases of laser linewidth, ring length, polarization state, and modulation scheme. In all cases, the penalty is below 1.2 dB with 18-dB attenuation between reused wavelengths.<<ETX>>