Performance of an eight-wavelength bidirectional WDM add/drop multiplexer with 80-Gbit/s capacity

Reconfigurable wavelength-division multiplexed (WDM) networks can be employed to provide cost-effective, flexible capacity growth. Each WDM channel is transparent to signal format, bit-rate, and protocol. One important element in optical networks is the WDM add/drop multiplexer (WADM), especially in a ring topology. To date, most WADMs are unidirectional in which the optical signal must add/drop in the same direction. The purpose of this work is to demonstrate a bidirectional WADM. Because the signal can be added/dropped in both directions, only a single fiber is required for bidirectional transmission, as in the case of single fiber for a bidirectional ring. For a unidirectional ring, a signal must pass through all fiber nodes to reach the upstream node. A bidirectional ring can increase the throughput because the signal can pass through a smaller number of hops to reach some of the fiber nodes