Bidirectional Quasi-Passive Reconfigurable (Bi-QPAR) Remote Node for Future Optical Access Networks

A bidirectional quasi-passive reconfigurable node is proposed and studied in this paper. The bidirectional quasi-passive reconfigurable node is capable of dynamic wavelength and power allocations in both downlink and uplink directions. In the uplink direction, bidirectional quasi-passive reconfigurable nodes can reduce power discrepancies between different users’ signals reaching the central office. Simulation results show that uplink power variations can be significantly reduced. The impact of minimum power splitting ratios, users’ distributions, and numbers of users supported by bidirectional quasi-passive reconfigurable nodes on the system performance is investigated as well. 2 × 2 × 2 and 2 × 4 × 4 bidirectional quasi-passive reconfigurable nodes are experimentally demonstrated. Our results show that the maximum insertion loss of the 2 × 4 × 4 node is about 16.2 dB, and the power penalty of resource sharing and bidirectional operation is smaller than 0.8 dB for both downlink and uplink. In addition, the proposed bidirectional quasi-passive reconfigurable node can be remote powered by sending a pump signal directly from the central office to eliminate the need for local power supplies at the remote node. Remote power operation of bidirectional quasi-passive reconfigurable nodes is experimentally demonstrated as well with a negligible power penalty.