A novel bidirectional add/drop module using waveguide grating routers and wavelength channel matched fiber gratings

We propose and experimentally demonstrate a novel bidirectional add/drop module for single-fiber bidirectional self-healing wavelength-division-multiplexed (WDM) ring networks. The key components of this module are waveguide grating routers (WGRs) and fiber gratings. Using two circulators, the bidirectional fiber link is transformed into two separated unidirectional transmission paths within the module. The module can operate in two different WDM schemes: nonoverlapping scheme and overlapping scheme. The feasibility of these operation schemes has been confirmed by the experimental results.