Devices and methods are provided for a re-configurable optical add/drop
multiplexer (ROADM) having a static circulator, a selectable grating and a
reversible circulator. The use of a reversible circulator in a known
optical drop multiplexer configuration allows the selectable grating to be
used for selecting both the add-wavelength and the drop-wavelength while
maintaining an East/West architectural split to allow for SONET compliant
maintenance. This invention provides a cost-effective enhancement to a
duplex reflective wavelength selective ROADM.
