Patent ID: 6931176

Claim:
An optical add/drop multiplexer (OADM) inside a node in an optical network with a buried dispersion compensation module, the OADM comprising: an OADM input port for receiving a wavelength division multiplexed (WDM) optical signal; an OADM output port for passing the WDM optical signal from the OADM; an optical through path for carrying the WDM optical signal from the OADM input port to the OADM output port inside the node; an optical drop module inside the node for receiving the WDM optical signal from the OADM input port and to divert one or more wavelengths of the WDM optical signal to an OADM drop port; an optical add module for adding one or more wavelengths from an OADM add port to the WDM optical signal at the OADM output port; and a dispersion compensation module positioned in the optical through path between the optical drop module and the optical add module inside the node adapted to compensate only for dispersion in the WDM optical signal passing through the through path inside the node.