Patent ID: 7499652

Claim:
An expandable network element, comprising: a wavelength selective switch having a plurality of input ports and a plurality of output ports, each of said plurality of input ports being coupled to a respective one of a plurality of input optical communication paths, and each of said plurality of output ports being coupled to a respective one of a plurality of output optical communication paths, wherein one of said input optical communication paths carries an optical service channel; a plurality of first optical splitters, each of said plurality of first optical splitters being coupled to a respective one of said plurality of input optical communication paths; a second optical splitter having an input coupled to one of said first plurality of optical splitters, a first output and a second output; an optical demultiplexer coupled to said first output, said second output being a supplemental output not coupled to an optical demultiplexer, wherein said optical demultiplexer comprises a plurality of optical filtering elements, each of said optical filtering elements being tunable; an additional optical demultiplexer coupled to said input optical communication path, said additional optical demultiplexer being configured to select said optical service channel; and a control circuit coupled to said additional demultiplexer and said optical demultiplexer, said control circuit being configured to control said optical filtering elements in response to said optical service channel.