Patent ID: 6950609

Claim:
An optical add/drop multiplexer (OADM) arranged to add v optical channels to, and remove w optical channels from, an input wavelength division multiplexed optical communication signal containing x optical channels, in order to generate an output wavelength division multiplexed optical communication signal containing y optical channels, said OADM comprising a programmable demultiplexer having an input port and K output ports, said programmable demultiplexer arranged to receive said input signal containing said x optical channels on said input port and distribute one or more of said channels to each of said K output ports, wherein one of said K output ports is a through port containing z optical channels and wherein the remaining K−1 of said output ports are the drop ports of said OADM, and wherein said K−1 output ports cumulatively contain said w optical channels, a programmable multiplexer having M input ports and a single output port, said programmable multiplexer arranged to receive said z optical channels on one of said input ports and said v optical channels on the remaining M−1 of said input ports, and combine all of said channels on said M input ports onto said output port, to generate said output wavelength division multiplexed optical communication signal containing said y optical channels, and means for controlling (a) said demultiplexer to route desired drop and through channels from said input port of said OADM to said K output ports and (b) said multiplexer to route desired add and through channels from said M input ports to said output port of said OADM, wherein M and K are integers equal to or greater than 2 and wherein v, w, x, y and z are integers.