Patent ID: 7324751

Claim:
A reconfigurable optical switching system for selectively coupling one or more frequencies of first and second input frequency division multiplexed signals comprising N channels to first and second output ports, wherein said system comprises: a demultiplexer comprising at least a first input port and a second input port that receive respectively said first and second frequency division multiplexed signals comprising N channels, and at least N+2 output ports, in which said demultiplexer, for all values of i from 1 to N, the output port numbered i of said demultiplexer receives the corresponding frequency numbered i of the first multiplexed signal received at the first input port, and, for all values of i from 3 to N+2, the output port numbered i of said demultiplexer receives the frequency numbered i−2 of the second multiplexed signal received at the second input port, a multiplexer comprising at least N+1 input ports and at least two output ports, in which said multiplexer, for all values of i from 2 to N+1, the input port numbered i of said multiplexer routes the frequency numbered i−1 to the first output port of said multiplexer, and, for values of i from 1 to N, the input port numbered i of said multiplexer routes the frequency numbered i to the second output port of said multiplexer, and an optical switching circuit, wherein for i from 3 to N, any output port numbered i of said demultiplexer may be selectively connected to the input port numbered i−2 of said multiplexer, to the input port numbered i−1 of said multiplexer, or to the input port numbered i+1 of said multiplexer, and wherein the output ports numbered 1 and 2 of said demultiplexer are selectively and respectively connected to the input ports numbered 1 or 2 of said multiplexer and to the input ports numbered 2 or 3 of said multiplexer, and wherein the output ports numbered N+1 and N+2 of said demultiplexer are selectively and respectively connected to the input ports numbered N−1 or N of said multiplexer and to the input ports numbered N or N+1 of said multiplexer.