All-optical DGD monitor for packet-switched networks based on an integrated active Mach-Zehnder interferometer operating as logic XOR gate

An all-optical differential group delay (DGD) monitor for packet-switched networks is proposed. The monitoring approach consists of an integrated active Mach-Zehnder interferometer acting as a logic XOR gate. According to the estimated DGD value, a latching switch is employed to route the input packets “on-the-fly”. The simulation results show a successful operation which has been confirmed with the experimental validation of the XOR-based monitoring subsystem.