Photonic 640-Gb/s Reconfigurable OTDM Add–Drop Multiplexer Based on Pump Depletion in a Single PPLN Waveguide

All-optical time-domain channel extraction and clearing operations based on nonlinear effects in a periodically poled lithium niobate (PPLN) waveguide is investigated at 640 Gb/s. The suitability of this device for 640-Gb/s signal processing has been confirmed exploiting only pump depletion. Moreover, a 640-Gb/s reconfigurable optical time-division multiplexing (OTDM) add-drop multiplexer is demonstrated, using a single PPLN waveguide based on a counterpropagating configuration. Error-free operation confirms the effectiveness of a single device for simultaneous add-drop functions. Reconfigurable operations have been verified through bit error rate measurements, including the case of simultaneous add-drop of multiple channels in the OTDM frame.