Review on PPLN waveguide-based photonic processing for phase-coded signals in new generation optical networks

Periodically poled lithium niobate waveguides enable a wide range of optical operations on phase-coded signals. They guarantee high bit rate operation, high compactness and low penalty, allowing an efficient signal processing in new generation optical networks both exploiting differential or coherent receiver. They allow to avoid a large number of optical-electro-optical conversions thus reducing the network total power budget. Format conversion and simultaneous wavelength conversion of on-off keying and phase-shift keying (PSK) signals, logic operations, data swapping and multicasting of PSK signals can be achieved. These operations in the optical domain represent the key elements for the development of a future optical network more efficient and with higher capacity.