PPLN-based all-optical QPSK regenerator

An all-optical regenerator architecture for quadrature phase shift keying format using periodically poled lithium niobate waveguides is presented. As opposed to current fiber-based solutions, the proposed phase-sensitive structure offers small size and good stability while granting similarly efficient operation. Direct quadratic non-linear interactions are exploited instead of the commonly used cascaded non-linear solutions to reduce complexity and increase efficiency. Mathematical models of the main components are implemented and regeneration efficiency is found to be sufficient for future applications.