All-optical wavelength conversion for mode-division multiplexing signals using four-wave mixing in a dual-mode fiber

All-optical wavelength conversion for mode-division multiplexing (MDM) signals is theoretically demonstrated by using the four-wave mixing (FWM) effect in a dual-mode fiber. The theoretical model is analyzed for FWM processes between a signal with two MDM channels (LP01 and LP11 modes) and a pump with LP01 and LP11 modes. A method is presented to realize mode-preserving wavelength conversion by simultaneously converting the two signal mode channels to the corresponding idler modes with low crosstalk. The required dispersion performance of the dual-mode fiber is determined, and the fiber structure is optimized to support the MDM wavelength conversion. The 3 dB MDM conversion bandwidth is predicted to be as broad as 69.3 nm with a conversion efficiency of −4.7 dB in a 200-m-long dual-mode fiber.