Broadband Wavelength Conversion for Mode-Division-Multiplexing Signals in a Width-Modulated Quasi-Phase-Matching Multimode Silicon Waveguide

A broadband wavelength conversion method for mode-division-multiplexing (MDM) signals is proposed in a width-modulated multimode silicon waveguide. The quasi-phase-matching (QPM) conditions of four-wave mixing (FWM) processes are met simultaneously for the fundamental and first-order transverse electric modes (TE0 and TE1) by altering the waveguide width periodically. With a 200-mW continuous-wave pump at 1550 nm, the MDM conversion bandwidth is numerically predicted to be over 100 nm with the peak efficiencies of -22 dB for the TE0 mode and -24.5 dB for the TE1 mode, respectively.