Mode-Division-Multiplexing (MDM) of 9.4-Tbit/s OFDM Signals on Silicon-on-Insulator (SOI) Platform

Silicon photonic (SiPh) technology applied for optical communication systems and network-on-chips have attracted many attentions. We propose and demonstrate the use of a 4 × 4 modedivision-multiplexing (MDM) - multiplexer (MUX) and demultiplexer (DEMUX) to provide 200-Gbit/s orthogonal-frequency-division-multiplexing (OFDM) per wavelength signal transmission. The MDM MUX and DEMUX are implemented by asymmetric directional couplers (ADCs), which are constructed by an access waveguide for the transmission of fundamental mode; and the bus waveguide for the transmission of higher order modes. When phase matching condition is satisfied between the access waveguide and bus waveguide, mode conversion can be achieved. Here, 47 wavelengths are successfully mode multiplexed and de-multiplexed achieving a total transmission capacity 9.4 Tbit/s. Numerically study and analysis of the SiPh MDM MUX/DEMUX are presented, and the experimental evaluations are performed.