4-Channel All-Optical Mode Demultiplexing on a Silicon Photonic Chip

Mode-division multiplexing (MDM) is a promising approach to boost the capacity of optical fibers [1]. Yet coherent detection and power hungry multiple-input multipleoutput (MIMO) digital signal processing (DSP) are typically required to unscramble mixed modes. Here, we demonstrate a 4-channel silicon photonic MIMO demultiplexer performing all-optical unscrambling of four mixed modes using a mesh of cascaded Mach-Zehnder interferometers (MZIs). Demultiplexing of 10 bits channels with less than -20 dB crosstalk and with a power penalty of 1.5 dB at BER level of 10-8 is achieved.