Three-mode multiplexer and demultiplexerbased on Mach-Zehnder interferometer

Mode division multiplexing (MDM) is a groundbreaking technology that meets future optical network capacity demand in conjunction with the wavelength multiplexing division (WDM). In our work, we propose a three-mode mux/demux device that comprises a three-arm unbalanced Mach-Zehnder interferometer (MZI) inserted between three Y-junctions. The device is compact and offers a high extinction ratio. Moreover, it has a simple structure. The maximum simulated excess loss is 0.37 dB with a minimum extinction ratio of 25.71 dB in the 1.550 µm wavelength, in different multiplexing and demultiplexing conditions. The device will find application in expanding the fiber transmission capacities in future MDM systems.