A Mode MUX/DEMUX for Multicore Fibers With 2D Core Arrays

In this letter, a mode multiplexer/demultiplexer (MUX/DEMUX) for multicore fibers with 2D aligned cores is proposed. The device is based on the concept of 2D multimode interference (2DMMI) effect. If the 2D waveguide array is aligned within a square lattice, the supermodes of the array will obey the sinusoidal function and coincide with the transfer matrix of the 2DMMI couplers with phase shifter arrays. Therefore, a mode MUX/DEMUX with high mode extinction ratio can be realized based on this principle.