Design and Optimization of Optical Mode Exchange Based on Cascaded Multimode Interferences

This paper presents a structure realizing an optical mode exchange function using three multimode interferences on silicon-on-insulator substrate, and optimized its performance through 3D beam propagation method simulation with effective index method. Simulations demonstrate a successful exchange of two mode TE0 and TE1 with only 0.38 power loss and small crosstalk of −19 dB within a whole C band. Furthermore, large fabrication tolerance is also an advantage of the device. We believe that the proposed optical mode exchange would be used as an important component to improve the flexibility and efficiency of optical networks using mode-division multiplexing.