Optimized 2×2 3dB multi-mode interference coupler

摘要

An optimized SOI 2×2 multimode interference (MMI) coupler is designed by use of the particle swarm optimization (PSO) algorithm. Finite Difference Time Domain (FDTD) simulation shows that, within a footprint of 9.4×1.6 μm2, <0.1 dB power unbalance and <1 degree phase error are achieved across the entire C-band. The excess loss of the device is <0.2 dB.

主权项

1. A 2×2 multi-mode interference coupler, comprising:
a multi-mode interference region having a length LMMI and having a plurality of segments having widths W1, . . . , WN, . . . , W1, where N in an integer greater than one, with at least five of said widths W1 to W5 between the first end and the central distance LMMI/2 being different one from the other, said widths varying in a symmetric pattern relative to the central distance LMMI/2 along said length; and four ports p1, p2, p3 and p4, two of said ports in optical communication with said multi-mode interference region at a first end thereof and spaced apart by a distance Dgap and the other two of said ports in optical communication with said multi-mode interference region at a second end thereof, at least one of said four ports configured as an input port and two others of said four ports configured as output ports.