Compact and broadband data exchange for mode-division-multiplexed networks.

Recently, mode-division multiplexing (MDM) technology has been used to enable high-bandwidth data transmission. Information swapping or data exchange is an essential function in such high-capacity networks. This paper presents a small, broadband on-chip optical data exchange between two multiplexed modes on the silicon-on-insulator platform. The device consists of a three-waveguide coupler in which the middle waveguide has a hybrid plasmonic structure and the two other ones are silicon waveguides. The total length and the width of the proposed structure are 15.25 μm and 1.0885 μm, respectively. The 3D finite-difference-time-domain simulation results show that the insertion loss is less than 2 dB for a broad bandwidth of 100 nm, over which the crosstalk is lower than -14.7  dB and -21.9  dB for TM0 to TM1 and TM1 to TM0 conversion, respectively.