Experimental Demonstration of Silicon On-Chip MDM-Link Based on Triple Subwavelength-Grating Coupler

With the need for further increase in communication capacity, mode division multiplexing (MDM) technology has become a more promising technical approach. In this paper, we perform an experimental demonstration of a subwavelength grating assisted on-chip silicon MDM-link. The device is fabricated on the silicon-on-insulator with 220-nm thick silicon and a silica cladding. The length of the entire MDM-link is less than
$100 ~\mu \text{m}$
. The measured insertion loss and crosstalk at 1550 nm are lower than 2.6 dB and −25 dB, respectively. The entire crosstalk of the MDM-link is measured to be <−10 dB over a bandwidth of >55 nm. The fabrication tolerances are also experimentally investigated.