Low-Crosstalk High-Order Mode Silicon Fiber-Chip Coupler by Utilizing Apodized Double Part Gratings With Mode Selective Trident

We propose and experimentally demonstrate a silicon integrated high-order mode fiber-chip coupler. By utilizing a structure of apodized double-part gratings with mode selective trident, TE₁ mode can be coupled with low mode crosstalk. Design details and the corresponding simulation results are presented. The coupler is fabricated on silicon integrated platform. Measured results show the loss is 4.68 dB for TE₁-LP₁₁ mode coupling with the mode crosstalk <−23 dB. The proposed coupler could be utilized in the advanced mode division multiplexing (MDM) system.