Sub-1 dB Loss SiN-to-Polymer Waveguide Coupling: an Enabler for Co-Packaged Optics

We report the design, fabrication and characterization of a broadband silicon nitride to polymer waveguide adiabatic coupling interface with sub-1 dB loss around 1310 nm, enabling a sub-2 dB chip-to-chip and chip-to-fiber coupling loss.