Fabrication of buried corrugated waveguides by wafer direct bonding

A new fabrication method of deeply buried corrugated waveguides is presented. It uses a direct bonding process and allows us to make efficient grating couplers in waveguides. The efficiency of the grating is enhanced by enclosing air in its grooves during the fabrication process. A demonstrator based on a waveguide produced by ion exchange has been fabricated and tested. Theoretical and experimental results are compared.