Fabrication of silicon slanted grating by using modified thermal deposition technique to enhance fiber-to-chip coupling

Grating couplers are an efficient means for fiber to chip coupling, as they require no facet preparation and enable wafer scale testing. In this paper, we have fabricated the slanted binary grating with angle of 11° and 30° by using some modification in PhiSweep GLAD method. A slanted grating is proposed on Si wafer that achieves a coupling efficiency of 65% in -1 diffraction order in third telecommunication window calculated by numerical simulations. These grating can be fabricated by following simple lithography procedure.