摘要 |
An optical device comprising a planar waveguide located on a planar substrate, the planar waveguide including a light-transmissive layer and an optical grating coupler being located along the planar substrate and being adjacent to and optically coupled to the planar waveguide. The optical coupler includes an optical grating of the light-transmissive layer. The optical grating includes a periodic arrangement of light-refractive structures and one or more slotted openings separating the optical grating into two or more grating segments that have long axes that are substantially parallel to a propagation direction of a light beam configured to pass between the planar waveguide and the optical coupler. Pitch distances between adjacent ones of the grating segments are less than a wavelength of the light beam divided by the effective refractive index of the light-refractive layer.
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