GRATING COUPLER AND PREPARATION METHOD THEREFOR

摘要

A grating coupler and preparation method therefor. The grating coupler comprises: a substrate layer (0), a lower confining layer (1), a waveguide core layer (2) and an upper confining layer (3) which are sequentially arranged. The waveguide core layer (2) comprises a submicron waveguide (4), a first tapered waveguide (5) and a waveguide array (6). The waveguide array (6) comprises at least two waveguide groups; the waveguide group comprises at least one waveguide chain; the waveguide chain comprises at least two waveguides of different widths; and the waveguides in the waveguide chain are connected to one another. Widths and arrangement structures of the waveguides in the waveguide chain of the same waveguide group are the same, and widths and/or arrangement structures of the waveguides in the waveguide chains of different waveguide groups are different. One end of the waveguide chain in the waveguide array (6) is connected to a wide end of the first tapered waveguide (5), and a narrow end of the first tapered waveguide (5) is connected to the submicron waveguide (4). The grating coupler can increase bandwidths.