Highly directional waveguide grating antenna for optical phased array

A highly directional waveguide grating antenna by patterning top cladding has been proposed. Spatial separation of the grating structure from the waveguide reduces the strength of perturbation to achieve a millimeter-scale emission. The optimized grating structure offers above 70% directionality with 800 nm waveguide width. The vertical field-of-view of 15° is achieved with 100 nm wavelength bandwidth. Thanks to the its simple structure and large critical dimension, the proposed structure is suitable for manufacturing in CMOS foundries with DUV lithography.