Dual-layer waveguide grating antenna with high directionality for optical phased arrays.

Development of the waveguide grating antenna with high directionality is significantly important for the optical phased array. A SiN/Si dual-layer structure with the grating pattern on the SiN layer is proposed to improve the directionality of the waveguide grating antenna. High directionality of more than 89% can be achieved, and the length of the waveguide grating antenna is longer than 4 mm.