Efficient and Perfectly Vertical Binary Blazed Grating Coupler with Slit

Experimental data from "Efficient and Perfectly Vertical Binary Blazed Grating Coupler with Slit". Abstract: Eigenmode expansion method is applied to discretize the stepped shine grating into a binary shine grating. Various strategies to increase the directionality of the coupling efficiency have been optimized and replicated using this binary shining grating. We discussed and analyzed the impact of distributed Bragg reflectors, slits, and metal reflectors on the coupling efficiency of grating couplers. A metal reflector and slit were included in the design of a binary shine grating coupler. The coupling efficiency from fiber to waveguide for vertically incident electrically polarized light is 75.07\% at 1600 nm. A 2.22 dB bandwidth of 52 nm from 1566 nm to 1618 nm is obtained. The research further demonstrates that the 1.55 dB bandwidth is 30 nm.