Apodized grating coupler using fully-etched nanostructures

Wu Hua^{1, 2}, Li Chong¹, Li Zhi-Yong³, Guo Xia^{1, 4, †,}

Value distributions of the i-th groove D_i, equivalent refractive index n_eq,i of the grating grooves, and longitudinal grating period Λ_z,i for apodized grating couplers using nanoholes as refractive index tuning layer, versus longitudinal grating period number.