Figure 1
From: High efficiency DBR assisted grating chirp generators for silicon nitride fiber-chip coupling
(a) Shows a 3D illustration of a chirped fiber-waveguide focusing grating coupler with a bottom DBR mirror. (b) Shows 2D schematic of grating couplers for design A and (c) for design B, considered in this work. As indicated, no constraints on etch depth te is imposed for design A, where as only full etched gratings are considered for design B.
