Figure 4
From: High efficiency DBR assisted grating chirp generators for silicon nitride fiber-chip coupling
(a) Shows top view of some of the fabricated grating couplers. Inset shows an SEM image of one of the chirped focussing gratings. (b and c) Show side-view cross sectional SEM images of the etched grating couplers (see yellow trace) with the underneath DBR stack for (b) partial etched gratings of design A and (c) fully-etched gratings of design B prior to SiO2 cladding deposition.
