Fig. 3
From: High-sensitivity nanophotonic sensors with passive trapping of analyte molecules in hot spots
a Schematics of the device fabrication process. b SEM images of the fabricated devices taken at an electron accelerating voltage of 20 kV. The left and upper-right images are top views of a device structure, in which the Al ribbons, the underlying nano-trenches (darker gray color) and Ge ribbons (brighter gray color) are clearly visible. The lower right image is the cross-sectional view of a resonator structure cut using FIB. The scale bar in the left image is 2 μm, and the scale bars in the right two images are 600 nm. c–f Optical microscope images of c the bare device, d the device with l-proline precipitate, e the device with d-glucose precipitate, and f the device with sodium chloride precipitate. The scale bars in c–f are all 5 μm
