Fig. 4: Darkfield and total-internal-reflection imaging enabled by the photonic chip.
From: Planar photonic chips with tailored angular transmission for high-contrast-imaging devices
a Schematic of the brightfield microscopy with the photonic chip. The specimen to be imaged is a polymer nanowire placed on a polymer microwire. b, f The brightfield images of the specimens, when they were placed on a bare coverslip. c, d C-DFM images, g, h C-TIRM images. For c, g, the bottom multilayer of the photonic chip was removed, to demonstrate the role of the bottom multilayer in the C-DFM and C-TIRM. e Intensity profiles extracted along the white dashed lines on b, d. i Intensity profiles extracted from f, h. The red lines indicate the levels used to determine the image contrasts (CR). From b to e, the incident wavelength is 750 nm, and from f to i, the wavelength is 640 nm. Scale bars, 20 μm. TIR total internal reflection.
