Fig. 4: Extracting ϵ(ω) of hBN.
From: Far-field extraction of the dielectric function of exfoliated flakes near phonon resonances
a Microscope images of three hBN flakes of different thicknesses. (b) Thickness profiles measured by AFM of the three flakes shown in panel a. The extracted thicknesses d are 285 nm, 220 nm, and 160 nm, and these were measured along the paths marked with the dashed lines in panel (a). c FTIR-measured reflectance spectra for the three flakes. d Extracted real part of the refractive index, nx(ω) as a function of frequency. The solid circles are values extracted directly from Eq. (4), whereas the solid curves are the result of fitting Eq. (1) to the data points depicted as solid circles. Results are color-coded according to the three different flakes shown in panel (a). The estimation error on n(ωd) is shown in panel (d).
