Fig. 20.

(a) Example Fourier transform of spectrum for $L=2\mu \mathrm{m}$, generated by FDTD (blue) and the decay fit (black). (b) Thickness predicted from decay tail for various SNR (solid lines in red for $L=3\mu \mathrm{m}$, green for $L=2\mu \mathrm{m}$, blue for $L=1\mu \mathrm{m}$). True sample thickness is indicated by dashed lines of the corresponding color. (c) Thickness predicted from decay tail measured from FDTD-simulated spectra for a wide range of true sample thicknesses.