Fig. 15.

Bright-field epi-illumination microscope images of inhomogeneous samples with $L=2\mu \mathrm{m}$ (a) $l_c=20\mathrm{nm}$ and a smooth surface, (b) $l_c=100\mathrm{nm}$ and a smooth surface, (c) $l_c=100\mathrm{nm}$ and a rough surface with standard deviation of height variations ${\sigma }_h=36\mathrm{nm}$. Corresponding $\mathrm{\Sigma }(x^{\prime },y^{\prime })$ images, (d) $l_c=20\mathrm{nm}$ and a smooth surface, (e) $l_c=100\mathrm{nm}$ and a smooth surface, (f) $l_c=100\mathrm{nm}$ and a rough top surface. ${\mathrm{\Sigma }}^{\prime }(x^{\prime },y^{\prime })$ images, obtained after a second-order polynomial subtraction from detected spectra, are shown in panels (g)–(i) correspondingly. (j) Example spectra for $l_c=20\mathrm{nm}$ smooth (black), $l_c=100\mathrm{nm}$ smooth (red), and $l_c=100\mathrm{nm}$ rough (blue). (k) Average $\tilde{\mathrm{\Sigma }}$ and for the above samples, 10 samples per statistical condition. (l) Average ${\tilde{\mathrm{\Sigma }}}^{\prime }$ and for the above samples, 10 samples per statistical condition eighth error bars corresponding to standard deviations. Scale bar 300 nm on all panels.