Fig. 5.

Cross section of single spatial-frequency medium with $1/k_{\mathrm{LS}}$ of (a) 15 and (b) 20 nm ($k_{\mathrm{LS}}$ evaluated in vacuum). Cross section of PSD of an infinite (red) and thin ($L=0.5\mu \mathrm{m}$) media with $1/k_{\mathrm{LS}}$ of (c) 15 and (d) 20 nm. The sensitivity of $\tilde{\mathrm{\Sigma }}$ to periodic structures with subdiffractional frequencies illustrated in the clear difference in the value of $\mathrm{\Sigma }(x,y)$ corresponding to the media with $1/k_{\mathrm{LS}}$ of (e) 15 and (f) 20 nm. Note that the subdiffractional structures are not resolved in the diffraction-limited $\mathrm{\Sigma }(x,y)$ image.