Figure 3

(a) Dispersion, (b) propagation length, (c) localization length, and (d) figure of merit of the SPhPs supported by air/LiF waveguides of thickness t on a glass substrate, respectively; t = 10 nm (solid blue line), t = 50 nm (dashed red line), t = 100 nm (dotted black line), and t = 150 nm (dashed-dotted pink line). Dashed black lines in panel (a) show the edges of the polaritonic gap of LiF.