Figure 2
(a) Dispersion relation inside the (blue) first and (red) second slits of a metadiffuser for the lossless case (continuous lines) and accounting for the thermo-viscous losses (dashed lines), and wavenumber in air (dashed-dotted). The resonance frequencies of the HR are shown as f 1 and f 2. (b) Corresponding phase speed. (c) Phase of the reflection coefficient for each individual slit.
