Fig. 3: Frequency-dependent collective modes in hyperbolic PoCs.
From: Hyperbolic polaritonic crystals with configurable low-symmetry Bloch modes
a Experimentally measured near-field amplitude images of PoCs (P = 2.3 μm) at frequencies close to polariton resonance frequencies. b Numerically simulated electric field distribution images (normalized to the one at 855 cm−1). Scale bar for (a) and (b), 1 μm. c IFC contours (red curves) and Fast Fourier Transform (FFTexp) amplitude maps of the measured near-field images in (a). The mode orders were determined by the contrast of FFT maps as well as the intersections between IFC contours and reciprocal space points (orange circles).
