Fig. 2

Near-field imaging of a Bloch mode in the h-BN polaritonic crystal. a Schematics of the experiment. b, c Experimental near-field image (b) and simulated field distribution (c) of the hole array with L = 900 nm at the resonant frequency 1428 cm⁻¹. Black arrows indicate the direction of the electric field, E_inc, and in-plane wave vector of the incident wave, k₀. The effective induced dipole and the k-vectors of (0, 1) and (0, −1) diffraction orders constituting the Bloch mode are indicated in (c) by the black arrows. Scale bars in (b, c): 450 nm