Fig. 3: Experimental realization of topological order multiplication via SPhP dispersion.
From: Multiplication of the orbital angular momentum of phonon polaritons via sublinear dispersion
a, Simulated overlap integral as a function of frequency for an L = −2 VG excited with RCP light designed at ω = 880 cm−1. The purple and orange lines indicate overlap with ℓ = −3 and ℓ = −5 modes, respectively. b, False-colour SEM image of the L = −2 VG used for the experiments. Scale bar, 2.5 μm. c, Overlap integral of the experimental data at different frequencies (top). The purple and orange bars correspond to ℓ = −3 and ℓ = −5, respectively. Corresponding FFT-filtered experimental phase maps (bottom). The arrows and Roman numbers indicate the position of the predicted overlap integral at the corresponding experimental frequencies.
