Fig. 4: Observation of naturally canalized PhPs in thin LiV2O5 layers.
From: Observation of naturally canalized phonon polaritons in LiV2O5 thin layers
a Schematics of the near-field visualization of PhPs in LiV2O5 placed on a SiO2 substrate. Einc and Esca represent the incident and scattered electromagnetic field. A resonant Au-antenna illuminated with s-polarized infrared light efficiently launches PhPs, which are probed by an s-SNOM (scattering-type scanning near-field optical microscopy) microscope employing a metallic tip. b, c Near-field amplitude s-SNOM images (s3) and numerically simulated images (\({{{Re}}}({E}_{z})\)) for LiV2O5 thin layers with thicknesses of 213 nm and 116 nm, respectively. The excited PhPs exhibit elliptic propagation at \(\omega=\) 997 cm−1 and \(\omega=\) 1010 cm−1, respectively. d, e Same as b, c for \(\omega=\) 1003 cm−1. The excited PhPs exhibit anisotropic propagation. f, g Same as b, c for \(\omega=\) 1007 cm−1. The excited PhPs exhibit canalized propagation. White dashed lines are guides to the eye in all panels.
