Ultrathin samples with surface phonon polariton enhance photoinduced dipole force
Phonon polariton enhanced nano-IR contrast imaging platform. (a) Sketch of the substrate-enhanced nano-IR contrast imaging platform based on a polar crystal substrate under the metallic tip. (b) Typical PiFM spectra were observed on the sample near its IR resonance and on the substrate near the tip-induced nearfield resonance. (c, d) Schematics for imaging of (c)