Influence of tip geometry on the spatial resolution of tip enhanced Raman mapping
Zhang Chao1, Chen Bao-Qin2, Li Zhi-Yuan1, †,
       

The schema for the TERS configuration, where R is the radius of the tip apex, θ is the conical angle, r(rx, rz) is the site of the molecule with scalar polarizability β, and d is the tip–substrate distance. The excitation wavelength is 532 nm, the excitation light is p-polarized, and the incident direction is 60° with the z axis.