Study of evanescent waves for transmission near-field optical microscopy

This paper considers the evanescent vectorial field occurring when light is focused by a high-aperture lens through a planar interface between media of mismatched refractive index. Using a rigorous vectorial electromagnetic treatment developed previously for a similar problem by Török et al. in 1995, the time-averaged electric energy density distributions in the vicinity of the interface are numerically evaluated for a number of refractive indices. Axial distributions are shown for sine and Herschel conditions and the two-dimensional time-averaged electric energy density distributions are shown in the 0° and 90° meridional planes.