FDTD simulations of transmission increase in corrugated tip of near-field scanning optical microscope

Abstract

This paper studies mechanisms of nano-focusing and transport of energy of a light through a tip with a sub-wavelength aperture diameter for scanning near-field optical microscopy (NSOM). In particular, we considered the problem of increasing the transmission of energy through the tip of the microscope. One way to improve transmission is to create a periodic metal-dielectric interface, which provides a coupling effect of the plasmon-polariton waves propagating at the boundary of the interface.