Size-dependent amplitude and phase distribution under a high NA objective

Abstract

The interactions between light and sub-wavelength sized dielectric particles have been paid more attentions especially in biotechnology and photonics. Base on Mie scattering method, we calculate the electrical field distribution scattered by a single dielectric particle which is focused by a high numerical aperture (NA) objective. The theoretical result indicates a size dependent amplitude and phase distribution, which agrees well with the experimental measurement. This method provides a way to evaluate the particles size down to the range of less than diffraction limitation.