Comparative Analysis of Key Parameters of Photonic Nanojets from Axisymmetric Nonspherical Microparticles

Abstract

The effect of photonic nanojets (PNJ) in the scattering near field nearby the surface of dielectric axisymmetric microparticles (hemisphere, axicon, and combined particles) under optical illumination is theoretically considered. Key PNJ parameters (length, width, and peak intensity) are calculated using the discrete-dipole approximation; the dependence of these parameters on the geometric shape of microparticles is analyzed. We show that the use of a special type of combined transparent particle, which consists of an axicon and two attached hemispheres, can produce ultralocalized light fluxes with a peak intensity which considerably exceeds the corresponding values for simple particles (hemisphere and axicon).