Transmission of focused light signal through an apertured probe of a near-field scanning microscope

Abstract

The process of scanning a focused light beam by a metal coated fiber probe with a subwavelength aperture is simulated using the finite element method for the two and three dimensional cases. Intensity pic tures of a focal spot are obtained. For various configurations of the probes, sensitivity to electromagnetic components is investigated. Qualitative differences in the results of the two and three dimensional simula tion are discussed. In the two dimensional case, the probe response is found to be independent of the aperture size. However, in the three dimensional case, the probe response depends heavily on the aperture diameter.

Study of Superoscillating Functions Application to Overcome the Diffraction Limit with Suppressed Sidelobes

“…One of the directions effectively used to achieve super-resolution is near-field optics [2][3][4][5][6][7][8][9][10][11][12]. Near-field optics study fields near a radiation source or an impact surface, which implies consideration of evanescent waves [13,14].…”

Diffraction by an axicon with taking into consideration multiple internal reflections

“…Metalized axicons with small cone angles are also utilised as near-field probes and tapers for sharp focusing in Nanophotonics [5,6] and especially in nearfield microscopy [7][8][9] and spectroscopy [10]. To determine the optimum parameters of such tapers we need to provide simulation in accordance with the assumptions of the rigorous vectorial diffraction theory [11][12][13][14].…”

“…Metalized axicons with small cone angles are also utilised as near-field probes and tapers for sharp focusing in Nanophotonics [5,6] and especially in nearfield microscopy [7-9] and spectroscopy [10]. To determine the optimum parameters of such tapers we need to provide simulation in accordance with the assumptions of the rigorous vectorial diffraction theory [11][12][13][14].Working of metal conical structure is explained by the lightning-rod effect [15] which can be observed near dielectric structures [16]. The lightning-rod effect lies in the fact that longitudinal electric field component are enhanced near sharp structures.…”