Experimental demonstration of generation of longitudinal component of the electric field on the optical axis by high-aperture binary axicon for linear and circular polarization of the incident beam

Abstract

We consider the diffraction of the laser radiation with different polarization on high-aperture binary axicon with different structures. We have performed theoretical analysis of axicon diffraction with expansion in plane waves and shown that depending on the polarization either the longitudinal or the transverse components of the electric field are focused on the optical axis. Analytically and numerically shown that the asymmetry in the structure of the axicon can provide the longitudinal component on the optical axis for the linear and circular polarization of the incident beam. High-aperture binary axicons of three configurations - axisymmetric, bi-axicon and spiral - are produced by electron beam lithography technology. We have performed experimental measurements in the near-field diffraction for the most common and easily implemented types of polarization of the incident beam - linear and circular. The experimental results show agreement with the theoretical studies.

Professor S.V. Karpeev is 60 years old

“…It was in this subject that he for the first time was able to publish an article [36] in one of the highly rated magazines Optics Letters (impact factor 3.34). One of the main applications of inhomogeneously polarized beams is sharp focusing, so the study of electromagnetic fields with subwavelength localization by methods of near-field microscopy [40][41][42][43][44][45][46][47][48][49][50][51] also becomes one of the main Karpeev`s research topics. His publication in Optics Letters [43] has been prepared on this subject.…”

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

“…The key element of a near field microscope is a scanning probe, since it has a consid erable effect on measurement of radiation intensity distribution. Specifically, this problem arises when studying sharp focusing by means of scanning near field optical microscopy (SNOM) [3][4][5][6][7][8][9][10][11][12][13].…”

“…On the other hand, in [8][9][10][11][12][13], experimental inves tigations are described that employ a NT MDT near field microscope with a metal coated apertured fiber probe to measure both the longitudinal and the trans verse components of the electric field. Moreover, in these works, the selective sensitivity of such a probe to various components of the electric field was demon strated [13].…”

“…Moreover, in these works, the selective sensitivity of such a probe to various components of the electric field was demon strated [13]. In particular, the experiments showed a higher sensitivity to the longitudinal component [8][9][10][11][12] for subwavelength apertures as well as an increase in sensitivity to the transverse components with increase in the aperture size [13].…”

“…In this case, by introducing linear or vortex like phase singularity [11,[17][18][19][20], we can form the longitudinal component on the optical axis even with linear or circular polar ization.…”