Phase reconstruction of the focused Gaussian beam with optical vortex

Abstract

In the previous paper the new scanning technique was proposed. The sample was illuminated by a focused laser beam with an optical vortex. The vortex was introduced to the laser beam by vortex lens. When shifting the vortex lens the optical vortex in the focused beam moves and scans the sample. In order to use this new scanning technique for microscopic imaging a method for the focused vortex beam phase reconstruction is necessary. In this paper a fast and accurate method for phase reconstruction of the focused vortex beam is investigated. It is shown that the propose method is accurate enough to explore even small optical vortex shifts inside the focused beam.

Half-plane diffraction of Gaussian beams carrying two vortices of equal charges

“…The creation and annihilation of the phase singularities of Gaussian beams focused by an aperture lens were studied theoretically and experimentally by Karman et al [10,11] Masajada dealt with the half-plane diffraction of Gaussian background vortex beams. [12,13] Vasnetsov et al discovered the self-reconstruction of an optical vortex in the diffraction field when the screen cuts off part of the incident beam. [14] Half-plane diffraction is of interest in singular optics because for such a case analytical results are often available, [15,16] and it can be easily realized in experiments.…”