Generating Bessel-Gaussian Beams with Controlled Axial Intensity Distribution

Nikita Stsepuro,Sergey Kudryashov,Michael Kovalev,Pavel Nosov,George Krasin,Maxim Galkin

doi:10.3390/app10217911

Nikita Stsepuro, Sergey Kudryashov + Show 4 more

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https://doi.org/10.3390/app10217911

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Abstract

This paper investigated the diffraction of a Gaussian laser beam on a binary mask and a refractive axicon. The principles of the formation of a zero-order Bessel beam with sharp drops of the axial field intensity edges were discussed. A laser optical system based on an axicon for the formation of a Bessel beam with quasi-uniform distribution of axial field intensity was proposed. In the laser optical system, the influence of the axicon apex did not affect the output beam. The results of theoretical and experimental studies are presented. It is expected that the research results will have practical application in optical tweezers, imaging systems, as well as laser technologies using high-power radiation.

Highlights

Research on the methods of focusing light beams associated with the names of such scientists as Ernst Abbe, George Airy, and John Strutt have a long history and remain relevant to this day.Tight focusing of laser radiation, which allows one to obtain high power densities and directivity, is in demand in many problems of photonics and laser physics [1,2,3,4,5,6].In practice, Gaussian laser beams are widely used
When they are focused using an optical system with spherical surfaces, it is possible to concentrate laser radiation in the region corresponding to the beam waist diameter
The use of the mask with annular aperture allowed to obtain two amplitude diaphragm set in front of the axicon, and can be explained by the presence of aberrations in sharp edges in the distribution of the axial field intensity

Summary

Introduction

Tight focusing of laser radiation, which allows one to obtain high power densities and directivity, is in demand in many problems of photonics and laser physics [1,2,3,4,5,6]. When they are focused using an optical system with spherical (or parabolic) surfaces, it is possible to concentrate laser radiation in the region corresponding to the beam waist diameter. In Gaussian beams, the wavefront is flat only in the waist region, the length of which is equal to the confocal parameter. With a decrease in the waist diameter of a Gaussian beam, its confocal parameter decreases [7,8,9]

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