Method for generating perfect flat-topped light beam/flat-topped vortex light beam

Abstract

The invention discloses a method for generating a flat-topped light beam / flat-topped vortex light beam, relates to a regulation and control method of a paraxial light beam space structure and belongs to the field of optics. The method comprises the following steps of 1, calculating space Fourier transform of a perfect flat-topped beam / flat-topped vortex beam space complex amplitude to obtain space complex amplitude information after Fourier transform; 2, determining a blazed grating phase depth modulation factor according to the spatial complex amplitude information after Fourier transform; 3, loading the blazed grating phase depth modulation factor serving as an intensity mask to the phase mask to obtain a complex amplitude mask; and 4, modulating incident light by using the complex amplitude mask, and performing Fourier transform on the modulated light beam to obtain the perfect flat-topped light beam / flat-topped vortex light beam. The method is advantaged in that the phase holography technology is expanded, the complex amplitude modulation technology of the non-adiabatic process is adopted, and incident light can be converted into any flat-topped light beam / flat-topped vortex light beam within the focal field range.

Description

technical field [0001] The invention relates to a method for regulating and controlling the spatial structure of a paraxial light beam, belonging to the field of optics. Background technique [0002] A flat-top beam with spatially uniform light intensity and phase distribution, and a flat-top beam with a vortex phase (or Orbital Angular Momentum, OAM) on this basis and a smooth change in light intensity at the central vortex singularity Beams are of special significance in applications based on the interaction of light and matter (such as optical tweezers, nonlinear optical microscopy, etc.), however, there are no reports that can effectively generate or convert the above two flat-hat beams from Gaussian beams. technology. As early as 1997, "Analytical beam shaping with application to laser-diode arrays" published in "Journal of the Optical Society of America A" Volume 14, page 1549, introduced the method of using phase holography to shape Gaussian beams into flat-hat beams...

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Problems solved by technology

[0003] The purpose of the present invention is to solve the problem that the prior art cannot take both intensity modulation and phase modulation into account, so it is impossible to produce a flat-hat beam with spatially uniform light intensity and phase distribution, and on this basis, it carries a vortex phase and a central vortex singularity. The problem of flat-top beams with smooth changes in light intensity, providing a method to generate perfect flat-top beams / top-top vortex beams

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