Method and system for measuring complex coherence degrees of partially coherent vortex light beams

Abstract

The invention discloses a method and a system for measuring complex coherence degrees of partially coherent vortex light beams. The method includes recording the light intensity of the to-be-measuredpartially coherent vortex light beams; introducing disturbance with cubic different phase assigned values into the to-be-measured partially coherent vortex light beams; carrying out Fourier transformation on the disturbed to-be-measured partially coherent vortex light beams and recording the light intensity of Fourier planes under the conditions of the cubic different phase assigned values; carrying out inverse Fourier transformation according to the cubic different phase assigned values and the light intensity of the Fourier planes under the conditions of the cubic different phase assigned values to obtain cross-spectrum density functions of the to-be-measured partially coherent vortex light beams; acquiring the complex coherence degrees of the to-be-measured partially coherent vortex light beams by the aid of the cross-spectrum density functions and the light intensity of the to-be-measured partially coherent vortex light beams. The method and the system have the advantages that coherent singular points can be directly observed from phase distribution graphs of the complex coherent degrees, accordingly, topological charge number magnitude and positive-negative information of theto-be-measured partially coherent vortex light beams can be obtained, and the method and the system have important significance in the fields of laser processing, optical tweezers, atom cooling and the like.

Description

Technical field [0001] The invention relates to the field of optical measurement, in particular to a measurement of a partially coherent vortex beam of Method and system for complex coherence. Background technique [0002] As an important branch of modern optics, singularity optics has attracted the attention of a large number of researchers at home and abroad. The so-called singularity is a point that cannot be defined by certain parameters in the light field. For example, the phase singularity proposed and defined by Nye and Berry. The most typical phase singularity is a vortex beam. Under the condition of complete coherence, the light intensity at the center of the vortex beam It is zero, and the phase presents a gradual spiral structure, and the phase of the cross midpoint is uncertain, which is the phase singularity. [0003] Vortex beams have great application prospects in laser particle capture, micromanipulation, information encoding, and optical information transmission. ...

AI Technical Summary

Problems solved by technology

If the complex coherence of a partially coherent vortex beam can be measured, then the distribution of phase singularities can be observed from the amplitude and phase distribution diagrams of the complex coherence, so that the topological charge and the positive value of the partially coherent vortex beam can be obtained Negative information, and currently there is a lack of a method that can measure the complex coherence of partially coherent vortex beams

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