Beam splitter prism and method and device for detecting topological charge of vortex beam

Abstract

The invention relates to a beam splitter prism and a method and device for detecting the topological charge of a vortex beam. The vortex beam is divided into two light beams through the beam splitter prism, and the beam splitter prism is used for carrying out interference so that the topological charge of the vortex beam can be measured; a cube prism is cut open in the direction parallel to a pair of edge opposite angles, after cut surfaces are ground and polished, one of the cut surface is plated with a metal film, and then the two prism bodies are bonded to form a cube again. The beam splitter prism and the method and device for detecting the topological charge of the vortex beam have the advantages that the method for measuring the topological charge of the vortex beam on the basis of a beam splitter prism self-interference technology is provided for overcoming the defects in an existing method for measuring the topological charge of the vortex beam; an optical path for measuring the vortex topological charge through the single beam splitter prism is compact and practical, and the measuring method is simple, fast and stable in experiment results.

Description

technical field [0001] The invention belongs to the field of coherent optical measurement, and in particular relates to a spectroscopic prism and a method and device for detecting the topological charge of a vortex beam. Background technique [0002] Vortex beams are a class of singular light fields with a helical phase wavefront, with a wavefront phase structure that can be expressed in the form of exp(ilθ). Among them, the azimuth θ is a function of the Cartesian coordinate axes x and y, defined as tanθ=y / x; l is a topological charge, which can be positive or negative, indicating that the phase changes by 2lπ around the center of the beam, and different The topological charge signs correspond to opposite helical directions. The center point of the spiral phase structure of the vortex beam is on the same phase line as any radial direction, so the phase at this point cannot be defined, so it is called phase singularity. The spiral phase structure of the vortex beam makes t...

AI Technical Summary

Problems solved by technology

[0005] In order to avoid the deficiencies of the prior art, the present invention proposes a spectroscopic prism and a method and device for detecting the topological charge of a vortex beam, which solves the limitations of the existing methods for measuring the topological charge of a vortex beam such as complexity and instability It is a measurement method with compact optical path, simple and fast measurement, and stable results

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