Radial shearing interference spatial light modulator calibration method based on double-vortex light

Abstract

The invention relates to a radial shearing interference spatial light modulator calibration method based on double-vortex light. The method comprises the following steps that: a pair of vortex light phase diagrams is generated, the two phase diagrams are superposed, the superposed phase diagrams are loaded on a spatial light modulator, and a petal-shaped interference light spot is generated on a CCD after coherent light irradiation; a gray value loaded on the spatial light modulator is changed, so that the phase of one vortex light beam can be changed, at the moment, the interference light spot on the CCD can rotate, the phase of the vortex light loaded on the spatial light modulator is multiplied by a specific coefficient, so that the rotation angle of the light spot can be made be equalto the phase change amount of the vortex light; and finally, the gray value on the spatial light modulator is gradually increased from 0 to 255, so that a series of interferograms can be obtained, therotation angle of the light spot in each interferogram is obtained by adopting a rotation angle algorithm, and the rotation angle is made to correspond to the gray value loaded on the spatial light modulator. Therefore, calibration of the spatial light modulator is realized. The method has the advantages of high precision, simple light path and convenience in processing.

Description

technical field [0001] The invention relates to a spatial light modulator, in particular to a calibration method for a spatial light modulator. Background technique [0002] The current spatial light modulator calibration methods are mainly divided into interferometry, which uses the interference principle to detect the movement of interference fringes, and the light intensity measurement method, which loads a two-dimensional grating on the spatial light modulator to detect the change of light intensity. According to the design of the optical path, the interferometry method is divided into two types: the common optical path of the wave surface and the dual optical path of the amplitude. Typical split-wavelength common optical path methods include double-slit interferometry, radial shearing interferometry, and transverse shearing interferometry. The characteristic of this type of method is that it is not easily affected by the experimental environment, but it has the disadva...

AI Technical Summary

Problems solved by technology

This method has a simple optical path and is not easily disturbed by the external environment, but it also has the disadvantage that the accuracy is not high enough and it is not suitable for all spatial light modulators.

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