Vortex phase plate-based laser beam reference calibration method and device

Abstract

The invention discloses a vortex phase plate-based laser beam reference calibration method and a vortex phase plate-based laser beam reference calibration device. After the laser emitted by a laser device is reflected through a reflector and a pyramid prism, phase coding is performed on the laser beams by adopting a vortex phase plate; an interference dark spot serving as a position reference of the laser beams is generated in the center of the coded parallel beams by using the far field interference diffraction principle of the parallel beams, and the position of the dark spot is determined by the central point of the vortex phase plate, is not changed together with the drift of the beams and is not affected by the quality of light spots; and finally, the central position of the dark spot is acquired through a charge coupler. The reference can be used as the reference for linearity error detection of a linear guide rail or the reference for monitoring the two-dimensional position change of an object. The device has simple structure and avoids introducing additional errors; the system has strong stability and is favorable for practical application; and the positioning is accurate and is not easily affected by the surrounding environment.

Description

technical field [0001] The invention belongs to the field of optical testing, in particular to a laser beam reference calibration method and device based on a vortex phase plate. Background technique [0002] Due to the characteristics of good directionality, strong monochromaticity, and energy concentration, laser light has been more and more widely used in the fields of microscopic observation, distance measurement, optical storage, and data transmission with the development of science and technology. In many practical applications, it is often necessary to use various position-sensitive devices to receive the laser beam spot signal, obtain the relative position information of the laser spot, and then generate feedback or test signals to achieve the purpose of the system. Since the laser spot cannot appear as an ideal image point on the surface of the position-sensitive device, but has a certain area of ​​the spot, therefore, technical means must be used to designate a spe...

AI Technical Summary

Problems solved by technology

However, when the area of ​​the central light-blocking part of the annular aperture diaphragm is too large, it is not easy to accurately locate due to the increase in the area of ​​the dark spot; and when the area of ​​the central light-blocking part is too small, due to the inherent diffraction characteristics of the beam, the central dark spot The spot is easily annihilated due to the diffraction effect, and the dark spot disappears, which is especially obvious when the optical path of the laser is too long

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