Optical beam drifting amount fast feedback controlling type high precision laser aligning method and device

Abstract

A method and equipment for high-precision laser collimation controlled by fast feedback of optical beam shift integrates optical intensity modulation, optical fibre collimation and fast feedback and control techniques. Said method includes modulating the laser beam to become alternative beam, primary collimation by use of single-mode fibre, decomposing the beam shift into horizontal shift and angle shift, high-precision phase-lock amplifying and detecting, and using the feedback control mechanism to decrease the shifts by alternative regulations.

Description

technical field [0001] The invention relates to a fast feedback control type high-precision laser alignment method and device for beam drift, which are used in precision or ultra-precision processing equipment and measurement. Background technique [0002] Due to its good single directionality, high brightness and high stability, the laser beam is often used as a measurement standard and widely used in ultra-precision processing equipment and measurement equipment. However, the laser beam emitted by the laser often drifts during the propagation process, mainly manifested as flat drift, angular drift and random drift of the laser beam, and its magnitude is generally in the order of 10 -4 ~10 -6 rad, this weakness limits the further improvement of laser beam collimation accuracy and affects its practical application. The main reasons for laser beam drift are: 1) temperature deformation of the laser resonator; 2) uneven refractive index of the air in the beam propagation path...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the deficiencies of the low collimation accuracy of the existing collimation technology, the present invention integrates beam intensity modulation technology, optical fiber collimation technology and high-speed feedback control technology of beam drift to provide a fast feedback control of beam drift with high precision Laser collimation method and device, which modulates the laser beam into an alternating beam of a specific frequency (such as 465 Hz) that is a non-integer multiple of the power frequency of 50 Hz, uses a single-mode fiber for primary collimation, and then primary collimates the single-mode fiber Finally, the beam drift is decomposed into flat drift and angular drift, which are respectively subjected to high-precision phase-locked amplification detection, and the corresponding beam flat drift and angular drift feedback control mechanism is used to make the beam flat drift and angular drift The reduced direction is alternately adjusted with high-speed feedback to achieve high-precision collimation of the outgoing beam

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