Method of Calibration of a Laser-Based Galvanometric Scanning System with Submicron Resolution

Abstract

A method used for calibration of scanning modules on the basis of galvanometric deflectors is considered. The method is based on an iterative two-step algorithm of processing of the profilometry map of the test writing of the calibrated module. It is demonstrated that high accuracy and robustness of determining the coordinates of the reference points of the test writing can be obtained by means of finding the approximate positions of such points and identifying the fragment in the vicinity of these points at the first step and searching for the exact values of the coordinates by the correlation method at the second step. The use of this method and a simple algorithm of piecewise-planar interpolation offers a possibility of laser beam positioning with a relative error of 10−5 from the writing field.