MEASURING METHOD AND APPARATUS FOR CONTROLLING POSITION OF FOCAL POINT OF HIGH-OUTPUT-POWER LASER BEAM IN THREE DIMENSIONS

摘要

PURPOSE: To control the focus and gradient of the high-output laser beam for material machining in three dimensions. CONSTITUTION: To measure deviations in the gradient and focus of the laser beam, a beam splitter ST which spreads over the entire section of the beam S extracts part Sm of the beam, an optical system V/Z which generates astigmatism focuses the beam on a quadrature detector Q, and various patterns generated on the quadrature detector 1 and their pattern position are evaluated according to the defocusing and the gradient of the beam by using an electronic circuit to generate corresponding control signals KF, KT, and KTy .