MEASURING PROCESS AND ARRANGEMENT FOR THE THREE-DIMENSIONAL POSITION CONTROL OF THE FOCAL POINT OF HIGH-ENERGY LASER BEAM

摘要

A process and apparatus for three-dimensional position control of the focal point of a high-energy laser beam by measuring its directional and focal point deviation. A portion of the energy of the laser beam is split off by means of a beam splitter extending over the whole cross-section of the laser beam and is focussed on a quadrant detector by means of an optical system which introduces an astigmatic aberration. The various patterns and pattern positions generated on the quadrant detector as a function of the defocussing and directional deviation are analyzed by means of an electronic system, and corresponding control signals are generated.