System and method for focal position control

Abstract

The present disclosure relates to a beam analysis device for determining a light beam state, e.g., determining the focal position of a light beam, where the device has a partial beam imaging device having at least one first selection device for forming a first partial beam from a first partial aperture region of the first measurement beam, and an imaging device for imaging the first partial beam for generating a first beam spot onto a detector unit having a spatially-resolving detector. The beam analysis device also can have an evaluation unit for processing the signals of the detector unit, for determining a lateral position (a) of the first beam spot, and for determining changes in the lateral position (a, a') of the first beam spot over time. An optical system for focal position control with a laser optics and with a beam analysis device. Additionally, the disclosure relates to a corresponding beam analysis method and methods for focal position control of a laser optics and for focal position tracking of a laser optics.