Method and apparatus for determining the position and the diameter of the focal spot (focus) of a laser beam, in particular for use for the processing of materials with a high power laser beam

摘要

In a method for determining the position and diameter of the focal spot of a laser beam, especially of a high-power laser beam, a rotationally symmetrical reflector which images the laser beam on a focal line is inserted into the beam path of a focused laser beam. The laser beam reflected at the reflector is detected via at least one sensor permanently assigned to the reflector on the focal line, and the focal plane, the lateral position of the focal point and the diameter of the focal spot are then determined via measured values detected in the sensor, the sensor being displaced relative to the focusing optical system of the laser beam or relative to the reflector. …??As a result, there is available a method of the generic type in which the power flux density of the laser is reduced so far that the laser can be measured reliably and clearly with the aid of sensors. …IMAGE…