Method for monitoring laser machining process and associated laser machining system

The invention relates to a method for determining the depth of a steam capillary during a laser machining process, comprising: irradiating a machining laser beam onto at least one workpiece for forming a steam capillary, the machining laser beam being deflected on the workpiece along a machining path in a first scanning field by means of a first deflection device; irradiating an optical measuring beam onto the workpiece, the optical measuring beam being deflected on the workpiece by means of a second deflection device in the detection region relative to the machining laser beam along the detection path and subsequently deflected together with the machining laser beam by means of a first deflection device; detecting a distance measurement along a detection path on the basis of the portion of the optical measurement beam reflected by the workpiece; the depth and/or position of one of the steam capillaries is determined on the basis of the detected distance measurements, the size of the detection region being de