The external light path of the laser  die cutting machine is mainly composed of a circularly polarized reflection lens, a linearly polarized reflection lens and a focusing lens. At present, the laser beam of the laser die cutting machine emitted by the civilian laser generator  of the laser die cutting machine has a certain divergence angle. When the length of the optical path changes, the diameter of the beam acting on the surface of the lens changes at a moment, which causes a change in the focus size and depth of focus, and the focus for the laser die cutting machine.

 There are currently three measures for optical path length compensation of the laser die cutting machine.

Beam collimation using a beam expander for the laser die cutting machine.

The beam waist diameter is inversely proportional to the far field divergence angle of the laser die cutting machine. The larger the beam waist diameter of the laser die cutting machine , the smaller the far field divergence angle. The main function of the beam expander is to improve the transmission characteristics of the beam by changing the beam waist position and size for the laser die cutting machine, thereby improving the cutting instability caused by the change of the optical path length for the laser die cutting machine.

Variable curvature radius lens (VRM)

The VRM control system changes the water pressure in the water tank of the VRM lens by adjusting the output flow of the variable pump for the laser die cutting machine, so that the radius of curvature of the VRM lens can be changed to improve the transmission characteristics of the beam for the laser die cutting machine.