The focusing lens has the general characteristics of a conventional optical lens but has its own unique features. It can be used to make an ultra-short focal length lens, or it can form a real image on the end face, and it is easy to obtain an erect real image of the same size as the object.
The laser pipe cutting machine uses the energy of the laser beam to cut, and the original beam emitted by the laser must be focused by the lens to form a spot of high energy density. The transmissive lens is very simple to use. When the laser beam passes through the lens, the lens focuses the laser beam on the workpiece in the axial direction. In the common industrial laser system, the nozzle has the function of gas washing, that is, A gas jet is introduced at the nozzle to help improve the performance of the laser beam and material interaction, while the high velocity gas stream also acts to isolate the optical system. The gas jet prevents material from processing contaminants into the nozzle and contaminating the lens surface. The reflective focusing system uses an additional beam deflector and a back focus mirror. In this condition, there are two additional optical systems, a zinc selenide window and a beam deflector, the window functioning to seal the focusing system over the nozzle.
In high power laser systems, laser tube cutters often have difficulty reaching the diffraction limit. For soldering, small spots are not always required, so mirrors are suitable for this type of application. In recent years, the demand for high-power lasers has increased, and the focal depth and focal spot of conventional lenses have a restrictive relationship. Increasing the depth of focus will inevitably lead to the expansion of focal spot size. In many cases, the requirements for laser processing cannot be met, and the depth of focus is deep. High resolution focusing lenses have become a new market demand. The focal length and focus position of the focusing lens have an influence on the laser cutting quality. Therefore, the laser cutting machine is suitable for selecting a short focal length lens for high-speed cutting of thin materials, and a long focal length lens for cutting thick workpieces.
