Three types of beam transmission methods and processing optical paths of solid-state lasers

This article introduces the three types of beam transmission methods and processing optical paths of solid-state lasers (SSL), and introduces how to reduce the thermal focus shift by using the reflected optical path; through the use of dual coaxial core optical cables, the same optical fiber can transmit two beams of different qualities. How to improve the beam quality to enhance the flexibility of the laser in a creative way; how to better use the galvanometer to scan the optical path of the high-quality beam to complete remote welding.　　Control thermal focus shift 　　When the wavelength of the laser beam is 1 micron, it is very important to keep the light path surface clean. Since the wavelength of a solid-state laser is much shorter than that of a carbon dioxide laser, even a small particle in the optical path can cause major damage or power loss. If you compare a zero-degree (straight-angle) processing head with a camera and a 90-degree (right-angle) processing head with a camera, it is easy to see the effect of thermal focus shift. In the case of a zero-degree angle configuration, in order to reflect visible light to the camera, a transmissive optical plate needs to be added between the lens and the collimator. When configured at a 90-degree angle, in order to reflect the laser wavelength and transmit visible light to the camera, a right-angled optical path needs to be coated.　　In the transmissive lens, the laser beam passes through the optical material, and about 2% of the energy is absorbed by the loose material and the lens surface, even the clean and well-designed lens is no exception. It can be expected that 2% of 1000 watts is quite easy to control, but 2% of 16,000 watts is difficult to eliminate from the material because the material is not particularly easy to conduct heat in terms of heat elimination characteristics. On the other hand, reflective lenses can reflect almost all of the energy, with only a small loss on the coating and surface, generally no more than 0.3%, so the heat loss in the optical material link is very small.　　 For high-power and high-load rate laser welding applications, the reflective optical processing head is an ideal choice. Both the collimating lens and the focusing lens have been replaced with reflective optical paths. Moreover, a coating is applied to the reflective focusing light path to transmit visible light to the camera located behind. This makes the protective cover slide the only light-permeable optical component in this configuration.