The main technical parameters of welding field mirror are: working wavelength, incident pupil, scanning range and focusing spot diameter.
Working wavelength:It mainly depends on the wavelength of the laser. The lens of the field mirror is coated at a given laser wavelength. If the field mirror is not used within a given wavelength range, the field mirror may be burned out by the laser or the required laser transmittance is very low.
Pupil:Also called maximum incident spot. If a single mirror is used, the mirror is placed at the entrance pupil, and the diameter of the maximum available beam is equal to the diameter of the entrance pupil. The larger the incident pupil, the smaller the diameter of the focusing spot focused by the focusing lens. Therefore, when marking is required to be particularly fine, we will consider using a field lens with larger incident pupil, such as fine marking and galvanometer welding.
Scan range:The larger the field mirror can scan, of course, the more popular it is with users. However, if the scanning range is increased, the focus point becomes larger and the distortion also increases. In addition, if the scanning range is increased, the focal length and working distance of the field mirror should also be increased. The lengthening of working distance will inevitably lead to the loss of laser energy. In addition, the focused spot diameter is directly proportional to the focal length, which means that the scanning range is increased, the focused spot diameter is increased, the spot is not fine enough, and the laser power density decreases very fast (the power density is inversely proportional to the second power of the spot diameter), which is not conducive to processing. Therefore, users should select the most suitable field mirror according to different processing areas, or reserve several field mirrors with different scanning ranges.
Focal length:It has something to do with the working distance, but it is not equal to the working distance.
Focus spot diameter:For the scanning system with incident laser beam diameter D, field mirror focal length f and beam quality factor Q, the focusing spot diameter d = 13.5qf/d (mm). Therefore, a smaller focusing spot can be obtained by using a beam expander.
Optical fiber welding field mirror:The focused high-energy laser melts the workpiece and forms a specific molten pool between the parts that need to be welded to accurately weld the parts. We provide a variety of lenses with different power, incident light spot and working range to meet complex application scenarios. At the same time, the achromatic lens is specially designed and processed to make the focal plane of laser band 915 / 1064nm coincide with that of imaging band 420-680nm, so as to realize coaxial monitoring and imaging capture in the whole field of view.
The field mirror focuses the collimated laser beam at one point, improves the energy density of the laser beam, and uses the high energy of the laser to process various materials such as cutting, marking, welding, cleaning and surface treatment. At the same time, when the direction of the incident laser beam changes, the field mirror can still maintain the spot with the same relative size and energy density, The laser beam can process points at different material positions. The combination of field mirror and galvanometer which can quickly and accurately change the direction of laser beam can realize the high-speed and precise processing and processing of materials.
Function of optical fiber welding field mirror:
(1) Improve the ability of edge beam incident on the detector;
(2) In the same main optical system, the additional field mirror will reduce the area of the detector. If the same detector area is used, the field of view can be expanded and the incident flux can be increased;
(3) The modulation disc can be placed at the position of the image plane to solve the problem that there is no place to place the modulator;
(4) The non-uniform illumination on the photosensitive surface of the detector can be homogenized;
(5) When the flat field mirror is used, the flat field image plane can be obtained;
(6) In the aspect of aberration correction, the field curvature and distortion of the system can be compensated.