Maintenance of collimating beam expander: First of all, the distance between laser semi-reflective diaphragm and collimating beam expander should not be too close or too far. Secondly, when assembling and disassembling the collimating beam expander, it is necessary to ensure that the lens and lens barrel are clean, and the lens surface cannot be stained with dust and other stains. Especially the small eyepiece at the front end of the collimating beam expander needs extra care because it bears the largest energy density. Finally, the collimating beam expander is adjusted by the four-dimensional adjusting bracket, so that the laser vertically passes through the center of the collimating beam expander, and the output with high beam quality is ensured. There is little difference between 45 total reflection mirror and ordinary total reflection mirror, but the reflection angle and lens size and shape are different. Its maintenance is relatively simple, mainly to keep the mirror clean and the lens evenly cooled. The adjustment of 45 total reflection mirror is realized by a special two-dimensional adjustment bracket, which needs the cooperation of subsequent optical paths. Relatively speaking, the maintenance of focusing mirror is the most common and key maintenance in the external optical path system of solid-state laser. On the one hand, the structure of focusing mirror is varied, on the other hand, the working environment of focusing mirror is more complicated, and some minor faults are most likely to occur. When maintaining the focus lens, we should not only ensure the cleanliness of the lens, but also pay attention to the assembly position order and orientation of the lens for the compound lens. In addition, after the focusing lens is assembled, pay attention to reasonable adjustment of defocus and calibration.

Collimating beam expander is to shape the Gaussian beam output by laser, compress its divergence angle and expand the spot size, so as to obtain better comprehensive beam quality. Judging from the sequence of light passing through the device, the collimating beam expander is the first optical element to receive the high energy density laser output from the laser. It is very important and difficult to keep the collimating beam expander under the impact of high-energy laser, plus the unique structure and clamping adjustment bracket of the collimating beam expander.