Today, laser processing technology has become the darling of industrial applications due to its high efficiency, high precision, non-contact processing and other characteristics, opening up broad prospects for high-quality, efficient and environmentally friendly processing and production. CO2 lasers, fiber lasers, and semiconductor laser pointer are the mainstream lasers in industrial applications. Their laser pulse widths are in the microsecond and nanosecond levels. The laser of this pulse width level removes the material by the action of light and heat, and will have the effect of "hot processing".
Laser, as an emerging processing technology, is facing more challenges. The heat-affected zone caused by the "hot working" effect, slag residues and strain cracks are the main reasons that limit the machining accuracy, efficiency and process repeatability of the workpiece. With the development of industrial applications, higher requirements have been placed on the feasibility of processing, the quality of processing and the efficiency of processing. For some demanding processing tasks in the field of laser micromachining, the adverse effects derived from "hot processing" make microsecond and nanosecond pulse width lasers unable to meet their requirements.
In order to further improve the processing accuracy and reduce the thermal influence existing in the processing process and the derivative adverse effects caused by the thermal influence, the picosecond laser gradually penetrates into the industrial application field. Picosecond lasers have ultrashort pulse widths of picoseconds. When processing materials, green laser pointer photons directly destroy the bond of the target material. This is relatively a "cold" processing process. The heat affected zone is small and there is almost no heat effect. Area, the entire processing process is very clean, there is no recast material, so there is little need for post-processing. These characteristics of picosecond laser doomed it to an important position in the field of laser micromachining.
The beams of the gravitational wave detectors of all laser systems currently used have a higher intensity at the center than at the edges. This will cause an undesirable measurement accuracy problem of the gravitational wave detector caused by the fluctuation of the mirror surface. This so-called thermal noise can be improved by a more uniform laser intensity distribution.