Large scanning field laser concurrent drilling system with a five-axis independent control for special-shaped holes.

Five-axis laser scanning technology is an effective drilling method for special-shaped holes. Due to a gap in laser angle-of-incidence (AOI) control within a large scanning field, current technologies are challenging for fabricating large-size holes or special-shaped hole arrays. In this paper, a large scanning field five-axis laser concurrent drilling system was proposed. The laser AOI was independently controlled using two pairs of synchronous deflection mirrors. The laser control deviations under a large scanning field were investigated systematically by simulation and experiment. By establishing a complete correction method, the laser AOI control within a scanning field diameter of up to 35 mm was achieved. A series of special-shaped holes were fabricated concurrently on a 3.6 mm thick glass fiber reinforced plastic (GFRP), verifying that the AOI can be controlled by the five-axis laser scanning system. Our work provides a novel method to increase the scanning field of the five-axis laser scanning technology, expanding the application scope of the five-axis laser processing.

Single-pass cutting of frosted glass via change of laser incident medium.

We report a water medium-assisted composite laser cutting (WMACLC) technology for what is believed to be the first time to achieve single-pass separation of frosted glass (FG). The water medium was used to flatten the surface of FG to reduce the diffuse reflection and random refraction of the incident laser. The simulation results of picosecond pulsed laser Bessel beam (PPLBB) intensity distribution in FG showed that the peak intensity in the presence of water can reach about 24 times and 2.3 times that in the absence of water when the PPLBB is 0.08 mm and 0.3 mm below the upper surface of FG, respectively. A PPLBB with higher intensity can be formed along the thickness direction to realize the material modification. A coaxial CW laser provides the thermal tensile stress required for separation. Finally, high-quality separation of FG was achieved using the WMACLC technology with a speed of 50 mm/s. No deviation in the separation track and no edge collapse occurred. The roughness Sa of the separated sidewall is less than 0.3 µm.

Extending the 3D scanning range of reflective dynamic focusing device-based laser scanners.

Reflective dynamic focusing devices (RDFDs) have shown their potential in laser scanning as high-performance laser Z-direction focusing devices. However, the scanning range of RDFD-based scanners is limited by aberrations during dynamic focusing. An aspheric symmetry correction (ASC) method was proposed to extend the effective scanning range. An aspheric lens was introduced to correct the optical path difference (OPD) and optimize aberrations. As a result, the scanning range in the three-dimensional (3D) space increased by 15.2%. The ASC method has been proven to extend the 3D scanning range of RDFD-based scanners and may have broad application prospects.