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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.

An efficient and flexible method using femtosecond laser bursts assisted by wet etching is presented to fabricate large-area high-quality microlens arrays (MLAs) on a silica glass surface. In this method, femtosecond laser bursts can ablate micro craters on silica glass in a fast, single-step process by controlling the electron density and a high-speed scanning galvanometer, and the influence mechanism of the number of pulses within a burst on the accuracy and quality of micro craters is analyzed in detail. The experimental results show that the preparation efficiency of micro craters is significantly improved to approximately 32,700 per second. By subsequent acid etching, concave microlenses with controllable dimensions, shapes, and alignments are easily obtained. A large area close-packed hexagonal concave MLA is successfully fabricated by using this method and shows high surface quality and uniformity, which excellently demonstrates the feasibility and flexibility of rapidly fabricating MLAs in the burst regime.

By combining a picosecond Bessel laser and a continuous-wave (CW) fiber Gaussian laser with the same optical axis, a composite laser beam separation (CLBS) technology that allows the fast, high-quality separation of brittle transparent materials was developed for the first time, to the best of our knowledge. In this experiment, 1-mm-thick soda lime glass was separated using this CLBS technology, and the CLBS separation mechanism was analyzed. The experimental results show that a separated surface similar to frosted polishing can be obtained by CLBS, and the edge chipping of the separated upper surface was no more than 0.5 µm. The separated sidewall was flat and smooth without separation defects such as cracks or broken edges, and the surface roughness (Ra) was 0.12 µm. The separation speed reached 12 mm/s and can be further improved by increasing the CW laser power density. This research provides a new way for lasers to separate brittle transparent materials.