Research on picosecond laser-assisted polishing of K9 optical glass: investigation of processing parameters and physical mechanism.

During the grinding process, K9 optical glass exhibits poor machinability, leading to issues such as crack growth, machining costs, low machining efficiency, and many other problems, seriously restricting its manufacture and application. This paper evaluated the feasibility of picosecond laser-assisted polishing of optical glass workpieces as an economical production method. This study involves a comprehensive exploration of several key aspects, including workpiece dimension control, the surface quality after picosecond laser ablation assessment, the parameters of the picosecond laser equipment optimization, and fine-tuning the parameters of the polishing equipment. The results show that the workpiece surface exhibits a recast layer with an uneven thickness distribution after laser processing, leading to a 38% reduction in luminous flux. Additionally, the roughness of the ablated surface decreases as the pulse repetition rates increase from 40 to 120 kHz. Due to the nonlinear absorption of energy by the amorphous body, the maximum ablation depth occurs around 80 kHz. Furthermore, the unevenly distributed recast layer affects the polishing process. Nevertheless, the efficiency of the picosecond laser-assisted polishing method is greatly improved compared to the conventional method of precision grinding followed by polishing. [ABSTRACT FROM AUTHOR]