Ultrashort pulse laser processing that facilitates high-speed and fine processing of glass materials has received considerable attention in recent years, despite mechanical processing or etching having been the mainstream methods. However, the physical mechanisms of this technique and the influence of various parameters, such as the processing conditions and physical properties of the processed material, on generated shapes are not yet fully understood. In this work, we comprehensively investigated the influence of various parameters of ultrashort pulse lasers on the processing mechanisms through experiments conducted by changing the wavelength, pulse width, repetition rate, and pulse energy over a wide range. The physical effects of the laser parameters on the reflection of light and heat generation were discussed by analyzing the experimental results, and the influence of the parameters on the generated shapes, processing speed, and saturated depth was clarified. In addition, cracks around the ablated area, which are one of the problems concerning glass processing with ultrashort pulse lasers, were observed, and the influence of the pulse energy on the cracks was evaluated. It is expected that this research will allow for a thorough understanding of the laser parameters that are suitable for glass processing and widen the range of laser processing applications.
In situ imaging of hole shape evolution in ultrashort pulse laser drilling
