Simulation of ultrashort pulse laser drilling of glass considering heat accumulation.

In accordance with the increasing demand for high-speed processing, the repetition rate of ultrashort pulse lasers has continued to increase. With the development of these lasers, there is a growing demand for the prediction of shapes processed at high repetition rates. However, the prediction of these shapes is a major challenge, because of the difficulty associated with the estimation of heat accumulation.

Dynamics of pressure waves during femtosecond laser processing of glass.

Although femtosecond lasers enable microfabrication of transparent materials, precise processing is difficult owing to the inevitable damage caused to the surroundings of the processed region. In the present work, we combine pump-probe imaging with a high-speed camera to capture the dynamics of pressure waves varying from pulse to pulse, before a desired shape is created by hundreds of pulses. The results demonstrate that the pressure waves change their forms and locations as the number of pulses increases.