Simultaneous spatial and temporal focusing optical vortex pulses for micromachining through optically transparent materials

We introduce the optical vortex beam into simultaneous spatial and temporal focusing (SSTF) technique, and theoretically and experimentally demonstrate the local control of peak intensity distribution at the focus of a simultaneous spatiotemporally focused optical vortex (SSTF OV) beam. To avoid nonlinear self-focusing in the conventional focusing scheme, a spatiotemporally focused femtosecond laser vortex beam was employed to achieve doughnutshaped ablation and high aspect ratio (similar to 28) microchannels on the back surface of 3 mm thick soda-lime glass and fused silica substrates. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

In this study, the optical vortex beam is introduced into the simultaneous spatial and temporal focusing (SSTF) technique, and the local control of peak intensity distribution at the focus of a simultaneous spatiotemporally focused optical vortex (SSTF OV) beam is demonstrated theoretically and experimentally. To avoid nonlinear self-focusing in the conventional focusing scheme, a spatiotemporally focused femtosecond laser vortex beam is employed to achieve doughnut-shaped ablation and high aspect ratio microchannels on the back surface of glass and silica substrates.