Characterizing focusing units for micromachining with ultrashort laser pulses

Abstract

We investigate the focusing performance of optical tools for materials processing with ultrashort laser pulses. Here, focus distributions generated by high-NA microscope objectives and f-theta objectives are evaluated in terms of peak intensities and symmetry breaks when pulses of ≲ 100 fs are applied. With our simulations, we additionally examine the effects of spatial beam shaping and uncover associated spatio-temporal focusing phenomena, when diffractive optical concepts are used, for example, to shape customized non-diffracting beams or 3D-focus distributions.