<title>Laser microhole drilling using Q-switched radially and tangentially polarized beams</title>

Abstract

Laser microhole drilling using radially and tangentially polarized Q-switched laser radiation has been analyzed comparatively. Tangential polarization exhibited a significantly higher drilling speed compared to radial polarization. Light attenuation through interaction with the walls of a microhole was found to be weaker in the case of tangential polarization than in the case of radial polarization, thus leading to the assumption that the observed higher drilling rates utilizing tangential polarization are due to more energy being deposited at the bottom of a microhole. The required radiation has been generated using a Q-switched Nd:YAG laser resonator in a configuration that exploits thermally induced birefringence to render the laser resonator stable only for radial polarization.