Active control of focus position of laser beams using thermally induced lensing

Abstract

In this paper, we present a method for active control of thermally induced lensing in high-power lasers. We used thermal lensing to study the advantages of high-power lasers. Many delivery optics are sensitive to the thermally induced lens, which can change the focus position of the transmitted beam. To compensate for this, we used thermal lensing by pumping a crystal that had no absorption or amplification at the seed beam wavelength. By controlling the strength of the heat source, we demonstrate acute control of the focus position. Our modelling work is based on the finite-volume method (FVM) to analyse thermal effects in end-pumped solid-state crystals. This work has the potential to pave the way for active control of a thermally induced lens in high-powered laser-based applications.