Thermal lensing in high-power diode-pumped Yb:KGW laser

Abstract

We investigated thermal-lensing effects in a diode end-pumped Yb:KGW laser with slab shaped active element. Performance and thermal lensing properties for Ng cut Yb:KGW and Yb:KGW cut for athermal propagation direction are presented. It is found that crystal cut along athermal direction provides weaker thermal lens than Ng cut active element, however, due to anisotropic Yb:KGW characteristics, thermal lens is highly astigmatic. End bulging contribution to thermal lensing under intense pump was measured (for Ng cut active element). Keywords: Yb:KGW, thermal lens, diode-pumped, athermal orientation