Thermal lensing in diode-pumped Yb:CALGO and Yb:KGW lasers

The thermal lensing effect in the Ng-cut Yb:KGW and a-cut Yb:CALGO laser crystals was evaluated and compared using a similar laser cavity and pumping scheme. The Yb:KGW crystal exhibited large anisotropy along the horizontal and vertical axes and the thermal lensing sensitivity factors of Mx=0.52 m-1/W (||Np) and My=0.18 m-1/W (||Nm) were determined. The Yb:CALGO crystal exhibited negligible anisotropy in the thermal lensing power, and thermal lensing sensitivity factors of Mx=0.452 m-1/W (⊥c) and My=0.458 m-1/W (||c) were measured.