Thermal lensing in Nd:GdVO4 laser with direct in-band pumping at 912 nm

Abstract

We report on the thermal lensing effect study in a 1063-nm Nd:GdVO4 laser with in-band diode pumping at 912 nm. The thermal lensing focal power was determined using the experimentally measured values of the laser beam width and beam quality factor (M2). The maximum observed thermal lens dioptric power was 9 m−1 at 11.3 W of output power (18.87 W of absorbed pump power) for the pump spot size diameter of ~ 394 µm. Finite element analysis simulation was also performed and strongly supported the experimental data. The effect of experimental conditions on the thermal lensing strength and comparison with previous values obtained with traditional 808 nm pumping were discussed. It was shown that pumping with 808 nm suffers from higher thermal lensing. A comparison with a well-known Nd:YVO4 laser crystal was also made.