Thermal lensing in a diode-end-pumped continuous-wave self-Raman Nd-doped GdVO4 laser

We have directly measured thermal lensing in a continuous-wave Nd-doped GdVO4 self-Raman laser under diode pumping at 808 and 879 nm. Thermal lensing increased significantly when generating first-Stokes emission, this most likely originating from impurity absorption and/or excited-state absorption at high pump powers. Pumping at 879 nm significantly reduced thermal lens effects in the laser crystal compared with pumping at 808 nm.