Experimental and Numerical Analysis of Thermal Aberrations in Nd:YVO4 Laser Amplifiers

Nd:YVO
4
is an excellent gain material for laser amplifiers used in gravitational wave detectors [1] because of several reasons. Nd:YVO
4
's anisotropic emission cross-sections and inherent birefringence enable stable output polarization and suppress thermally induced depolarization. Furthermore, Nd:YVO
4
saturates at low seed intensity. However, vanadate's low thermal conductivity poses a major challenge for the application of Nd:YVO
4
laser crystals, because the beam quality degrades at higher power levels as a result of thermal wavefront distortions [2], [3]. In this work, we analyse the aberrations of the thermal lens in Nd:YVO
4
amplifiers in order to design suitable counter-measures and increase the achievable single-mode output power.