Nd:YAG lasers with output power levels of tens of watts, a nearly diffraction-limited beam quality, and a linearly polarized continuous wave output are commonly pumped by laser diodes at a wavelength around 808 nm, where the pump light spectrum is matched well to the absorption maximum of Nd:YAG. As a consequence, low Nd 3-doping concentrations of the laser crystals are required in order to minimize thermally induced stress. The use of higher Neodymium concentrations requires pump wavelengths beside the 808 nm absorption maximum and will furthermore result in changed thermo-optical behavior of the material. We present simulations and experimental results on how the doping concentration of Nd3 influences the fraction of pump light converted into heat.