The side-pumped solid-state laser source comprises a resonant cavity defined by at least two spaced-apart mirrors, an active medium of laser crystal type placed in said resonant cavity, and a pumping source, the layout of the resonant cavity, defined by the crystal and by the mirrors, being arranged to cause spatial inversion of the oscillating mode within the active medium in the absorption direction of the pumping beam, such as to symmetrize the thermal focal length seen by the oscillating mode. The laser source comprises lenses for conditioning the pumping beam emitted by the pumping source, to form on the side face of the laser crystal a pumping spot arranged to symmetrize the spatial quality of the emitted laser beam and/or active control means for the laser crystal temperature, in order to correct its undesired astigmatic effects. The pumping process for the solid-state laser source generates on the side face of the laser crystal a pumping spot arranged to symmetrize the spatial quality of the emitted laser beam, in such a manner as to correct its undesired astigmatism effects.