An ablation system for ablating a material can include a laser source, a set of homogenizing optics, and a homogenizing optics adjustment device. The laser source is for generating a laser beam. The set of homogenizing optics receives the laser beam and includes a first homogenizer and a second homogenizer. The homogenizing optics adjustment device carries the homogenizing optics, the homogenizing optics adjustment device configured to selectably adjust the position of at least one of the first homogenizer and the second homogenizer in order change a size of the laser beam, with a change in size of the beam changing the fluence thereof. The ablation system can be incorporated within a laser-ablation based analytical system, where the laser-ablation based analytical system includes a spectrometer.