Sometimes it is important to know the kind of laser and also the nature of the active media where the photons are produced, mainly when the photon source is situated at long distance from the target, and you can have information, only from the photons. The authors considered many ways of theoretical and applied research, using models for different types of lasers. High-speed and high-accuracy applications in processing trend to increase in the field of some important applications like laser beam welding and laser beam cutting. Some time the source presents inconstant parameters, and so, the measurements must be made in a relative short interval of time. The study requires problems like: space resolved analysis -- the calculation of the average intensity distribution; time resolved analysis of the beam power, position or diameter. The statistical analysis that can be performed allow an estimation of the uniformity of laser pulses. The short-term stability of the laser beam sources is very important, because in the most cases we must do the analysis of a short time pulse. Some methods, proposed by scientists until now, are not overall applicable in all cases. For that, the authors proposed a new and more complete method.