Аннотация:Using numerical simulation, we study the influence of ratio between characteristic scales of a femtosecond mid-IR wave packet on the threshold power of filamentation and light bullets formation under condition of anomalous group velocity dispersion in transparent dielectrics. As the similarity parameter to determine the process of filament formation and light bullet creation was chosen a ratio of the diffraction length to the dispersion length of wave packet. It was found that the threshold power of filamentation, divided by the critical power of stationary self-focusing, does not depend on the wavelength of radiation and parameters of the medium and can be determined by the introduced similarity parameter. It was established that under condition of optimal choice of a parameter (the diffraction length is much smaller than the dispersion length) the threshold power of filamentation. With an increase of the similarity parameter, the threshold power of filamentation and light bullet formation increases. An optimal control of light bullets’ formation can be used at the problems of environmental sensing and transportation of high-density energy in the atmosphere.