This paper presents the results of numerical simulation of the dynamics of a vapor bubble at the end of an optical fiber. The bubble appears as a result of the absorption of laser radiation energy by water. Our model is prototyped by the level-set model that describes the movement of two phases (water and vapor) and the interface position. For the closing relationships we used the previously obtained experimental data of nucleus formation. Numerical calculations are based on our earlier hypothesis about the predominant influence of the hydrodynamic pattern on the formation and characteristics of the cumulative jet. We determined the influence of the hydrophilicity of the optical fiber surface on the pulse magnitude of the cumulative jet. The influence of the salt impurity content on the jet formation happened to be predictably small due to the insignificant change in the aqua solute viscosity. To confirm the correct understanding of the mechanics of the ongoing hydrodynamic processes, we compared the results of numerical simulation with the theoretical estimate for the velocity obtained for a cumulative jet. The results of the numerical simulation obtained in this work indicate the decisive influence of the properties of the optical fiber surface, since the variability of the velocity of the cumulative jet depending on the wettability and geometry of the end-face was at least 50%.