We report the production of color centers in LiF single crystals by ultrashort high intensity laser pulses (60fs, 10 GW). An intensity threshold for color centers creation of 2 TW/cm² was determined, which is slightly smaller than the continuum generation threshold. We could identify a large amount of F centers that gave rise to aggregates such as F₂, ${{\mathrm{F}}_2}^{+}$ and ${{\mathrm{F}}_3}^{+}$. The proposed mechanism of formation is based on multiphoton excitation that also produce short lived ${{\mathrm{F}}_2}^{+}$ centers. It is also shown that it is possible to write tracks in the LiF crystals with dimensional control.

We report the validation of the Diagonal Scan (D-Scan) technique to determine the incubation parameter for ultrashort laser pulses ablation. A theory to calculate the laser pulses superposition and a procedure for quantifying incubation effects are described, and the results obtained for BK7 samples in the 100 fs regime are compared to the ones given by the traditional method, showing a good agreement.