Determination of parameters of Cr4+:YAG crystalline absorbers from saturation of absorption

A method for determining absorption cross sections of chromium ions in the ground and excited states in addition to their concentration in Cr 4+ :YAG crystalline absorbers was presented. The method was based on a study of the saturation of absorption, the measurement of the absorber transmittance as a function of laser-pulse energy, and the modeling of this function that gave the best fit of the experimental data. Absorption cross sections and concentrations of chromium ions were determined for seven absorber samples. The χ 2 -confidence intervals and correlation matrices for those parameters were calculated. The parameters of different samples were shown to vary over rather wide ranges. Hence, it was necessary to characterize beforehand a specific absorber sample in order to calculate correctly the parameters of lasers with Cr 4+ :YAG absorbers.