Optimal Doping Concentrations of Nd³⁺ Ions in CYGA Laser Crystals

The kinetic process of the excited state population of Nd3+ ion in Nd: CaY0.9Gd0.1AlO4 (Nd: CYGA) crystal were studied in detail to estimate the optimal doping concentration, which maximize similar to 1 mu m fluorescence emission from the F-4(3/2) state to the I-4(9/2) state of Nd3+. The analysis was accomplished by revealing the dependence of the excited state population on the doping concentration in a relatively convenient way in theory. After comparing the theoretical prediction results with the experimental findings and approximating the results obtained using the aforementioned method, the optimal relative doping concentration of Nd: CYGA was determined to be 2.1 at.%, which closely matched the 2.0 at.% obtained through experimental comparison. This verifies the effectiveness and accuracy of the proposed method. In particular, it is worth mentioning that in this method only one doping concentration of the crystal is required to obtain the optimal concentration, which may be used to guide the concentration optimization process for improving efficiency and saving resources.