Simulation of f-d transition using the extended crystal-field model: parameter dependent study for Er3+ in various hosts

The 4f-5d transitions of Er3+ ions doped in crystals were widely studied due to their potential applications in quantum cutting phosphors and VUV lasers, etc. The theory to do the calculations of 4f-5d transitions and various related aspects, such as the ways to determining various parameters, were summarized. The impacts of various interactions on the spectra were also demonstrated clearly with Er3+ ions in crystals CaF2 and LiYF4. Predicted results were compared with measured spectra.