Optical properties of Er3+ ions in lithium borate glasses and comparative energy level analyses of Er3+ ions in various glasses

The electronic structure of Er3+ ions are studied in the following lithium borate (LBO) glasses: Li2CO3 + H3BO3 and RCO(3) + Li2CO3 + H3BO3 (R = Mg, Ca, Sr and Ba). The electronic structure of Er3+ (4f(11)) in these glasses as well as the data that are available for other systems in the literature are also analyzed in terms of a Hamiltonian model that consists of 20 interaction parameters of atomic nature. The energy level analyses resulted in good correlation between the calculated and experimentally observed energies. The matrix elements for the transitions of Er3+ :LBO glasses are calculated in the intermediate coupling scheme using the measured energies in these glasses. Using the Judd-Ofelt theory, the intensity parameters are obtained from these matrix elements and experimentally obtained oscillator strengths. Radiative properties for fluorescent levels of Er3+ ions in LBO glasses are evaluated. The similarities and differences in the radiative characteristics of Er3+ :LBO glasses and other Er3+ :glasses are discussed.