The spectroscopic properties of Er3+ : PbO - ZnO - CaO- Al2O3- B2O3 glasses have been studied. Racah coefficients (E1, E2 and E3), Slater Condon parameters (F2, F4 and F6), Spin orbit coupling parameters ( ξ 4f), Configuration interaction parameters (α and β) have been calculated by using the absorption spectra. The ratios of E1/E3 and E2/E3 do not deviate much from the hydrogenic ratios. In the present work we have studied nephalauxetic effect, covalency and bonding parameters for Er3+ glass systems. The phenomenological Judd-Ofelt intensity parameters Ω2 , Ω 4 and Ω 6 were determined from the spectral intensities. The radiative transitions probabilities A, radiative life times (), branching ratios () and absorption cross sections ( σ a) were evaluated for the lasing levels of certain exited states.
