Optical spectroscopy of Nd3+ in the Bi12SiO20 piezoelectric crystal

A systematic investigation of luminescence and optical absorption of the Nd3+ ion in the Bi12SiO20:Nd3+ crystal is presented. Most Stark energy levels have been identified. The Judd-Ofelt theory is applied to measured values of absorption line strengths to obtain the intensity parameters: Ohm(2), Ohm(4) and Ohm(6). These parameters are used to calculate the absorption line strengths, as well as the radiative lifetime and the branching ratios from the metastable F-4(3/2) state to the I-4(J) manifolds. The relevant spectroscopic parameters for laser applications: emission cross section and quantum efficiency, were then estimated. The spectroscopic quality factor (Ohm(4)/Ohm(6)) calculated is in agreement with those of other Nd3+ based laser crystals.