Optical bands and energy levels of Nd3+ ion in the YAl3(BO3)(4) nonlinear laser crystal

In this paper the polarized optical spectra (absorption and fluorescence) of the Nd3+ ion in the YAl3(BO3)(4) nonlinear crystal have been systematically investigated at low (10 K) and room temperature. Most energy levels of Nd3+ in this crystal (103) have been identified and conveniently labelled with their crystal field quantum numbers, mu = 1/2 and mu = 3/2. The radiative emitting states have been identified. Analysing the optical absorption spectra with the anisotropic Judd-Ofelt theory, the radiative lifetimes and branching ratios from the metastable state F-4(3/2) have been calculated. Then, relevant spectroscopic parameters (quantum efficiency and emission cross sections) for laser applications have been estimated. Infrared to visible up-conversion is reported for the first time in this host crystal.