Optical absorption and stimulated emission of neodymium in yttrium lithium fluoride

A spectroscopic investigation of Nd3+ in yttrium lithium fluoride was performed. Spectrally and orientationally resolved cross sections for the 4F3/2 − 4I11/2 and 4F3/2 − 4I9/2 transitions are presented. We applied the Judd–Ofelt theory to measured absorption spectra to determine the orientation-averaged intensity parameters Ω2 = 0.362 × 10− 20 cm2, Ω4 = 4.02 × 10− 20 cm2, and Ω6 = 4.84 × 10− 20 cm2. Using these intensity parameters, we predicted the radiative lifetime of the metastable 4F3/2 state to be 525 μS, in excellent agreement with measured 4F3/2 decay signatures. Finally, absorption cross-section data are presented that will be of interest to the laser designer.