Abstract

Optical absorption and emission intensities are investigated for trivalent neodymium ions in single crystals of CaF₂ and YLF. Oscillator strengths for numerous transitions are measured from absorption spectra recorded at room temperature. Corresponding oscillator strengths are calculated by using the Judd–Ofelt theory and are compared with the measured values. A least-squares fitting of the measured and calculated line strengths of the absorption spectra yields the values of the phenomenological intensity (Judd–Ofelt) parameters Ω₂, Ω₄, and Ω₆ for the chosen ionhost combinations. The Judd–Ofelt parameters are also used to calculate the spontaneous emission probabilities, radiative decay rates, and branching ratios from various excited levels of Nd³⁺ that fluoresce in CaF₂ and YLF. Finally, the spectroscopic quality factors, which are defined as the ratio of the intensity parameters (X = Ω₄/Ω₆), are computed and compared with those for other Nd³⁺-based laser materials.

© 1992 Optical Society of America