A spectral and dynamic study of spontaneous and stimulated emission of Nd<sup>3+</sup> in yttrofluorite CaF<sub>2</sub>–YF<sub>3</sub>(5%) crystals proves the existence of two main sites for the rare-earth ion in these crystals. Flash-lamp-pumped laser experiments show the existence of two laser output lines, centered at 1054 and 1063 nm, which correspond to stimulated emissions from the two resolved Nd<sup>3+</sup> sites. The dependence of the time-resolved laser output energy and relative intensities of both lines on the pump energy suggests the existence of some kind of coupling between the two emissions produced by the stimulated-emission field itself. The ratio between the output energies at the two wavelengths was modeled as a simple rate-equation laser model that takes the stimulated-emission coupling into account.
© 1999 Optical Society of America
(140.5680) Lasers and laser optics : Rare earth and transition metal solid-state lasers
(160.3380) Materials : Laser materials
(160.5690) Materials : Rare-earth-doped materials
(300.6360) Spectroscopy : Spectroscopy, laser
I. Iparraguirre, J. Azkargorta, J. Fernández, R. Balda, A. Oleaga, and A. A. Kaminskii, "Laser spectral dynamics of Nd3+ in CaF2–YF3 crystals," J. Opt. Soc. Am. B 16, 1439-1446 (1999)