Abstract

The two-photon spectra of the isoelectronic d³ ions Cr³⁺ and Mn⁴⁺ provide a new understanding of their spectral and photophysical properties not obtainable from the one-photon spectra. Using host crystals having cubic sites for the impurity, Cs₂GeF₆ for Mn⁴⁺; K₂LiGaF₆ for Cr³⁺ produces the simplest possible spectra. The local environment of the metal ion is the same in these two crystal structures out to second neighbors. The spectra can be described by adding spinorbit coupling to the Tanabe-Sugano matrices, and by taking account of vibronic coupling, Jahn-Teller effects and lattice coupling. Host crystals having lower symmetry are also useful for adding an additional perturbation.

© 1992 Optical Society of America