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An accurate model describes the energy transfer dynamics in holmium thulium (Ho:Tm) lasers using a classical dipole-dipole approximation to calculate energy transfer parameters. A rate equation method uses these energy transfer parameters to describe the Ho:Tm lasers and predicts the population densities as a function of time. The results can be used to predict the performance of Ho:Tm:yttrium aluminium garnet (YAG) and Ho:Tm:yttrium lithium fluoride (YLF) lasers under different experimental conditions.

Electron-spin resonances, absorption spectra and analytical titration methods, which help study the spectral characteristics of calcium fluorophosphate doped with Ca, indicate that charge-compensated substitution of Y3+ and Cr4+ for Ca2+ and P5+, respectively, causes Cr to exist in a tetravalent state. The Tanabe-Sugano diagram elucidates the Cr4+(3d2) crystal field-split levels. The d2 configuration enables diagonalization of the C4-symmetry-based parametrized Hamiltonian.

Optical spectra of trivalent thulium ions in gadolinium scandium gallium garnet (GSGG) revealed the presence of more than one kind of alternate site. This suggested that GSGG and its analog, yttrium scandinm gallium garnet, had intrinsically irregular crystal patterns. These crystals featured octahedral sites which were primarily occupied by scandium ions. Site-specific excitation investigations using Nd:Yag laser identified large portions of thulium ions, located at the usual D2 sites and alternate sites.

The energy levels of trivalent thulium in the laser host crystal yttrium aluminum garnet (YAG) are investigated. Two YAG crystal samples containing different concentrations of thulium are prepared by the Czochralski method. The crystals'absorption and fluorescence spectra are recorded at various wavelengths using aspectrophotometer and a double monochromator, respectively. Results reveal the presence of a number of Stark levels that deviates from those obtained by crystal-field splitting calculation for Tm3 ions in yttrium aluminum scandium garnets.

The optical absorption spectrum of trivalent holmium ions in an yttrium scandium gallium garnet at four Kelvin between 1.93 and 0.28 micrometers were investigated using laser excitation and laser-excited fluorescence measurements. The results showed that the holmium ions gave off unresolved emission from both slightly disturbed cation sites and regular cation sites with D2 symmetry. Crystal-field split levels in 24 excited manifolds were observed.

Deals with a study which examined the spectra and energy levels of stimulated emissions from samarium in yttrium aluminum garnet. Spectroscopic data; Calculations; Conclusions.

We report an analysis of new and previously existing optical absorption and fluorescence data, far-infrared data, and electronic Raman scattering data for Eu3+, Dy3+, and Er3+ in the C3i sites of Y2O3 and R2O3, where R=a rare earth. Our previous analysis of C2-site spectra yields an effective point-charge model for the host lattice that allows initial estimates to be calculated for the C3i-site crystal-field parameters Bkm. Best-fit values of B20, B40, and B43 are obtained for Eu, and best-fit values of all Bkm allowed by symmetry are obtained for Dy and Er. The best-fit Bkm are in relatively poor agreement with the model; in particular, B20 has the opposite sign from and B44 is much smaller than the model predictions. From the best-fit Bkm we obtain phenomenological crystal-field components Akm, from which we predict Bkm and C3i -site energy levels for the ground states of Tb3+, Ho3+, Tm3+, and Yb3+. While the effective point-charge model is apparently too crude to make accurate, quantitative, a priori predictions, the model and the data allow one to predict confidently the behavior of ions doped into C3i sites for which no data exist. [ABSTRACT FROM AUTHOR]