Inhomogeneous broadening and splitting of lines in spectra of YAG:Tm

The shape and fine structure of lines due to Tm³⁺ f –f electronic transitions in multifunctional Y₃Al₅O₁₂ garnet crystals have been studied by high-resolution spectroscopy. The observed inhomogeneously broadened lines have a Lorentzian shape, suggesting that point defects make a predominant contribution to the inhomogeneous broadening. Moreover, Y_Al antisite defects, which are formed during high-temperature melt growth, produce spectral satellites near the main lines.