Optical Transitions and Excited State Absorption Cross Sections of SrLaGaO(4) Doped with Ho(3+) Ions

The spectroscopic properties of SrLaGaO(4) (SLO) crystal doped with Ho(3+) ions were studied in this work. Absorption, emission spectra and decay dynamics of excited states have been measured and discussed using the Judd–Ofelt model. Photoluminescence emissions were attributed to transitions from the excited (3)D(3), (5)S(2), (5)F(5), (5)I(6) and (5)I(7) multiplet manifolds. The experimental lifetimes for five excited states have been compared to the theoretical values, calculated using Judd–Ofelt theory, allowing for the determination of the multiphonon relaxation rates (W(nR)) of the respective states. The experimental data were approximately on a line expressed by W(nR) = W(0) exp(−αΔE) with W(0) = 0.5 × 10(7) s(−1) and α = 2.6 × 10(−3) cm. To discuss the excited state absorption (ESA) pathways, that originated from several excited levels, we used the Judd–Ofelt formalism allowing determination of the integrated cross section for ESA transitions.