Spectroscopic studies of Nd3+ and Er3+ in KGd(WO4)2 single crystals

Single crystals of KGd(WO4)2 doped with Nd3+ and Er3+ ions were grown by the top seeded solution growth method. Detailed analysis of the room-temperature absorption spectra was performed using the conventional Judd–Ofelt theory and actual dependence of the refractive index on the wavelength. In addition to the intensity parameters Ω2,Ω4,Ω6, the branching ratios and radiative lifetimes were estimated for all possible transitions in the studied spectral region. Those transitions which can be potentially used for laser applications have been identified for both ions.