Temperature study of Tb3+, Yb3+ and Tm3+ tridoped KGd(WO4)2 crystals by raman spectroscopy

In the last few years a significant interest has been motivated in the development of novel rare earth doped solid state laser materials allowing infrared to visible frequency up-conversion has been motivated by their potential applications in optoelectronic devices [1,2]. The lanthanide doubly doped KGd(WO4)2 host crystals have been recognized as one of the most efficient up-conversion materials. In the present work the vibrational properties of the Tb³⁺, Yb³⁺ and Tm³⁺ tridoped KGd(WO4)2 crystals have been studied by Raman spectroscopy. The vibrational studies of the KGd(WO4)2 host lattice are particularly important due to its role in transfer of excitation energy between Tb³⁺, Yb³⁺ and Tm³⁺ ions in energy conversion process.