Second-order Raman spectra in LiNbO3:Tb crystals

LiNbO3:Tb (2.24 wt%) crystals are studied by Raman spectroscopy. The data are compared with Raman spectra of congruent lithium niobate crystal. Raman spectra were excited by dark red (λ=785nm) laser radiation and recorded with a BWS465-785H spectrometer. Еhe optical axis Z of lithium niobate single crystals was oriented parallel or perpendicular to the direction of the exciting laser radiation in order to provide proper geometry. The files present Raman spectra of studied crystals in different geometries.