Growth and optical characterization of Tm3+-doped LiNbO3

Single LiNbO3:Tm3+ crystals, with variable Tm3+ content, have been grown by using the Czochralski method. The incorporation of Tm3+ ions into LiNbO3 crystals has been determined by using X-ray fluorescence spectroscopy. At moderated doping levels the active ion incorporation is driven by a linear regime, with a segregation coefficient Keff = 1.19 ± 0.08. Saturation effects have been observed only for highly concentrated crystals. The absorption spectra of Tm3+-doped crystals indicate that the melt congruent composition is preserved within the crystals. The Tm3+ absolute absorption cross sections have been obtained.