Effect of Sc³⁺ doping on defect structure and optical performance in Tm: LiNbO₃ crystals

Sc (0, 1, 2, 3 mol%): Tm: LiNbO 3 crystals were prepared by the Czochralski method. The inductively coupled plasma-atomic emission spectrometry (ICP-AES) analysis test shows that, as the concentration of Sc[Formula: see text] increases, the effective segregation coefficient of Sc[Formula: see text] and Tm[Formula: see text] decreases. The X-ray diffraction (XRD) analysis test shows that the lattice size increases first and then decreases. The optical homogeneity analysis test shows that the birefringence gradient of the Sc-3 sample is [Formula: see text] [Formula: see text]R/cm[Formula: see text], which is 1/3 of pure LiNbO 3 . Research demonstrates that when the Sc[Formula: see text] content reaches or exceeds the threshold value, [Formula: see text] is replaced completely, thus introducing non-intrinsic defects [Formula: see text] and [Formula: see text]. These defects are able to form [Formula: see text] charge self-compensating defect groups, it will greatly increase optical homogeneity.