Birefringence Gradient and Exposure Energy of Hf:Yb:Nd:LiNbO3 Crystals with Various [Li]/[Nb] Ratios

Abstract

A series of Hf:Yb:Nd:LiNbO3 crystals with different [Li]/[Nb] ratios (0.946, 1.05, 1.20, and 1.38) were grown using the Czochralski method. X-ray diffraction phase results of the samples show that the LiNbO3 doped Hf4+, Yb3+, and Nd3+ only have a slight change in the lattice constant. The birefringence gradient of the HfYbNd4 sample measured using the birefringence gradient method was 3.3 × 10−5 ∆R/cm−1, which was the best optical uniformity. The optical damage resistance ability was measured using the light-induced scattering exposure energy flus threshold method. When the [Li]/[Nb] ratios in the melt achieve 1.38, the exposure energy achieves 120.74 J/cm2, which is approximately 87 times higher than HfYbNd1.

Keywords

• Hf:Yb:Nd:LiNbO3 crystals
• birefringence gradient
• exposure energy