Bulk Growth and Characterization of a Novel Nonlinear Optical Crystal BaTeMo₂O₉

A new nonlinear optical crystal BaTeMo₂O₉ was grown from the TeO₂−MoO₃ flux system with sufficient size (30 × 23 × 18 mm³) and optical quality that allowed the characterization of its properties. It crystallizes in the noncentrosymmetrical system, space group P2₁ (no. 4), with a = 5.5346 Å, b = 7.4562 Å, c = 8.8342 Å, and β = 90.897°. The as-grown BaTeMo₂O₉ crystal has well-developed faces with the major forms {100}, {001}, {011}, and {011̅}. The transmission spectra results suggest that it can transmit well from 0.5 to 5.0 µm. The refractive indices were also measured. The smaller refractive indices n_x and n_y are in the ac-plane, and the largest refractive index n_z polarization direction is parallel to the crystallographic b-axis.