Birefringent materials are of great importance in optical communication and the laser industry, as they can modulate the polarization of light. Limited by their transparency range, few birefringent materials, except alpha-BaB2O4 (alpha-BBO), can be practically used in the deep ultraviolet (UV) region. However, alpha-BBO suffers from a phase transition and does not have enough transparency in the deep UV region. By introducing the relatively small alkali metal Na+ cation and the F anion to keep the favorable structural features of alpha-BBO, we report a new birefringent crystal Na3Ba2(B3O6)(2)F (NBBF), which has the desirable optical properties. NBBF not only maintains the large birefringence (Delta n = n(o) - n(e) = 0.2554-0.0750 from 175 nm to 3.35 mu m) and extends its UV cutoff edge to 175 nm (14 nm shorter than alpha-BBO) but also eliminates the phase transition and has the lowest growth temperature (820 degrees C) among birefringent materials. These results demonstrate that NBBF is an attractive candidate for the next generation of deep UV birefringent materials.