Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.
1] Beijing Center for Crystal R&D, Key Lab of Functional Crystals and Laser Technology of Chinese Academy of Sciences, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China [2] University of Chinese Academy of Sciences, Beijing 100049, China.
Nat Commun. 2014 May 29;5:4019. doi: 10.1038/ncomms5019.
Nonlinear optical (NLO) materials are of great importance in laser science and technology, as they can expand the wavelength range provided by common laser sources. Few NLO materials, except KBe2BO3F2 (KBBF), can practically generate deep-ultraviolet coherent light by direct second-harmonic generation process, limited by the fundamental requirements on the structure-directing optical properties. However, KBBF suffers a strong layering tendency and high toxicity of the containing beryllium, which hinder the commercial availability of KBBF. Here we report a new beryllium-free borate, Li4Sr(BO3)2, which preserves the structural merits of KBBF, resulting in the desirable optical properties. Furthermore, Li4Sr(BO3)2 mitigates the layering tendency greatly and enhances the efficiency of second-harmonic generation by more than half that of KBBF. These results suggest that Li4Sr(BO3)2 is an attractive candidate for the next generation of deep-ultraviolet NLO materials. This beryllium-free borate represents a new research direction in the development of deep-ultraviolet NLO materials.
非线性光学（NLO）材料在激光科学与技术中具有重要意义，因为它们可以扩展常见激光源提供的波长范围。除了 KBe2BO3F2（KBBF）之外，很少有 NLO 材料可以通过直接倍频过程实际产生深紫外相干光，这受到对结构导向光学性质的基本要求的限制。然而，KBBF 具有强烈的分层趋势和含铍的高毒性，这阻碍了 KBBF 的商业可用性。在这里，我们报告了一种新的无铍硼酸锂 Li4Sr(BO3)2，它保留了 KBBF 的结构优点，从而具有理想的光学性质。此外，Li4Sr(BO3)2 大大减轻了分层趋势，并将倍频效率提高了超过一半，超过了 KBBF。这些结果表明，Li4Sr(BO3)2 是下一代深紫外 NLO 材料的有吸引力的候选材料。这种无铍硼酸锂代表了深紫外 NLO 材料开发的一个新的研究方向。
