DESIGN AND SYNTHESIS OF AN ULTRAVIOLET-TRANSPARENT NONLINEAR-OPTICAL CRYSTAL SR2BE2B2O7
DESIGN AND SYNTHESIS OF AN ULTRAVIOLET-TRANSPARENT NONLINEAR-OPTICAL CRYSTAL SR2BE2B2O7
复制标题
DOI：
10.1038/373322a0
复制
发表时间：
1995-01-26
期刊：
影响因子：
64.8
通讯作者：
YU, LH
中科院分区：
文献类型：
--
作者：
CHEN, CT;WANG, YB;YU, LH
许多光谱应用都需要强大的可调谐紫外激光源，它依赖于可见光范围内激光的倍频。这种二次谐波产生（SHG）依赖于具有高SHG系数、宽紫外透明区和适度双折射的非线性光学（NLO）材料的发展。很少有这样的材料可用;目前使用最广泛的是无机晶体beta-BaB 2 O 4（BBO）（1）和LiB 3 O 5（LBO）（2）。这些晶体仅对波长低至205 nm的SHG有效（参考文献3），因为前一种情况下的紫外透明范围有限，而后者存在双折射问题。我们以前已经开发了（4）一种新的无机NLO晶体，KBe_2BO_3F_2（KBBF）;它在很大程度上避免了这两个问题。但由于KBBF的层状结构单元之间的结合力较弱，很难生长出大的晶体。我们现在已经通过合理的设计开发了一种改进的材料：Sr 2Be 2B 2 O 7（SBBO），它具有KBBF的所有有利的NLO特性（实际上略有改进），并且易于生长为高光学质量的大晶体（迄今为止高达7 x 7 x 3 mm）。大的二次谐波系数和宽范围的紫外透明性使该材料成为紫外倍频的有希望的候选者。
POWERFUL, tunable ultraviolet laser sources, required for many spectroscopic applications, rely on the frequency-doubling of lasers in the visible range. Such second-harmonic generation (SHG) depends on the development of nonlinear optical (NLO) materials with high SHG coefficients, a wide transparent region in the ultraviolet, and moderate birefringence. Few such materials are available; those most widely used at present are the inorganic crystals beta-BaB2O4 (BBO)(1) and LiB3O5 (LBO)(2). These crystals are effective for SHG only down to wavelengths of 205 nm (ref. 3), because of a limited ultraviolet-transparent range in the former case and birefringence problems in the latter. We have developed previously(4) a new inorganic NLO crystal, KBe2BO3F2 (KBBF); which avoids both of these problems to a large degree. But it is hard to grow large crystals of KBBF because of weak binding between its layered structural units. We have now developed an improved material by rational design: Sr2Be2B2O7 (SBBO), which shares (and in fact slightly improves on) all of the favourable NLO properties of KBBF and is easy to grow as large (so far up to 7 x 7 x 3 mm) crystals of high optical quality. The large SHG coefficients and wide range of ultraviolet transparency make this material a promising candidate for frequency doubling into the ultraviolet.