Du Xiaoli, Guo Xiaojie, Gao Zeliang, Liu Fuan, Guo Feifei, Wang Siyuan, Wang Haoyuan, Sun Youxuan, Tao Xutang
State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, China.
Angew Chem Int Ed Engl. 2021 Oct 18;60(43):23320-23326. doi: 10.1002/anie.202108978. Epub 2021 Sep 17.
Oxide crystals have been widely used in nonlinear optics (NLO) in the ultraviolet-visible and near-infrared regions. Most traditional oxide crystals are restricted to the mid-infrared region due to their narrow transmission window. Hence, attempting to extend infrared cutoff wavelength of oxides has attracted much attention. Herein, we report two new tellurates Li TiTeO (LTT) and Li SnTeO (LST) with broad transparent regions of 0.38-6.72 and 0.38-6.86 μm, respectively, as excellent candidates for mid-infrared NLO applications. Both LTT and LST crystallize in the orthorhombic space group Pnn2. The LTT crystal exhibits intense powder second-order generation efficiency (26×KDP) under the fundamental wavelength of 1064 nm. First-principles calculations and dipole moments were used to illustrate the results of the powder second-harmonic generations based on the crystal structures. Our results provide a novel oxide NLO crystal with a strong SHG and wide transparency range. They also pave a way for the design of new oxide mid-IR NLO crystals.
氧化物晶体已在紫外-可见和近红外区域的非线性光学（NLO）中得到广泛应用。大多数传统氧化物晶体由于其窄的透射窗口而局限于中红外区域。因此，尝试扩展氧化物的红外截止波长已引起了广泛关注。在此，我们报道了两种新型碲酸盐LiTiTeO（LTT）和LiSnTeO（LST），它们分别具有0.38 - 6.72和0.38 - 6.86 μm的宽透明区域，是中红外NLO应用的优秀候选材料。LTT和LST均结晶于正交空间群Pnn2。LTT晶体在1064 nm的基波波长下表现出强烈的粉末二次谐波产生效率（26×KDP）。基于晶体结构，使用第一性原理计算和偶极矩来说明粉末二次谐波产生的结果。我们的结果提供了一种具有强SHG和宽透明范围的新型氧化物NLO晶体。它们也为新型氧化物中红外NLO晶体的设计铺平了道路。
