Second‐Order Nonlinear Optical Switch of a New Hydrogen‐Bonded Supramolecular Crystal with a High Laser‐Induced Damage Threshold
Second‐Order Nonlinear Optical Switch of a New Hydrogen‐Bonded Supramolecular Crystal with a High Laser‐Induced Damage Threshold
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DOI：
10.1002/adom.201400301
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发表时间：
2014-12
影响因子：
9
通讯作者：
Zhihua Sun;Shenhui Li;Shuquan Zhang;F. Deng;M. Hong;Junhua Luo
中科院分区：
文献类型：
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作者：
Zhihua Sun;Shenhui Li;Shuquan Zhang;F. Deng;M. Hong;Junhua Luo
有机非线性光学（NLO）材料有望成为无机化合物在高度可控光子器件中的有力竞争者。在这里，一种新的超分子晶体，双（咪唑盐酸盐）二水合物18-冠-6（1），表现为二次非线性光学响应的潜在调制器。结果表明，（1）具有高达12 μ m的上级非线性光学开关对比度，显著的开关可逆性，以及较高的激光损伤阈值（高达8.9 GW/cm 2），这可以保证其器件应用。此外，机理研究表明，热激活分子振动的冻结和原子位移都对非线性光学开关有很大贡献。在（1）中的这种特殊耦合区别于先前的有序-无序转变，并且远远上级其他NLO开关的化学变化。据信，这些发现提供了固态NLO开关的具体示例，并将推动这些理想器件的进一步开发，以及建立新的设计策略。
Organic nonlinear optical (NLO) materials are anticipated as the competitive successors to inorganic compounds in the highly controllable photonic devices. Here, a new supramolecular crystal, bis(imidazolium hydrochlorate) dihydrate 18‐crown‐6 (1), behaves as a potential modulator of quadratic NLO responses. It is found that (1) possesses a superior NLO switching‐contrast of up to ∼12, a remarkable switching reversibility, and a quite high laser‐induced damage threshold (up to ∼8.9 GW/cm2), which may guarantee its device application. In addition, mechanism studies reveal that both the freezing of thermally activated molecular vibrations and atomic displacements are greatly contributive to its NLO switching. Such an exceptional coupling in (1) is distinguishing from the prevenient order–disorder transition and much superior to the chemical changes of other NLO switches. It is believed that the findings provide a concrete example of a solid‐state NLO switch and will urge further development of these desirable devices, as well as to establish new design strategies.