Efficient Second-Harmonic Generation from Silicon Slotted Nanocubes with Bound States in the Continuum
Efficient Second-Harmonic Generation from Silicon Slotted Nanocubes with Bound States in the Continuum
复制标题
连续体中具有束缚态的硅开槽纳米立方体的高效二次谐波产生
DOI：
10.1002/lpor.202100498
复制
发表时间：
2022-02-13
影响因子：
11
通讯作者：
Hao, Yue
中科院分区：
文献类型：
--
作者：
Fang, Cizhe;Yang, Qiyu;Hao, Yue
具有中心对称性的光学材料，如硅和锗，不幸的是缺乏二阶非线性光学响应，阻碍了它们在高效非线性光学器件中的发展。在这里，提出了一种具有开槽纳米立方体阵列的设计，以实现显着的二次谐波产生（SHG）从中心对称的硅，它利用扩大的表面二阶非线性，加强在空气槽表面的电场，以及共振增强的束缚态的连续。与无空气缝的纳米立方体阵列相比，空气缝纳米立方体阵列的倍频性能提高了两个数量级以上。实验测得的硅开槽纳米立方体阵列的二次谐波效率高达1.8 × 10（-4）W-1，这有望通过修改空气槽的几何形状来进一步工程化。这一结果为拓展中心对称材料的非线性光学效应和器件提供了一种新的思路。
Optical materials with centrosymmetry, such as silicon and germanium, are unfortunately absent of second-order nonlinear optical responses, hindering their developments in efficient nonlinear optical devices. Here, a design with an array of slotted nanocubes is proposed to realize remarkable second harmonic generation (SHG) from the centrosymmetric silicon, which takes advantage of enlarged surface second-order nonlinearity, strengthened electric field over the surface of the air-slot, as well as the resonance enhancement by the bound states in the continuum. Compared with that from the array of silicon nanocubes without air-slots, SHG from the slotted nanocube array is improved by more than two orders of magnitude. The experimentally measured SHG efficiency of the silicon slotted nanocube array is high as 1.8 x 10(-4) W-1, which is expected to be further engineered by modifying the air-slot geometries. The result can provide a new strategy to expand nonlinear optical effects and devices of centrosymmetric materials.