论文标题
从连续体中有结合状态的硅插入式纳米管的有效第二次谐波生成
Efficient Second Harmonic Generation from Silicon Slotted Nanocubes with Bound States in the Continuum
论文作者
论文摘要
不幸的是，具有中心对称性的光学材料（例如硅和锗）没有二阶非线性光学响应，从而阻碍了它们在有效的非线性光学设备中的发展。在这里，提出了一种带有一系列开槽的纳米管的设计，以实现中心对称硅的显着第二次谐波产生（SHG），它利用了扩大的表面二阶非线性的优势，增强了空气插槽表面上的电场，并通过持续状态在持续状态下增强了振荡状态。与没有空气槽的硅纳米管的阵列相比，带有两个以上的数量级以上的纳米管阵列中的SHG提高了。实验测量的硅开槽纳米管阵列的SHG效率高达1.8*10^-4 W^-1，预计通过修改空气槽几何形状来进一步设计。我们的结果可以提供一种扩大非线性光学效应和中心对称材料设备的新策略。
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*10^-4 W^-1, which is expected to be further engineered by modifying the air-slot geometries. Our result could provide a new strategy to expand nonlinear optical effects and devices of centrosymmetric materials.
