标题： 非线性光学超材料的非晶ABC异质结构原子尺度系统研究 显示英文标题

标题： Systematic Study of Amorphous ABC Heterostructures at the Atomic Scale as a Nonlinear Optical Metamaterial

摘要： 对ABC型异质结构的系统研究揭示，纳米尺度的形态修饰显著改善了非线性光学性能，以最大化人工体第二阶极化率。 这些非晶双折射异质结构通过三种氧化物的循环等离子体增强原子层沉积制备，有效打破了中心对称性。 我们观察到光学非线性与三种组成材料厚度变化之间的依赖关系：SiO$_2$ (A)、TiO$_2$ (B) 和 Al$_2$O$_3$ (C)，其厚度范围从数十纳米到原子尺度，这些材料在其界面上表现出二阶极化率。 我们的研究结果表明，非线性光学性能的增强与高密度的层和优良的界面质量密切相关，在此处界面二阶非线性过渡到类似体的二次谐波产生。 实现了有效的体二阶极化率为$\chi_{zzz}\nobreakspace{}=\nobreakspace{}2.0\nobreakspace{}\pm\nobreakspace{}0.2$ pm/V，与传统单晶非线性材料的典型值相当。 显示英文摘要

摘要： The systematic exploration of ABC type heterostructures reveals that nanoscale morphological modification markedly improves nonlinear optical properties to maximize the artificial bulk second-order susceptibility. These amorphous birefringent heterostructures are fabricated through cyclic plasma-enhanced atomic layer deposition of three oxides, effectively breaking centrosymmetry. We observe a dependence of optical nonlinearity on the thickness variation of three constituent materials: SiO$_2$ (A), TiO$_2$ (B), and Al$_2$O$_3$ (C), ranging from tens of nanometers to the atomic scale, and these materials exhibit second-order susceptibility at their interfaces. Our findings reveal that the enhancement of nonlinear optical properties is strongly correlated with a high density of layers and superior interface quality, where the interface second-order nonlinearity transitions to bulk-like second-harmonic generation. An effective bulk second-order susceptibility of $\chi_{zzz}\nobreakspace{}=\nobreakspace{}2.0\nobreakspace{}\pm\nobreakspace{}0.2$ pm/V is achieved, comparable to typical values for conventional monocrystalline nonlinear materials.