揭示介电元原子的不变光学特性
J Carlos Basilio-Ortiz1, Ivan Moreno1
1Unidad Académica de Ciencia y Tecnología de la Luz y la Materia, UAZ, Zacatecas 98060, Mexico.
Nano letters
|April 11, 2024
概括
与预期相反,介电纳米基原子的形状不会影响它们的相位移或极化特性. 对于具有C3或更高旋转对称度的形状,光学特性是不变的,影响平面光学设计.
科学领域:
- 纳米光子和元材料
- 光学工程是指光学工程.
背景情况:
- 超原子是先进光学元件 (如金属镜头和全息图) 的基本构建块.
- 了解它们的光学特性对于设计新型平面光学至关重要.
研究的目的:
- 为了研究元原子截面形状对光学特性的影响.
- 探索元原子几何和光相互作用之间的关系.
- 在元原子中确定光学不变的设计原则.
主要方法:
- 通过各种几何形状 (圆柱体,三角形,方形,六角形,八角形,截断的) 的介电纳米元原子模拟光传播.
- 在多个波长 (632.8,545和50纳米) 上分析了相位移,传导和极化.
主要成果:
- 发现相位移和偏振反应与截面形状无关.
- 发射率显示了部分形状独立性.
- 确定了相位移对有效横截面积的新型依赖.
- 对于具有C3或更高旋转对称度的元原子,光学特性是不变的.
结论:
- 在某些对称条件下,元原子的光学特性,特别是相位移和极化,表现出形状不变性.
- 这一发现简化了用于平面光学应用的元表面的设计和优化.
- 有效的横截面积是调节相位移的一个关键参数,为拓优化提供了新的途径.
更多相关视频
相关概念视频
Susceptibility, Permittivity and Dielectric Constant
1.5K
When placed in an external electric field, a dielectric material gets polarized. The charge density in the dielectric material is given by the sum of the bound and free charge densities, while the total charge density can also be written in terms of the total electric field. The bound charge density can be measured in terms of polarization, leading to the relationship between electric displacement and polarization.
1.5K
Potential Due to a Polarized Object
398
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
398
Stereoisomerism
11.9K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
11.9K
Electromagnetic Waves in Matter
3.0K
Electromagnetic waves can travel in the vacuum as well as in matter. For example light, which is an electromagnetic wave, can travel through air, water, or glass.
Consider the electromagnetic wave passing through a dielectric medium. In such a case, Maxwell's equations get modified. In Ampere's law, ε0 , the dielectric permittivity of free space is replaced with ε, the permittivity of dielectric. Also, the vacuum permeability μ0 is replaced by the permeability of the...
Consider the electromagnetic wave passing through a dielectric medium. In such a case, Maxwell's equations get modified. In Ampere's law, ε0 , the dielectric permittivity of free space is replaced with ε, the permittivity of dielectric. Also, the vacuum permeability μ0 is replaced by the permeability of the...
3.0K
Induced Electric Dipoles
4.2K
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
4.2K
Properties of Enantiomers and Optical Activity
17.0K
It is essential to understand the difference between chiral and achiral interactions and the implications thereof in optical activity and their applications. Just as our feet, which are chiral, interact uniquely with chiral objects, such as a pair of shoes, but identically with achiral socks, enantiomers of a molecule exhibit different properties only when they interact with other chiral media. An example of a significant implication from this facet is the phenomenon known as optical activity,...
17.0K


