Nanooptics with Plasmonic-Nanomaterials

本项目将从理论上研究不同结构纳米材料的光学性质。要解决的基本问题是纳米结构材料的对称性如何影响其光学特性，以及与此相关的，应该选择什么样的几何结构来获得最佳的材料性能。我们特别关注金属介电晶体和复合材料，可以支持各种等离子体模式，从而产生强烈增强的光学响应。在我们的研究中，我们特别考虑发生在亚波长，纳米尺寸的材料区域的局部光学现象。我们计划研究由周期性结构金属制成的光子晶体，我们称之为等离子体晶体。这里的目标是开发坚固的带隙材料，在可见光和近红外波段具有大而可扩展的间隙。由于金属的介电常数大且为负，它们本质上是隙材料，可以显著提高光子带隙晶体的性能并简化其制造。通过利用从金属中排出光的趋肤效应，可以大大减少损耗，这是金属的主要敌人。通过控制损耗，我们希望为等离子体晶体在光子学中的各种应用开辟新的途径。通过将等离子体晶体与由近渗透复合材料制成的亚微米级谐振器相结合，我们将开发ii)可见光和近红外的左手材料，在该光谱范围内具有负折射率。在这种情况下，等离子体网状晶体可以提供负介电常数，而复合谐振器则导致负磁导率。这种同时具有负介电常数和负磁导率的材料应具有负折射。另一种开发左手材料的可能性，我们也计划探索，是基于金属针的周期性阵列。这种左旋材料具有独特的光学特性，可以找到许多新的应用，例如用于开发能够完美重建图像的超级透镜。在这些项目中，我们还计划研究iii)通过光学厚度的金属薄膜进行光管理的非凡光学透射率。这个新想法源于我们最近的理论，该理论成功地解释了早先观察到的通过亚波长孔阵列的非凡透射率。由于薄膜的光学克尔非线性，干涉光束会导致薄膜折射率的周期性调制。这种调制可以作为一个周期性的“孔阵列”，由光本身产生，允许非凡的光透过薄膜。当这个想法发展成理论时，可以为光操纵光和开发全光晶体管、开关和调制器开辟新的途径。在这个项目中，将从理论上研究不同结构的纳米材料的光学性质。要解决的基本问题是纳米结构材料的对称性如何影响其光学特性，以及与此相关的，应该选择什么样的几何结构来获得最佳的材料性能。我们特别关注金属介电晶体和复合材料，可以支持各种等离子体模式，从而产生强烈增强的光学响应。在我们的研究中，我们特别考虑了发生在亚波长、纳米级材料区域的局部光学现象

In this project, optical properties of nanomaterials with different structures will be theoretically studied. The fundamental problem to address is how the symmetry of a nanostructured material influences its optical properties and, related to this, what geometrical structure should be chosen for best performance of the material. We specifically focus on metal-dielectric crystals and composites that can support various plasmon modes, resulting in strongly enhanced optical responses. In our research we particularly consider local optical phenomena that occur in sub-wavelength, nanometer-sized areas of the material.We plan to study photonic crystals made of periodically structured metal, which we refer to as i) plasmonic crystals. The goal here is to develop robust band-gap materials, with large and scaleable gaps in the visible and near-infrared. Because of large and negative permittivity of metals, they are intrinsically gap materials and can dramatically improve performance of photonic band-gap crystals and ease their fabrication. By employing the skin effect that expels light from metal, losses can be dramatically decreased, which is a major foe for metals. By taking control of losses we hope to open new avenues for various applications of plasmonic crystals in photonics.By combining plasmonic crystals with submicron-sized resonators made of nearly percolating composites, we will develop ii) left-handed materials in the visible and near-IR, which have a negative refractive index in this spectral range. The plasmonic mesh-like crystals, in this case, can provide negative permittivity, whereas the composite resonators lead to negative permeability. Such material with simultaneously negative permittivity and permeability should have negative refraction. Another possibility for developing left-handed materials, which we also plan to explore, is based on periodical arrays of metal needles. The left-handed materials have unique optical properties and can find a number of novel applications, for example for developing super-lenses, which are capable of perfect image reconstruction.In these projects we also plan to study iii) light-managed extraordinary optical transmittance through an optically-thick metal film. This new idea stems from our recent theory that has successfully explained the earlier observed extraordinary transmittance through subwavelength hole arrays. Because of the optical Kerr nonlinearity of a film, the interfering light beams can result in a periodic modulation of the refractive index in the film. This modulation can act as a periodic "hole array," created by light itself, allowing the extraordinary light transmittance through the film. This idea, when developed into a theory, can open new avenues for manipulating light with light and for developing all-optical transistors, switchers, and modulators.%%%In this project, optical properties of nanomaterials with different structures will be theoretically studied. The fundamental problem to address is how the symmetry of a nanostructured material influences its optical properties and, related to this, what geometrical structure should be chosen for best performance of the material. We specifically focus on metal-dielectric crystals and composites that can support various plasmon modes, resulting in strongly enhanced optical responses. In our research we particularly consider local optical phenomena that occur in sub-wavelength, nanometer-sized areas of the material.***