Defect modes in metallo-dielectric photonic crystals

我们提出研究和控制平面金属介电光子晶体中的光子缺陷模式。利用电子束光刻技术在介质表面沉积了金纳米粒子和银纳米粒子阵列，构成了光子晶体结构。缺陷将被有意地引入到阵列中，并且由此产生的光子缺陷模式将使用具有波长和亚波长空间分辨率的先进光学技术进行实验研究。来自单个缺陷的光散射将被测量并用于表征光谱特性和缺陷模式的对称性。使用近场扫描光学显微镜（NSOM）技术测量与局部缺陷模式相关的空间模式分布和光场增强。系统地改变光子晶体的结构参数，以便了解和控制缺陷模式的性质，包括晶体中的空间位置、空间尺寸、光谱分布以及与模式局域化相关的场增强。特别是，我们将尝试将其与与表面等离子激元共振激发相关的金属表面的局部场增强相结合，以最大化场增强。我们的最终目标是使用这种方法来创建具有极高局域光场的光子晶体结构，这些光场可用于非线性光学应用和单分子光谱学。

We propose to study and control photonic defect modes in plenar metallo-dielectric photonic crystals. The photonic crystal structures consist of arrays of gold and silver nanoparticles deposited on dielectric surfaces using electron beam lithography. Defects will be intentionally introduced into the arrays, and the resulting photonic defect modes will be experimentally studied using advanced optical techniques with wavelength and sub-wavelength spatial resolutions. Light-scattering from individual defects will be measured and used to characterize the spectral properties and the symmetries of the defect modes. The spatial mode distribution and optical field enhancement associated with the localized defect-mode will be measured using near-field scanning optical microscopy (NSOM) techniques. The structural parameters of the photonic crystals will be varied systematically in order to understand, and make controllable, the properties of the defect modes, including spatial position in the crystal, spatial size, spectral distribution, and field enhancement associated with the mode localization. In particular, we will attempt to maximize the field enhancement by combining it with the local-field enhancement at the metal surface related to resonant excitation of surface plasmons. Our ultimate objective is to use this approach to create photonic crystal structures with extremely high, localized, optical fields which may be used, e.g., in nonlinear optical applications and for single-molecule spectroscopy.