Toolbox for building photonic/plasmonic crystals in a glass matrix containing metallic nanoparticles

该项目将研究一种产生光子（等离子体）晶体的新方法，该方法基于由介电介质（通常是玻璃）和嵌入的金属纳米颗粒组成的纳米复合材料。通过使用不同的成分（金属/基质），以及改变纳米颗粒的大小、浓度和形状，这种基础材料的光学特性可以在很宽的参数范围内变化。将采用两步程序从这些具有明确缺陷的材料中生产光子晶体：第一步，将利用最近开发的方法在电场的帮助下将局部横向结构从结构电极（例如二维硅光子晶体）转移到基材；在接触区域，电介质通过溶解纳米颗粒在基体中再次变得透明，而在非接触区域，纳米颗粒团块仍然存在。只要电极的长度尺度远大于颗粒尺寸，这些区域的光学性质就非常接近基材的光学性质。用超短激光脉冲处理允许进一步局部修改光学特性，例如通过引入局部二色性来创建特殊缺陷结构。只有将光子结构的模拟预测能力与所提出的实验相结合，才能有效地探索所提出的材料体系在制备具有多种光学性质的不同结构方面的高灵活性。

This project will investigate a new approach to generate photonic (plasmonic) crystals, based on nanocomposite materials consisting of a dielectric (usually glass) and embedded metallic nanoparticles. The optical properties of this base material can be varied within a wide range of parameters by using different components (metal/matrix), and by varying size, concentration and shape of the nanoparticles. A two-step procedure will be applied to produce photonic crystals from such materials with well-defined defects: in a first step, a method developed very recently will be utilized to transfer local lateral structures from a structured electrode (e.g. a 2D Si photonic crystal) to the base material by help of an electric field; in the contact regions, the dielectric becomes transparent again by dissolving the nanoparticles in the matrix, while in non-contact regions nanoparticle clumps remain. As long as the length scale of the electrodes is much larger than the particle size, the optical properties in these regions are very close to that of the base material. Treatment with ultrashort laser pulses allows further local modification of the optical properties, e.g. creation of special defect structures by introducing local dichroism. The high flexibility of the propesed materials system in preparing different structures with large variety of optical properties can only be effectively explored if the predictive power of simulations of the photonic strucutres is combined wit the proposed experiments.