有源纳米天线研究

Active nano-antennas can greatly improve the efficiency of optical absorption and radiation. Being resonant with a highly sub-wavelength size, they have great potential and have experienced widespread interest in the world. However, the development of active nano-antennas is still in its infancy. Their EM models are not yet perfected, and the radiation and coupling mechanisms are not yet fully understood. Active nano-antennas work primarily at a specific high frequency and exhibit relatively narrow bandwidths and large dispersions. Their performance is largely affected by their own dispersive medium and scattering environment. They currently have low feeding efficiencies and are difficult to manufacture. Real active nano-antennas exist in clusters in which their interaction and coupling mechanisms are uncertain. Currently the standard models to evaluate active nano-antennas are also inconsistent and, consequently, are difficult to yield effective evaluations of their performance. To overcome these problems, we propose to research the EM models of active nano-antennas through EM theory and nano-size methods, to explore their feeding, radiation and coupling mechanisms to solve a variety of their basic problems and to explore applications. By investigating the long range active nano antenna, we further explore the broadband, high gain and being suitable for processing nano antenna and EM models of active nano-cluster arrays. We will accomplish this in a multi-disciplinary fashion by combining EM theory, atomic and microscopic circuit theory, and electron models, to form effective analysis and evaluation methods. These studies will provide the theoretical and technical foundations to high gain long range nano antenna, nano cluster array, nano system integration and wireless interconnection.

有源纳米天线可极大提高纳米天线的吸收效率和辐射能力，可在子波长实现谐振，应用前景广阔。但目前对于有源纳米天线的研究还处于起步阶段，电磁模型尚不完善，辐射和耦合机理尚不很清楚。其性能受材料色散特性及散射环境影响很大，很难满足实际需要和加工要求，而且对其性能评价标准不一。本课题通过电磁场理论与和纳米尺度研究方法结合开展有源纳米天线电磁模型研究，探求有源纳米天线的电磁辐射及耦合机理，完善并建立广泛的有源纳米天线电磁模型；分析有源纳米天线的馈电机理和辐射机理，研究反对称结构的有源纳米天线和长程有源纳米天线，探索宽带、高增益和适于加工的有源纳米天线及其簇阵列电磁模型；同时把电磁理论、电路理论和微观原子、电子的分析方法结合，形成分析和评价有源纳米天线的有效方法。本项目的研究成果将为基于有源纳米天线实现高增益长程有源纳米天线和纳米天线簇阵列、纳米系统集成及无线互连等提供理论与技术基础。

针对有源纳米天线的电磁模型不完善、辐射和耦合机理不清楚及其制备工艺缺失等问题，本项目主要研究了这几方面的内容：（1）研究了圆柱形核壳包层的有源纳米颗粒电磁模型，尤其是单个有源纳米颗粒的散射特性与颗粒参数之间的变化关系，发现了增益媒质谐振点两侧的对称谐振点现象。研究了圆柱形逆-核壳包层的有源纳米颗粒，同样发现了对称谐振现象。探索了磁性纳米天线。另外，还研究了纳米颗粒的组合模型，可适当增加带宽，提高有源纳米天线的增益。（2）研究了球形纳米天线的制备工艺，并通过仿真和实验对比，分析了蓝移现象。（3）研究了球形纳米天线阵列特性，尤其是结合实际的纳米颗粒形态，并通过插入无源介质颗粒来保持适当的阵元间距。通过仿真对比，分析了不同阵元对阵列性能的影响。并通过两种核壳包层有源纳米颗粒的组合，探索了长程有源纳米天线阵列。（4）研究了有源纳米天线的阵列扩展特性，发现了有增益的球形纳米天线单元与无源的SiO2颗粒组合时的极化旋转特性，以及由此扩展的纳米天线阵列辐射特性。通过本项目的研究，形成了分析和评价有源纳米天线的有效方法。相关研究成果也为基于有源纳米天线实现高增益长程有源纳米天线和纳米天线簇阵列、纳米系统集成及无线互连等提供了理论与技术基础。