Near-field Enhanced Optomechanical NAnoresonators – NEONA

在频率高达太赫兹的等离子体机械纳米谐振器中，相干声学振动是超小型和高度可积的全光射频信号发生器的一个重要特征。相关的本征介电特性的超快调制允许直接反馈到特征特征，如局部表面等离子体共振及其高度明显的消光行为。由于以下几个原因，迄今为止尚未实现将这一特性集成到与现代硅光子学兼容的等离子体系统中的有意义的集成：(i)在典型的自上而下制造的纳米结构中，光学和机械损耗都相对较高。（ii）由于与尺寸有关的影响，目前可实现的光谱调制深度有限。（iii）高频调制只能在等离子体纳米结构中实现，例如尺寸足够小的贵金属纳米颗粒，因此只适用于紫外/可见光谱范围。本课题主要研究近场耦合双共振等离子体机械纳米谐振器，以优化其近红外光谱范围。这样，固有局域表面等离子体共振的相关光谱杂交实现了光谱和力学性质的灵活适应。与孤立的纳米结构相比，利用电磁粒子间近场耦合及其定向调制将实现光谱特性的高频调制并显著增强。这种方法要求粒子间距离在~ 10nm范围内，这对于经典的自上而下的制造工艺来说是一个挑战。自下而上的方法在要求的精度方面更实用，在显著降低光学和机械损耗方面也更有利。因此，DNA折纸自组装的单晶纳米粒子湿化学合成将被应用。为了实现组装的纳米谐振器在集成纳米光子学中的有意义的应用，必须实现从湿相的选择性定位固定。为此，将开发一种薄膜系统，使地形辅助表面固定成为可能。在这个项目中，两个在纳米结构设计和表征方面具有强大背景的团队（德累斯顿工业大学，射频和光子学工程主席）以及在纳米结构和微电子制造方面具有丰富专业知识的团队（开姆尼茨工业大学，光电系统）。结合这些经验，我们将讨论所设想的全光增强调制行为以及光学超表面的实现。通过对单个纳米结构以及复合材料的光谱和动态特性的综合分析，以及优化的制造工艺，为理解新型高集成光学纳米器件做出了重要贡献。

Coherent acoustic vibrations in plasmomechanical nanoresonators with frequencies up to the terahertz range are an important feature in terms of ultra-small and highly integrable all-optical RF signal generators. The associated ultrafast modulation of intrinsic dielectric properties allows direct feedback to characteristic features such as localized surface plasmon resonances and their highly pronounced extinction behavior.A meaningful integration of this feature into plasmonic systems compatible with modern silicon photonics has not been realized to date for several reasons: (i) Both optical and mechanical losses are comparatively high in typically top-down fabricated nanostructures. (ii) The achievable depth of spectral modulation is currently limited due to size-related effects. (iii) High frequency modulation is only possible in plasmonic nanostructures such as noble metallic nanoparticles with sufficiently small sizes and is therefore only suitable for the UV / VIS spectral range.This research proposal focuses on near-field coupled double-resonant plasmomechanical nanoresonators to be optimized for the NIR spectral range. This way, the associated spectral hybridization of the intrinsic localized surface plasmon resonances realizes a flexible adaptation of spectral as well as mechanical properties. In contrast to isolated nanostructures, high-frequency modulation of the spectral properties combined with a significant enhancement will be realized by exploiting the electromagnetic interparticle near-field coupling and its directed modulation.This approach requires interparticle distances in the range of ~10 nm which is a challenge for classical top-down manufacturing processes. Bottom-up methods are more practical in terms of the required precision and also more advantageous in terms of significantly lower optical and mechanical losses. For this reason, DNA origami self-assembly of wet-chemically synthesized single-crystalline nanoparticles will be applied. To achieve a meaningful use of the assembled nanoresonators in integrated nanophotonics, a selectively positioned immobilization from the wet phase has to be realized. For this purpose, a thin-film system will be developed that enables topographically assisted surface immobilization.For this project, two groups with strong background in nanostructure design and characterization (TU Dresden, Chair for RF and Photonics Engineering) as well as with great expertise in nanostructure and microelectronic manufacturing (TU Chemnitz, Opto-electronic Systems) team up. Combining the experience, the envisioned all-optical enhanced modulation behavior as well as the realization of optical metasurfaces will be tackled. Supported by comprehensive analyses of the spectral and dynamic properties of the individual nanostructures as well as in the composite, and the optimized fabrication process, important contributions to the understanding of novel highly integrated optical nanodevices are achieved.