New Frontiers in Plasmonic Metamaterials: Flat-Lens Microscopy and Tractor Beaming

最近有可能从头开始创造具有在自然界中不可能找到的光学特性的材料，这引发了光学的复兴。这种材料被称为“超材料”，是基于“人造原子”的原理，其特性由远低于光波长的尺度上雕刻的形态特征所定义。当波长只有几百纳米时，很难制造出具有足够空间分辨率的人造原子。克服这一限制的一个有希望的途径是使用“等离子体”超材料，将光转化为波长更短的振荡，称为表面等离子体激元(SPPs)-束缚在金属表面上的光波。这些材料提供了令人兴奋的新方法来塑造紫外线到可见频率的光，这是一个对人类视觉，显示器，太阳能技术和显微镜至关重要的光谱区域。最近的研究已经表明，等离子体超材料可以被量身定制，以模拟与假设的负折射率介质相关的奇异特性，比如光以“错误”的方式弯曲，或者光的压力是拉而不是推。***我的研究项目是利用等离子体超材料实现基于超薄金属层和介电层结构的新型负折射率行为。我过去的工作表明，这样的系统提供了一个平台来理解spp是如何共同引发负折射率行为的，并且可以用作制造独特光学元件（如平面透镜）的基石。拟议中的研究有两个目标。首先是找到新型平面透镜的配方，使其具有典型透镜所具有的一些令人满意的特性，例如在可见光谱上的透明度。第二个是探索等离子体超材料如何以及为什么可以绕向光源，这是一种尚未完全理解的牵引光束形式。该方法包括模拟等离子体超材料中的光学和光机械相互作用，以及验证其在成像和牵引光束中的应用的实验。牵引光束测量将基于在扫描电子显微镜下观察微小的光驱动位移，这是加拿大同类实验中的第一个。***平面透镜有望用于创新显微镜，可用于大面积成像，但使用喷涂制造的成本较低。更好地理解牵引机光束的努力将为物质中的光动量提供新的视角，这是一个挥之不去的争论话题，使电动力学理论的基础悬而未决。HQP获得了对加拿大不断发展的技术部门和支持其资源部门现代化有价值的高科技技能。创业培训机会将使HQP具备领导他人和创建公司的技能

A renaissance in optics has been sparked by the recent possibility of creating materials from the ground up with optical properties that are impossible to find in nature. Such materials, known as metamaterials, are based on the principle of "artificial atoms" having properties defined by morphological features sculpted on scales well below the wavelength of light.  ***When wavelengths are just hundreds of nanometres, it becomes difficult to fabricate artificial atoms with sufficient spatial resolution. A promising route to overcome this limitation is to use "plasmonic" metamaterials that transform light into shorter-wavelength oscillations known as surface plasmon polaritons (SPPs)- light waves bound on metallic surfaces.  These materials offer exciting new ways to mould light at UV to visible frequencies, a spectral region fundamentally important for human vision, displays, solar technologies, and microscopy.  Recent work has already shown that plasmonic metamaterials can be tailor-made to mimic exotic properties linked to a hypothetical negative-index medium, such as light bending the "wrong" way or light pressure that pulls rather than pushes.  ***My research program uses plasmonic metamaterials to realize new forms of negative-index behaviour based on the configuration of ultra-thin metallic and dielectric layers.  My past work has shown that such systems provide a platform to understand how SPPs conspire to elicit negative-index behaviour and can be used as a building block to make unique optical elements such as flat lenses. The proposed research has two goals. The first is to find recipes for new types of flat lenses having some of the desirable traits found in typical lenses, such as transparency over the visible spectrum. The second is to explore how and why plasmonic metamaterials can re-coil towards a light source, a form of tractor beaming yet to be fully understood. The methodology consists of simulations to model optical and opto-mechanical interactions in plasmonic metamaterials and experiments to validate their use for imaging and tractor beaming.  Tractor-beaming measurements will be based on visualizing tiny, light-driven displacements in a scanning electron microscope, the first experiment of its kind in Canada.***Flat lenses hold promise for innovative microscopes that can be used to image over large areas, yet made at a low cost using spray-on fabrication. Efforts to better understand tractor beaming will provide new perspectives on the momentum of light in matter, the topic of a lingering debate that leaves the foundations of electrodynamic theory unsettled.  HQP gain high-technology skills that are valuable to Canada's growing technology sector and support modernization of its resource sector. Entrepreneurship training opportunities will equip HQP with the skills to lead others and build companies.**