Collaborative Research: Three-Dimensional Laser Holographic Nanopatterning Using Metamaterial Phase Masks

存在对在空间和激光波长中可数字控制的纳米制造技术的强烈需求。这些新技术被期望产生用于从电子到光子到能量存储的广泛应用的空间变化的纳米结构。实例包括梯度多重对称纳米结构，以改善有机发光器件的光提取效率、光伏器件中的光耦合效率以及光电检测器中的光吸收。该奖项研究纳米结构和工艺设计原理，涉及通过超材料光掩模和选择性激光材料去除的激光束转向，从而形成复杂的功能纳米系统。尽管在单波长方面取得了进展，但仍然缺乏一种基于光掩模的纳米纤维技术，可以在多个波长以高分辨率控制激光。该项目为未来的并行，多波长，空间变化的三维纳米图案化铺平了道路，可以显着简化半导体行业使用的光刻工艺。该项目为本科生和研究生提供纳米制造、光学设计、模拟和表征领域的教育机会。该项目还包括通过沃斯堡科学和历史博物馆开展外联活动，吸引妇女和代表性不足的少数民族参与研究，并针对公众。当前的相位掩模图案化技术顺序地控制光。例如，在具有两层光栅的传统介电相位掩模中，由第一层光栅调制的光再次由第二层光栅调制。 为了实现在空间和波长上的选择性激光调制，新的相位掩模概念由分布在一层或两层中的谐振器组成，所述谐振器可以用于在多个波长处独立地和同时地（即，并行地）实现期望的相位和幅度分布。使用新的基于等离子体谐振器的超材料相位掩模，激光仅由设计预先确定的谐振器调制，从而导致在空间梯度光子超晶体结构中制造具有高空间分辨率和从微米到100 nm的特征尺寸减小的3D纳米架构。总的来说，单等离子体激元元件和基于单等离子体的纳米纤维工艺提供了具有简单光学设置的高效方法，用于实现用于许多应用的空间梯度纳米结构。

There is a strong need for nanomanufacturing technologies that are digitally controllable in space and in laser wavelength. These new technologies are desired to generate spatially varying nanostructures for a wide range of applications from electronics to photonics to energy storage. Examples include gradient multiple-symmetry nanostructures to improve light extraction efficiency of organic light emitting devices, light coupling efficiency in photovoltaic devices, and light absorption in photo-detectors. This award investigates nanostructure and process design principles involving laser beam steering through a metamaterial photomask and selective laser material removal, leading to the formation of complex functional nanosystems. Despite progress at single wavelengths, a photomask-based nanofabrication technology that can steer lasers at multiple wavelengths at high resolution is lacking. This project paves the way for future parallel, multi-wavelength, spatially varying three-dimensional nanopatterning that can significantly simplify the photolithography process used by the semiconductor industry. The project provides education opportunities in the fields of nanomanufacturing, optical design, simulation and characterization to students at both undergraduate and graduate levels. It also includes outreach activities engaging women and under-represented minorities in research and targeting the general public via the Fort Worth Museum of Science and History.This project investigates laser holographic nanofabrication of a new type of spatially-gradient nanostructure using new metamaterial phase masks designed and operated at multiple laser wavelengths. The current phase mask patterning technology controls light sequentially. For example, in traditional dielectric phase masks with gratings in two layers, the light modulated by the first layer grating is modulated again by the second layer grating. In order to realize selective laser modulation in space and in wavelength, the new phase mask concept consists of resonators distributed in one or two layers that can be used to realize desired phase and amplitude profiles at multiple wavelengths independently and simultaneously, namely, in parallel. Using the new plasmonic resonator-based metamaterial phase mask, the laser light is only modulated by resonators pre-determined by design, leading to the manufacturing of 3D nano-architectures with high spatial resolution and feature size reduction from microns to 100 nm in spatially-gradient photonic super-crystal structures. Overall, the single plasmonic element and single exposure-based nanofabrication process provides a highly efficient approach with a simple optical setup for realizing spatially-gradient nanostructures for many applications.