Reconfigurable free-form metamaterials: a new design paradigm for integrated optoelectronics based on 2D materials

非技术性：硅光子学是一个快速增长的行业，在未来十年内可能达到每年超过10亿美元的价值。与此同时，光子集成电路的复杂性增加了一个数量级以上。然而，硅在用于电信的波长处的光学响应相对较弱。因此，目前的光电子技术依赖于将其他材料与所需的性能相结合。在这种背景下，石墨烯已经成为实现硅兼容光电器件的优秀候选者。石墨烯是一种由碳制成的原子厚度的二维材料。它的强度是钢的近100倍，导热和导电效率高，并具有不寻常的光学特性。最近的实验报告已经接近石墨烯基器件的预测性能极限。如何在减小器件尺寸的同时进一步增强器件性能并不明显。因此，需要石墨烯基光电器件的新范例。本项目将开发一种实现集成光电子器件的新方法。纳米纤维将用于将石墨烯集成到有源器件中，并以纳米级分辨率设计有效的光学特性。这些器件将与CMOS技术完全兼容，并有望大幅减少器件尺寸和损耗，同时提供低能耗的快速性能。该项目汇集了来自美国，北方爱尔兰和爱尔兰共和国的研究人员通过NSF-美国/爱尔兰研发伙伴关系的多学科团队。作为本项目的一部分，国际合作将为国际学生交流和研究合作提供特殊的机会。技术：拟议的工作旨在开发一个新的石墨烯基CMOS兼容光电子产品系列。所提出的方法背后的两个前提是：（i）通过纳米纤维，可以在深亚波长维度上对器件的局部折射率进行空间工程设计;以及（ii）通过集成二维材料层，可以在减小的区域中提供有源功能。这些器件的操作依赖于多个谐振纳米光子模式之间的耦合，这不仅使它们对制造误差具有鲁棒性，而且还能够在减小的占地面积中实现宽的光学带宽。确定了三个主要研究方向：（a）开发高性能超紧凑型石墨烯电光调制器。(b)将所提出的设计概念扩展到调制器之外的其他光电器件（例如，移相器、有源耦合器、偏振器和传感器）。(c)在一个光学芯片上单片集成多个器件，并使用适当的CMOS电路进行驱动。该研究项目结合了两个新兴的研究概念，克服了当前集成光电子技术的主要局限性，因此具有很强的变革性。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical:Silicon photonics is a rapidly growing industry, potentially reaching an annual value of over a billion dollars in the coming decade. In parallel, the complexity of photonic integrated circuits has increased by more than an order of magnitude. The optical response of silicon at wavelengths used for telecommunications, however, is relatively weak. Current optoelectronic technologies therefore rely on integrating other materials with the desired properties. In this context, graphene has emerged as an excellent candidate to realize silicon-compatible optoelectronic devices. Graphene is an atom-thick, two-dimensional material made from carbon. It is nearly 100 times stronger than steel, conducts heat and electricity efficiently, and has unusual optical properties. Recent experimental reports have already approached the predicted performance limits of graphene-based devices. It is not obvious how the device performance can be further enhanced while simultaneously reducing device size. Thus, new paradigms in graphene-based optoelectronic devices are required. This project will develop a new approach for realizing integrated optoelectronic devices. Nanofabrication will be used to integrate graphene into active devices and engineer the effective optical properties with nm scale resolution. These devices will be fully compatible with CMOS technology and promise dramatic reductions in device footprint and losses, while providing fast-speed with low energy consumption. The project brings together a multidisciplinary team of researchers from the United States, Northern Ireland, and the Republic of Ireland through the NSF-US/Ireland R&D Partnership. International cooperation will provide exceptional opportunities for international student exchange and research collaboration as part of this project.Technical:The proposed work aims to develop a new family of graphene-based CMOS-compatible optoelectronics. The two premises behind the proposed approach are that: (i) via nanofabrication, it is possible to spatially engineer the local refractive index of the device at deep sub-wavelength dimensions; and, (ii) by integrating two-dimensional material layers, it is possible to provide active functionality in a reduced area. The operation of these devices relies on the coupling between a number of resonant nano-photonic modes, which does not only make them robust to fabrication errors but also enables broad optical bandwidth in a reduced footprint. Three main research thrusts are identified: (a) development of high-performance ultra-compact graphene electro-optic modulators. (b) Extension of the proposed design concept to other optoelectronic devices beyond modulators (e.g., phase shifters, active couplers, polarizers, and sensors). (c) Monolithically integrate multiple devices on an optical chip and drive with proper CMOS circuitry. The proposed research is highly transformative since it combines two emerging research concepts so to overcome the main limitations of current integrated optoelectronic technologies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.