EAGER: Gate tunable thermo-plasmonic mid-IR coherent light emitters

这项工作的目标是在芯片上展示波长可调谐的、类似激光的中红外光发射器。这将首次通过碳化硅中的表面共振与石墨烯膜中的等离子体共振的耦合来实现。所提出的可调谐中红外源与现有的相干红外源（例如可调谐激光器）相比具有许多优点，包括波长的完全机械运动自由可调谐性、用于各种轻型和移动的平台的小尺寸以及用于高速应用的极快响应。这些设备的小形状因子，可调谐性和集成潜力将迎来新一代的光学芯片实验室设备，其中相关生物标志物，细胞和配体化学物质的检测可以通过光谱实现，因此将能够开发廉价的下一代护理点生物传感器。频率可调谐发射器的可用性可能在迄今为止被认为是繁琐的片上光通信和光数据传输领域中打开机会。这种系统提供的潜在带宽可能会使数据传输速率和容量发生革命性变化。EAGER计划将为该项目提供一个由研究生和本科生组成的强大的研究和指导计划。该计划旨在探索，调查和演示在11 - 12 μm波长范围内实现可调谐相干辐射源的可能性。为了实现这一点，我们建议将诸如碳化硅的块状热等离子体材料的局部表面共振与诸如石墨烯的二维材料的栅极可调表面等离子体共振杂交，以操纵热辐射源的发射特性。所提出的实验研究将检查石墨烯的施加的栅极电压调制的光学性质之间的关系，以及耦合等离子体共振和声子共振中的相应移位。该研究旨在加深对辐射表面的表面声子共振和石墨烯片的门可调谐表面等离子体共振之间的耦合的理解。表面声子和表面等离子体分别是共振离子和电子的结果，这一事实提出了一个有趣的问题，即不同静止质量的粒子之间的动量匹配如何平衡。本研究将详细介绍在不同温度和不同波长下的理论和实验获得的发射/吸收特性，特别是，可以实现与栅极电压和温度的波长偏移的最小分辨率。从实验的角度来看，拟议的工作将系统地调查等离子体调谐的发射特性。将使用具有新颖的微米和纳米制造方法的异质集成技术。电子控制将允许发射器的可编程性，以自动扫过感兴趣的波长带，以确定光谱应用中样品的吸收光谱。光谱仪的波长扫描时间范围可以在毫纳秒内完成，从而允许实现超快IR可调谐源。门可调谐等离子体发射器的快速窄带发射特性可以在下一代神经形态计算和感测设备的背景下提供近场红外通信解决方案。初步计算表明，这些光源可以产生约200 µW/mm 2的强度，对于光谱学和通信应用来说应该足够了。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。

The goal of this work is to demonstrate wavelength-tunable, laser-like, mid-infrared light emitters on a chip. This will be achieved, for the first time, by coupling of surface resonance in silicon carbide with plasmonic resonance in graphene films. The proposed tunable, mid-infrared source has many advantages over existing coherent infrared sources such as tunable lasers which include complete mechanical motion free tunability of wavelength, small size for various lightweight and mobile platforms, and extremely fast response for high speed applications. The small form factor, tunability and integration potential of these devices will usher a new generation of optical lab-on-chip devices where detection of relevant biomarkers, cells, and ligand chemistries can be spectroscopically realized and thus will enable the development of inexpensive, next generation point of care biosensors. The availability of frequency tunable emitters is likely to open opportunities in the area of on-chip optical communications and optical data transfer that are hitherto considered as cumbersome. The potential bandwidth afforded by such systems may revolutionize data transfer rates and volumes. A robust research and mentoring program consisting of a graduate and undergraduate student working on the project is proposed for this 1-year EAGER proposal.This proposal aims to explore, investigate, and demonstrate the possibility of achieving tunable, coherent radiation sources in 11 - 12 μm wavelength range. To accomplish this, we propose to hybridize the localized surface resonance of bulk thermo-plasmonic materials such as silicon carbide with gate-tunable surface plasmonic resonance of two-dimensional materials such as graphene to manipulate the emission characteristics of thermal radiation sources. The proposed experimental study will examine the relation between applied gate-voltage modulated optical properties of graphene, and the corresponding shift in coupled plasmonic and phononic resonance. The study is aimed at deepening the understanding of the coupling between surface phonon resonances of a radiating surface and gate tunable surface plasmon resonance of graphene sheets. The fact that surface phonons and surface plasmons are consequences of resonant ions and electrons respectively raises interesting questions of how momentum matching is balanced between particles of different rest masses. This study will present details of theoretical and the experimentally obtained emission/absorption properties at different temperatures and different wavelengths, specifically, the minimum resolution of wavelength shift that can be achieved with gate-voltage and temperature. From an experimental standpoint, the proposed work will systematically investigate plasmonic tuning of the emission characteristics. Heterogeneous integration techniques with novel micro and nanofabrication methods will be used. The electronic control will allow for programmability of the emitter to auto-sweep through a band of wavelength of interest, to determine the absorption spectrum of samples in spectroscopy applications. The wavelength sweep timeframes of the spectrometers can be potentially accomplished in the milli – nano seconds allowing for the realization of ultrafast IR tunable sources. The fast, narrowband emission characteristics of the gate-tunable plasmonic emitters can provide nearfield infrared communication solutions in the context of next generation neuromorphic computing and sensing devices. Preliminary calculations show that these sources can generate an intensity of ~200 µW/mm2 and should be enough for spectroscopy and communication applications.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.