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的、类似激光的中红外发光器。这将首次通过碳化硅的表面共振和石墨烯薄膜的等离子体共振的耦合来实现。与现有的相干红外光源相比，这种可调谐中红外光源具有许多优点，例如可调谐激光器，包括完全机械运动的波长自由调谐，适用于各种轻型和移动平台的小尺寸，以及对高速应用的极快响应。这些器件的小尺寸、可调谐性和集成潜力将带来新一代光学芯片实验室器件，在这些器件中，相关生物标志物、细胞和配体化学的检测可以通过光谱实现，从而使廉价的下一代护理点生物传感器的开发成为可能。频率可调发射器的可获得性可能会在迄今被认为是繁琐的片上光通信和光数据传输领域打开机会。这种系统提供的潜在带宽可能会彻底改变数据传输速率和数据量。针对这个为期一年的项目，提出了一个由研究生和本科生组成的强有力的研究和指导计划。该计划旨在探索、调查和展示在11-12μm波长范围内实现可调谐的相干辐射源的可能性。为此，我们提出将碳化硅等体热等离子体材料的局域表面共振与石墨烯等二维材料的栅极可调谐表面等离子体共振相结合，以控制热辐射源的发射特性。这项拟议的实验研究将考察外加栅压调制的石墨烯光学性质与耦合等离子体和声子共振的相应位移之间的关系。这项研究旨在加深对辐射表面的表面声子共振和石墨烯的栅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是如何平衡的。这项研究将给出不同温度和不同波长下的理论和实验获得的发射/吸收特性的详细信息，特别是随栅极电压和温度所能获得的波长漂移的最小分辨率。从实验的角度来看，这项工作将系统地研究等离子体对发射特性的调谐。将使用具有新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，以自动扫描感兴趣的波长带，以确定光谱学应用中样品的吸收光谱。分光计的波长扫描时间范围可能在毫纳秒内完成，从而实现超快红外可调谐光源。门可调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传感设备的背景下提供近场红外通信解决方案。初步计算表明，这些源可以产生约200微瓦/平方毫米的强度，应该足以用于光谱学和通信应用。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.