THz metamaterial/graphene optoelectronic modulators

该项目的目标是实现在太赫兹频率范围内工作的创新类光电设备。太赫兹光谱区域（1-10太赫兹对应于30和300微米之间的真空波长）位于电子和光子范围之间。尽管这个频率范围在许多应用中具有巨大的潜力，从光谱学到通信，再到成像和天文学，但它还没有得到广泛的开发。太赫兹范围的全部潜力受到在这些频率下工作所固有的固有障碍以及缺乏有效设备的限制。特别是，基本的光电构件，如频率和偏振调制器，能够主动操纵这种辐射目前缺失，从而阻碍了其在基础研究和工业应用中的充分利用。该提案旨在通过实现基于超材料共振和石墨烯之间的相互作用的新型有源集成和高效器件来提供此类工具。由于它们在功耗、效率和重新配置速度方面具有独特的多功能性和性能，这些设备将在已经建立的学术/工业环境中实施。该项目应用的主要研究领域被确定为太赫兹成像，光谱学，通信和量子电子学。太赫兹成像是一项成熟的技术，目前用于各种关键领域，从安全和国防到半导体检测，再到药品表的无损检测和生物样品的成像。太赫兹气体和固态光谱学也有几个应用：众所周知，药物或爆炸物在太赫兹范围内具有强吸收特性，而相反，塑料材料对这种辐射是透明的。这自然适用于安全检查，例如在机场，并应用于药物检测。常见的污染物和温室气体在这个频率范围内具有独特的光谱指纹，因此在环境监测中有明显的应用。这些设备与已经建立的源，如量子级联激光器或时域光谱系统相结合，将增加成像能力，并允许新的光谱方法和实验配置。太赫兹无线通信的研究源于目前通信频率的饱和和对更高通信速度的追求。THz范围独特地解决了这两个问题，即未分配的频率区域和高载波频率，这是实现快速数据传输的必要前提。未来太赫兹通信平台的发展，必然要经过快速、集成的频率和偏振调制器的发展，它们是许多通信协议中的基本部件。因此，该提案的成功将独特地解决战略公共/私营部门未来的几个挑战，能够影响外行的生活质量。与此同时，该提案的目标是为不同学术环境的健康和进步做出贡献，例如研究新型碳基材料的研究领域和量子级联激光社区。事实上，这项研究将有助于为电子设备中的2D材料找到新的具体实现方式，并在THz范围内建立它们的利用。最后，与量子级联激光器相结合，这些设备将为探索基本量子电子场的新概念和配置提供强大的工具集，并增加这种特定源的光谱操作的广度。

This project targets the realization of an innovative class of optoelectronic devices operating in the terahertz frequency range. The THz spectral region (1-10 THz correspond to vacuum wavelengths between 30 and 300 micrometers), lies between the electronics and the photonics range. This frequency range is vastly unexplored despite its huge potential in many applications, ranging from spectroscopy to communications, to imaging and astronomy. The full potential of the THz range is limited by the intrinsic hurdles inherent to working at these frequencies and by the lack of efficient devices. In particular, the basic optoelectronic building blocks, such as frequency and polarization modulators, capable of actively manipulating this radiation are currently missing, thus hindering its full exploitation in fundamental research and in industrial applications. This proposal aims to provide such tools by realizing a novel class of active integrated and efficient devices based on the interplay between metamaterial resonances and graphene. Because of their unique versatility and performance in terms of power consumption, efficiency and reconfiguration speed, these devices will be readyly implemented with already established academic /industrial environments. The main research areas where this project finds application are identified as terahertz imaging, spectroscopy, communications and quantum electronics. Terahertz imaging represents a mature technology which is currently used in diverse key sectors, ranging from security and defense, to semiconductor inspections, to non-destructive testing of pharmaceutical tables and imaging of biological samples. THz gas and solid-state spectroscopy have several applications as well: it is widely known that drugs or explosives present strong absorption features in the THz range while, conversely, plastic material are transparent to this radiation. This lends itself naturally into security screening, e.g. at airport, and into applications in drug detection. Common pollutants and greenhouse gases have unique spectral fingerprints in this frequency range, thus finding obvious applications in environmental monitoring. These devices in combination with already established sources such as the quantum cascade laser or time domain spectroscopic systems will increase the imaging capability and allow novel spectroscopic methodologies and experimental configurations. The interest in THz wireless communication stems from the saturation of the present communication frequencies and from the ambition of higher communication speed. The THz range uniquely addresses both issues, being an unallocated frequency region and with high carrier frequencies, mandatory prerequisite for achieving fast data transfer. The development of future THz communication platform, necessary passes through the development of fast and integrated frequency and polarization modulators, which are the basic components in many communication protocols. Therefore, the success of this proposal will uniquely address several future challenges in strategic public/private sectors, capable of impacting on the layman quality of life. At the same time, this proposal has the ambition to contribute to the health and progress of different academic environments such as the research area investigating novel carbon-based materials, and the quantum cascade laser community. This research in fact will help finding novel concrete implementations for 2D materials in electronic devices and establishing their utilization in the THz range. Finally, in combination with the quantum cascade laser, these devices will provide a formidable tool set for exploring novel concepts and configurations in fundamental quantum electron field, and increase the breadth of spectroscopic operations for this particular source.