Nanostructures for Assisted Spectroscopy and Nonlinear Optics

集成光子学的下一个前沿领域之一是将光学技术的使用扩展到纳米长度尺度，克服衍射所施加的限制，这使得光不能聚焦在小于大约半波长的尺寸上。金属纳米等离子体结构已经被证明是一种有效的方式来“挤压”这种尺寸的光，同时显著增强局部场。这些特性最近在可见光谱区域得到了一些应用，包括增强拉曼散射和单分子荧光。鉴于这种毋庸置疑的兴趣，我的目标是在INRS-EMT开发一个关于在电磁波谱的中红外（~2 - 20 μ m）和太赫兹（~20 - 1000 μ m）区域开发纳米等离子体的有力研究计划。在目前的发现基金框架内，我打算阐明金属纳米结构在辅助长波直接吸收光谱和非线性光学方面的应用。更具体地说，在未来五年，我将研究：(I)考虑到在疾病早期诊断中的一些令人兴奋的应用，采用“纳米天线”阵列来增强生物分子太赫兹光谱的可能性；（ii）纳米等离子体介导的局域太赫兹非线性光学，因为它的基本兴趣和可能用于下一代太赫兹纳米电子器件；（iii）一种新型中红外纳米显微镜，能够以纳米级分辨率获取表面的化学图谱；（iv）用于促进硅光子学中红外非线性光学过程的新型纳米等离子体工具。

One of the next frontiers of integrated photonics is represented by the challenge of extending the use of optical techniques to nanometer length scales, overcoming the limit imposed by diffraction, which does not allow focusing light on dimensions smaller than roughly half a wavelength. Metallic nanoplasmonic structures have proven to be an efficient way to "squeeze" light on such dimensions, significantly enhancing the local field at the same time. These properties have been recently exploited for several applications in the visible spectral region including, for example, enhanced Raman scattering and single-molecule fluorescence. Given this unquestionable interest, I aim at developing at INRS-EMT a vigorous research program regarding the exploitation of nanoplasmonics in the mid-infrared (~2 - 20 µm) and terahertz (~20 - 1000 µm) regions of the electromagnetic spectrum. In the framework of the present Discovery Grant, I intend to shed some light on the use of metallic nanostructures for assisting long-wavelength direct-absorption spectroscopies and nonlinear optics. More specifically, in the next five years, I will study: (i) the possibility of employing arrays of "nanoantennas" for enhancing terahertz spectroscopy of biomolecules, in view of some exciting applications in the early diagnosis of diseases; (ii) localized terahertz nonlinear optics mediated by nanoplasmonics, for its fundamental interest and for its possible use in next-generation terahertz nanoelectronic devices; (iii) a novel kind of mid-infrared nanoscope, capable of acquiring chemical maps of surfaces with nanometric resolution; and (iv) new nanoplasmonic tools for boosting mid-infrared nonlinear optical processes for applications in silicon photonics.