Nanostructures for Assisted Spectroscopy and Nonlinear Optics

集成光子学的下一个前沿之一是挑战，将光学技术的使用扩展到纳米级，克服衍射带来的限制，后者不允许聚焦尺寸小于大约半个波长的光。金属纳米等离子体结构已被证明是一种有效的方式来在这样的维度上“挤压”光，同时显著增强局域场。这些性质最近已被用于可见光谱区域的几个应用，包括例如增强的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开发一个关于在中红外(~2-20微米)和太赫兹(~20-1000微米)电磁光谱区域开发纳米等离子体的强有力的研究计划。在目前发现基金的框架内，我打算阐明利用金属纳米结构来辅助长波直接吸收光谱和非线性光学的一些情况。更具体地说，在未来五年，我将研究：(I)鉴于在疾病早期诊断中一些令人兴奋的应用，利用“纳米天线”阵列来加强生物分子的太赫兹光谱的可能性；(Ii)由纳米等离子体介导的局域太赫兹非线性光学，因为它具有基本的兴趣，并可能用于下一代太赫兹纳米电子器件；(Iii)一种新型的中红外纳米显微镜，能够获取纳米分辨率的表面化学地图；以及(Iv)新的纳米等离子体工具，用于增强硅光子学中的中红外非线性光学过程。

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.