Dynamically Reconfigurable Bipolar Optical Gradient Force Induced by Mid‐Infrared Graphene Plasmonic Tweezers for Sorting Dispersive Nanoscale Objects
Dynamically Reconfigurable Bipolar Optical Gradient Force Induced by Mid‐Infrared Graphene Plasmonic Tweezers for Sorting Dispersive Nanoscale Objects
复制标题
DOI：
10.1002/adom.202101744
复制
发表时间：
2021-12
影响因子：
9
通讯作者：
Puspita Paul;P. Liu
中科院分区：
文献类型：
--
作者：
Puspita Paul;P. Liu
现有的光学捕获和操纵微观物体的技术，例如光镊子和等离子体镊子，大多基于可见光和近红外光源。由于通常更难以将光限制在较长波长的特定长度范围内，因此这些光学捕获和操纵技术尚未扩展到中红外光谱区域或之外。研究表明，利用许多材料在中红外区域具有大介电常数色散的事实，与可见光和近红外区域的现有技术相比，使用中红外激发的光捕获和操纵可以实现额外的功能和优势。特别是，研究证明，通过利用中红外石墨烯等离子体激元的极高场限制和大频率可调性，可以实现高性能和多功能的中红外等离子体镊子，以动态可重构的方式选择性地捕获或排斥不同材料的纳米级物体。这项新技术可用于对混合物中的纳米级物体进行分类、过滤和分级。
Existing techniques for optical trapping and manipulation of microscopic objects, such as optical tweezers and plasmonic tweezers, are mostly based on visible and near‐infrared light sources. As it is in general more difficult to confine light to a specific length scale at a longer wavelength, these optical trapping and manipulation techniques have not been extended to the mid‐infrared spectral region or beyond. Here, it is shown that by taking advantage of the fact that many materials have large permittivity dispersions in the mid‐infrared region, optical trapping and manipulation using mid‐infrared excitation can achieve additional functionalities and benefits compared to the existing techniques in the visible and near‐infrared regions. In particular, it is demonstrated that by exploiting the exceedingly high field confinement and large frequency tunability of mid‐infrared graphene plasmonics, high‐performance and versatile mid‐infrared plasmonic tweezers can be realized to selectively trap or repel nanoscale objects of different materials in a dynamically reconfigurable way. This new technique can be utilized for sorting, filtering, and fractionating nanoscale objects in a mixture.