分类： 光学 >> 量子光学 提交时间： 2023-02-19
摘要： Dielectric microspheres or microbeads can squeeze light into the subwavelength scale via photonic nanojet (PNJ) focusing. This enables strong light-matter interactions within its focus and induces extraordinary effects such as enhancements in light emission, signal collection and various other applications. However, critical challenges exist on how to efficiently and precisely loading the studied objects into the desired location of the PNJ focusing, and subsequently measure the field and signal of interests precisely and reliably. Such technique is currently missing. We present for the first time a unique microwell-decorated microsphere lens (u-well lens), with a semi-open microwell sample compartment directly fabricated on top of the microsphere lens. The u-well lens confines PNJ in a semi-open microwell and allows passive trapping of individual micro-object into the PNJ focusing area with high efficiency and spatial accuracy. We demonstrate that individual fluorescent microsphere of different sizes can be readily introduced to the designated location with loading efficiency >70% and generates reproducible enhanced fluorescence signals with standard deviation better than that can be quantitatively measured. A comprehensive analysis on the optical properties of the u-well lens reveals the synergistic effect of field enhancement and collection efficiency on the optical enhancement. We finally employ this special microsphere lens for fluorescent-bead-based biotin concentration analysis. The results suggest a greatly enhanced sensitivity and highly improved detection limit, opening the door for its application in highly sensitive and quantitative detection.
分类： 光学 >> 量子光学 提交时间： 2023-02-19
摘要： Subwavelength imaging by microsphere lenses is a promising label-free super-resolution imaging technique. There is a growing interest to use live cells to replace the widely used non-biological microsphere lenses. In this work, we demonstrate the use of yeast cells for such imaging purpose. Using fiber-based optical trapping technique, we successfully trapped a chain of yeast cells and bring them to the vicinity of imaging objects. These yeast cells work as near-field magnifying lenses and simultaneously pick up the sub-diffraction information of the nanoscale objects under each cell and project them into the far-field. Blu-ray disc of 100 nm feature can be clearly resolved in a parallel manner by each cell, thus effectively increasing the imaging field of view and imaging efficiency. Our work will contribute to the further development of more advanced bio-superlens imaging system
分类： 光学 >> 量子光学 提交时间： 2023-02-19
Lingya Yu
Zengbo Wang
Lizhou Xu
Liyang Yue
Bing Yan
Igor V. Minin
Oleg V. Minin
Baidong Wu
Yiduo Chen
摘要： Photonic hook (PH) is a new type of artificial self-bending beam focused by a dielectric particle-lens with a curved waist smaller than the wavelength, which has the potential to revolutionize mesoscale photonics in many applications, e.g., optical trapping, signal switching, imaging, etc. In this paper, we discover a new mechanism that the highly curved PHs can be realised by the light interaction with the fully or partially metal-coated microchannels. The generated W-shaped and J-shaped PHs have bending angles exceeding 80-degree. Compared to other PH setups, the proposed design has a larger range to flexibly control the bending angle through the coating process and can be easily integrated with the established microfluidic systems.
点击量
待评议
点击量
下载量
评论
