title: Single Nanoparticle Detection Using Far-field Emission of Photonic Molecule around the Exceptional Point.
abstract: Highly sensitive, label-free detection methods have important applications in fundamental research and healthcare diagnostics. To date, the detection of single nanoparticles has remained largely dependent on extremely precise spectral measurement, which relies on high-cost equipment. Here, we demonstrate a simple but very nontrivial mechanism for the label-free sizing of nanoparticles using the far-field emission of a photonic molecule (PM) around an exceptional point (EP). By attaching a nanoparticle to a PM around an EP, the main resonant behaviors are strongly disturbed. In addition to typical mode splitting, we find that the far-field pattern of the PM is significantly changed. Taking a heteronuclear diatomic PM as an example, we demonstrate that a single nanoparticle, whose radius is as small as 1 nm to 7 nm, can be simply monitored through the variation of the far-field pattern. Compared with conventional methods, our approach is much easier and does not rely on high-cost equipment. In addition, this research will illuminate new advances in single nanoparticle detection.
authors.affiliation: Integrated Nanoscience Lab, Department of Electrical and Information Engineering, Harbin Institute of Technology, Shenzhen, 518055, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Integrated Nanoscience Lab, Department of Electrical and Information Engineering, Harbin Institute of Technology, Shenzhen, 518055, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Liu
authors.affiliation: Integrated Nanoscience Lab, Department of Electrical and Information Engineering, Harbin Institute of Technology, Shenzhen, 518055, China.
authors.forename: Kaiyang
authors.initials: K
authors.lastname: Wang
authors.affiliation: Integrated Nanoscience Lab, Department of Electrical and Information Engineering, Harbin Institute of Technology, Shenzhen, 518055, China.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Gu
authors.affiliation: Integrated Nanoscience Lab, Department of Electrical and Information Engineering, Harbin Institute of Technology, Shenzhen, 518055, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Material Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China.
authors.forename: Ningbo
authors.initials: N
authors.lastname: Yi
authors.affiliation: Department of Material Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China.
authors.forename: Shumin
authors.initials: S
authors.lastname: Xiao
authors.affiliation: 1] Integrated Nanoscience Lab, Department of Electrical and Information Engineering, Harbin Institute of Technology, Shenzhen, 518055, China [2] State Key Laboratory of Tunable Laser Technology, Harbin Institute of Technology, Harbin, 158001, China.
authors.forename: Qinghai
authors.initials: Q
authors.lastname: Song