Research Institute for Electronic Science, Hokkaido University


LAST UPDATE 2019/06/05

  • 研究者氏名
    Researcher Name

    パン・クリストフ Pin Christophe
    助教 Assistant Professor
  • 所属
    Professional Affiliation

    Research Institute for Electronic Science, Hokkaido University

    Photonics and Optical Science division, Laboratory of Photo-System Physics
  • 研究キーワード
    Research Keywords

    Optical Forces
    Optical Trapping and Manipulation
    Nanoparticle Deposition
    Optical sorting

Research Subject
Optical manipulation of nanoparticles using photonic and plasmonic systems

研究の背景 Background

Among the large range of light-matter interactions, optical forces refer to optomechanical interactions that arise from the transfer of momentum between photons and pieces of matter. The mechanical action of light interacting with nanoparticles give rise to many different physical phenomena such as optical trapping, optical propulsion, optical rotation, optical assembly and crystallization, optical binding, optical deformation, etc. Understanding the mechanisms underlying these phenomena is of great interest for investigating not only light-matter interactions but also other phenomena occurring at the nanoscale.

Originating from the evanescent field at the surface of photonic or plasmonic structures, near-field optical forces enable enhanced optical trapping and manipulation of nanoparticles. However, their action is always combined with those of other nanoscale interactions such as electrostatic forces, thermal and fluidic phenomena, chemical reactions, etc. Although nanoscale systems are often complex, this complexity can be advantageously exploited for achieving unprecedented results.

研究の目標 Outcome

Optical trapping and manipulation of nanoparticles provide a versatile, non-contact way to apply a mechanical action on both single or numerous nanoparticles. It can be used for positioning, rotating, transporting, assembling, depositing, and sorting nanoparticles. It can also be used to probe light-matter interactions and other physical, chemical, or biological phenomena at the nanoscale.

My current research focuses on the trapping and the deposition of nanoparticles in the nano-gap of plasmonic structures. This technique enables the fast assembly of hybrid nanostructures designed for probing and exploiting light-matter interactions in plasmonic nano-gaps.

Another research topic deals with optical manipulation of nanoparticles inside tapered glass capillaries. The tapered capillaries used in this work allow both light and nanoparticles to be confined and to interact with each other on a centimeter-long distance, making it possible to investigate new optical sorting techniques.

研究図Research Figure

Fig.1. Dye-molecule nanoparticles deposited in the nano-gap of a plasmonic bowtie antenna. Deposition is achieved under intense infra-red laser light irradiation for a few-second time duration. The long-range attraction and the fast time-scale of the deposition process is attributed to thermal phenomena.

Fig.2. Optical propulsion of nanodiamonds (NDs) inside a tapered glass capillary. SEM images of (a) a tapered capillary and (b) fluorescent NDs. (c) Fluorescence microscopy images of NDs propelled by optical force inside a tapered capillary. The NDs’ velocity is proportional to the input laser power.

Fig.3. 500 nm and 1 µm fluorescent polystyrene beads trapped in near-field optical lattices along a few-mode silicon waveguide. Near-field optical lattices are formed by the superposition of pairs of co-propagating modes excited inside the waveguide. The period of the optical lattice can be finely tuned by adjusting the laser wavelength. E. coli bacterium cells were also successfully trapped using this technique.

文献 / Publications

Lab Chip 18, 1750-1757 (2018),  ACS Omega 3, 4878- 4883 (2018),  ACS Photonics 2, 1410-1415 (2015),  Appl. Phys. Lett. 105, 171108 (2014)