High-resolution and massive trapping and separation of dielectric nanoparticles in an optical potential well array

Yuzhi Shi, Din Ping Tsai, Yi Zhang, Ai Qun Liu

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review


Optical tweezers are versatile tools capable to separate microparticles, yet present formidable challenges in the separation of nanoparticles smaller than 200 nm. The difficulties arise from the controversy on the requirement of a tightly focused light spot in order to create strong optical forces while a large area is kept for the sorting. To overcome this problem, we create a near-field potential well array with connected tiny hotspots in a large-scale. This can separate nanoparticles with sizes from 100 to 500 nm, based on the differentiated energy depths of each potential well. In this way, nanoparticles of 200, 300 and 500 nm can be selectively trapped in this microchannel by appropriately tuning the laser power. Our approach provides a unprecedent solution for optical trapping and separation of nanoparticles and biomolecules, so that it presents a huge potential in the physical and biomedical sciences.

Original languageEnglish
Title of host publicationComplex Light and Optical Forces XV
EditorsEnrique J. Galvez, Halina Rubinsztein-Dunlop, David L. Andrews
ISBN (Electronic)9781510642379
Publication statusPublished - Mar 2021
EventComplex Light and Optical Forces XV 2021 - Virtual, Online, United States
Duration: 6 Mar 202111 Mar 2021

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceComplex Light and Optical Forces XV 2021
Country/TerritoryUnited States
CityVirtual, Online


  • lab on a chip
  • nanophotonics
  • optical forces
  • optical sorting
  • potential wells
  • silicon photonics

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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