Chirality-assisted lateral momentum transfer for bidirectional enantioselective separation

Yuzhi Shi, Tongtong Zhu, Tianhang Zhang, Alfredo Mazzulla, Din Ping Tsai, Weiqiang Ding, Ai Qun Liu, Gabriella Cipparrone, Juan José Sáenz, Cheng-Wei Qiu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

26 Citations (Scopus)

Abstract

Lateral optical forces induced by linearly polarized laser beams have been predicted to deflect dipolar particles with opposite chiralities toward opposite transversal directions. These “chirality-dependent” forces can offer new possibilities for passive all-optical enantioselective sorting of chiral particles, which is essential to the nanoscience and drug industries. However, previous chiral sorting experiments focused on large particles with diameters in the geometrical-optics regime. Here, we demonstrate, for the first time, the robust sorting of Mie (size ~ wavelength) chiral particles with different handedness at an air–water interface using optical lateral forces induced by a single linearly polarized laser beam. The nontrivial physical interactions underlying these chirality-dependent forces distinctly differ from those predicted for dipolar or geometrical-optics particles. The lateral forces emerge from a complex interplay between the light polarization, lateral momentum enhancement, and out-of-plane light refraction at the particle-water interface. The sign of the lateral force could be reversed by changing the particle size, incident angle, and polarization of the obliquely incident light.
Original languageEnglish
Article number62
Pages (from-to)1-12
Number of pages12
JournalLight: Science and Applications
Volume9
Issue number1
DOIs
Publication statusPublished - 1 Dec 2020

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics

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