Conteduca D, Khan SN, Martínez Ruiz MA, Bruce GD, Krauss TF, Dholakia K. Fano Resonance-Assisted All-Dielectric Array for Enhanced Near-Field Optical Trapping of Nanoparticles.
ACS Photonics 2023;
10:4322-4328. [PMID:
38145167 PMCID:
PMC10740001 DOI:
10.1021/acsphotonics.3c01126]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/24/2023] [Accepted: 10/24/2023] [Indexed: 12/26/2023]
Abstract
Near-field optics can overcome the diffraction limit by creating strong optical gradients to enable the trapping of nanoparticles. However, it remains challenging to achieve efficient, stable trapping without heating and thermal effects. Dielectric structures have been used to address this issue but usually offer weak trap stiffness. In this work, we exploit the Fano resonance effect in an all-dielectric quadrupole nanostructure to realize a 20-fold enhancement of trap stiffness, compared to the off-resonance case. This enables a high effective trap stiffness of 1.19 fN/nm for 100 nm diameter polystyrene nanoparticles with 4.2 mW/μm2 illumination. Furthermore, we demonstrate the capability of the structure to simultaneously trap two particles at distinct locations within the nanostructure array.
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