dc.contributor.author | Hasan, Md Rabiul | |
dc.contributor.author | Hellesø, Olav Gaute | |
dc.date.accessioned | 2023-08-07T11:27:03Z | |
dc.date.available | 2023-08-07T11:27:03Z | |
dc.date.issued | 2023-02-09 | |
dc.description.abstract | Optical trapping combined with Raman spectroscopy have opened new possibilities for analyzing biological nanoparticles. Conventional optical tweezers have proven successful for trapping of a single or a few particles. However, the method is slow and cannot be used for the smallest particles. Thus, it is not adapted to analyze a large number of nanoparticles, which is necessary to get statistically valid data. Here, we propose quasi-bound states in the continuum (quasi-BICs) in a silicon nitride (Si3N4) metasurface to trap smaller particles and many simultaneously. The quasi-BIC metasurface contains multiple zones with high field-enhancement (‘hotspots’) at a wavelength of 785 nm, where a single nanoparticle can be trapped at each hotspot. We numerically investigate the optical trapping of a type of biological nanoparticles, namely extracellular vesicles (EVs), and study how their presence influences the resonance behavior of the quasi-BIC. It is found that perturbation theory and a semi-analytical expression give good estimates for the resonance wavelength and minimum of the potential well, as a function of the particle radius. This wavelength is slightly shifted relative to the resonance of the metasurface without trapped particles. The simulations show that the Q-factor can be increased by using a thin metasurface. The thickness of the layer and the asymmetry of the unit cell can thus be used to get a high Q-factor. Our findings show the tight fabrication tolerances necessary to make the metasurface. If these can be overcome, the proposed metasurface can be used for a lab-on-a-chip for mass-analysis of biological nanoparticles. | en_US |
dc.identifier.citation | Hasan, Hellesø. Metasurface supporting quasi-BIC for optical trapping and Raman-spectroscopy of biological nanoparticles. Optics Express. 2023;31(4):6782-6795 | en_US |
dc.identifier.cristinID | FRIDAID 2151298 | |
dc.identifier.doi | 10.1364/OE.473064 | |
dc.identifier.issn | 1094-4087 | |
dc.identifier.uri | https://hdl.handle.net/10037/29757 | |
dc.language.iso | eng | en_US |
dc.publisher | Optica Publishing Group | en_US |
dc.relation.ispartof | Hasan, M.R. (2023). Dielectric nanoantennas and metasurfaces for optical trapping. (Doctoral thesis). <a href=https://hdl.handle.net/10037/30504>https://hdl.handle.net/10037/30504</a>. | |
dc.relation.journal | Optics Express | |
dc.rights.accessRights | openAccess | en_US |
dc.rights.holder | Copyright 2023 The Author(s) | en_US |
dc.rights.uri | https://creativecommons.org/licenses/by/4.0 | en_US |
dc.rights | Attribution 4.0 International (CC BY 4.0) | en_US |
dc.title | Metasurface supporting quasi-BIC for optical trapping and Raman-spectroscopy of biological nanoparticles | en_US |
dc.type.version | publishedVersion | en_US |
dc.type | Journal article | en_US |
dc.type | Tidsskriftartikkel | en_US |