Analytical model of optical force on supercavitating plasmonic nanoparticles

Optical manipulation of nanoparticles (NPs) in liquid has garnered increasing interest for various applications, ranging from biological systems to nanofabrication. A plane wave as an optical source has recently been shown to be capable of pushing or pulling an NP when the NP is encapsulated by a nanobubble (NB) in water. However, the lack of an accurate model to describe the optical force on NP-in-NB systems hinders a comprehensive understanding of NP motion mechanisms. In this study, we present an analytical model using vector spherical harmonics to accurately capture the optical force and the resultant trajectory of an NP in an NB. We test the developed model using a solid Au NP as an example. By visualizing the vector field line of the optical force, we reveal the possible moving paths of the NP in the NB. This study can provide valuable insights for designing experiments to manipulate supercaviting NPs using plane waves. (c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

In this study, an analytical model using vector spherical harmonics was developed to accurately describe the optical force and trajectory of nanoparticles in nanobubbles. The model was validated using a solid Au nanoparticle as an example. By visualizing the vector field line of the optical force, possible paths of nanoparticles in nanobubbles were revealed. This study provides valuable insights for designing experiments to manipulate supercaviting nanoparticles using plane waves.