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On-Axis Optical Trapping with Vortex Beams: The Role of the Multipolar Decomposition
Iker Gómez-Viloria1, Álvaro Nodar1, Martín Molezuelas-Ferreras1
1Centro de Fisica de Materiales (CFM), CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 Donostia-San Sebastian, Spain.
ACS Photonics
|February 26, 2024
Summary
Researchers explored on-axis optical trapping using light vortex beams to trap silica particles. This method centers particles in the beam
Area of Science:
- Physics, Optics, Nanotechnology
Background:
- Traditional optical trapping centers particles on beam maxima, limiting applications.
- On-axis trapping with doughnut-shaped beams offers advantages like reduced light interaction and increased trapping strength.
Purpose of the Study:
- To experimentally and theoretically investigate on-axis trapping using light vortex beams.
- To analyze the influence of topological charge on trapping characteristics.
Main Methods:
- Experimental trapping of micron-sized silica (SiO2) particles in water using vortex beams.
- Measurement of trap stiffness constant (κ) via the power spectrum density method.
- Theoretical calculation of optical forces using generalized Lorentz-Mie theory.
Main Results:
- Demonstrated successful on-axis trapping of silica particles with vortex beams.
- Measured trap stiffness constants for various topological charges.
- Showed excellent agreement between experimental measurements and theoretical predictions of κ.
Conclusions:
- On-axis trapping with light vortex beams is a viable technique for particle manipulation.
- The generalized Lorentz-Mie theory accurately predicts experimental trapping outcomes.
- Numerical modeling provides insights into electromagnetic field interactions within trapped particles.
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