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Optical pulling force on Janus particles via azimuthally-polarized Bessel beams.
Optics Express
|August 13, 2025
Summary
Researchers explored optical pulling forces on Janus nanoparticles using a specialized Bessel beam. They found this beam generates stronger forces than other polarizations, enabling better control over these particles for nanophotonic applications.
Area of Science:
- Nanophotonics and Plasmonics
- Optical Manipulation of Particles
Background:
- Janus particles exhibit unique properties driving interest in applications like optical manipulation, sensing, and imaging.
- Controlled manipulation of Janus particles using optical fields remains a significant challenge.
Purpose of the Study:
- To investigate the optical pulling forces on Janus nanoparticles illuminated by an azimuthally polarized zero-order vector Bessel beam.
- To explore how particle properties and beam polarization affect optical forces.
Main Methods:
- Simulated optical pulling forces on Janus nanoparticles (polystyrene microspheres half-coated with gold).
- Utilized an azimuthally polarized zero-order vector Bessel beam for illumination.
- Compared forces generated by vector Bessel beams with linearly and radially polarized beams.
Main Results:
- The vector Bessel beam generated stronger optical pulling forces compared to linearly and radially polarized beams.
- The asymmetric Janus particle structure is crucial for generating optical pulling forces.
- Particle size and gold layer orientation significantly influence the magnitude and direction of optical forces.
Conclusions:
- Demonstrated enhanced optical pulling forces on Janus nanoparticles using a vector Bessel beam.
- Highlighted the importance of particle asymmetry, size, and composition for optical force control.
- Provides new avenues for advancing nanophotonic and biophotonic applications of Janus particles.
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