Manipulation of metallic nanoparticle with evanescent vortex Bessel beam

Area of Science:

• Optics and Photonics
• Nanotechnology
• Materials Science

Background:

• Optical manipulation techniques are crucial for controlling micro- and nanoparticles.
• Existing methods face limitations in precision and applicability to metallic nanoparticles near surfaces.
• The development of novel optical beams is essential for advancing particle manipulation capabilities.

Purpose of the Study:

• To propose and investigate a novel strategy for optically trapping and manipulating metallic nanoparticles.
• To demonstrate the generation of an evanescent Bessel beam with tunable optical angular momentum.
• To explore the dynamics of metallic nanoparticles within this specialized optical beam.

Main Methods:

• Generation of an evanescent Bessel beam with tunable optical angular momentum by focusing a radially polarized vortex beam onto a 1D photonic band gap structure.
• Numerical simulation of metallic nanoparticle behavior within the evanescent vortex Bessel beam (EVBB).
• Analysis of trapping stability and orbital motion induced by the beam's properties.

Main Results:

• Stable optical trapping of metallic nanoparticles near a surface was achieved using the EVBB.
• The orbital angular momentum of the EVBB successfully induced orbiting motion in the metallic nanoparticles.
• The direction of nanoparticle orbiting was precisely controlled by the handedness of the beam's helical phase front.

Conclusions:

• The proposed EVBB strategy offers a versatile and controllable method for optical manipulation of metallic nanoparticles.
• The non-contact, tunable orbiting dynamics present significant potential for applications in high-resolution imaging.
• This work opens new avenues for advanced optical manipulation techniques in nanotechnology.