Tunable photon-recoil forces and negative torque at flat-top beam edges

Area of Science:

• Optics
• Nanotechnology
• Materials Science

Background:

• Traditional optical tweezers rely on Gaussian beams and intensity gradients for particle manipulation.
• Flat-top beams offer control via phase gradients but have limitations.
• Existing photon-recoil forces are often structure-dependent, limiting tunability and reversibility.

Purpose of the Study:

• To present a novel photon-recoil-based manipulation technique (PMT) for micro/nano-manipulation.
• To demonstrate tunable and reversible particle control independent of traditional optical gradients.
• To explore new avenues in optical manipulation using light-recoil forces.

Main Methods:

• Developed a photon-recoil-based manipulation technique (PMT) utilizing polarization modulation.
• Shaped the imaginary Poynting momentum (IPM) within a flat-top beam.
• Applied PMT to manipulate simple nanospheres and single nanowires.

Main Results:

• Achieved tunable and reversible lateral forces on nanospheres via IPM shaping.
• Created edge-specific pathways for nanoparticle transport and stable potential wells.
• Demonstrated negative optical torque on single nanowires, overcoming previous limitations.

Conclusions:

• The developed PMT offers a promising alternative for micro/nano-manipulation.
• PMT enables precise control over particle movement and trapping using light-recoil forces.
• This technique expands the possibilities of optical manipulation for various applications.