Optical Force Effects of Rayleigh Particles by Cylindrical Vector Beams

Area of Science:

• Optics and Photonics
• Electromagnetism

Background:

• High-order cylindrical vector beams offer unique polarization properties crucial for advanced optical systems.
• Existing analytical models struggle to describe highly focused beams with complex polarization orders.

Purpose of the Study:

• To develop a comprehensive vector theory and analytical model for high-order cylindrical vector beams in high numerical aperture focusing systems.
• To provide precise vectorial diffraction integrals for describing tightly focused fields with space-variant polarization.

Main Methods:

• Developed a vector theory for high-order cylindrical vector beams within the Richards-Wolf diffraction framework.
• Derived analytical formulae for electric and magnetic field components in the tightly focused region.
• Applied the formulae to calculate forces (gradient, scattering, curl-spin) on Rayleigh particles.

Main Results:

• Achieved exact analytical formulae for the three Cartesian components of electric and magnetic fields.
• Demonstrated the calculation of gradient, scattering, and curl-spin forces on trapped Rayleigh particles.
• The model accurately describes tightly focused fields with space-variant polarization orders.

Conclusions:

• The developed vector theory and analytical formulae are essential for designing and engineering tightly focused optical fields.
• This work enhances the capabilities of optical tweezers and optical manipulation by precisely controlling polarization.
• The theoretical framework extends to optical vortex vector fields and diffractive optical element design.