Interception force assisted optical pulling of a dipole nanoparticle in a single plane wave.

Area of Science:

• Optics
• Nanotechnology
• Condensed Matter Physics

Background:

• Optical forces typically involve pushing forces from light momentum transfer.
• Optical pulling forces are usually attributed to recoil from multipole excitation.
• Interception force is conventionally associated with optical pushing forces.

Purpose of the Study:

• To demonstrate optical pulling force induced by interception force in gain particles.
• To analytically derive optical forces on spherical particles using multipole expansion theory.
• To investigate the role of gain in altering optical force characteristics.

Main Methods:

• Derivation of a rigorous analytical expression for optical force on spherical particles.
• Application of multipole expansion theory for arbitrary particle size and composition.
• Analysis of optical force components, including interception and recoil forces.

Main Results:

• The interception force can induce optical pulling force on spherical particles with gain.
• Gain introduction causes the interception force to transition from positive to negative.
• Optical pulling force magnitude, assisted by interception force, is stronger than conventional optical pushing force.

Conclusions:

• Interception force is a viable mechanism for inducing optical pulling force in gain nanoparticles.
• Gain engineering offers a novel pathway to control optical forces beyond traditional methods.
• This finding expands the understanding of light-matter interactions and optical manipulation.