Estudio del modelo de fuerza óptica para el análisis del comportamiento dinámico de partículas dieléctricas en el regimen de Rayleigh

Abstract

This study analyzes the effect of optical forces, which include the gradient force and the scattering force, on the trajectory of a dielectric particle confined in an optical field under the Rayleigh regime. The study examines how the initial optical and environmental conditions affect the dynamic behavior and stability of the particle, in order to determine the optimal parameters that ensure its stability within the trap. Based on existing models, a mathematical analysis of the optical forces on dielectric particles in optical traps under the Rayleigh regime was carried out, extending the model for charged particles to dielectric particles in order to deduce the gradient and scattering forces acting on dielectric particles by a Gaussian beam. Additionally, numerical simulations with a polyethylene particle and a fiber laser were conducted to analyze its three-dimensional trajectory, considering projections in the transversal and longitudinal planes. The results showed that the gradient force dominates in the transversal plane, while the scattering force influences the longitudinal plane, varying with the laser intensity. A simple harmonic motion was observed in the transversal plane within the interval [−w05,+w05 ], and a polynomial curve trajectory in the longitudinal plane within the interval [0,zR5 ], with errors below 8%. This research enhances the understanding of the mechanisms behind particle trapping and manipulation, opening new opportunities for precise control at microscopic and nanometric scales, with applications in science and technology. Keywords: Optical forces, Rayleigh regime, Gaussian beam, trajectory of a dielectric particle.