Particle capture analysis based on fiber optical tweezers

Simulation and calculation of single tapered fiber optic tweezers capturing polystyrene particles are performed based on time-domain finite element simulation software (Finite-Difference Time-Domain, FDTD). The capture by tapered fiber optical tweezers was simulated and calculated by modeling the physical structure. The optical field maps of the fiber structure were calculated separately, and the force analysis of the captured particles was carried out to calculate the transverse and axial capture forces of the particles using Maxwell's stress tensor method. Simulations were performed to calculate the light field maps of the captured particles at different alcohol concentrations，different refractive index environments, focusing distances, and force analysis of the particles. We find that the focal position of fiber optic capture changes with refractive index at different alcohol concentrations, the focus drifts, and the capture force is maximum at alcohol concentration. Finally, this experiment builds a simple capture system for the capture experiment of 5um polystyrene particles, and the polystyrene particles are successfully captured, and the simulation results are basically consistent with the experimental data.