Multi-Particle sorting using signals from particles trapped by single optical fiber tweezers

Abstract

We propose a multi-particle sorting method based on single optical fiber tweezer particle-trapped signals. When particles are trapped to the optical axis, the instantaneous trapped signal is collected by the photodetector. There are significant differences in the instantaneous trapped signal intensity for particles with different refractive indices. Specifically, the variation in instantaneous trapped signal intensity correlates well with changes in the refractive index of the particles in a linear relationship. We conducted 60 sets of experiments, which showed that the method accurately sorts yeast cells, silica (SiO₂) microspheres, and polystyrene (PS) microspheres. Additionally, the method’s simple structure, high accuracy, ability to simultaneously sort multiple particles, and potential to handle large quantities of particles provide a new approach to particle identification and detection. Consequently, this method is widely used in chemistry, microbiology, and medical diagnostics.