Structural parameter optimization of a fused all-fiber probe for light manipulation and multi-particle capture

We propose and experimentally demonstrate an economical optical tweezers probe based on the fusion of several commercial optical fibers. By optimizing the structural parameters of the probe, non-contact active capture and manipulation of single or multiple biological particles were achieved. First, the probe structural parameter range was analyzed theoretically, and the theory was cross-verified by the finite element method. Second, the influence of the probe structure and length parameters on the laser focusing performance and particle capture ability was studied, and the optimal structural parameters of the probe in particle capture were determined. The measured capture distance exceeded 50 µm, and the movement velocity of the particle during manipulation was measured. Finally, the capture performance before and after parameter optimization was compared with the dynamic effect of the particles, and the generation mechanism of multiple light traps and the mechanical properties of multi-particles during multi-particle capture were studied. The results indicate that this probe is expected to be used in biological or chemical micromanipulation research.