Simple OFT with yeast particles summoning for enhanced mulitple particles capture

Conventional optical fiber tweezers (OFTs) often suffer from limited trapping range, low multi-particle capture efficiency, and high power demand, which hinder their scalability in biological and microfluidic applications. To overcome these limitations, we present a novel optical-fiber-tweezer (OFT) probe employing a single-mode fiber for efficient trapping and aggregation of yeast particles. The probe incorporates two major innovations. First, an LP₀₁ - LP₁₁ mode conversion followed by orbital-angular-momentum (OAM) generation creates a hollow annular trap that enhances trapping stability. Second, the tapered fiber tip is coated with a carbon-based colloid that amplifies the local electromagnetic field and improves optical trapping efficiency. These two effects act synergistically: the OAM-generated halo provides a geometrically stable annular trap, while the micro-packed colloid intensifies the local gradient field through Mie scattering and multi-path interactions, enabling robust multiparticle manipulation. Experimental and simulation results confirm that the probe captures yeast particles under a 980 nm laser without mechanical translation of the fiber. The device achieves approximately 5 times higher trapping efficiency, 3 times larger capture area, and 10 times lower power consumption than conventional fiber tweezers, demonstrating the effectiveness of the dual-enhancement strategy. This cost-effective and scalable design opens up new opportunities for advanced multiparticle manipulation and paves the way for energy-efficient optical trapping systems in biophysics and chemical sciences. This approach not only advances optical manipulation techniques but also paves the way for scalable, energy-efficient optical systems for future photonic and biomedical applications.