Flat-head taper single-hole dual-core suspended-core fiber optical tweezers.

• In the study of special fiber optic tweezers with hollow holes, in order to preserve the hollow holes inside the fiber optic probe, grinding method is mostly used to make fiber optic probes. In this article, the melt taper method is chosen, which can preserve the patency of the hollow holes inside the probe during the production process, providing a foundation for using hollow holes to achieve particle manipulation and sterile transportation. The production method is simple and has high repeatability. • Single hole dual core suspended optical fiber has one hollow hole and two asymmetric cores, which leads to an asymmetric and complex distribution of the outgoing light field. Based on the designed single hole dual core suspended optical fiber probe structure, simulations were conducted to analyze the asymmetric light field distribution, and further analysis was conducted on the optical trap force distribution in the asymmetric and complex optical field in both the horizontal and axial directions. Preliminary conclusions were obtained. • Based on the characteristics of single hole dual core suspension fiber optic cables and combined with melt taper technology, two types of single hole dual core suspension optical simulation calculation fiber probes were designed and manufactured, namely parabolic type and flat head oblique cone type. Through simulation analysis and some experiments, it is known that the flat head oblique cone type single hole dual core suspension fiber optic probe can achieve particle capture, and the parabolic type single hole dual core suspension fiber optic probe can achieve particle ejection or capture for particles of different diameters, providing a new idea for single fiber optic tweezers to achieve particle sorting with different particle diameters. In order to achieve the manipulation performance of particles and improve the integration and miniaturization of optical fiber tweezers systems, this paper proposes a flat-head taper single-hole dual-core suspended-core optical fiber tweezers structure based on the characteristics of single-hole dual-core suspended-core optical fibers. By establishing a model of the optical fiber probe's force on micrometer-sized particles according to the principle of momentum conservation and using the finite-difference time-domain method, the distribution of optical trapping forces along each axial direction and the possible influence of particle diameter on the optical trapping forces are simulated and analyzed. Additionally, the capability of the flat-head taper single-hole suspended-core optical fiber to trap particles is verified through experiments. Through analysis and validation, the flat-head taper single-hole dual-core suspended-core fiber optical tweezers with 2 μm diameter hollow hole can achieve diverse manipulation of 2 μm, 5 μm, and 10 μm polystyrene particles. This research provides new insights into the application of single-hole suspended-core optical fibers in optical fiber tweezers. [ABSTRACT FROM AUTHOR]