Fig. 1. The computational model of the tapered and beak-shaped annular core fiber tip

Fig. 2. The normalized light intensity distribution under different bending radiuses. (a) The bending radius is 100 μm; (b) the bending radius is 150 μm; (c) the bending radius is 200 μm; (d) the bending radius is ∞

Fig. 3. The computational model for trapping particles on beak-shaped annular core fiber tip

Fig. 4. Trapping location changed with trapping force when bending radius of particle r_p=2.5 μm. (a) Normal component of the trapping force F_n changed with trapping location;(b) the tangential component of the trapping force F_t changed with trapping location

Fig. 5. Trapping location changed with trapping force of particles with different radiuses when bending radius of beak-shaped annular core fiber tip r=150 μm. (a) Normal component of the trapping force F_n changed with trapping location; (b) the tangential component of the trapping force F_t changed with trapping location