Optical funnel for living cells trap

We proposed and experimentally demonstrated an optical funnel for living cells trap based on an annular-core optical fiber. The proposed optical funnel employed the annular dark field to trap the living cell to avoid the laser damages. To perform the dark field trap, we placed the living cells in the glycerol solution. The refractive index of glycerol liquid was higher than yeast cells, which helped to perform the dark field trap; the viscosity of glycerol was significant, which helped to perform the viscosity-assisted 3-D trapping. The experimental results showed that the donut shape intensity field introduced by a single fiber probe performed 3D trapping easily and efficiently. Such funnel-shaped hollow conical beam could find ample potentials in optical manipulation on biological living cells, avoiding optical damages. All-fiber and seamlessly integrated structure of the proposed scheme could find ample potentials in manipulating biological cells.