A three-dimensional (3D) ring-shaped laser trap has been built using axicons. The diameter of this laser trap ranges from 70 to 140 μm and is adjusted by simply changing the position of one axicon in the optical path. Parallel 3D trapping of 5 μm silica microspheres and 3D confinement of cells along the ring are demonstrated. In this system the special optical properties of axicons are used to create a continuous annular trap with high power efficiency and a constant numerical aperture. This new approach, without any mechanical scanning, offers significant potential for applications in cell motility analysis and biotropism studies.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics