Optical micromanipulation using a Bessel light beam

We demonstrate a technique for optical manipulation of micron-sized particles, including biological samples, using a zeroth-order Bessel light beam. The central maximum of such a beam offers a “non-diffracting” focal line of light. This line focus is well suited to rotationally align rod-like particles along the beam direction and to build stacks of particles. We have stacked up to nine m spheres above one another and manipulated this particle chain as a whole. Furthermore, we have observed laser guiding (transport) of m particles along the Bessel beam axis over 1 mm, which is over 10 times the Rayleigh range for a comparable Gaussian beam.