Optical trapping of air-borne light-absorbing particles with various laser beams

Abstract

Abstract.We demonstrate optical trapping carbon nanoparticle agglomerations in the air employing photophoretic forces. Three types of laser beams were used for optical trapping: a focused Hermite-Gaussian laser beam (TEM 10 ), an optical bottle beam and a hollow optical beam generated by Bessel beams superposition. The experimental results for each of the laser beams types are shown. Description of trapping features in each case is shown. Perspectives of application for each type of laser beams for three-dimensional optical manipulation are discussed.

Focusing of Gaussian beam passed under small angle to optical axis of uniaxial crystal

“…The bottle beams were successfully used for the optical manipulation of non-transparent absorbing particles in free space [8,10,12,16] (and can also be used in other media) by ensuring a particle in the dark (hollow) area inside the bottle beam. However, in order to upload and unload a particle to and from the beam one should physically insert some obstacle in the way of the beam, to 'open' it.…”