We demonstrate a new principle of optical trapping and manipulation increasing more than 1000 times the manipulation distance by harnessing strong thermal forces while suppressing their stochastic nature with optical vortex beams. Our approach expands optical manipulation of particles into a gas media and provides a full control over trapped particles, including the optical transport and pinpoint positioning of ∼100  μm objects over a meter-scale distance with ±10  μm accuracy.

We study theoretically and verify experimentally the detailed dynamics of spin-to-orbital angular momentum conversion for a circularly polarized Gaussian beam propagating along the optical axis of a uniaxial crystal. We extend the results to the case of white-light beams when each of the spectral components undergoes its own wavelength-dependent angular momentum conversion process.

We suggest a new approach for selective trapping of light absorbing particles in gases by multiple optical bottle-beam-like traps created by volume speckle field. We demonstrate stable simultaneous confinement of a few thousand micro-particles in air with a single lowpower laser beam. The size distribution of trapped particles exhibits a narrow peak near the average size of an optical speckle. Thus, the speckleformed traps act as a sieve with the holes selecting particles of a similar size.

We demonstrate that a speckle pattern in the spatially coherent laser field transmitted by a diffuser forms a multitude of three-dimensional intensity micro-pockets acting as particle traps for airborne light absorbing particles. Confinement of up to a few thousand particles in air with a unidirectional single beam has been achieved. Theoretical analysis of the speckle defined trapping volume is in a good agreement with experimental results on capturing of aggregates of carbon nanoparticles in air.