Experiments on microscopic object movement along various fixed trajectories caused by spiral beams (Invited Paper)

The range of possibilities ofthe laser manipulation with microscopic objects could be sufficiently expanded by using of the beams with predetermined spatial intensity and orbital momentum density distributions in the focusing plane. Such beams permit to realize rotation and fixed trace movement of absorbing particles. The spiral beams having intensity in the shape of triangular boundary, the line with self-intersection and Archimedes spiral were formed by composition of amplitude and phase masks produced on the base of bichromated gelatin. The spiral beams keep their intensity structure unchanged under propagation except scale and rotation. The Ar-laser and microscope MIN-8 with immersion micro objective (60x, NA=O.85) were used in experimental set-up. Particles of the cetylpiridiniumbromide and colored latex spheres were chosen as an objects for manipulation. Experimental results are presented on microobjects movement effectuated with spiral beams along different fixed trajectories. The motion direction is determined by the direction of the beams orbital momentums.