Configurable vortex laser beams for optical manipulations of microparticle ensembles
The formation of phase holograms by the modulation superposition method for producing a set of vortex laser beams is presented. Produced vortex laser beams are considered to be used in the scheme of optical tweezers for optical trapping and manipulation of ensembles of latex microspheres. Applying the method of modulation superposition is regarded to synthesize phase holograms by adding harmonic functions with specific parameters. The possibility of independent control of the position of produced vortex beams and their orbital angular momentum is experimentally demonstrated, being in a good agreement with theoretical analysis. The use of structured light in combination with optothermal traps is likely to expand the traditional methods of microobject optical manipulation. The results obtained open up new possibilities for optical manipulation in biomedical applications.