Optoacoustic tweezers with focused laser beam
The possibilities of the opto-acoustic tweezers with a focused laser beam to control the position of microparticles suspended in a liquid are studied. The estimation of the average radiation pressure force acting on a small spherical particle is presented. It is shown that changing the laser radiation geometry you can change not only the amplitude of the average acoustic force, but also its direction, making it possible to move and hold the microparticles at the definite distance from the beam axis in the plane of the laser beam's waist.