2D and 3D multiple optical tweezers

摘要

In this article, we present the way how to generate an interference field created by two or three beams having their optical axes in one plane, therefore got the so called 2D interferometric optical tweezers. Firstly, we analyzed the arrangement where two co-propagating laser beams intersect at an angle and interfere there, the fringes so produced behave as an array of two-dimension multiple optical tweezers. Then we quantified the property of these traps by analyzing the forces exerted on the polystyrene beads. The last, we added the third counter-propagating beam that balanced the radiation pressure of the other two beams but did not interfere with them. Through this method, we can confine polystyrene beads at a given distance between the two surfaces of the sample cell. This also can be called the 3D traps. We also theoretically compared the lateral optical trap forces between 2D and 3D tweezers.