New publication in Light: Science & Applications

Recently, increasing attention has been devoted to mastering a new technique of optical delivery of micro-objects – tractor beam. Such beams have uniform intensity profiles along their propagation direction and can exert a negative force that, in contrast to the familiar pushing force associated with radiation pressure, pulls the scatterer toward the light source. It was experimentally observed that under certain circumstances, the pulling force can be significantly enhanced if a non-spherical scatterer, for example, a linear chain of optically bound objects, is optically transported. We demonstrate that motion of two optically bound objects in a tractor beam strongly depends on their mutual distance and spatial orientation. Such configuration-dependent optical forces add extra flexibility to our ability to control matter with light. Understanding these interactions opens the door to new applications involving the formation, sorting or delivery of colloidal self-organized structures.
See the paper here.