Laser Tractor Beam Now A Possibility?
Using a Bessel Beam, a group of physicists foresee the realization of an age-old sci-fi device.
From its inception in 1920s science literature, tractor beams – devices with the ability to attract objects from a distances, have always been thought of as fictional. However, a group of physicists have found a potential way to create one using a Bessel Beam. In their paper titled Backward Pulling Force from a Forward Propagating Beam, physicists Jun Chen, Jack Ng, Zhifang Lin, and C. T. Chan argue that a Bessel beam contains properties that make attractive optical force possible.
From the abstract:
The underlining physics is the maximization of forward scattering via interference of the radiation multipoles. We show explicitly that the necessary condition to realize a negative (pulling) optical force is the simultaneous excitation of multipoles in the particle and if the projection of the total photon momentum along the propagation direction is small (as in some propagation invariant beams), attractive optical force is possible. This possibility adds “pulling” as an additional degree of freedom to optical micromanipulation.