title: Mutual attraction of laser beams in plasmas: braided light
abstract: Using a variational method, we show that an effective attractive force exists between two Gaussian laser beams in a plasma because of a mutual coupling from relativistic mass corrections. The effective force can be generalized to other nonlinearities. This force can cause two laser beams to spiral around each other with a rotation period that is proportional to the Rayleigh length. These orbits are stable if the ratio of the orbit diameter to the laser spot size d(0)/W(0)</=sqrt[2]. Three-dimensional particle-in-cell simulations are presented which confirm the mutual attraction.
authors.affiliation: Department of Physics & Astronomy, University of California, Los Angeles, California 90095-1547, USA.
authors.initials: C
authors.lastname: Ren
authors.initials: RG
authors.lastname: Hemker
authors.initials: RA
authors.lastname: Fonseca
authors.initials: BJ
authors.lastname: Duda
authors.initials: WB
authors.lastname: Mori