title: Self-focusing and merging of two copropagating laser beams in underdense plasma.
abstract: The propagation of two laser beams copropagating in underdense plasma has been studied numerically by solving their coupled envelope equations. It shows that two beams can merge each other, or split into three beams, or propagate with unstable trajectories, depending upon their power and initial beam separation. During the merging process, strong emission of radiation is observed. It also shows that the density cavitation channels due to the transverse ponderomotive force of the beams tend to trap them inside and prevent them from merging each other.
authors.affiliation: Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Science, Beijing 100080, China.
authors.forename: Quan-Li
authors.initials: QL
authors.lastname: Dong
authors.forename: Zheng-Ming
authors.initials: ZM
authors.lastname: Sheng
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang