Vortex-antivortex-assisted nondiffracting light beams

Nondiffracting light beam has attracted much attention owing to its unique properties. Previous techniques for achieving the nondiffracting light rely on engineering the optical wavefront so as to form a nondiffracting form. Here we report a fundamentally different mechanism for generating the nondiffracting light that arises purely from the intrinsic vortex-antivortex interaction of light. We utilize complex polynomial functions to form an interactive vortex-antivortex configuration. In the course of propagation, vortices and antivortices annihilate via mutual interaction, producing a bright central spot that maintains nearly constant transverse size over a long distance. We experimentally and numerically demonstrate the unique vortex-antivortex interaction and the resultant nondiffracting light field. Our demonstration provides a different approach for the generation of nondiffracting light, benefiting potential applications such as optical communication and particle manipulation.