Effect of light polarization on plasma distribution and filament   formation
  We show that, for 200 fs light pulses at 790 nm, the formation of filaments is strongly affected by the laser light polarization . Filamentation does not exist for a pure circularly polarized light, propagating in vacuum before focusing in air, while there is no difference for focusing the light in air or vacuum for linearly polarized light. 
L. Arissian, D. Mirell, J. Yeak, S. Rostami and J.-C. Diels
physics.optics physics.plasm-ph