Induction of long-lived optical waveguides in the atmosphere by laser filaments

Long Lived Wave guides
An optical laser filament

A high intensity femtosecond laser pulse that is propagating in the atmosphere can form a filament due to dynamical balance between self-focusing and plasm defocusing. The time scales of the physical effects supporting the filaments are very short: self-focusing and multiphoton ionization are instantaneous, while plasma effects survive a few nanoseconds after the femtosecond pulse has passed. For this reason, all waveguiding phenomena associated with femtosecond laser filaments were believed to last no more than a nanosecond. In contrast to this general belief, we have recently discovered that atomospheric filaments induce long-lived waveguides [1]. With the group of Mordechai Segev, we experimentally demonstrated waveguiding effects that live for a microsecond range, long after the plasma is gone. These waveguides are based on air density and acoustic waves effects.


  1. O. Lahav, L. Levi, I. Orr, R. Nemirovsky, Y. Nemirovsky, I. Kaminer, M. Segev, and O. Cohen, Long-lived waveguides and sound wave generation by laser filamentation, Phys. Rev. A 90, 021801(R) (2014)