Atmospheric clearness is a key issue for free space optical communications
(FSO). We present the first active method to achieve FSO through clouds and
fog, using ultrashort high intensity laser filaments. The laser filaments
opto-mechanically expel the droplets out of the beam and create a cleared
channel for transmitting high bit rate telecom data at 1.55 microns. The low
energy required for the process allows considering applications to
Earth-satellite FSO and secure ground based optical communication, with
classical or quantum protocols.Comment: 4 pages + 2 pages supplementary text and movie