Laser Beams Deflected Off of Nothing but Air for First Time Ever in Breakthrough Patent Pending Process - The Debrief::An international team of scientists report that they have successfully used acoustics to deflect laser beams in an engineering first.
Doesn’t need to be air “in space”, there just needs to be air somewhere between the laser weapon and whatever it is you don’t want the weapon to destroy…
… although it’d probably be easier to use a mirror. Maybe one pointing directly at the person holding a laser weapon. ;-)
Corner reflector. Send it back where it came from, without knowing where they are ahead of time.