Effect of spherical aberration on laser beam self-focusing in the atmosphere.

The effect of spherical aberration on the laser beam self-focusing in the atmosphere to assist delivering powerful laser beams from orbit to the ground is studied. It is found that for the small orbital mirror size, a Gaussian beam with negative spherical aberration might be more strongly compressed without filamentation than that without spherical aberration, and its spot size on the ground can be reduced well below the diffraction limit. However, for the large orbital mirror size, spherical aberration will result in an increase of receiver size on the ground.