The scaling laws of laser beam spreading induced by turbulence and thermal blooming

摘要

The beam spreading, induced by atmospheric turbulence and thermal blooming when a high-energy laser beam propagates through the atmosphere, is numerically calculated and analyzed. The simple scaling relation between the beam quality factor and the characteristic parameters of atmospheric effects is obtained, and can be given by the expression β_(tt)~2 = 1+0.636N~(1.558). Moreover, when the distortion parameter N is less than one, the beam spreading is mostly dependent on the linear effects because of the weak thermal blooming effects. However, with the thermal blooming effects strong gradually, the beam spreading induced by the combined effects of turbulence and thermal blooming increases rapidly.