Laser Tracking and Pointing at a Target with Stimulated Brillouin Scattering

Laser tracking and pointing at a simulated moving target in atmosphere 1.27km away is realized experimentally, in which stimulated Brillouin scattering (SBS) phase conjugation technology and velocity compensation mirror are used. Only if the angle between the SBS phase conjugation laser and the illumination laser is smaller than the atmosphere isoplanatic angle ψ₀ , is the wave-front aberration of laser beam produced by atmospheric turbulence compensated for in real time. This experiment was carried out with horizontal ranges 1.27km at 50m height above the ground, and Nd:YAG lasers are used. By changing the angle of a velocity compensation mirror reflecting the SBS phase conjugation laser to the simulated target, simulated targets with different moving velocities are tracked and pointed by the laser beam. The spot and energy distribution of illumination laser spot and SBS phase conjugation laser are recorded. The energy back to target is up to 75mJ. The SBS phase conjugation laser spot shows that it is focused at the simulated moving target within a small area.