Improvement of Transmitting Laser Beam Quality by Using Two Deformable Mirrors

The use of two deformable mirrors (DM) with finite conjugate ranges is studied for compensating amplitude and phase distortions due to laser propagation through turbulence atmosphere. The Strehl ratio versus the log-amplitude variance (also known as the Rytov parameter) and the conjugate range of the second deformable mirror are plotted. The conclusion is drawn that an adaptive optics transmitting system with two DMs can clearly improve theoretical performance (compared to a system with one DM) in delivering energy on target through atmospheric turbulence. The second DM placed at a finite conjugate range can minimize lost energy outside the radius of the first deformable mirror and thus maximize the Strehl ratio.