Adaptive optics: wave-front correction by use of adaptive filtering and control

class of adaptive-optics problems is described in which phase distortions c aused by atmospheric turbulence are corrected by adaptive wave-front recons truction with a deformable mirror, i.e., the control loop that drives the m irror adapts in real time to time-varying atmospheric conditions, as oppose d to the linear time-invariant control loops used in conventional adaptive optics. The basic problem is posed as an adaptive disturbance-rejection pro blem with many channels. The solution given is an adaptive feedforward cont rol loop built around a multichannel adaptive lattice filter. Simulation re sults are presented for a l-m telescope with both one-layer and two-layer a tmospheric turbulence profiles. These results demonstrate the significant i mprovement in imaging resolution produced by the adaptive control loop comp ared with a classical linear time-invariant control loop. (C) 2000 Optical Society of America OCIS codes: 010.1080, 010.1290, 010.7060, 010.1330, 110. 6770.