| Popis: |
We investigate a fundamental limit of atmospheric compensation for adaptive optical systems that use uncooperative beacons or laser guide stars. Laser guide stars are generated by backscattering processes that are naturally incoherent. The limit arises because the wavefront sensing component of the adaptive optics cannot differentiate between the incoherency introduced by atmospheric turbulence from that of the laser guide star generation process. The limit is significant and restrictive. Under absolutely ideal conditions with perfect compensation, the compensated Strehl ratio must be less than 0.3. Realistic conditions will reduce this by more than a factor of 2. |
