Closed-loop operation of SAM prototype

Corrected image Image with DM off

On March 2, 2005, Rolo Cantarutti has successfully closed the AO loop on the SAM prototype in the laboratory. The images show a point source in the closed-loop compensation (left) and with zero voltage on the DM (right). The second image is distorted by imperfect shape of the DM and static aberrations in the system. Only about 20% of the DM dynamic range is used for its self-compensation.

The picture of the prototype setup. The DM is in the background, behind the big F=1016mm collimating lens and covered by a mask with 50mm hole. The Wavescope (on the left) was used to measure the response of the BIM-60 DM in detail.

Close-up of the prototype near the entrance to the S-H WFS. DM and collimator.

Snapshot of the computer screen with the SAM software running in closed loop. The main purpose of this prototyping is to characterize the real critical components to be used in SAM (DM, WFS, TurSim) and, mostly, to develop the software.

To do:

  1. Compensate static simulated turbulence (so far, only static DM figure and astigmatism were compensated). [done]
  2. Compensate dynamic simulated turbulence [done]
  3. Implement modal control
  4. Estimators of atmospheric parameters and compensation quality
  5. Self-optimization of the loop

See the SAM-AD-02-1301 on further work with the Prototype.

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