Abstract

Wavefront measurements have been made with the COME-ON adaptive optics prototype system on the ESO 3.6 m telescope at La Silla (Chile). Two types of data have been recorded : the atmospheric wavefronts and the residual wavefront errors after correction by the adaptive optics system.

A spatial and temporal characterization is performed through both angle-of-arrival fluctuation analysis and wavefront modal expansion. Correlation times and atmospheric cut-off frequencies are deduced for different seeing conditions. The outer scale of the turbulence is also determined.

The servoloop transfer function is analysed. The adaptive optics gain is expressed in terms of wavefront fluctuation attenuation. Different types of servoloop control are compared. During these experiments, the maximum servoloop bandwidth has reached 25 Hz for a 100 Hz sampling frequency.

© 1992 Optical Society of America