Date: Tue, 13 Apr 2004 11:22:46 +0200
From: Jerome Paufique <jpaufiqu@eso.org>
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To: salmon@cfht.hawaii.edu
CC: Robin Arsenault <rarsenau@eso.org>
Subject: bimorph deformable mirror
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Hi
Last month, we met to talk about our MACAO systems.
We had a topic in which we discussed about the localisation of the curvature created by an actuator.
I had a look at some data I took on SINFONI-like mirror (optical aperture 60 mm), and I looked at the curvature components along both axis, as you suggested.
The result is less localised than when considering the sum (laplacian). Already making a cut of the phase shows a bell-shape of the phase, illustrating a inversion of the "radial curvature" -with respect to the center of the electrode- while the perpendicular keeps the same sign; the combination beeing still 0.
In each case (x and y axis), the extension of the influence function seems to be more of the order of 1 sub-pupil on each side.

These data were measured on the 60 mm diameter mirror.
I remind some better homogeneity of the curvature over the electrode itself than what is seen on this measurement; it could be interesting to check that on other electrodes, especially the central ones.

Hoping it can help you,
Best regards,
Jerome



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