At the end of March, I use measurements of actuator “pokes” to derive the control matrix for the deformable mirror on our test bench. Now we can dial in Zernike modes to control the surface. Here I’ve plotted a few examples, as seen by the pupil shearing interferometer.
I wrote a python/matplotlib script to visualize the command I send to our deformable mirror in terms of voltage applied to the bimorph electrodes. We want to avoid using too much stroke to compensate for the rest state trifoil figure. The max/min voltage is +/- 400 V. From this plot, it’s clear that only the outer actuator ring is a concern, where we use upwards of 100 V in some cases to achieve the flattened figure I showed a few weeks ago.