Photo-controlled deformable mirror based on silicon photoconductor

Deformable mirrors are becoming more and more important elements in the astronomical field, both for development of active and adaptive optics. PCDMs behave in a completely different way respect to the traditional ones, since a pattern of light creates virtual actuators, whose size and density can be freely modulated. PCDMs consist in a slab of photoconductive material with a reflective membrane placed at a certain distance from the photoconductor, creating a capacitor. In this paper will be presented the mechanical solution adopted in order to realize a prototype and the setup used in order to start the characterization of the different component. A critical analysis will be performed on the sensitivity of the system to the different dimension that characterize the system itself, like the distance between the membrane and the photoconductor and the membrane tension. The result presented will be relate to the static deformation of the membrane using the DC current.