Control of membrane mirror profile by electrostatic field

Nowadays, membrane mirrors are being under study. They are interesting from the application standpoint in telescopes with aberration correction (by phase conjugation or real-time holography methods). To give the required spherical or parabolic shape to these mirrors to be employed in the space, the mirror surface is exposed to, for example, gas pressure. For this is the cavity between two membranes, one being transparent (canopy) and the other specular, is filled with the gas. The transparent membrane appears to be undesired in a number of cases since its possible distortions have to be compensated for that a high quality image of the object observed through the telescope to be achieved. However in a number of cases the gas pressure action may be simulated with a proper electrostatic field. In this paper results of electrostatic field effect on the shape of the mylar-film mirror with reflecting coating are presented. Here is also given an analysis of the shape of the membrane mirror exposed to both an electrostatic-field load normal to and a strain load along its surface. It is shown that in the case of the electrostatic load the surface shape can be more close to a parabolic one than that in the uniform pressure case.