<title>Tunable membrane mirrors used with real-time holography</title>

Abstract

Space-based inflatable technology is of current interest to NASA, DOD, and in particular to the Air Force Research Laboratory. Potentially large gains in lowering launch costs, through reductions in structural mass and volume are driving this activity. Diverse groups are researching and developing this technology for radio and radar antennae, optical telescopes, and solar power and propulsion applications. Regardless of the use, one common requirement for successful application is the accuracy of the inflated surface figure. This paper gives a very cursory description of the research being performed at the Air Force Research Laboratory in the fields of membrane mirrors and real time holography. First, the article will show a shape modification method for the membrane mirror, achieved through enforced boundary displacements. The membrane mirror shape modification, resulted in moving the inflated membrane shape towards a desired optical profile. Minimization of the optical figure error is further discussed. Next, the optical requirements levied from the membrane mirror to an optically addressed spatial light modulator performing real time holographic correction are discussed. A proposed optical configuration in which a real time holographic optical element could be combined with the membrane mirror to achieve near diffraction limited optical performance is discussed.