Active Optics—Progress in Modeling of Tulip-like Variable Curvature Mirrors

We present new results obtained from the modeling of a tulip-like variable curvature mirror (VCM) in case central force that reacts to its contour. From Nastran finite element analysis, we shows 3-D optimizations, using non-linear static flexural option, with an appropriate solution sequence, provide accurate VCM thickness distribution. This allows us take into account boundary conditions, including thin outer collarette and link rigid ring. Modeling quenched stainless steel chromium substrate provides diffraction-limited optical surfaces. Rayleigh’s quarter-wave criterion is performed over zoom range flat up f/3.5 convexity 13 mm clear aperture 10 daN force. The testing prototype elaborated previous analytic theory, show quasi-diffraction-limited figures for f/5. should significantly help future construction such VCMs extended f/3.5.