The woofer–tweeter concept in adaptive optics consists in correcting for the turbulent wavefront disturbance with a combination of two deformable mirrors (DMs). The woofer corrects for temporally slow-evolving, spatially low-frequency, large-amplitude disturbances, whereas the tweeter is generally its complement, i.e., corrects for faster higher-order modes with lower amplitude. A special feature is that in general both are able to engender a common correction space. In this contribution a minimum-variance solution for the double stage woofer–tweeter concept in adaptive optics systems is addressed using a linear-quadratic-Gaussian approach. An analytical model is built upon previous developments on a single DM with temporal dynamics that accommodates a double-stage woofer–tweeter DM. Monte Carlo simulations are run for a system featuring an 8×8 actuator DM (considered infinitely fast), mounted on a steering tip/tilt platform (considered slow). Results show that it is essential to take into account temporal dynamics on the estimation step. Besides, unlike the other control strategies considered, the optimal solution is always stable.
© 2010 Optical Society of America
Original Manuscript: April 6, 2010
Revised Manuscript: August 2, 2010
Manuscript Accepted: August 13, 2010
Published: September 20, 2010
Carlos Correia, Henri-François Raynaud, Caroline Kulcsár, and Jean-Marc Conan, "Minimum-variance control for woofer–tweeter systems in adaptive optics," J. Opt. Soc. Am. A 27, A133-A144 (2010)