Adaptive control of a micromachined continuous-membrane deformable mirror for aberration compensation

The nonlinear response and strong coupling of control channels in micromach ined membrane deformable mirror (MMDM) devices make it difficult for one to control the MMDM to obtain the desired mirror surface shapes. A closed-loo p adaptive control algorithm is developed for a continuous-surface MMDM use d for aberration compensation. The algorithm iteratively adjusts the contro l voltages of all electrodes to reduce the variance of the optical wave fro nt measured with a Hartmann-Shack wave-front sensor. Zernike polynomials ar e used to represent the mirror surface shape as well as the optical wave fr ont. An adaptive experimental system to compensate for the wave-front aberr ations of a model eye has been built in which the developed adaptive mirror -control algorithm is used to control a deformable mirror with 19 active ch annels. The experimental results show that the algorithm can adaptively upd ate control voltages to generate an optimum continuous mirror surface profi le, compensating for the aberrations within the operating range of the defo rmable mirror. (C) 1999 Optical Society of America.