A composite piezoelectric deformable mirror with woofer-tweeter configuration

A composite piezoelectric deformable mirror (DM) with woofer-tweeter configuration is proposed for astronomy applications. This DM consists of unimorph DM and piezoelectric actuators array. Compared with conventional DM, the composite piezoelectric DM has a characteristic of both large stroke and high bandwidth, which is suitable for correcting those aberrations introduced by atmospheric turbulence in real time. The prototype of the composite DM is prepared, and an adaptive optical testing system based on Shack-Hartmann sensor is established. Experimental results indicate that the woofer–tweeter DM has the capability to compensate for the first 20 terms of Zernike aberrations with normalized RMS wavefront errors less than 15%. The proposed composite piezoelectric DM has good performance and great potential in astronomical applications.