The deformable mirror with the size of $410~\text{mm}\times 468~\text{mm}$ controlled by the bimorph piezoceramic plates and multilayer piezoceramic stacks was developed. The results of the measurements of the response functions of all the actuators and of the surface shape of the deformable mirror are presented in this paper. The study of the mirror with a Fizeau interferometer and a Shack–Hartmann wavefront sensor has shown that it was possible to improve the flatness of the surface down to a residual roughness of $0.033~{\rm\mu}\text{m}$ (RMS). The possibility of correction of the aberrations in high-power lasers was numerically demonstrated.

The effects of photon noise, aliasing, wavefront chromaticity and scintillation on the PSF contrast achievable by ground-based adaptive optics (AO) are evaluated for different wavefront sensing schemes. I show that “classical” AO (sensing in the visible, imaging in the near-IR) is limited to about $10^5$ PSF contrast in the central arcsecond because of scintillation chromaticity.

This comparative study shows that a focal-plane based wavefront sensor (WFS), combining wavefront sensing and scientific imaging on the same detector is optimal for high contrast imaging. This approach combines high WFS sensitivity, immunity to aliasing and non common path errors and optical design simplicity. Its theoretical performance is compared to commonly used WFSs, illustrating the advantages of this technique.

I show that such a system can be efficiently used as a second stage after a low-order AO system. Control and data reduction algorithms are presented, as well as possible optical designs incorporating a coronagraph. A laboratory demonstration of this technique is currently being done at Subaru Telescope.