Performance evaluation of phase plate and deformable mirror for adaptive optics (AO) system

Spatial resolution of the ground-based optical telescopes is limited by the Earth's atmospheric turbulence rather than the size of the telescope aperture. To restore the performance of a telescope to near diffraction limit, adaptive optics (AO) system should be designed and developed based on the turbulence characteristics at the telescope site. Crucial part in developing the AO system is, simulating the turbulence conditions of the atmosphere, estimation of its effect on wavefront and correction of the distorted wavefront in the laboratory. The essential components of laboratory AO system are phase plate and deformable mirrors (DMs). Phase plate simulates the turbulent conditions, and DM corrects the distorted wavefront. Performance of AO system depends on the characterization of these two devices. Fizeau interferometer and Shack-Hartmann wavefront sensor (SHWS) are used for the performance evaluation. Current work provides a detailed discussion about the tests carried out to characterize these two components and the results obtained.