Deformable Mirror (DM) is the key part in the AO system. Characterization of DM is important as it maps between input voltage signal and output mirror deformation. The precision of characterization largely affects the control performance. While characterizing the DM with wavefront sensors is easy and straightforward, there is very few research on the characterizing the DM in a Wavefront sensorless (WFSless) setup. Existing research focuses on using Phase Diversity Phase Retrieval (PDPR) methods to retrieve phase, while introducing diversity phase by using various additional hardware.

This thesis tries to use PDPR methods to characterize the DM in a WFSless setup without using any additional hardware. Diversity phase are introduced by the DM itself and calibrated afterwards. Simulation results show that the proposed method is capable of characterizing the DM. Experiments on the setup are also conducted and further validates the proposed method, while unstable setup is accountable for the undesired results of the characterization.