Approach for deformable mirror wavefront error correction

Adaptive optics (AO) is receiving wide applications for diffraction-limited imaging in astronomical observations and biomedical research. In an AO system, the deformable mirror (DM) is commanded to correct wavefront errors (WFEs) and is a key component. However, a DM may not be perfect, and it may have strong static WFEs, which may be inherited from the DM manufacturing process or be induced by external factors such as the vibration during the transportation of delivery, which must be corrected before it is integrated into an AO system. To correct this static WFE, we introduce a simple approach. Our approach is based on a two-beam Michelson interferometer configuration, in which a high-quality flat mirror is used as a reference mirror whose surface wavefront can be copied to that of the DM, and thus the DM WFEs can be effectively corrected through an optimization procedure. Our experiments demonstrated that this approach is simple to conduct. Using an iteration optimization approach, the Strehl ratio of the DM can be improved from the initial 0.198 to the 0.997, within 30 min of the optimization run.