Eliminating hysteresis of piezoelectric deformable mirror by charge control

• Hysteresis of piezoelectric deformable mirror is eliminated by charge control method.
• Deformation of deformable mirror is controlled by charge for the first time.
• Digitization control of a piezoelectric deformable mirror is proposed.
• Charge driven circuit based on switched capacitor charge pump was developed.

Inherent hysteresis of piezoelectric deformable mirror (DM) limits the performance of adaptive optics (AO) systems including bandwidth and residual wavefront error. A charge control method based on switched capacitor charge pump was proposed to eliminate the hysteresis of piezoelectric DM. Experimental results show that the hysteresis of a unimorph DM was reduced from 11% to less than 1%. It indicates that the proposed charge control method has the potential to improve the deformation precision for one step correction as well as the bandwidth of the AO systems.