Simulation and analysis of deformable mirror driven by piezoelectric actuator array

Adaptive optics (AO) is the key technology to correct wavefront aberrations. An adaptive optics system is composed of a wavefront sensor, a controller, and a wavefront corrector. Deformable mirror (DM) is the most popular wavefront corrector, which determines the effect of wavefront correction in some way. There are various driving methods for DMs, such as electrostatic forces, piezoelectric driving, and electromagnetic forces. The piezoelectric driving is the most common compelling method for DMs. The actuator made of traditional piezoelectric stack-driven has the advantages such as a large driving distance and high reliability. However, they are not suitable for low-cost AO systems. A design of potentially low-cost DM is proposed in this paper. The models of DMs are constructed, which are driven by unimorph piezoelectric actuator arrays with 19, 37, and 61 units. Then all kinds of parameters are obtained by using the finite element method. The simulations about wavefront aberrations fitting and the parameter optimizations are conducted. The results show that the DM with 19-actuators has moderate correction capability for the first 9 Zernike polynomial aberrations, the DM with 37-actuators exhibits favorable correction performance for the first 14 Zernike polynomial aberrations, and the DM with 61-actuators achieves optimal correction for the first 20 Zernike polynomial aberrations. In addition, the fundamental resonant frequencies of the DMs are 1.5 kHz, 2.7 kHz, and 5.5 kHz, respectively.