Structural Design of a Displacement-amplified Piezoelectric Actuator Considering the Driving Performance of a Fast Steering Mirror

The development of robust and flexible systems to steer laser beams with high accuracy and precision has been widely recognized as essential in applications such as inter-satellite communications and high-energy laser weapon systems. In particular, fast steering mirror (FSM) systems direct a laser beam toward a target by rotating a mirror using the driving force of an actuator, requiring a large steering angle and high bandwidth. In this study, an amplified piezoelectric actuator (APA) was designed to overcome the limited stroke of conventional piezoelectric actuators. A piezo-structural coupled analysis model incorporating piezoelectric effects was developed and validated using finite element and modal analyses. Based on the relationship between the first natural frequency of an FSM and the equivalent stiffness of the APA, a design strategy was proposed to simultaneously satisfy the required steering angle and improve the natural frequency of the FSM.