Design and Simulation of High-Bandwidth 4-DOF Fast Steering Mirror

The accuracy and stability of the laser are affected not only by the external environment, but also by laser structure, heat source, input source, etc., resulting in four-degree-of-freedom (4-DOF) fluctuation errors. To reduce the laser fluctuation errors and improve laser quality, this study proposes a high-bandwidth 4-DOF fast steering mirror (FSM) with double Porro prisms driven by a voice coil motor (VCM), and has the advantage of shorter optical path length, fewer elements, and easier set-up at different locations in laser beam stabilization. The proposed 4-DOF FSM is verified by using the finite element analysis software ANSYS and MATLAB/Simulink. The proposed 4-DOF FSM has the movement range of ±0.1 mm and ±5 mrad along X and Y axis, respectively; the open-loop bandwidths of translational part and rotational part are 111 Hz and 113 Hz, respectively; and the closed-loop bandwidths of translational part and rotational part are 371 Hz and 379 Hz, respectively.