Design And Simulation Of Edge-driven Low Order Deformable Mirror

Edge-driven mirror is important for the compensation of low order aberrations in high power solid state laser systems, for it has many advantages,such as simple frame, few driven unites, large stroke, and free of Print-Through effect. In this paper, optimal design and simulation analysis of edge-driven deformable mirror are presented:Firstly, three kinds of single actuator edge-driven mirror which respectively correct focus, astigmatism, coma aberration are designed. The relationship between residual wavefront error and structural parameter of edge-driven mirror was calculated by finit elements simulation. And the optimal structure parameters to achieve minimum residual wavefront error are selected. For defocus with PV value of 20μm, the residual wavefront error is reduced to 0.7308μm in RMS. For Astigmatism with PV of 10μm, the residual wavefront error is 0.0948μm in RMS. And for comas with PV of 10μm, the residual wavefront error is 0.0948μm in RMS.Secondly, the design concept of four-arm edge-driven deformable mirror is presented. And the structural mechanics model of four-arm edge-driven deformable mirror is built. Aimed at minimize the residual error, the influence function of the driven unit are calculated. And optimal parameters of edge-driven deformable mirror are selected according the simulations with various design parameters. The optimized four-arm edge-driven deformable mirror can compensate different combination of defocus, astigmatism and comas, with stroke as large as 40μm. The residual wavefront error is less than 0.2366μm in RMS.