Fig. 1.

(a) Photograph of a released 4 mm diameter mirror with its four electrodes labeled. The resulting electrostatic force from the applied voltage is shown in the cross-section diagram. (b) Voltages resulting in the parabolic shape of the mirror allow for sharp imaging of infinite conjugate rays, while a non-parabolic shape leads to spherical aberration, where rays focus at different distances along the center axis. The total deflection, δ, represents the mirror sag of the reflective surface.