High speed, large deflection deformable mirrors for focus and spherical aberration control

Micromachined dynamic lensing elements have become technologically viable components for optical systems. Circular mirrors 300 /spl mu/m, 750 /spl mu/m, 1000 /spl mu/m, and 1500 /spl mu/m in diameter were designed for use as focus and spherical aberration control mirrors. These membrane deformable mirrors, with two annular actuation zones and various perimeter modifications, were studied. A large air gap beneath the membranes allowed for several microns of displacement. Differences in actuation and dynamic behavior were observed for the segmentation and to a lesser extent thinning of the perimeter. An increased cavity depth will allow for greater focal length and spherical aberration correction ranges than those reported. The practical limit of the focal length and spherical aberration correction range is the maximum electric field that can be sustained by the materials used.