In one embodiment, a rotatable element includes a plate, a plate support,
a cradle, and a cradle support. The plate is coupled to the cradle via
the plate support. The cradle is coupled to a surrounding frame by the
cradle support. The plate and cradle are suspended over a cavity so that,
in conjunction with the plate support and the cradle support, both the
plate and cradle are capable of freely rotating about different axes of
rotation when suitably actuated. Since the plate is capable of rotating
independently of the cradle, yet also rotates when the cradle is rotated,
the plate is rotatable about two axes of rotation. In some cases, the
axis of rotation of the plate is perpendicular to the axis of rotation of
the cradle. Since the cradle does not surround the plate, the plates of
adjacent rotatable elements can be placed very close to one another
(i.e., as close as about 1 micron) to provide, for example, an array of
very-closely-spaced mirrors.