In a folded three-dimensional free-space optical switch including a set of fibers
and an optical system for producing collimated beamlets aligned to intersect an
array of dual axis micromirrors of coplanar input and output mirror elements, and
a folding mirror, the input and output micromirrors are arranged in a pattern wherein
either the input or output mirror set is disposed along an annulus and wherein
the complementary output or input mirror set is disposed within the annulus in
order to globally minimize maximum tilt angles for a two-dimensional locus of tilt
angles of the micromirror set. The beamlets are routed from assigned input fibers
to corresponding input moveable mirrors to assigned output fibers via the static
folding mirror and corresponding output moveable mirrors.
