An optical beam path directing system has a field-flattening optically
transmissive wedge installed in spatially dispersed beam paths upstream of
the planar surface of a micro electro-mechanical switch (MEMS) or liquid
crystal array. The parameters of the field-flattening wedge and its
location in the diffracted beam paths are defined such that the wedge
effectively rotates a `best fit` planar surface approximation of the
curvilinear focal plane of a concave reflector into coplanar coincidence
with the optical signal-receiving surface of the MEMS. As a result, loss
variation is essentially flat and minimized across the optical signal
transmission band.
