  A simplification strategy for Segmented Mirror Splitters (SMS) used as beam
combiners is presented. These devices are useful for compact beam division and
combination of linear and 2-D arrays. However, the standard design requires
unique thin-film coating sections for each input beam and thus potential for
scaling to high beam-counts is limited due to manufacturing complexity. Taking
advantage of the relative insensitivity of the beam combination process to
amplitude variations, numerical techniques are used to optimize
highly-simplified designs with only one, two or three unique coatings. It is
demonstrated that with correctly chosen coating reflectivities, the simplified
optics are capable of high combination efficiency for several tens of beams.
The performance of these optics as beamsplitters in multicore fiber amplifier
systems is analyzed, and inhomogeneous power distribution of the simplified
designs is noted as a potential source of combining loss in such systems. These
simplified designs may facilitate further scaling of filled-aperture coherently
combined systems.
