  Driven by the demands for speed and field of view in the holographic
photostimulation community, we designed, built, and tested a liquid crystal on
silicon (LCoS) spatial light modulator (SLM) with a 1536x1536 square pixel
array and high-voltage LC drive. We discuss some of the engineering work that
made the MacroSLM possible, including the custom FPGA board for handling huge
data rates, the large pixel size for minimizing rolloff and crosstalk, and the
temperature control to handle heating effects from the high-voltage controls
and high-power laser illumination. We also designed an FPGA implementation of
the overdrive method for increasing liquid crystal switching speed, allowing us
to overcome the significant data bottlenecks that limit frame rates for large
arrays. We demonstrate 500 Hz hologram-to-hologram speed at 1064 nm operating
wavelength, and discuss the new science that these speeds and array sizes have
enabled.
