  We report on the design and construction of a microlens-array (MLA)-based
pupil slicer and double scrambler for MAROON-X, a new fiber-fed, red-optical,
high-precision radial-velocity spectrograph for one of the twin 6.5m Magellan
Telescopes in Chile. We have constructed a 3X slicer based on a single
cylindrical MLA and show that geometric efficiencies of >85% can be achieved,
limited by the fill factor and optical surface quality of the MLA. We present
here the final design of the 3x pupil slicer and double scrambler for MAROON-X,
based on a dual MLA design with (a)spherical lenslets. We also discuss the
techniques used to create a pseudo-slit of rectangular core fibers with low FRD
levels.
