The mechanical design of the machined image slicer integral field units for the diffraction-limited near-IR spectropolarimeter

With the recent advancement of ultra-high-precision micro-optics fabrication technologies, it is now possible to fabricate IFUs based on machined image slicers with slicer width of 30 um or less. We have developed a machined image slicer IFU (MISI) to replace the BiFOIS IFU of the DL-NIRSP Instrument, one of the first light instrument for the DKIST Telescope. Overall, the IFU contains a total of 336 micro mirrors and a common collimator. The large number of micro optical elements of MISI present a great challenge to the optical and mechanical design process of the IFU. Typical design method that model and position each optical element manually would result in a tedious and lengthy mechanical design process. This paper describes the CAD design process of MISI using Solidworks macros that were developed to automatically generate all the optical surfaces based on the ZEMAX model data output and also simulating the tool shape and path to generate a precise model of the IFU.