Development of mid-infrared spectrometer with an image slicer (MIRSIS) for ground-based astronomy: developing optical and mechanical mounts

Mid-Infrared Spectrometer with an Image Slicer (MIRSIS) is a 10micron band spectrometer for ground-based observations. Based on the optical design reported in Okamoto et al. (2006),1 we recentlydeveloped most of optical elements and their mounts. There, we adopted designs based on an ultra-precision cut for the slice mirrors and the pupil mirrors. We also designed and partly manufactured the optical parts with switching/adjusting mechanism with cryogenic step motors. Since MIRSIS has a very complicated stereoscopic con.guration of optical elements, we developed a method to adjust the optical alignment where relative positional markers and a three-dimensional measuring system are combined. We con.rmed that we can achieve position and angular adjustment with error down to 0.1mm and 0.05degree through alignment test with a pair of mirrors.