The Mid-Infrared Instrument for the James Webb Space Telescope, III: MIRIM, The MIRI Imager · HackerPapers discussionshttps://hackerpaper.kaipfister.de/p/1508.02488/Collected HN comments and submissions linking this paper.enMon, 02 Nov 2026 11:16:22 GMTThe Mid-Infrared Instrument for the James Webb Space Telescope, III: MIRIM, The MIRI Imager — mentioned by nullchttps://news.ycombinator.com/item?id=29734191urn:hackerpapers:mention:1508.02488:29734191Thu, 30 Dec 2021 06:21:57 GMT<p>Mirrors, mostly yes. The situation for lenses is more complicated. Fused silica is falls off in the mid IR and is opaque for long wave IR, and optimizing for UV costs you IR response. ( https://escooptics.com/pages/materials-fused-silica-quartz ) The main optical path of JWST is all reflective for this reason. There are refractive optics in some the instruments, but those are more wavelength specific. E.g. NIRcam uses refractive elements made from LiF, BaF2, and ZnSe ( http://ircamera.as.arizona.edu/nircam/pdfs/5904-9_Ryder.pdf ) while I don&#x27;t think MIRI ( https://arxiv.org/pdf/1508.02488.pdf…</p><p><a href="https://hackerpaper.kaipfister.de/p/1508.02488/">Paper and discussion history</a>. A mention is not an endorsement.</p>astro-ph.IM