Missile seeker windows could be designed with sapphire optics that can withstand high temperature

- Sapphire optics are the stack-eye upgrade the physical layer has been begging for. Meller Optics is now custom-fabricating Al₂O₃ lenses and windows rated from -200°C to +1,600°C — that's furnace inspection, semiconductor fab gear, pyrometers and vacuum chambers all getting windows that refuse to melt, scratch or quit. Mohs hardness of 9 means these lenses shrug off fast particles and fluid hammering, plus fluorine resistance up to 300°C for the chemically spicy fab lines. For automation stacks, that's sensor integrity where conventional glass would curl up and die — machine vision systems watching molten processes through a window that stays optically honest under thermal cycling. Whoa, that's mega-illegal levels of durable. Sizes run 0.25 to 6 inches diameter, up to 1.5 inches thick, with stepped edges, slots and wedges for tight mounting, and surface finishes down to 40-20 scratch-dig with 0.5-fringe HeNe flatness. In defense and aerospace, these are seeker windows and instrumentation ports surviving reentry-grade heat. Pluto Uplink taught us to call this research — but really, it's the armor your robots' eyes deserve.