Sapphire Step Windows

Manufactured in the USAManufactured in the USA


Sapphire step windows are a specialty of Guild Optical Associates. Step windows, aka T-Windows, are excellent for use in viewports, pressure, and vacuum situations. Sapphire step windows also make great viewports for deep ocean vehicles. Sapphire pressure windows stand up well to the abusive salt water and debris while being less thick than other traditional glass counterparts.

Contact us for help determining the minimum thickness needed for your pressure of vacuum window.

Optical windows used in high pressure situations have plenty to gain by losing a lot of thickness. Sapphire optical windows can be up to 65% thinner than Fused Silica windows, while also being much more scratch resistant. Guild Optics will help you determine the thickness needed to start utilizing sapphire in your project.


Diameter: From 10 mm (.393”) to 305 mm (12”) in any optical axis
Thickness: Varies by Diameter but can be sub millimeter and up
Flatness: Varies by thickness but can be 1/20 wave or better if needed
Parallelism: Varies by size but can be as tight as 1 arc second
Surface Quality: Down to 10/5 Scratch/Dig
Quantities: From singles to full large scale production runs
Guild Optics recommends C-Plane material for sapphire pressure windows and vacuum windows

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Durable, scratch resistant, stronger than glass

learn the benefits of sapphire optics