MPF manufactures Sapphire and Fused Silica viewports using proprietary vacuum brazing and welding techniques. Fused Silica viewport designs are available with diameters up to 8 inches and include zero length designs for low profile applications. These are all bakeable to 200˚C. Several standard grades of Fused Silica windows are offered Several standard grades of Fused Silica windows are offered having excellent transmission from 193m to 2 microns.