Sapphire Viewports – DUV Grade

These viewports employ a synthetic single crystal sapphire as the window material. Single crystal synthetic sapphire displays very different optical, physical and thermal characteristics depending upon the direction of the axis of the crystal structure. LewVac’s DUV sapphire viewports are offered as standard with the crystal axis at 0°, i.e. parallel to the surface of the viewport. (UV – Random crystal orientation versions are available, as are versions with 90° orientation on request)

Features:
• UHV Compatible.
• Bakeable to 450°C.

Specifications:
Materials
Window : Sapphire, single crystal
Carrier : Kovar^®
Flanges : St.St.

Max. Bakeout Temperature* :
CF flanged viewports : 450°C
KF flanged viewports : 150°C
Weldable viewports : 450°C

Max. Thermal Gradient : 25°C per minute

Optical properties
Crystal orientation : 0°
Surface finish : 20/10 scratch/dig
UV transmission @ 248nm (internal) : 99.8%
parallelism : <10 arc seconds
Homogeneity grade : A
Inclusion class : 0
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* – Assembly rating is reduced to that of the lowest rated component.

Anti-Reflective Coating :- Anti-reflective coatings are available, please call our sales office to discuss your specific requirements.