Sapphire Viewports – UV 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 sapphire viewports are offered as standard with the crystal axis Randomly orientated wrt the optical axis. (DUV versions would specifically have this axis at 0°)

Features:
• UHV Compatible.
• Bakeable to 450°C.
• Crystal orientation is random – not specified (specific orientation available on request).

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 : Random – not specified
Surface finish : 50/20 scratch/dig
UV transmission @ 250nm (external) : 50%
parallelism : <3 arc minutes
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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.