Fused Silica Zero Length Viewports

VacTechniche Vacuum Optics – Viewports

Fused Silica Zero Length Viewports

VacTechniche fused silica viewports are offered in CF, ISO and KF flange styles. The viewports comprise a high purity laser quality fused silica optic with precise flatness, parallelism, scratch and dig specifications.

The ultra high vacuum (UHV) CF versions are offered using high grade 304L or 316LN stainless steel flanges. Non-magnetic viewports are offered for low energy applications or surface science applications needing low magnetic welds. The non-magnetic viewports use a non-magnetic weld ring instead of the regular kovar weld ring. Flanges in 316L stainless steel are used for the high vacuum KF and ISO viewports.

Category:

Description

TSL viewports are manufactured in cleanroom conditions and helium leak tested, cleaned and packed to UHV standards. The rugged construction of the fused silica viewports allows repeated bake-out with UHV performance, whilst the window offers broadband optical transmission through deep UV, visible to near infra-red. Various anti-reflective coatings to match customer reflectance requirements are processed at TSL and available as options listed in the AR coated viewport section of the catalogue.

Laser viewports with a VAR coating optimised or specific customer specified laser wavelength, reducing reflectance to below 0.5% per face, are also offered. Non-standard viewports can be manufactured on request, including re-entrant style microscope/camera viewports. Annealed copper gaskets and other component accessories are also upplied by TSL.

Transmission Curve – Fused Silica

Specifications

Seal Type Braze
Maximum Temperature 200°C (KF & ISO versions 150°C)
Minimum Temperature minus 20°C
Maximum Rate of Temperature Change 3°C per minute
Leak Rate <1×10-10 atm-cc/sec (He)
Pressure range 1 bar to 1×10-11 mbar
Surface quality 20/10 scratch/dig
Parallelism < 3 arc minutes
Flatness < 8λ (λ/8 at 632.8nm over 75% of central area before brazing)
Laser Damage Threshold 2 J/cm2 at 530nm (note, varies with wavelength, laser type and cleanliness of optic)

Cross Sections / Diagrams

Parts & Variations

Part Number Flange Type OD mm View Diameter mm Optic Thickness mm Flange Thickness mm Flange Material Weld Ring Material Non-Magnetic
VPZ16Q NW16CF 34 15 1.5 12.7 304L Kovar
VPZ16Q-LN NW16CF 34 15 1.5 12.7 316LN Kovar
VPZ16Q-NM NW16CF 34 15 1.5 12.7 316LN Niobium Yes
VPZ38Q NW35CF 70 32 3 12.7 304L Kovar
VPZ38LAQ NW35CF 70 38 3.5 12.7 304L Kovar
VPZ38Q-LN NW35CF 70 32 3 12.7 316LN Kovar
VPZ38QLA-LN NW35CF 70 38 3.5 12.7 316LN Kovar
VPZ38Q-NM NW35CF 70 32 3 12.7 316LN Niobium Yes
VPZ64Q NW63CF 114 63 4.5 17.4 304L Kovar
VPZ64Q-LN NW63CF 114 63 4.5 17.4 316LN Kovar
VPZ64Q-NM NW63CF 114 63 4.5 17.4 316LN Niobium Yes
VPZ100Q NW100CF 152 89 6 19.9 304L Kovar
VPZ100Q-LN NW100CF 152 89 6 19.9 316LN Kovar
VPZ100Q-NM NW100CF 152 89 6 19.9 316LN Niobium Yes
VPZ150Q NW150CF 203 136 9.5 22.3 304L Kovar
VPZ150Q-LN NW150CF 203 136 9.5 22.3 316LN Kovar
VPZ150Q-NM NW150CF 203 136 9.5 22.3 316LN Niobium Yes