Fused Silica UHV Viewports With Broadband Anti-Reflective Coatings

VacTechniche Vacuum Optics – Viewports

Fused Silica UHV Viewports With Broadband Anti-Reflective Coatings

VacTechniche fused silica viewports are offered with a four-layer broadband anti-reflective (BBAR) coating on both sides of the window optimised to a customer specified laser wavelength range. In many cases, the coating reduces reflection to below 0.5% per face or 1% total at the key wavelengths specified.

Please advise the important wavelengths or wavelength range with your enquiry or order. Wavelength ranges between 240 nm and 1550 nm can be accepted as standard, although coatings for other wavelength ranges can be quoted on request. Viewports with ‘V’ coatings for a single wavelength for laser applications are also offered. The viewports comprise a high purity laser quality fused silica optic with precise flatness, parallelism, scratch and dig specifications.

Category:

Description

Reflectance Curve

Please note that the optical reflectance curves are approximations and should be used for reference only

 

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 fields.

The non-magnetic viewports use a non-magnetic weld ring instead of the regular kovar weld ring. 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.

Non-standard viewports can be manufactured on request, including re-entrant style microscope/camera viewports. Annealed copper gaskets and other component accessories are also supplied by VacTechniche.

 

Specifications

Specification
Seal Type Braze
Maximum Temperature 200°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
Flatness  <8λ
Laser Damage Threshold 2 J/cm2 at 530nm (note, varies with wavelength, laser type and cleanliness of optic)
Coating 4-layer BBAR coating optimised to customer specified wavelength range between 240nm and 1550nm

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
VPZ16QBBAR NW16CF 34 15 1.5 12.7 304L Kovar
VPZ16QBBAR-LN NW16CF 34 15 1.5 12.7 316LN Kovar
VPZ16QBBAR-NM NW16CF 34 15 1.5 12.7 316LN Niobium Yes
VPZ38QBBAR NW35CF 70 32 3 12.7 304L Kovar
VPZ38LAQBBAR NW35CF 70 38* 3.5 12.7 304L Kovar
VPZ38QBBAR-LN NW35CF 70 32 3 12.7 316LN Kovar
VPZ38LAQBBAR-LN NW35CF 70 38* 3.5 12.7 316LN Kovar
VPZ38QBBAR-NM NW35CF 70 32 3 12.7 316LN Niobium Yes
VPZ64QBBAR NW63CF 114 63 4.5 17.4 304L Kovar
VPZ64QBBAR-LN NW63CF 114 63 4.5 17.4 316LN Kovar
VPZ64QBBAR-NM NW63CF 114 63 4.5 17.4 316LN Niobium Yes
VPZ100QBBAR NW100CF 152 89 6 19.9 304L Kovar
VPZ100QBBAR-LN NW100CF 152 89 6 19.9 316LN Kovar
VPZ100QBBAR-NM NW100CF 152 89 6 19.9 316LN Niobium Yes
VPZ150QBBAR NW150CF 203 136 9.5 22.3 304L Kovar
VPZ150QBBAR-LN NW150CF 203 136 9.5 22.3 316LN Kovar
VPZ150QBBAR-NM NW150CF 203 136 9.5 22.3 316LN Niobium Yes