Bringing quality into focus [email protected] +44 (0)1622 859444
My Cart
Currency

Looking For a Custom Optical Solution? Enquire

Knight Optical’s N-BK7 (equivalent) windows are an excellent choice for sealing optical enclosures and are well-suited for low-power laser applications. Our stock range includes uncoated and AR-coated options with extended BBAR coatings for visible and NIR applications (450-900nm), as well as the telecom region of 1050-1700nm. Featuring highly parallel faces for minimal beam deviation and tightly controlled flatness and surface quality, these windows ensure reliable optical performance.

N-BK7 windows can also be custom-coated for specific wavelengths, including beamsplitter and mirror coatings, to meet bespoke requirements.

Stock options can be quickly edged to custom diameters and sizes—contact our sales team for more details.

Material:
Diameter:
Length/Width:
Thickness:
Flatness:
Surface Quality:
Parallelism:
Coating:
N-BK7 or equivalent
+0/-0.2 mm
± 0.1mm
± 0.1mm
<λ/4 over 85% of aperture
<40:20 scratch/dig
1 arc minute

Windows with suffix "AV2" are coated on both faces with:
Extended broadband multilayer antireflective coating <0.5%@450-900nm

Windows with suffix "AI1" are coated on both faces with:
Extended broadband multilayer antireflective coating <0.4%@630-1100nm

Windows with suffix "AI2" are coated on both faces with:
Extended broadband multilayer antireflective coating <0.4%@1050-1700nm

Edge down of stock windows to smaller diameters.
Stock windows can be machined to custom square/ rectangular apertures.
Mounting options.
Custom AR coatings.
Custom mirror and beamsplitter coatings can be applied to uncoated precision grade BK7 windows.
Please enquire about flatter options.

Windows with suffix "AV2" are coated on both faces with:
Extended broadband multilayer antireflective coating <0.5%@450-900nm

Windows with suffix "AI1" are coated on both faces with:
Extended broadband multilayer antireflective coating <0.4%@630-1100nm

Windows with suffix "AI2" are coated on both faces with:
Extended broadband multilayer antireflective coating <0.4%@1050-1700nm

Items 1-10 of 55

Name Material Coating Coated Sides Diameter (mm) Length (mm) Width (mm) Thickness (mm) Price Buy
WQK1000 BK7 or equivalent Uncoated 10 3
US$39.34
WQK1500 BK7 or equivalent Uncoated 15 3
US$40.31
WQK2511 BK7 or equivalent Uncoated 25 4
US$48.09
WQK2500 BK7 or equivalent Uncoated 25 6
US$49.76
WQK2501 BK7 or equivalent Uncoated 25.4 6.35
US$46.29
WQK4000 BK7 or equivalent Uncoated 40 6
US$46.29
WQK5000 BK7 or equivalent Uncoated 50 6
US$74.37
WQK6500 BK7 or equivalent Uncoated 65 8
US$114.54
WQK7500 BK7 or equivalent Uncoated 75 8
US$139.00
WQK1010 BK7 or equivalent Uncoated 10 10 3
US$40.31
Page
per page
1

N-BK7 (equivalent) Windows

Shop By
Shopping Options
Price
Coating
Thickness (mm)