Esco Optics, Inc.

Commercial Quality Windows, Circular, N-BK7 Optical Glass*

Commercial Quality Windows, Circular, N-BK7 Optical Glass* - Main image
Commercial Quality Windows, Circular, N-BK7 Optical Glass* - View 2Commercial Quality Windows, Circular, N-BK7 Optical Glass* - View 3
$8.35 $12.1 In stock

Category: Commercial Quality Circular

Diameter Tolerance

+/- 0.125 mm

Thickness Tolerance

+/- 0.125 mm

Surface Accuracy

1.0-3.0 mm thickness ≤ 5λ per inch
4.76-12.7 mm thickness ≤ 2λ per inch

Surface Quality

60-40 Scratch-Dig or better

Parallelism

<15'

Edges

Fine ground and safety beveled1

Clear Aperture

90%


1parts under 25.4mm in diameter may not have beveled edges

Commercial windows are used for sight glasses, instrument windows, beamsplitter substrates, vacuum windows, welding window substrates. Esco carries a complete inventory of square commercial optical windows of N-BK7 Optical Glass or equivalent glass.* Indicate in order notes if N-BK7 is required. Windows are polished both sides with ground edges. 

Don't see a part that matches exactly what you need, perhaps you'd like to modify a dimension or add a coating?  Use our fast online quote tool to find out what a custom part would cost. 

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Standard Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

Express Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

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Express Shipping · United States: $3.99

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United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

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Customer Reviews (4.6 / 5 · 5 reviews)

Victoria Y. ★★★★★

I needed a few clear windows for a laser project, and the surface accuracy at ≤2λ per inch for the 6mm thick ones is spot on for my needs. They arrived well-packed and the edges are clean, no chips or scratches.

George I. ★★★★★

Ordered the 4.76mm version and the 2λ surface accuracy is genuinely impressive for the price. Interferometer showed a clean figure right out of the packaging, no edge chips or scratches. Using it as a replacement window in a laser setup and it's holding up perfectly.

Ellie N. ★★★★★

I checked the diameter on a few of these and they all landed within the 0.125 mm spec, which is reassuring. Under a knife edge test the surface accuracy looks like it's holding to the 2λ per inch claim, nice and flat.

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