N-BK7 Optical Windows

Our laser grade optical windows have excellent < 30 arc-seconds parallelism resulting in minimal transmitted beam deviation. The windows are available with broadband AR coatings on both sides for use in visible or IR applications.

Laser-grade, suitable for the most demanding applications
≤λ/20 surface flatness and 10-5 scratch-dig
Parallel to less than 30 arc sec for minimal transmitted beam deviation
High quality Grade A N-BK7
Broadband AR coatings for visible, or NIR applications

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Showing 10 of 11 total products

Compatibility:

Description	Compatibility	Diameter	Thickness	Antireflection Coating	Avail.	Price
05BW40-30Optical Window, Parallel, N-BK7, 12.7 mm, λ/20, Uncoated	UNIVERSAL	12.7 mm	6.0 mm	Uncoated	In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$115
05BW40-30AR.14Optical Window, Parallel, N-BK7, 12.7 mm, λ/20, 430-700 nm	UNIVERSAL	12.7 mm	6.0 mm	430-700 nm	In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$127
05BW40-30AR.18Optical Window, Parallel, N-BK7, 12.7 mm, λ/20, 1000-1550nm	UNIVERSAL	12.7 mm	6.0 mm	1000-1550 nm	In Stock	$145
10BW40-30Optical Window, Parallel, N-BK7, 25.4 mm, λ/20, Uncoated	UNIVERSAL	25.4 mm	6.0 mm	Uncoated	In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$157
10BW40-30AR.14Optical Window, Parallel, N-BK7, 25.4 mm, λ/20, 430-700 nm	UNIVERSAL	25.4 mm	6.0 mm	430-700 nm	In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$169
10BW40-30AR.16Optical Window, Parallel, N-BK7, 25.4 mm, λ/20, 650-1000 nm	UNIVERSAL	25.4 mm	6.0 mm	650-1000 nm	In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$186
10BW40-30AR.18Optical Window, Parallel, N-BK7, 25.4 mm, λ/20, 1000-1550nm	UNIVERSAL	25.4 mm	6.0 mm	1000-1550 nm	In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$186
20BW40-30Optical Window, Parallel, N-BK7, 50.8 mm, λ/20, Uncoated	UNIVERSAL	50.8 mm	10.0 mm	Uncoated	In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$258
20BW40-30AR.14Optical Window, Parallel, N-BK7, 50.8 mm, λ/20, 430-700 nm	UNIVERSAL	50.8 mm	10.0 mm	430-700 nm	In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$272
20BW40-30AR.16Optical Window, Parallel, N-BK7, 50.8 mm, λ/20, 650-1000 nm	UNIVERSAL	50.8 mm	10.0 mm	650-1000 nm	In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$290

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Specifications

Material
Grade A N-BK7
Surface Flatness
λ/20 @ 632.8 nm
Surface Quality
10-5 scratch-dig
Thickness Tolerance
±0.25 mm
Transmitted Beam Deviation
±30 arc sec
Chamfers
12.7 & 25.4 mm: 0.25-0.75 mm face width
50.8 mm: 0.38-1.14 mm face width

Chamfers Angle/Tolerance
45° ±15°
Cleaning
See How to Clean Optics
Clear Aperture
Central 85% of diameter
Diameter Tolerance
+0/-0.15 mm
Wedge
≤30 arc sec
Damage Threshold
7.5 J/cm², 10 ns pulses, 20 Hz for coated models

Features

High Precision Manufacturing

These N-BK7 parallel windows are manufactured to the highest precision with flatness better than λ/20 for low distortion and < 30 arc second parallelism for exceptionally low beam deviation.

N-BK7 for VIS and NIR Applications

N-BK7 is an excellent lens material for most visible and near infrared applications. It is the most common borosilicate crown optical glass, and it provides great performance at a good value. Its high homogeneity, low bubble and inclusion content, and straightforward manufacturability make it a good choice for transmissive optics.

Broadband Visible Antireflection Coatings

Our AR.14 broadband multilayer antireflection coating markedly improves the transmission efficiency of these lenses by reducing surface reflections over a 430-700 nm wavelength range. This AR coating performs effectively for multiple visible wavelengths and tunable lasers eliminating the need for several sets of optics.

Broadband Multilayer NIR Antireflection Coating

Our AR.16 coating is recommended for NIR applications in the 650-1000 nm range.

Broadband Multilayer IR Antireflection Coating

Our AR.18 coating is for IR applications in the 1000-1550 nm range.

RoHS Compliant

These windows have been tested for dangerous substances like Pb, Cd, Hg, Hex-Cr, PBB, and PBDE and have been found to be in compliance with RoHS allowable levels.

Accessories

Description	Compatibility	Avail.	Price
LH-0.5AFixed Lens Mount, 0.50 in. (12.7 mm) Diameter, 8-32 Thread, A-LINE	IMPERIAL	In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$20
LH-1AFixed Lens Mount, 1.0 in. (25.4 mm) Diameter, 8-32 Thread, A-LINE	IMPERIAL	In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$20
LH-2DBMirror Mount, Fixed, 50.8 mm Diameter, 8-32 Thread, A-LINE	IMPERIAL	In Stock FREE 2-day shipping on thousands of products on Newport.com Learn More	$31