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TECHSPEC® components are designed, specified, or manufactured by Edmund Optics. TECHSPEC® components are designed, specified, or manufactured by Edmund Optics. Learn More

20mm Dia., 1mm Thick, NIR I Coated λ/4 N-BK7 Window

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Stock #23-427 Contact Us
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€91,00
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€91,00
Qty 6+
€73,00
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Specifications

General

Type:
Protective Window

Physical & Mechanical Properties

Bevel:
Protective as needed
Clear Aperture (%):
90
Clear Aperture CA (mm):
18.00
Diameter (mm):
20.00 +0.00/-0.25
Thickness (mm):
1.00 ±0.20
Edges:
Fine Ground
Knoop Hardness (kg/mm2):
610
Parallelism (arcmin):
<1
Poisson's Ratio:
0.206
Young's Modulus (GPa):
82

Optical Properties

Abbe Number (vd):
64.17
Coating:
NIR I (600-1050nm)
Coating Specification:
Ravg ≤0.5% @ 600 - 1050nm
Index of Refraction (nd):
1.516
Substrate: Many glass manufacturers offer the same material characteristics under different trade names. Learn More
N-BK7
Surface Quality:
60-40
Transmitted Wavefront, P-V:
λ/4
Wavelength Range (nm):
600 - 1050
Damage Threshold, By Design: Damage threshold for optical components varies by substrate material and coating. Click here to learn more about this specification.
7 J/cm2 @ 1064nm, 10ns

Material Properties

Coefficient of Thermal Expansion CTE (10-6/°C):
7.1 (-30 to +70°C)
8.3 (+20 to +300°C)
Density (g/cm3):
2.51

Regulatory Compliance

RoHS 2015:
Compliant
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Certificate of Conformance:
View
×
Reach 235:
Compliant
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Product Details

  • Circular and Rectangular Sizes from 2mm to 200mm
  • 8 Broadband Anti-Reflection Coating Options Available
  • World's Largest Selection of Standard N-BK7 Windows
  • Also Available with Ultra-Thin N-BK7 Windows

TECHSPEC® λ/4 N-BK7 Precision Windows are ideally suited for industrial and low-power laser applications. The high tolerance design yields minimal beam distortion and scatter. Broadband coating options extend the range of these precision windows through the visible and near-infrared spectra. TECHSPEC® λ/4 N-BK7 Precision Windows are offered in circular and rectangular sizes ranging from 2mm to 200mm.

Note: New additions to this product family may be specified with a transmitted wavefront distortion (TWD) specification instead of a surface flatness. For more information on the difference between these two specifications, see our application note on Understanding Optical Windows. 

Technical Information

N-BK7

Typical transmission of a 3mm thick, uncoated N-BK7 window across the UV - NIR spectra.

Click Here to Download Data

Typical transmission of a 3mm thick N-BK7 window with MgF2 (400-700nm) coating at 0° AOI.

The blue shaded region indicates the coating design wavelengh range, with the following specification: 

Ravg ≤ 1.75% @ 400 - 700nm (N-BK7)

Data outside this range is not guaranteed and is for reference only.

Click Here to Download Data

Typical transmission of a 3mm thick N-BK7 window with VIS-EXT (350-700nm) coating at 0° AOI.

The blue shaded region indicates the coating design wavelengh range, with the following specification: 

Ravg ≤ 0.5% @ 350 - 700nm

Data outside this range is not guaranteed and is for reference only.

Click Here to Download Data

Typical transmission of a 3mm thick N-BK7 window with VIS-NIR (400-1000nm) coating at 0° AOI.

The blue shaded region indicates the coating design wavelengh range, with the following specification: 

Rabs ≤ 0.25% @ 880nm
Ravg ≤ 1.25% @ 400 - 870nm
Ravg ≤ 1.25% @ 890 - 1000nm

Data outside this range is not guaranteed and is for reference only.

Click Here to Download Data

Typical transmission of a 3mm thick N-BK7 window with VIS 0° (425-675nm) coating at 0° AOI.

The blue shaded region indicates the coating design wavelengh range, with the following specification: 

Ravg ≤ 0.4% @ 425 - 675nm

Data outside this range is not guaranteed and is for reference only.

Click Here to Download Data

Typical transmission of a 3mm thick N-BK7 window with YAG-BBAR (500-1100nm) coating at 0° AOI.

The blue shaded region indicates the coating design wavelengh range, with the following specification: 

Rabs ≤ 0.25% @ 532nm
Rabs ≤ 0.25% @ 1064nm
Ravg ≤ 1.0% @ 500 - 1100nm

Data outside this range is not guaranteed and is for reference only.

Click Here to Download Data

Typical transmission of a 3mm thick N-BK7 window with NIR I (600 - 1050nm) coating at 0° AOI.

The blue shaded region indicates the coating design wavelengh range, with the following specification: 

Ravg ≤ 0.5% @ 600 - 1050nm

Data outside this range is not guaranteed and is for reference only.

Click Here to Download Data

Typical transmission of a 3mm thick N-BK7 window with NIR II (750 - 1550nm) coating at 0° AOI.

The blue shaded region indicates the coating design wavelengh range, with the following specification: 

Rabs ≤ 1.5% @ 750 - 800nm
Rabs ≤ 1.0% @ 800 - 1550nm
Ravg ≤ 0.7% @ 750 - 1550nm

Data outside this range is not guaranteed and is for reference only.

Click Here to Download Data

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Resources

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Application Note

Anti-Reflection (AR) Coatings

Anti-reflection (AR) coatings are applied to optical components to increase throughput and reduce hazards caused by back-reflections.

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Application Note

An Introduction to Optical Coatings

Optical coatings are used to influence the transmission, reflection, or polarization properties of an optical component.

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