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

50mm Dia., 4mm Thick, NIR II Coated λ/4 N-BK7 Window

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Stock #25-825 New 3-4 days
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€120,00
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€120,00
Qty 6+
€102,00
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Abbe Number (vd):
64.17
Bevel:
Protective as needed
Clear Aperture (%):
90
Clear Aperture CA (mm):
45.00
Diameter (mm):
50.00 +0.00/-0.25
Thickness (mm):
4.00 ±0.20
Coating:
NIR II (750-1550nm)
Coating Specification:
Rabs ≤1.5% @ 750 - 800nm
Rabs ≤1.0% @ 800 - 1550nm
Ravg ≤0.7% @ 750 - 1550nm
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
Edges:
Fine Ground
Index of Refraction nd:
1.516
Knoop Hardness (kg/mm2):
610
Parallelism (arcmin):
<1
Poisson's Ratio:
0.206
Substrate: Many glass manufacturers offer the same material characteristics under different trade names. Learn More
N-BK7
Surface Flatness (P-V):
λ/4
Surface Quality:
60-40
Type:
Protective Window
Wavelength Range (nm):
750 - 1550
Young's Modulus (GPa):
82
Type of Window:
Glass
Damage Threshold, By Design: Damage threshold for optical components varies by substrate material and coating. Click here to learn more about this specification.
8 J/cm2 @ 1064nm, 10ns

Regulatory Compliance

RoHS 2015:
Compliant
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Certificate of Conformance:
View
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Reach 235:
Compliant
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Product Family Description

  • Circular and Square Sizes from 5mm to 150mm
  • 7 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.

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.