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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

150mm Dia., 4mm Thick, MgF2 Coated, B270 Window

See More by SCHOTT Optical Components
Stock #17-181 10 to 12 days
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Abbe Number (vd):
Protective as needed
Clear Aperture CA (mm):
Diameter (mm):
150.00 +0.00/-0.25
Thickness (mm):
4.00 ±0.20
MgF2 (632.8nm)
Coating Specification:
Ravg ≤1.50% @ 632.8nm (N-BK7)
Coefficient of Thermal Expansion CTE (10-6/°C):
9.4 (+20 to +300°C)
Density (g/cm3):
Fine Ground
Index of Refraction nd:
Knoop Hardness (kg/mm2):
Poisson's Ratio:
Substrate: Many glass manufacturers offer the same material characteristics under different trade names. Learn More
Surface Flatness (P-V):
1λ (per 25.4mm Dia. within CA)
Surface Quality:
Protective Window
Wavelength Range (nm):
400 - 700
Young's Modulus (GPa):
Damage Threshold, By Design: Damage threshold for optical components varies by substrate material and coating. Click here to learn more about this specification.
10 J/cm2 @ 532nm, 10ns

Regulatory Compliance

RoHS 2015:
Certificate of Conformance:
Reach 235:

Product Family Description

  • Large Selection of Sizes
  • Available Uncoated, MgF2, or VIS-NIR Anti-Reflection (AR) Coated
  • Custom Sizes Available for Volume OEM Requirements

TECHSPEC® B270 Windows offer a high transmission from the visible to the near-infrared (NIR). They have a similar refractive index to N-BK7 while being more cost-effective. These windows are often used as a protective element due to their high solarization stability and chemical resistance, making them ideal for standard window applications. TECHSPEC® B270 Windows are available either uncoated or coated with a MgF2 or VIS-NIR Anti-Reflection (AR) Coating. Both circular and square options are offered in various sizes, and custom sizes and coatings are available for OEM applications. 

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