Product added to cart
TECHSPEC® components are designed, specified, or manufactured by Edmund Optics. TECHSPEC® components are designed, specified, or manufactured by Edmund Optics. Learn More

20mm Diameter x 3.3mm Thickness, NIR Coated, BOROFLOAT® Window

See More by SCHOTT Optical Components
TECHSPEC BOROFLOAT Borosilicate Windows

TECHSPEC BOROFLOAT Borosilicate Windows

Stock #12-189 3-4 days
Quantity Selector - Use the plus and minus buttons to adjust the quantity. +
Qty 1-5
Qty 6+
Volume Pricing
Request Quote
Prices shown are exclusive of VAT/local taxes
Get Product Downloads
Abbe Number (vd):
Protective as needed
Clear Aperture (%):
Clear Aperture CA (mm):
Diameter (mm):
20.00 ±0.5
Thickness (mm):
3.30 ±0.2
NIR (700-1150nm)
Coating Specification:
Ravg <1.0% @ 700 - 1150nm
Coefficient of Thermal Expansion CTE (10-6/°C):
3.25 (+20 to +300°C)
Density (g/cm3):
Index of Refraction nd:
Knoop Hardness (kg/mm2):
Operating Temperature (°C):
1 hour @ 500; >100 hours @ 450
Poisson's Ratio:
Resistance to Temperature Difference (K):
Short Term, 1 hr: 110K
1 - 100 hrs: 90K
Long Term, >100 hrs: 80K
Substrate: Many glass manufacturers offer the same material characteristics under different trade names. Learn More
Surface Flatness (P-V):
4 - 6λ
Surface Quality:
Thermal Shock (K):
Up to 4mm Thick: 175K
4 - 6mm Thick: 160K
6 - 15mm Thick: 150K
Transformation Temperature (°C):
Transmission (%):
Protective Window
Wavelength Range (nm):
700 - 1150
Young's Modulus (GPa):

Regulatory Compliance

RoHS 2015:
Certificate of Conformance:
Reach 240:

Product Family Description

  • Low Coefficient of Thermal Expansion
  • Visible to Near Infrared Transmission
  • High Resistance to Thermal Shock

TECHSPEC® BOROFLOAT® Borosilicate Windows are ideal for high temperature and harsh environment applications. The windows have a low coefficient of thermal expansion of 3.25 (+20 to +300°C). TECHSPEC® BOROFLOAT® Borosilicate Windows feature visible to near infrared transmission. Unlike common borosilicate that is drawn flat, BOROFLOAT® is produced by a float technique that yields superior surface flatness — typically 4 - 6λ per inch. BOROFLOAT® is about three times more resistant to thermal shock than standard soda lime glass.

Can’t find what you need? Get a quick custom quote.