Our partnerAndover Corp.

Infrared windows and substrates

from Andover

Andover stocks a variety of optical-quality infrared-transmitting substrates. All substrates are optically polished. AR coatings are also available.

For convenience, we offer the windows in two standard sizes: 25 mm and 50 mm dia. In addition, we can produce custom sizes and shapes. Contact our expert on the right for a quotation.

  • High optical quality
  • Available from stock
  • Custom sizes available


General Specifications
Diameter Tolerance+0/-0.1 mm
Surface Quality60/40 per MIL-C-48497A
CTECoefficient of Thermal Expansion (see tables)
OptionalThreaded ring mounting available. Contact our expert on the right for thread sizes
 Size, Shape & Part Number
Substrate Material25 mm Ø50 mm Ø
Silicon (Si)IRWS100-25IRWS100-50
Germanium (Ge)IRWS200-25IRWS200-50
Sapphire (AI2O3)IRWS300-25IRWS300-50
Water-Free Fused Silica (SiO2)IRWS400-25IRWS400-50
Calcuim Fluoride (CaF2)IRWS500-25IRWS500-50
Zinc Selenide (ZnSe)IRWS600-25IRWS600-50
Silicon (Si) is an economical choice for many IR applications.

Refractive index: 3.43 at 3.0µm
CTE (10-6/°C): 4.15
Hardness (Knoop): 820
Germanium (Ge) is widely used for lenses and windows in the Mid-IR region.

Refractive index: 4.00 at 10.6µm
CTE (10-6/°C): 5.7
Hardness (Knoop): 692
SapphireWater-free fused Silica
Sapphire (Al2O3) is transparent over a wide range, and has excellent mechanical strength.

Refractive index: 1.737 at 2.0µm
CTE (10-6/°C): 7.7
Hardness (Knoop): 1920
WF Fused silica (SiO2) has excellent transmission in VIS and near IR and exhibits minimal fluorescence.

Refractive index: 1.45 at 1.0µm
CTE (10-6/°C): 0.55
Hardness (Knoop): 741
Calcium FluorideZinc Selenide
Calcium Fluoride (CaF2) has good transmission from the UV to the Mid-IR.

Refractive index: 1.40 at 5.0µm
CTE (10-6/°C): 18.9
Hardness (Knoop): 160
Zinc Selenide (ZnSe) is widely used for lenses and windows in the Mid-IR region.

Refractive index: 2.40 at 10.6µm
CTE (10-6/°C): 7.6
Hardness (Knoop): 100


Thermal Imaging
Detector Windows
IR Photography


Staffan Eriksson
Staffan Eriksson


Quantum Design GmbH

Roddarestigen 3
SE 182 35 Danderyd

Phone:+46 8 41071791
Staffan ErikssonSales Manager
+46 8 410 71791