Infrared Materials

SCHOTT’s Infrared Materials are key elements of some of the world’s most sensitive, high-tech optical equipment, and are robust enough to maintain their impressive technical qualities whatever the world throws at them.

Key qualities of Infrared Materials

Low athermalization

Infrared Chalcogenide Glass boasts excellent transmission capabilities, with consistently low thermal changes in refractive index and dispersion, which simplifies AR lens systems.

Clear view in VIS and IR

SCHOTT combines the knowledge of high-end polishing processes with unique coating technology for multi-band, scratch-resistant surfaces that can withstand all common environmental tests.

Flexible manufacturing

SCHOTT can adapt its production of Infrared Chalcogenide Glass to any customer need. The wide range of glasses can be manufactured by conventional grinding and polishing, single-point diamond turning or molding to deliver both large and small unit volume.

Protective strength

Scratch- and shock-resistant, SCHOTT Sapphire is renowned for its extreme hardness and impressive mechanical strength, so combined with extremely hard AR coating, it’s a go-to material for protecting sensitive optical equipment.
SCHOTT Infrared Chalcogenide Glass

Forms of Supply

We offer infrared chalcogenide glasses up to 95 mm in diameter and thicknesses up to 150 mm. Typical forms of supply will depend on customer's requirements.

Our polished blanks for sample parts are offered up to 95 mm in diameter and thicknesses up to 30 mm.

 

Material Properties IRG 22 – IRG 27

Infrared Chalcogenide Glasses
Material Properties IRG 22 IRG 24 IRG 25 IRG 26 IRG 27
Composition Ge33As12Se55 Ge10As40Se50 Ge28Sb12Se60 As40Se60 As2S3
Density 4.41 g/cm3 4.47 g/cm3 4.66 g/cm3 4.63 g/cm3 3.20 g/cm3
Thermal expansion
(20 – 100°C)
12.5 · 10–6/K 20.0 · 10–6/K 14.0 · 10–6/K 21.4 · 10–6/K 22.5 · 10–6/K
Transition
temperature
368 °C 225 °C 285 °C 185 °C 197 °C

Thermal
change
dn/dT*
94.8 · 10–6/K
(1 μm)
46.0 · 10–6/K
(1 μm)
79.2 · 10–6/K
(1 μm)
76.2 · 10–6/K
(1 μm)
15.6 · 10–6/K
(1 μm)
67.7 · 10–6/K
(5 μm)
21.15 · 10–6/K
(5 μm)
62.0 · 10–6/K
(5 μm)
33.4 · 10–6/K
(5 μm)
-3.2 · 10–6/K
(5 μm)
67.1 · 10–6/K
(10 μm)
20.3 · 10–6/K
(10 μm)
61.1 · 10–6/K
(10 μm)
32.2 · 10–6/K
(10.6 μm)
-3.7 · 10–6/K
(10.6 μm)
Refractive
index
2.5971 (1 μm) 2.7249 (1 μm) 2.7284 (1 μm) 2.9316 (1 μm) 2.4841 (1 μm)
2.5104 (5 μm) 2.6192 (5 μm) 2.6183 (5 μm) 2.7909 (5 μm) 2.4129 (5 μm)
2.4968 (10 μm) 2.6090 (10 μm) 2.6030 (10 μm) 2.7781 (10 μm) 2.3842 (10 μm)

 

Transmission of Infrared Glass IRG 22 – IRG 27 (10 mm thickness)

Infrared Chalcogenide02

 

IR Transmission

Infrared Chalcogenide03

 

 
Sapphire

Material Properties

  • Extreme hardness and high mechanical strength
  • Excellent thermal conductivity and heat resistance
  • High transmittance (UV to IR)
  • Low dn/dT
  • High electrical resistance (1,014 Ohm-cm)
  • High dielectric constant (9.39 from 1.0 MHz to 8.5 GHz)

 

Specifications

Depends on the geometry
Attribute Commercial Quality Precision Quality Ultra-Precision Quality
Size (round and square) Ø from 10 to 300 mm
 from 10 to 210 mm
Size tolerance1 ± 0.2 mm ± 0.10 mm ± 0.05 mm
Thickness1 From 1 to 40 mm
Thickness tolerance1 ± 0.2 mm ± 0.10 mm ± 0.05 mm
Parallelism1 < 5 arc minutes < 1 arc minute < 30 arc seconds
Surface accuracy (PV)1 5 λ (546 nm) λ/2 (546 nm) λ/10 (546 nm)
Surface quality (scratch& dig) According to MIL 80 - 50 According to MIL 40 - 20 According to MIL 20 – 10
Surface roughness (Rq) < 10 nm < 3 nm < 1 nm
AR coating Custom-designed
Order quantity Depending on customer specifications. Please contact us.
Delivery time (weeks) 6 - 10 weeks, assuming raw materials are available.

 

1 psi = 6.9 kPa
Mechanical Properties2
Tensile strength 40,000 – 60,000 psi (design criterion) 0.27 – 0.41 GPa
Flexural strength 70,000 –130,000 psi (design criterion) 0.48 – 0.89 GPa
Young’s modulus, E (25 °C)
(modulus of elasticity)
50 x 106psi 345 GPa
Compressive modulus, K 55 x 106psi 379 GPa
Flexural modulus
(modulus of rupture)
52 x 106psi 358 GPa
Shear modulus, G
(modulus of rigidity)
21.5 x 106psi 148 GPa
Bulk modulus, k (volumetric modulus
of elasticity) Poisson’s ratio
35 x 106psi
0.29
241 GPa

 

 

Supply Forms Thicknesses Dimensions
Customized processing
  • polishing
  • coatings (e.g. anti-reflective coatings)
from 1 mm to 40 mm Ø from 10 to 300 mm
 from 10 to 210 mm
Plano surface
Spherical surface
Various shapes from round to square

 

Transmission Curve

Transmission Curve02

Want to know more? Let’s talk

Whether you need more information, samples, a quote, or advice for a project, we would be delighted to talk to you.

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