Chalcogenide glass sphere/asphere (IR glass)
CPG is working with a lot of material vendor in chalcogenide glass: Schott, Virton, Umicore, CDGM, NHG etc.
IR glass is a wonderful material can be: polished, molded, diamond turned etc. The key control to provide reliable components with this material is the knowledge in production process control and the coating process.
Below is the excellent introduction of the materials:
Reliable solutions for the infrared industry
Infrared glasses (IRG) offer excellent transmission in the shortwave IR (SWIR), midwave IR (MWIR), and longwave (LWIR) range. Physical properties such as low dn/dT and low dispersion enable optical designers to engineer color-correcting optical systems without thermal defocusing. The IRG family of chalcogenide glasses is optimized for pairing with the family of IR glasses and other IR materials to support cost-effective and high-performance optical designs. These glasses encompass the common IR transmission bands 3 - 5 μm and 8 - 12 μm, but can transmit as low as 0.7 μm. Furthermore, the IR glass series offered by SCHOTT can be processed using conventional grinding and polishing techniques, single point diamond turning or molding to support low- to high-volume component-level manufacturing.
Advantages
- Low dn/dT and low dispersion
- Excellent transmission in SWIR, MWIR and LWIR
- Excellent transmission in SWIR, MWIR and LWIR
- Effective production from prototypes to mass volumes
- Superior quality and repeatable performance proven by internal measurements and process controls of batch material
- Effective performance for color correcting optical systems and athermal imaging designs
Technical Details
IR Transmission
Material Properties IRG 22 - IRG 27
| Material Properties | Infrared Chalcogenide Glasses | ||||
|---|---|---|---|---|---|
| IRG 22 | IRG 24 | IRG 25 | IRG 26 | IRG 27 | |
| Composition | Ge33As12Se55 | Ge10As40Se50 | Ge28Sb12Se60 | As40Se60 | As40Se60 |
| 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) |
|
*Please contact us or schott if you would like more information or have any questions.
Data sheet of Schott:
- Advanced Optics in Safety & Security (Product Flyer)
- Infrared Chalcogenide Glasses - IRG 22 (Product Flyer)
- Infrared Chalcogenide Glasses - IRG 24 (Product Flyer)
- Infrared Chalcogenide Glasses - IRG 25 (Product Flyer)
- Infrared Chalcogenide Glasses - IRG 26 (Product Flyer)
- Infrared Chalcogenide Glasses - IRG 27 (Product Flyer)
- Infrared Chalcogenide Glasses - Overview (Product Flyer)
- IRG data for ZEMAX (Catalog)