# Infrared glass

Chalcogenide glasses are a specialized class of optical materials made primarily from chalcogen elements like sulfur, selenium, and tellurium, combined with other elements such as arsenic, antimony, or gallium. These glasses are particularly noteworthy for their broad transmission range in the infrared (IR) spectrum, often extending from the near-infrared through to the mid- and far-infrared wavelengths. Unlike more common oxide-based glasses like fused silica, chalcogenide glasses are capable of transmitting IR light up to wavelengths of around 10–20 micrometers, making them ideal for applications like thermal imaging, IR spectroscopy, and fiber-optic communications in the IR range. They also offer other favorable optical and mechanical properties, including high refractive indices and lower dispersion. However, these glasses are typically more expensive to produce and may be sensitive to moisture or less chemically stable than their oxide-based counterparts. Nevertheless, the unique capabilities of chalcogenide glasses make them indispensable in specialized applications where IR transmission and performance are critical.

## Infrared glass types/brands from different makers

- AMTIR (an acronym for "Amorphous Material Transmitting Infrared Radiation"): Amorphous Materials Inc. (AMI)
- IG: VITRON
- IRG: SCHOTT
- BD: LightPath
- OPTIR: Rochester Precision Optics (RPO)

## Cross-reference

Composition | AMI | VITRON | SCHOTT | LightPath | RPO
--- | --- | --- | --- | --- | ---
Ge33As12Se55 | AMTIR-1 | IG 2 | IRG 22 |  | OPTIR-1*
Ge30Sb13Se32Te25 |  | IG 3 | IRG 23* |  |
Ge10As40Se50 |  | IG 4 | IRG 24 |  |
Ge28Sb12Se60 | AMTIR-3* | IG 5 | IRG 25 | BD-2 | OPTIR-3*
As40Se60 | AMTIR-2 | IG 6 | IRG 26 | BD6 |
As40S60 | AMTIR-6 |  | IRG 27 |  |

(*) Out of production

## External Links

- Infrared - Wikipedia
- Chalcogenide glass - Wikipedia
- AMTIR amorphous material transmitting IR radiation - Amorphous Materials
- Brief introduction: chalcogenide glasses - VITRON
- Infrared Chalcogenide Glasses - SCHOTT
- Optical resources and technical information - LightPath