Chalcogenide IR Optics

Chalcogenide glass represents a cutting-edge material in infrared (IR) optics, particularly suited for demanding applications in thermal imaging, EO/IR systems, defense, industrial monitoring, and civilian surveillance. At IREO _CAM&SYS, we leverage chalcogenide glass to deliver high-performance IR optics that meet the rigorous requirements of modern electro-optical systems.

 

What is Chalcogenide Glass?

Chalcogenide glass is an amorphous material primarily composed of chalcogen elements-such as sulfur (S), selenium (Se), and tellurium (Te)-combined with elements like arsenic (As) or germanium (Ge). Unlike traditional oxide-based glasses, this non-oxide composition enables exceptional transparency across broad portions of the infrared spectrum, making it an ideal substrate for IR lenses, windows, and aspheric elements.

These images showcase typical chalcogenide glass IR lenses and components, highlighting their characteristic reddish tint and polished surfaces optimized for infrared transmission.

 

Key Properties and Advantages

Chalcogenide glass stands out for its unique combination of optical, mechanical, and thermal characteristics:

• Broad Infrared Transmission - Excellent performance in the mid-wave infrared (MWIR, 3–5 µm) and long-wave infrared (LWIR, 8–12 µm) bands, with some formulations extending from ~1 µm to 14–20 µm depending on composition. This enables high transmission (>64% uncoated in LWIR, up to 95% with anti-reflective coatings) for thermal imaging and sensing.
• Low Dispersion and Refractive Index - Lower refractive index than germanium (typically 2.4–2.8) and high Abbe number, reducing chromatic aberrations and the need for complex corrective elements.
• Thermal Stability and Athermalization - Low thermo-optic coefficient (dn/dT) allows for passive athermal designs-optical performance remains stable across wide temperature ranges without mechanical compensation, outperforming germanium (which becomes nearly opaque above ~100°C).
• Lightweight and Cost-Effective - Significantly lighter than crystalline IR materials like germanium, enabling compact, portable systems. Moldable into complex aspheric shapes, it reduces manufacturing costs and supports high-volume production.
• Durability - Good resistance to thermal shock and environmental conditions (up to ~300°C), with hard coatings available for enhanced scratch resistance.

Compared to traditional germanium optics, chalcogenide glass offers greater design flexibility, supply chain reliability (amid germanium export constraints), and superior athermal performance-critical for field-deployed EO/IR systems.

 

What's More important and Critical -  Geopolitical Supply Chain Urgency: China's Export Controls on Germanium

Germanium, a cornerstone material for traditional LWIR IR optics in thermal imaging, remains exposed to supply risks from China's ~60% dominance in global production and its retaliatory export restrictions since 2023 amid U.S. semiconductor curbs. After initial licensing hurdles in 2023, sparking shortages and price spikes.  China suspended this ban as of March 2026, nevertheless, this provides short-term relief but leaves persistent vulnerability, price volatility, lead-time uncertainties, and the risk of reimposition, heightening the real and urgent need to transition suitable EO/IR applications to resilient alternatives like chalcogenide glass, reducing dependence on geopolitically sensitive critical minerals.

 

More information:

https://www.ireocam.com/info/2024-germanium-crisis-chalcogenide-glass-vs-102044946.html

 

 

Applications in EO/IR Systems

Chalcogenide glass powers advanced IR optics in:

• Thermal Imaging Cameras - Uncooled LWIR detectors for surveillance, firefighting, and predictive maintenance.
• Defense and Security - Missile guidance, target acquisition, night vision, and border surveillance systems requiring lightweight, high-contrast optics.
• Industrial and Civilian Uses - Gas detection, process monitoring, automotive night vision, and medical thermography.
• Multispectral EO/IR - Integration in common-aperture systems combining visible, SWIR, MWIR, and LWIR channels.

 

 

Why Choose IREO Cam's Chalcogenide IR Optics?

We outsource premium chalcogenide materials (e.g., IRG series equivalents) and apply precision molding, diamond turning, and advanced coatings to produce optics that balance performance, reliability, and affordability. Whether for custom defense payloads or industrial thermal modules, our solutions ensure superior IR transmission, thermal resilience, and system integration.

 

Explore our full range of IR optics under the IR Optics section or contact us for tailored chalcogenide-based components that advance your EO/IR projects.

 

 

Below are our standard on-shelf Chacogenide IR lens catalogue, for more requirements please contact us for information.

 

Uncooled LWIR Manual Focusing
Applied Sensor type	EFL (mm)	Spectrum          μm	F#	FOV (Calculated)
640×512,12μm	9.1	8-12	1.00	45.76°× 37.31°
640×512,17μm	11	8-12	1.05	54.64° × 41.8°
1280×1024,12μm	14	8-12	1.00	57.49°× 47.38°
640×512,12μm	15	8-14	1.00	28.72°×23.15°
640×512,17μm	19	8-14	1.00	31.95°×25.80°
640×512,12μm	25	8-12	1.00	17.46°×14.01°
256×192,12um	25	8-12	0.95	8.8°×7.03°
640×512,12um	25	8-12	1.00	17.46°×14.01°
640×512,12um	25	8-12	1.00	17.46°×14.01°
640×512,12μm	35	8-12	1.00	12.52°×10.03°
640×512,12μm	35	8-14	1.00	12.52°× 10.03°
640×512,12um	35	8-12	1.00	12.52°× 10.03°
640×512,12μm	35	8-14	1.00	12.52°× 10.03°
640×512,12um	35	8-12	1.00	12.52°× 10.03°
640×512,12μm	50	8-14	1.00	8.78°× 7.03°
640×512,12μm	50	8-14	1.00	8.78°× 7.03°
640×512,12μm	50	8-14	1.00	8.78°× 7.03°
640×512,12μm	50	8-14	1.00	8.78°× 7.03°
640×512,12μm	50	8-14	1.00	8.78°× 7.03°
640×512,12μm	50	8-14	1.00	8.78°× 7.03°
640×512,12μm	50	8-14	1.00	8.78°× 7.03°
640×512,12μm	70	8-12	1.00	6.27°× 8.02°
640×512,17μm	75	8-14	1.00	8.29°× 6.64°
Uncooled LWIR Vari-focal
1280×1024, 12μm	15-45	8-12	1.2 (@NFOV)	56.8°×45.9° 18.9°×15.3°