Skip to content 
Barium Fluoride (BaF₂) Windows
A barium fluoride window (BaF₂) is a high-transmittance optical window made from barium fluoride crystal. Coligh manufactures high-precision barium fluoride windows for infrared optics and precision instruments.
- Ultra-wide spectrum 0.15um-12um
- Uncoated transmittance > 94% (visible light to infrared)
- Supports uncoated and coated options (AR protective film)
- Supports non-standard size and special-shaped cutting
Products Categories
Get A Free Quote
Barium Fluoride (BaF₂) Windows Description
Barium fluoride windows are ideal for infrared lasers, high-temperature observations, and multi-spectral formation, with wide spectral transmission, extreme environment resistance, and cost-effectiveness as their core competitiveness.
- The barium fluoride windows produced by Coligh cover a wide band from 0.15um to 12um in the far infrared, especially in the mid-infrared 2-8um region, suitable for multi-spectral applications.
- In particular, the transmittance is as high as 95% at the CO₂ laser wavelength (10.6μm), and the energy loss is extremely low.
- We can provide uncoated and coated barium fluoride windows with a size of less than 1000mm in diameter. The uncoated barium fluoride window maintains a transmittance of >94% from visible light to infrared. The substrate has a low refractive index n≈1.45, which can reduce surface reflection loss and improve optical efficiency without anti-reflection coating.
- We can also provide coated barium fluoride windows, which can be coated with wide-band anti-reflection coating and protective hard coating in 400-700nm, 8-12um and even full-band.
- We can provide large-size windows <1000mm, Any special-shaped and non-standard shapes can be processed.
Barium Fluoride (BaF₂) Windows Detail Display
Barium Fluoride (BaF₂) Windows Technical Datasheet
| Barium Fluoride (BaF₂) Substrate Parameters | ||
| Category | Parameter | Value/Description |
| Optical Properties | Transmission Range (μm) | 0.15 – 12.5 |
| Refractive Index | 1.4626 @2.58 μm | |
| Reflection Loss | 6.8% (both faces @2.58 μm) | |
| Thermal Properties | Thermal Expansion Coefficient (°C⁻¹) | 18.1 ×10⁻⁶ |
| Thermal Conductivity (W·m⁻¹·K⁻¹) | 11.72 @286 K | |
| Mechanical Properties | Knoop Hardness (kg/mm²) | 82 (with 500g indenter) |
| Elastic Constants (GPa) | C₁₁=90.4; C₁₂=40.6; C₄₄=25.3 | |
| Young’s Modulus (GPa) | 56.4 | |
| Density (g·cm⁻³) | 4.89 | |
| Cleavage Plane | {111} | |
| Chemical Properties | Solubility (g/100g H₂O) | 0.0017 @23°C |
| Melting Point (°C) | 1280 | |
| Customization Details | Typical AR Coating Range (μm) | 1–23, 0.11–7.0, 0.11–8.5, 1–12 |
| Maximum Size | <1000 mm | |
| Shape | Customizable | |
| Surface Roughness (RMS) | Full aperture: 13/60 nm | |
| Parallelism Error | 0.25 arcsec | |
| Surface Quality | 10/20 | |
| Coating Options | Customizable |
Barium Fluoride (BaF₂) Windows Applications
Barium fluoride windows are ideal for wide spectrum coverage from ultraviolet to infrared. With its excellent transmittance and low absorption characteristics, they are suitable for high-precision optical systems. Due to its wide spectral transmittance range (150nm-12μm), barium fluoride windows are widely used in the following fields:
- Infrared optics In the fields of military, security and industrial detection, barium fluoride windows are ideal for infrared imaging, and can clearly capture thermal radiation of different wavelengths
- Laser system Barium fluoride has excellent transmittance in the CO₂ laser band (10.6μm), which is suitable for high-power laser applications such as laser cutting, welding, and material processing. And it can be used in excimer laser systems for light-transmitting windows, optical lenses and other components, and can work stably in high-energy laser environments.
- High-temperature environment High-temperature furnace observation window: The high-temperature resistance of barium fluoride makes it very suitable for use at extremely high temperatures, such as the observation window for high-temperature furnaces, which allows researchers to clearly observe the process in the furnace.
- Medical equipment The transparency and resistance to laser radiation of barium fluoride make it an ideal material for optical windows in laser surgery. In infrared diagnostic equipment, barium fluoride windows are used to protect sensors, helping to capture infrared radiation emitted by the human body for disease diagnosis.
- Aerospace and astronomy Protecting satellite infrared sensors: The radiation resistance and wide spectrum transmittance of barium fluoride windows make them an important protective material for satellite infrared sensors, which can effectively block unnecessary radiation in the environment and ensure the long-term stable operation of satellite sensors. In the field of aerospace, barium fluoride windows can also be used in thermal sensors to monitor and analyze thermal radiation on the surface of aircraft.
