Skip to content 
Calcium Fluoride Windows (CaF₂ Window)
Calcium Fluoride Windows which is CaF₂ Window are high performance optical windows for using in the UV to IR range. Coligh produces calcium fluoride windows in a variety of sizes and shapes for high precision optical systems.
- Wide spectrum transmittance 140nm-9um
- Low absorption, low scattering, low refractive index
- Uncoated substrates and coated processing can be provided
- <1000mm any size and any shape can be customized
Products Categories
Get A Free Quote
Calcium Fluoride Windows CaF₂ Windows Description
Calcium fluoride optical windows are ideal for the deep ultraviolet DUV to mid-infrared MIR bands. The calcium fluoride optical windows produced by Coligh can meet the stringent requirements of high-end optical systems in scientific research, industry and medicine with the characteristics of wide spectrum transmission, low absorption scattering and low refractive index.
- The full-band ultra-wide spectrum transmission range of 140-9um is suitable for multi-spectral integrated systems. The high transmittance in the courseware and infrared regions can ensure the transmission of signals without attenuation.
- Low absorption, low scattering and low refractive index can reduce thermal damage to materials and reduce reflection loss at the interface.
- We can provide flexible customization services, support any specifications with diameter or side length <1000mm, and can process special designs such as round, square and special shapes to adapt to complex equipment integration.
- Coating options: provide uncoated substrates (economical) or customized anti-reflection coatings (AR), high damage threshold films, waterproof/anti-fouling films, etc. to meet diverse needs.
Optical Calcium Fluoride Windows Detail Display
Calcium Fluoride Windows CaF₂ Windows Technical Datasheet
| CaF₂ Window Substrate Property | |
| Transmission Range (μm) | 0.13-9.0um@T>90% |
| Refractive Index | 1.39908@5um |
| Reflection Loss | 5.6%@4um |
| Thermal Expansion Coefficient (°C⁻¹) | 18.85x10 –6 |
| Thermal Conductivity (W/m·K) | 9.71 |
| Knoop Hardness (kg/mm²) | 158.3(100) |
| Elastic Coefficients | C11 = 164, C12 = 53, C44 = 33.7 |
| Young’s Modulus (GPa) | 75.79 |
| Solubility (g/100g H₂O) | 0.0017 (@ 20°C) |
| Cleavage Plane | (111) |
| Density (g/cm³) | 3.18 |
| Melting Point (°C) | 1360 |
| Customization Details | AR Coating Range (μm) | Customizable |
| 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 |
Calcium Fluoride Windows CaF₂ Windows Applications
Calcium fluoride windows are widely used in the following applications due to their core properties, such as wide spectrum and low scattering:
- High-power laser transmission Calcium fluoride has a high transmittance (>90%) in the infrared band above 9μm, and can withstand high-power lasers such as CO₂ lasers and excimer lasers (such as ArF 193nm, KrF 248nm)
- In instruments for spectral analysis and detection such as UV-visible spectrophotometers and Raman spectrometers, calcium fluoride windows can replace quartz materials
- In thermal imaging systems, calcium fluoride windows can be used as protective windows for infrared lenses, and can also be used as infrared windows for night vision devices, resistant to sand and dust wear and salt spray corrosion
- In DUV lithography machines (193nm, 248nm), calcium fluoride is the core material of the projection lens of the lithography machine, and its low birefringence ensures the accuracy of lithography patterns
