Calcium Fluoride (CaF₂) Optical Windows
Calcium Fluoride (CaF₂) Optical Windows are broadband crystal components covering ultraviolet to mid-infrared wavelengths. Chenyu Optics manufactures CaF₂ windows uncoated or with UV AR, VIS AR, NIR AR, MWIR AR and LWIR AR coatings for spectroscopy, imaging and laser applications.
Calcium Fluoride Optical Windows Overview
Calcium Fluoride (CaF₂) Optical Windows, also referred to as CaF2 optical windows, are broadband optical crystal components covering ultraviolet to infrared wavelengths. They are widely used as UV optical windows and infrared optical windows due to low absorption and high transmission performance.
CaF₂ offers a stable optical response across a wide spectral range, making it suitable for multi-spectral and high-precision optical systems, including excimer laser optics, thermal imaging components and scientific instrumentation.
Chenyu Optics manufactures custom optical windows to customer drawings, including round, square and custom-geometry CaF₂ components. Surface quality, flatness, parallelism, thickness, edge treatment and coating design can be specified for prototype and repeat production.
Key Advantages of Calcium Fluoride Optical Windows
UV Spectroscopy & IR Imaging
CaF₂ windows are widely used as broadband transmission elements in UV spectroscopy instruments, thermal imaging systems, excimer laser systems and aerospace optical payloads.
Typical Specifications of Calcium Fluoride Optical Windows
| Material | Optical Grade Calcium Fluoride / CaF₂ |
|---|---|
| Material Type | Single crystal CaF₂ |
| Transmission Range | Approx. 0.13 – 8.0 μm, depending on thickness and coating |
| Refractive Index | Approx. 1.43 @ 1 μm |
| Dispersion | Low |
| Density | Approx. 3.18 g/cm³ |
| Hardness | Mohs approx. 4 (relatively soft) |
| Hygroscopicity | Low; avoid long-term humidity exposure |
| Laser Damage Threshold | High |
| Surface Quality | 20-10, 40-20 or custom |
| Surface Flatness | Up to λ/10 @ 633 nm or drawing-based |
| Parallelism | ≤ 10 arcsec or custom |
| Diameter / Size | 5 – 200 mm, round, square or custom geometry |
| Thickness | 0.5 – 50 mm or custom |
| Edge Treatment | Ground, chamfered or polished |
| Coating Options | Uncoated, UV AR, VIS AR, NIR AR, MWIR AR, LWIR AR, custom coating |
Optical Transmission Characteristics of Calcium Fluoride Optical Windows
Why Choose Chenyu Optics for Calcium Fluoride Optical Windows
Chenyu Optics focuses on drawing-based optical crystal manufacturing for spectroscopy, imaging and laser optical components. We support prototype verification, small-batch production and repeat manufacturing for non-standard CaF₂ optical windows.
Manufacturing Capability for Calcium Fluoride Optical Windows
Precision Polishing
Controlled lapping and polishing procedures to avoid subsurface damage and stress-induced birefringence in soft, brittle CaF₂ crystal.
Optical Coating
UV AR, VIS AR, NIR AR, MWIR AR and LWIR AR coating options for broadband and multi-spectral optical systems.
Inspection & Packaging
Dimensional inspection, surface review, optical performance checking and low-humidity protective packaging before shipment.
Custom Manufacturing Options for Calcium Fluoride Optical Windows
Dimensions & Geometry
Round, square and custom-geometry CaF₂ windows can be manufactured according to customer drawings, from 5 to 200 mm diameter and 0.5 to 50 mm thickness.
Surface & Mechanical Quality
Surface quality, flatness, parallelism and edge treatment can be selected according to optical performance, sealing method and assembly structure, with attention to the material's mechanical softness.
Coating & Wavelength Design
Uncoated, UV AR, VIS AR, NIR AR, MWIR AR, LWIR AR and custom AR coatings can be specified for spectroscopy, imaging or laser systems.
Calcium Fluoride Optical Windows Material Comparison
| Calcium Fluoride (CaF₂) | Silicon (Si) | Germanium (Ge) | Zinc Selenide (ZnSe) | Sapphire | |
|---|---|---|---|---|---|
| Transmission | UV to MWIR, approx. 0.13 – 8 μm | NIR to MWIR, approx. 1.2 – 7 μm | MWIR to LWIR, approx. 2 – 14 μm | Visible to far IR, commonly 0.6 – 20 μm | UV to MWIR, commonly 0.2 – 5.5 μm |
| Visible Transmission | High visible transmission | Opaque in visible wavelengths | Opaque in visible wavelengths | Transmits visible red and infrared wavelengths | High visible transmission |
| Mechanical Notes | Relatively soft and brittle, low hygroscopicity | Lightweight, hard and thermally conductive | High density, good rigidity, brittle material | Softer material, requires careful handling | Very hard and chemically durable |
| Typical Use | UV spectroscopy, excimer laser optics, multi-spectral imaging | MWIR windows, IR filters, lightweight assemblies | Thermal imaging windows, LWIR optics, IR sensors | CO₂ laser optics, IR windows, multispectral optics | Protective windows, harsh environment optics |
Applications of Calcium Fluoride Optical Windows
Infrared Imaging
Broadband infrared optical windows for MWIR and LWIR imaging systems.
Thermal Imaging / FLIR
Optical components for thermal imaging and FLIR camera systems.
UV Spectroscopy
Low-fluorescence UV optical windows for UV-VIS spectroscopy instrumentation and analytical systems.
Excimer Laser Systems
High laser damage threshold laser optical components for excimer and other UV laser systems.
Aerospace & Space Optics
Radiation-resistant windows for aerospace and space optical payloads.
Scientific Instruments
Broadband optical windows for semiconductor inspection, metrology and scientific instrumentation.
Calcium Fluoride Optical Windows FAQ
Is CaF₂ suitable for UV applications?
Yes. Calcium Fluoride provides high transmission down to approximately 130 nm, making it suitable for deep UV systems.
Can CaF₂ be used in high-power laser systems?
Yes. CaF₂ has a high laser damage threshold, making it suitable for many high-power laser applications, including excimer laser systems.
What is the difference between Calcium Fluoride and Magnesium Fluoride optical windows?
Calcium Fluoride and Magnesium Fluoride are both fluoride crystal materials used in UV and broadband optical systems, but they differ in transmission range and hardness. Calcium Fluoride typically provides broadband transmission from the deep UV to the mid-infrared with a low refractive index, while Magnesium Fluoride is harder and more scratch-resistant, and is often selected for UV and vacuum-UV windows and as a durable coating layer. Material selection depends on the operating wavelength range, mechanical durability requirements and environmental exposure of the application.
What coatings are available for Calcium Fluoride optical windows?
Calcium Fluoride optical windows can be supplied uncoated or with UV AR, VIS AR, NIR AR, MWIR AR, LWIR AR or custom broadband AR coatings, selected according to the operating wavelength range and application requirements.
Is CaF₂ environmentally stable?
CaF₂ is moderately stable but should be protected from long-term humidity exposure due to its hygroscopic nature.
What is the main limitation of CaF₂?
Its mechanical softness and brittleness require careful handling during machining, mounting and assembly to avoid subsurface damage.
What information should I provide for a quotation?
Please provide diameter or size, thickness, surface quality, flatness, parallelism, coating requirement, quantity, operating wavelength and drawing if available.
Related Products for Calcium Fluoride Optical Windows
Need Custom Calcium Fluoride Optical Windows?
Send us your drawing, wavelength range, size, thickness, coating requirements and quantity. Chenyu Optics will review the optical and mechanical specifications and provide a suitable Calcium Fluoride Optical Windows manufacturing suggestion.