Infrared windows are essential optical components designed to transmit specific infrared wavelength ranges while acting as a protective barrier between the environment and sensitive internal components. Depending on the application and wavelength band, different materials are selected to provide the best balance of optical performance, mechanical strength, and thermal stability.
Shape Optics manufactures IR windows to high surface quality and accuracy, ensuring minimal wavefront distortion and reliable performance in precision optical systems. These windows are suitable for MWIR and LWIR applications, as well as selected NIR and laser-based systems.
Key Features of Infrared Windows
- High Infrared Transmission: Optimized for maximum in-band transmission to ensure accurate signal capture and measurement.
- High Precision Manufacturing: Tight tolerances, excellent surface accuracy, and parallelism for high-performance optical systems.
- Wide Material Selection: Available in Silicon (Si), Germanium (Ge), Zinc Selenide (ZnSe), Zinc Sulfide (ZnS), Sapphire, Calcium Fluoride (CaF₂), and Barium Fluoride (BaF₂).
- Wide Size Range: Standard and custom dimensions available to support a broad range of system designs.
- Durable Optical Coatings: AR and AR+DLC coatings enhance transmission while protecting against abrasion, moisture, and harsh environments.
- Custom Design Support: Shapes, thicknesses, coatings, and materials can be tailored to application requirements.
Spectral Transmission Characteristics
Infrared window transmission depends on the substrate material and coating design. Typical characteristics include:
- High transmission in the target infrared band
- Controlled reflection losses through AR or AR+DLC coatings
- Stable performance across temperature and humidity variations
Custom transmission profiles, coatings, and window geometries can be provided to meet specific wavelength and system requirements.
Coating Quality & Reliability Testing
All SOT infrared windows are manufactured and qualified to stringent quality standards:
- Adhesion Test: Complies with MIL-C-675C (LT-90 tape test); no blistering or peeling.
- Temperature Cycling: −62 ± 1 °C to +71 ± 1 °C per MIL-C-675C; no coating detachment.
- Abrasion Resistance: Tested to MIL-C-675C / CCC-C-440; no damage after 25 abrasion cycles.
- Humidity Resistance: 95–100% RH at 49 ± 2 °C for 24 hours; no degradation observed.
- Solvent & Cleaning Resistance: Stable after acetone and alcohol cleaning.
- Salt Spray Test: 100 hours at 35 °C in 5% saline environment with no coating failure.
Standard Specifications (Typical)
| Parameter | Specification |
|---|---|
| Size Range | Ø3 mm – Ø260 mm, 33 mm – 260 × 260 mm |
| Surface Quality | 10–5 |
| Surface Accuracy | 0.5 fringe |
| Parallelism | 10 arc-sec |
| Materials | Ge, Si, ZnSe, ZnS, Sapphire, CaF₂, BaF₂ |
| Coating Bands | 3–5 µm, 7–12 µm, 8–14 µm, 10.6 µm |
Applications of Infrared Windows
- Thermography Systems: Used in thermal cameras for temperature detection and thermal analysis in industrial, medical, and defense environments.
- Infrared Detection & Monitoring: Integrated into IR sensors for environmental monitoring, security surveillance, and process control.
- Automotive Night Vision: Enhances visibility and safety in low-light and adverse driving conditions.
- CO₂ Laser Systems: Acts as protective windows while efficiently transmitting 10.6 µm laser radiation.
- Scientific & Industrial Optics: Protects sensitive IR instruments operating in harsh or contaminated environments.
SOT Strengths & Capabilities
Shape Optics Technologies is recognized for its expertise in high-precision infrared optical components, supported by advanced manufacturing equipment and rigorous quality control.
SOT is committed to delivering infrared windows that combine optical performance, durability, and consistency, even in the most demanding environments.