Sapphire Windows
Sapphire Windows for Stringent Applications
Avantier produces custom and stock sapphire windows for demanding environments where chemical, thermal, and mechanical stress rule out standard optical materials. As the second-hardest material after diamond, sapphire resists a wide range of acids and alkalis, along with scratching and abrasion, while offering a high dielectric constant and high thermal conductivity. Single-crystal sapphire’s mechanical strength allows fabrication of thinner windows with higher transmittance than other dielectric materials — uncoated sapphire transmits light from 170 nm to 5.5 µm. Avantier’s design team works with customers to tailor sapphire windows to application-specific requirements.
Sapphire Window Custom Specifications
Our factory standard entails a clear aperture covering at least 90 percent of the diameter, with a surface quality rating of 80-50 scratch dig. Birefringence for visible light in directions to the optic axis is 0.008, and the crystal axis cut is random. We can accommodate c-cut and tighter surface quality specifications upon request.
| Material: | Optical Sapphire (Al2O3) |
| Dimension: | +0, -0.2mm |
| Surface Flatness: | 1λ per 25 mm at 633 nm over clear aperture |
| Surface Quality: | 80-50 scratch and dig, beveled edges |
| Crystal axis cut: | random (c-cut available upon request) |
| Birefringence (nE-nO) | 0.008 for visible light in directions orthogonal to the optic axis |
| Refractive index | 1.77 @500nm |
| Center Thickness (CT) | +/-0.1 |
| Parallelism | 3 arc minutes |
| Clear Aperture | 90% of diameter |
| Coating | none |
Sapphire Round Windows: Typical Specification Examples
| Diameter(mm) | Thickness(mm) | Diameter(mm) | Thickness(mm) |
| 2.5 | 0.5 | 23.75 | 1.0 |
| 5.0 | 1.0 | 25.0 | 2.0 |
| 6.35 | 0.5 | 25.0 | 2.3 |
| 7.5 | 0.4 | 25.4 | 1.0 |
| 9.5 | 0.5 | 25.4 | 2.0 |
| 10.0 | 1.0 | 25.4 | 2.25 |
| 12.7 | 1.0 | 30.0 | 1.0 |
| 12.75 | 1.0 | 31.75 | 1.0 |
| 13.0 | 0.5 | 35.0 | 1.0 |
| 15.0 | 2.0 | 38.1 | 1.0 |
| 17.25 | 2.0 | 38.1 | 2.0 |
| 20.0 | 1.0 | 40.0 | 1.0 |
| 20.0 | 2.0 | 50.8 | 2.0 |
| 22.0 | 1.0 | 50.8 | 3.15 |
Stock Sapphire Windows
Avantier offers stock sapphire windows for applications that need sapphire’s durability without a custom design cycle. Available in standard sizes and thicknesses, these windows suit projects with typical dimensional requirements and shorter lead times. Sapphire’s hardness, chemical resistance, and broad transmission range make the stock line a practical option for prototyping, testing, and production runs where standard specifications meet the application’s needs.
| Part Number | Diameter (mm) | Thickness (mm) | Substrate | Surface Quality | Surface Flatness(P-V) | Coating | Price (USD) |
|---|---|---|---|---|---|---|---|
| AVTLB-0001 | 12.7 | 1.00 | Sapphire (Al2O3) | 60-40 | 0.5λ | uncoated | $25.00 |
| AVTLB-0002 | 20.0 | 1.00 | Sapphire (Al2O3) | 60-40 | 0.5λ | uncoated | $40.00 |
| AVTLB-0003 | 25.4 | 1.00 | Sapphire (Al2O3) | 60-40 | 0.5λ | uncoated | $50.00 |
| AVTLB-0004 | 38.0 | 1.50 | Sapphire (Al2O3) | 60-40 | 1λ | uncoated | $120.00 |
| AVTLB-0005 | 50.8 | 3.15 | Sapphire (Al2O3) | 60-40 | 1λ | uncoated | $200.00 |
| AVTLB-0006 | 68.0 | 2.00 | Sapphire (Al2O3) | 60-40 | 2λ | uncoated | $260.00 |
| AVTLB-0007 | 85.8 | 3.50 | Sapphire (Al2O3) | 60-40 | 2λ | uncoated | $500.00 |
Also available in volume pricing, please contact Avantier for details.
Please note that prices are subject to fluctuation and may change without prior notice. For the most accurate and up-to-date pricing information, kindly contact our office. Additional shipping fees will be calculated and added to your total order.
Sapphire Windows in High-Temperature Environments
- Rated for continuous use up to approximately 2000 °C
- Common in lamp shields, high-temperature combustion chambers, furnace systems, and gas processing equipment
- Supported sapphire windows hold peak optical performance up to 1700 °C
- Withstands temperatures up to 1950 °C without shape distortion, with only marginal loss of optical performance
- Outperforms fused silica, the next closest alternative, which begins degrading at 1000 °C and melts at 1650 °C
Additional Advantages of Sapphire Windows
- Chemical inertness: Resists molten metals, acids, and caustic agents (except hot caustic salts), suiting plasma chambers, sapphire lamps, and other high-heat, corrosive environments. This inertness also matters in medical and pharmaceutical applications, where the window must not contaminate surrounding substances.
- Structural robustness: Withstands high pressure where other optics would fail, suiting aircraft sensors, deep-sea windows, and sight windows on pressurized experiment vessels.
- Scratch resistance: Maintains optical clarity in abrasive conditions, including sand and grit exposure. Suited to smartphone camera windows, gun sights, and downhole and drilling vision systems.
- UV/IR transmittance: Transmits well across UV and IR ranges; thinner windows enable deeper transmission at both ends of the spectrum. Avantier’s ultra-thin sapphire windows are built for this extended range.
Custom Sapphire Windows at Avantier
Avantier designs and manufactures custom and stock sapphire windows built to order for clients in industry, research, and medicine. Avantier’s optical engineers and designers bring years of experience crafting high-performance optical components, and every component and assembly leaving the factory is tested to meet application-specific requirements. Contact us today to place a custom order or set up an initial consultation to discuss your sapphire window application.
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