Parameter Category | Parameter Name | Value / Description / Typical Value | Test Conditions / Notes |
Basic Information | Product Name | Sapphire Glass Optical Window | |
| Material Composition | Single Crystal α-Aluminium Oxide ( | |
| Crystal Structure | Hexagonal Crystal System | Anisotropic Crystal |
| Growth Method | Kyropoulos Method, Heat Exchanger Method (HEM), Edge-defined Film-fed Growth (EFG) | |
| Product Form | Flat, Spherical, Aspheric (Customizable) | Can be customized to requirements |
Physical Properties | Density | 3.97 - 3.99 g/cm³ | |
| Mohs Hardness | 9 | Second only to diamond (10) |
| Knoop Hardness | ~2000 kg/mm² | Load 100g |
| Young's Modulus | 345 GPa | |
| Shear Modulus | 145 GPa | |
| Poisson's Ratio | 0.25 - 0.27 | |
| Compressive Strength | >2.0 GPa | |
| Flexural Strength | > 690 MPa | Highly dependent on surface finish quality |
Thermal Properties | Melting Point | 2040 °C | |
| Maximum Operating Temperature | 1900 °C (Vacuum/Inert Gas) / ~1000°C (Air) | High temps in air may cause surface devitrification |
| Coefficient of Thermal Expansion (CTE) | | @ 25°C |
| Thermal Conductivity | 25 - 35 W/(m·K) | @ 20°C, ~30x higher than ordinary glass |
| Specific Heat Capacity | 750 J/(kg·K) | @ 25°C |
Optical Properties | Crystal Type | Uniaxial Negative Crystal | |
| Refractive Index (@587.6 nm) | no = 1.768 / ne = 1.760 | |
| Abbe Number | 72.2 (based on no) | Low dispersion |
| Transmission Range | 0.15 μm - 5.5 μm | Deep UV to Mid-IR |
| Internal Transmittance | >85% @ 0.3μm (1mm thick) / >80% @ 4μm (1mm thick) | Depends on thickness and coating |
| Refractive Index Homogeneity | | |
| Birefringence | 0.008 | Crystal orientation must be considered |
Surface Specifications | Diameter/Size Tolerance | ±0.02 mm or customized | |
| Thickness Tolerance | ±0.01 mm or customized | |
| Parallelism | < 3 arcsec (High Precision) / < 1 arcmin (Standard) | |
| Flatness | λ/10 @ 632.8nm / λ/4 (Standard) | MIL-O-13830 |
| Surface Finish (Quality) | 10-5 Scratch-Dig (Standard) / Up to 20-10 (High Grade) | MIL-PRF-13830B |
| Clear Aperture | > 90% | |
| Bevel | < 0.1mm x 45° (Protective bevel) | |
Chemical & Electrical Properties | Chemical Stability | Excellent. Insoluble in water, resistant to strong acids (e.g., HCl, HNO) and strong bases (slight corrosion at high temps). Not resistant to (HF) and hot Phosphoric Acid. | |
| Water Resistance | Class 1 | ISO 719 |
| Dielectric Constant (@1 MHz) | | |
| Volume Resistivity | | @ 25°C |
| Dielectric Strength | 480 kV/cm | |
Coating Options | Anti-Reflection (AR) Coating | Reduces reflection losses, increases transmission in specific bands (e.g., NIR, VIS, specific laser wavelength) | Single side R<0.25% @ specified wavelength |
| High Reflection (HR) Coating | Achieves high reflectivity at specific wavelengths (e.g., for laser cavities) | R>99.5% @ specified wavelength |
| Oleophobic/ Hydrophobic Coating | Anti-fingerprint, easy to clean, surface protection | Water Contact Angle > 110° |
| Conductive Coating (e.g., ITO) | Provides transparent conductivity or electromagnetic shielding | Sheet resistance customizable |
| Protective Coating | Provides extra protection against specific chemical environments | |
Application Fields | | High-End Consumer Electronics: Smartphone camera covers, smartwatch crystals, fingerprint sensor covers.
Industrial & Research: High-power laser windows, vacuum viewports, high-pressure/high-temperature viewports, spectrometer components.
Aerospace & Defense: Missile domes, EO/IR pod windows, periscopes, armored vehicle viewports.
Medical Devices: Endoscope protection lenses, surgical device windows, biosensors.
Semiconductor Industry: Viewports for wafer processing equipment. | |
