Sapphire Crystal Window
Sapphire windows are used in some non-ornamental applications, including infrared optical components, such as in scientific instruments; high-durability windows and movement bearings;Due to sapphire's remarkable hardness (third hardest mineral, right behind diamond and moissanite).
Features of Sapphire Crystal
1. High-hardness - abrasion resistance
2. Transparency - in the range from ultraviolet to infrared light (0.15 - 5.5 �µm)
3. Chemical resistance and heat resistance - resist almost all kinds of acid and alkaline, heat up to 2000 �ºC.
4. Suitable for the application of insulation property required.
Sapphire Crystal Property
Crystal structure: Hexagonal
Lattice: a=4.785Ã??, C=12.991Ã??
Density: 3.98g/cm3
Transmission Range: 150-5500nm
Melting Point: 2040�°C
Specific Heat: 0.418 W.s/g/K
Thermal Conductivity: 25.12 W/m/K
Thermal Shock Resistance: 790 W/m
Thermal Expansion Coefficient: 5.8x10E-6/K
dn/dT: 13x10E-6/K @633nm
Hardness: 9 Mohs
Refractive Index: 1.83 @0.26mm, 1.76 @0.63mm, 1.58 @5.57m
Sapphire Crystal Applications
- UV and IR Optics
- Windows for High Temperature and Pressure, Corrosion Resistance, Abrasion Resistance
- Heat Sink and Thermocouplers; Semiconductor Wafer Carriers
- Electrical Insulators
- Thin Film Deposition
- Transparent Electronic Substrate
- Silicon on Sapphire Wafers; Superconductor Substrate
Sapphire Crystal Window Specifications
Diameter Tolerance(mm): +0.0/-0.2 (General), +0.0/-0.1 (High Precision)
Thickness Tolerance(mm): �±0.2 (General), �±0.05 (High Precision)
Clear Aperture: >75% (Small Size), >90% (Large Size)
Parallelism: 3 min. (General), 10 sec. (High Precision)
Surface Quality: 80/50 (General), 40/20 (High Precision)
Flatness (per 25mm@633nm): �»(General), �»/4 (High Precision)
Bevel (face width x 450 0)
