Single crystal sapphire possesses a unique combination of excellent optical, physical and chemical properties. The hardest of the oxide crystals, sapphire retains its high strength at high temperatures, has good thermal properties and excellent transparency. It is chemically resistant to common acids and alkali at temperatures up to 1000 °C as well as to HF below 300 °C . These properties encourage its wide use in hostile environments where optical transmission in the range from the vacuum ultraviolet to the near infrared is required. Sapphire is anisotropic hexagonal crystal. Its properties depend on crystallographic direction (relative to the optical C-axis).

Attribute                                   Specification
Material：                                  Sapphire 
Typical Diameter (Φmm)：                   8.0, 10.0, 12.7, 15.0, 20.0, 25.4, 30.0,50.8
Typical Thickness (mm)：                    1.0, 2.0, 3.0, 4.0,6.35
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：                             >80% (Small Size), >90% (Large Size)
Parallelism：                                3 min. (General), 3 sec. (High Precision)
Surface Quality：                            80/50 (General), 20/10 (High Precision)
Flatness (per 25mm/633nm)：                  λ(General), λ/4 (High Precision)
Bevel (face width x 45°)：                  <0.25mm
Coating：                                    Uncoated, AR, HR, PR Coating, etc.

Note for Sapphire Window:

(1). Custom-made windows at any size are available.Besides round, windows at shape of quadrate, triangular, or other polygonal are available.
(2). Thickness from 1.0mm to 50.0 mm is available upon request.
(3). 100% clear aperture is available upon request.
(4). Better bevel is available upon request.
(5).Windows with Anti-Reflective(AR), High-Reflective(HR), Partial-Reflective(PR) coating are available.