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).
Features:
Transmission in 0.3-5.0μm, no absorption in 2-3μm
Extremely hard and durable
High thermal conductivity
High bulk damage threshold
Materials characteristics compare |
Item | B270 | CaF2 | Ge | MgF2 | N-BK7 | Sapphire | Si | UV Fused Sillca | ZnSe | ZnS |
Refractive index(nd) | 1.523 | 1.434 | 1.003 | 1.413 | 1.517 | 1.768 | 3.422 | 1.458 | 2.403 | 2.631 |
Coeffcient of dispersion(Vd) | 58.5 | 95.1 | N/A | 106.2 | 64.2 | 72.2 | N/A | 67.7 | N/A | N/A |
Density(g/cm3) | 2.55 | 3.18 | 5.33 | 3.18 | 2.46 | 3.97 | 2.33 | 2.20 | 5.27 | 5.27 |
TCE(μm/m℃) | 8.2 | 18.85 | 6.1 | 13.7 | 7.1 | 5.3 | 2.55 | 0.55 | 7.1 | 7.6 |
Soften Temperature(℃) | 533 | 800 | 936 | 1255 | 557 | 2000 | 1500 | 1000 | 250 | 1525 |
Knoop hardness(kg/mm2) | 542 | 158.3 | 780 | 415 | 610 | 2200 | 1150 | 500 | 120 | 120 |
grade: Sapphire optical
Orientation: C <0001>±1°,
size:60x5mmt
Thickness:5mm±0.02mm
SD:40/20;
transmittance 84.5% in the 308nm