Sapphire is an excellent material for windows and substrates requiring transmittance from UV to 6.0 microns. It is a tough, scratch resistant material that is excellent for abusive applications. It is available with AR coatings to improve its already excellent transmittance properties.
- Transmission from 200nm up to 6 µm
- Thickness from 0.3 to 10 mm
- Dimensions up to 160 mm
| Thermal Properties: | |
| Coefficient of Expansion | 5.3 (10°/K) // c axis @ 300 K 4.5 (10°/K) ┴ c axis @ 300 K |
| Max Usage Temperature | 2000 °C |
| Thermal conductivity | 40 (W/m.K) @ 300 K 4 (W/m.K) @ 1500 K |
| Specific heat | 750 (J/kg.K) |
| Mechanical properties: | |
| Young Modulus | 4.4 x 105 MPa @ 300 K |
| Shear Modulus | 400MPa @ 300 K |
| Knoop Hardness | 1.9 x 105 MPa |
| Traction resistance | 190 MPa @ 300 K |
| Poisson constant | 0.30 |
| Electrical properties: | |
| Di-electric constant | 10.6 // c axis @ 300K; 106Hz 8.6 c axis @ 300K; 10 6Hz |
| Loss Coefficient | < 103 @ 300K |
| Di-electric Resistance | 48 x 106V/m @ 60Hz |
| Resisitivity | 1016ohm-cm @300K 1011ohm-cm @ 573K |
| Optical Properties: | |
| Transmission | in the visible: excellent 0.75...4.5μm: ≥ 85% 0.25...0.4μm: 60% |
| Refractive Index @ 0.5893μm | 1.760 // c axis 1.768 ┴ c axis |
| Puissance dispersivity (nf-nc) | 0.011; λf = 0.4861μm λ c = 0.6563μm |
| Emissivity | < 0.02 @ 1153K λ = 2.6 @ 3.7μm |
| dn/dT | 13 x 10-6K-1 |
