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Sapphire Windows / Substrates

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
10
11ohm-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