28 Nov 2010 Large size Sapphire crystals up to 4' boule are available from Lasertec, As the hardest of oxide crystals, sapphire has a combination of optical and physical properties that make it the best choice for a variety of demanding online_orderings. Sapphire maintains its strength even at high temperatures. It has good thermal properties, excellent electrical and dielectric properties and is resistant to chemical attack. These properties encourage the use of sapphire in aggressive environments where reliability, optical transmission and strength are requied.
Main online_orderings Include: UV and IR Optics; Windows for High Temperature and Pressure, Corrosion Resistance, Abrasion Resistance; Heat Sinders and Thermocouplers; Semiconductor Wafer Carriers; Electrical Insulators; Thin Film Deposition; Transparent Electronic Substrate; Silicon on Sapphire Wafers; Superconductor Substrate.
Basic Properties:
Crystal structure Hexagonal System
Lattice a=4.785?, C=12.991?
Density 3.98g/cm 3
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 5.8x10 -6 /K
dn/dt, @633nm 13x10 -6 /K
Mohs Hardness 9
Refractive Index 1.83 @0.26 m m, 1.76 @0.63 m m, 1.58 @5.57 m m
Standard Specifications of Sapphire Windows and Mirrors:
Diameter +/-0.0, -0.1mm
Thickness +/-0.2mm
Flatness better than l per 25 @633nm
Parallelism better than 3'
Perpendicularity better than 5'
Scratch-Dig 80-50 per MIL-O-13830A
Wavefront Distortion less than l /2 per inch( l @1064nm)
Ohter high-precision Sapphire windows, AR- and HR-coatings are available upon request. Sapphire boule grown by CZ method and a-cut Sapphire blocks are also available.
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