Sapphire Due to the hardest of the oxide crystals, Sapphire has a combination of optical

and physical properties that makes it the best choice for a variety of demanding applications. 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 or strength is required.

Optoaxis offer the sapphire crystal with high quality, low cost. Careful selection of raw materials and strictly quality control at every stage of growth, ensure the best specifications for different application.

1. Basic Properties

Crystal Structure: Hexagonal System
Lattice: a=4.785A, c=12.991A
Density: 3.98g/cm 3
Transmission Range 0.15-5.5µm
Melting Point: 2042°C
Specific Heat: 0.418W×s/g/k
Thermal Conductivity: 25.12W/m/k(@100°C)
Thermal Shock Resistance: 790W/m
Thermal Expansion Coefficient: 5.8´10 -6 /K
dn/dt (@633nm) 13´10 -6 /K
Mohs Hardness: 9
Refractive Index(n o ): 1.83(0.26mm), 1.76(0.63mm), 1.58(5.57mm)

2. Standard Specifications of Sapphire Windows & Mirrors

Diameter: +0.0, -0.1mm
Thickness: ±0.1mm
Flatness: l/4
Parallelism: better than 1'
Perpendicularity: better than 5'
Scratch-Dig: 40/20 per MIL-O-13830A
Wavefront Distortion: l /4 per inch @1064nm