Sapphire Window

Sapphire Windows are manufactured from single crystal sapphire, making them ideal for demanding applications (such as laser systems) because of their extreme surface hardness, high thermal conductivity, high dielectric constant and resistance to common chemical acids and alkalis. Sapphire is the second hardest crystal next to diamonds and, because of their structural strength, sapphire windows can be made much thinner than other common dielectric windows with improved transmittance. Chemically, sapphire is single crystal aluminum oxide (Al2O3) and is useful in a transmission range from 0.2 – 5.5μm.


1 ) Features Extreme Surface Hardness Chemical Resistance

2 ) Transmits Wavelengths Ranging From UV to Mid-Infrared

3 ) Thinner and Stronger than Standard Glass Windows


1 ) Diameter: 3~250mm

2 ) Diameter Tolerance: +/-0.2mm

3 ) Thickness Tolerance: +/-0.03mm

4 ) Aperture: >90%

5 ) Surface Quality: 60/40~10/5 (S/D)

6 ) Parallelism: <1 arc minute

7 ) Chamfer: 0.3-0.5mmx45°

Optical Properties

Transmission Range

0.17 to 5.5 micron

Refractive Index

No 1.75449; Ne 1.74663 at 1.06 micron

Refractive Loss

14% at 1.06 micron

Crystal/Class Structure

Trigonal (hex), R3c

Cleavage Plane

(1011), (1012), imperfect

Mechanical Properties


3.97 g/cc


2000 with 2000g indenter

Youngs Modulus

335 GPa

Shear Modulus

148.1 GPa

Bulk  Modulus

240 GPa

Poisson Ratio


Elastic Limit

300Mpa (45.000psi)

Technical Images