Crystal Quartz (SiO2) and Fused Silica

Crystal quartz (SiO2) is a very useful material for fabrication of finished optics: laser beamsplitters, AO elements, polarizing optics, prisms, windows, lenses in the ultraviolet because of its high UV, VIS and NIR transmittance, birefringence, ability to rotate plane polarized light, high damage threshold and resistance to scratching. The optical grade material is featured by the highest possible transmittance throughout the range of 190 - 2900 nm, virtual freedom from bubbles and inclusions. Grown boules are Z - crystals and about 100 mm in the direction down the optic axis that limits corresponding dimension in an optical part.
   Silicon dioxide occurs naturally as sand or rock, and when melted, the resulting product is called Fused Quartz. If the silicon dioxide is synthetically derived, the material is often called Fused Silica. Fused Quartz is very pure, has a high chemical resistance, good thermal shock resistance and is very strong in compression. The low thermal expansion coefficient makes it ideal for mirrors and optical flats. It is used for viewing windows, being transparent to wavelengths from around 0.2 to 3.5 µm, insulators for electronic applications and for semi-conductor manufacturing.
Material properties of the Crystal Quartz:

Quality grade
Coefficient of absorption (±max at 190 nm), cm-1
Coefficient of absorption (±max at 2800 nm), cm-1
1
0.010
0.030
2
0.025
0.045
3
0.050
0.070
Properties:
Chemical Formula SiO2
Positive uniaxial crystal ne > no
Density, g/cm3 2.65
Mohs Hardness 7
Heat Capacity at 300K, J/kg·K 733
Thermal Expansion Coefficient at 300 K, 10-6· K-1 a|| = 7.64, a^= 14.00
Thermal conductivity at 300 K, W/(m×k) æ|| = 9.5, æ^= 6.10
  æ|| = 9.5, æ^= 6.10
Refractive indices at T = 291°K
Wavelength
no
ne
Wavelength
no
ne
193,6
1,65999
1,67343
706,5
1,540488
1,549472
250,3
1,60032
1,61139
766,5
1,539071
1,548005
303,4
1,576955
1,58720
844,7
1,537525
1,54640
340,4
1,56747
1,577385
1000,0
1,53503
1,54381
410,2
1,556502
1,566031
1300,0
1,53102
1,53962
467,8
1,551027
1,560368
1529,6
1,52800
1,53646
508,6
1,548229
1,557475
1600,0
1,52703
1,53545
546,1
1,546174
1,555350
1800,0
1,52413
1,53242
627,8
1,542819
1,551880
2058,2
1,51998
1,52814
Max. available size: 100 mm along axis and and axis. Quartz elements which we supply are manufactured as a rule according to customer's specifications.

Material properties of the Fused Silica:
Apparent porosity ( % ) 0
Density ( g cm-3 ) 2.2
Refractive index 1.46
Useful optical transmission range 180 - 2500 nm
Water absorption - saturation ( % ) 0
Dielectric constant 3.8
Dielectric strength ( kV mm-1 ) 25-40
Volume resistivity ( Ohmcm ) 1018 @ 25°C
Compressive strength ( MPa ) 1100
Hardness - Knoop ( kgf mm-2 ) 820
Hardness - Vickers ( kgf mm-2 ) 1000
Shear strength ( MPa ) 70
Tensile modulus ( GPa ) 72-74
Tensile strength ( MPa ) 48
Coefficient of thermal expansion ( x10-6 K-1 ) 0.54 @ 20-1000°C
Melting point (°C ) 1715
Specific heat ( J K-1 kg-1 ) 670-740 @ 25°C
Thermal conductivity ( W m-1 K-1 ) 1.46 @ 20°C
Upper continuous use temperature ( °C ) 1100-1400

Fused Silica has high homogenity and good transmission in the ultraviolet, visible and infrared spectral regions. Depending on transmission range, there are UV and IR Fused Silica grades: the useful range of UV grade is 0.17 - 2 µm and of IR grade is 0.23 - 3.5 µm. Products manufactured: Lenses, windows, wedges, optical beamsplitters, optical filters, prisms, etc.

   Cultured crystalline quartz is mostly used. The useful transmission range is represented from 0.18 µm to 2.8 µm by three grades of optical quartz defined by optical absorption.

I N Q U I R Y    F O R M :

Material:
Quantity of elements:
Application:

polished sites:

   or 
 a-b b-c a-c
or d  
Orientation:
(if applicated)
Dimensions/Tolerances:
For example:
10.0 +/- 0.1
AR-coating:
a = mm;
c = mm
b = mm or
dia. = mm;
This field is for additional information such as application,
comments, add. requirements etc.

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Quartz Glass Material Properties