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Quartz Glass, UV-Grade Fused Silica

Synthetic quartz glass with high ultraviolet transmission

Special Properties

  • Low coefficient of thermal expansion
  • Enormous operating temperature range
  • UV-grade glass with outstanding ultraviolet light transmittance
  • Very good temperature shock resistance
  • High purity glass
  • Low fluorescence
  • Very good chemical resistance
  • Completely free of soda

Typical Applications

  • UV-transparent optics
  • Very high temperature glass windows
  • Ultraviolet measurement technology
  • Glass substrates for thin film coatings
  • Optics for space technology
  • Windows for ultraviolet applications
  • Microscope slides and coverslips with high ultraviolet light transmissivity
  • Semiconductor applications

What is synthetic quartz glass and what is it used for?

Fused Silica (SiO2) is a synthetic, molten, high purity, amorphous, non-crystalline quartz glass material with exceptional technical characteristics. It is made by melting utmost pure ingredients and only contains silicon and oxygen. Fused Silica can be used whenever a very high thermal strength and an excellent optical transmission of wavelengths below the visible spectrum is required. The very high UV-transparency cannot be outperformed by any other industrial glass. Fused Silica window

Its excellent thermal properties allow fused silica glass to be used at very strong thermal loads. This allows the material to be used at extremely high operating temperatures. The low coefficient of thermal expansion ensures an excellent thermal shock resistance. Hence, amorphous quartz glass is often used for the fabrication of heat-resistant windows which must withstand high temperatures of up to 1000 °C without melting or breaking. Likewise, the superb chemical stability of quartz glass is remarkable. Its resistance is much higher than that of most other glass materials. The chemical durability of the glass against bases is top class and the material as well is extremely resistant against saline solutions, acids and water. Due to the exceptional purity, the material has very good electrical insulation properties. Electrical currents can flow essentially only by moving ionic impurities. Since these impurities are only very small in quartz glass, the glass has a particularly high insulation resistance. These electrical properties and the huge operating temperature range as well as the high grade of purity make quartz glass material a perfect choice for various semiconductor applications and for the production of semiconductor devices.


From raw fused silica glass blocks to quartz glass optics

Most of our quartz glass components are fabricated from large blocks of high quality non-crystalline fused silica materials, so called "boules". This very pure raw-glass is ground, polished, shaped and surface finished according to customer's specifications until finally optics have emerged from the raw glass block. If required, our UV-grade quartz glass can be selected for low amounts of inclusions, as well as for an increased refractive index homogeneity. Our company is processing numerous quality quartz glass materials with different properties from nearly any well-known raw glass manufacturer worldwide like Corning, Heraeus, Tosoh, SCHOTT, Saint Gobain, GE Quartz etc. The fabrication of glass-windows and substrates, wafer components and coated optics based on all these different glass grades is possible.

In order to request a quotation for optical windows, polished fused silica substrates or quartz glass microscope slides with custom dimensions, please use the button below. Please choose "UV-grade" glass for applications that require a high ultraviolet transmittance of > 80 % at 185 nm. Choose "sightglass" grade for applications that do not require such an enormous UV-transmissivity and whenever the optical properties of the quartz glass are less important or in cases you want to use the glass due to its low thermal expansion properties or at increased operating temperatures only:


Quotation for UV-grade
quartz glass

48h- Express Service icon

48-h Express Optics Service available

Within our express service only the following glass thicknesses are available: 0,30 mm ; 0,50 mm ; 1,00 mm; 2,00 mm and 3,00 mm.

Of course, with normal delivery time we can polish to any desired custom material thickness.



Quotation for sightglass
grade quartz glass

48h- Express Service icon

48-h Express Optics Service available

Within our express service only the following glass thicknesses are available: 1,00 mm ; 2,00 mm and 3,00 mm.

Of course, with normal delivery time we can polish to any desired custom material thickness.



Transmittance of fused silica

Typical transmittance of quartz glass / fused silica


Light Transmissivity

  • T > 80 % at 185 nm (only UV-grade quartz glass)
  • Transmittance of non-UV-grade material on request

Refractive Index

  • nd = 1,45846


  • 2,20 g/cm3


  • Homogeneity specifications per request
  • Index homogeneities down to ≤ 0,5 ppm possible
    on request

Inclusion Classes

Average Coefficient of Thermal Expansion

  • approximately 0,57 x 10-6/K

Thermal Properties

  • Softening point approximately 1585 °C
  • Annealing point approximately 1042 °C
  • Strain point approximately 893 °C


Note: Our website can only give an overview about the different grades of possible quartz glass materials. It is not practicable to provide all technical data about the many hundred grades of quartz materials we process in our web site. For further detailed specifications, such as electrical characteristics, mechanical strength, impurities, index homogeneity or any other additional technical information about the different grades of the quartz glass materials or for information about special material grades for semiconductor use, please send us your request. Quartz glass tubes are not part of our delivery program.



All given details and specifications are mean reference values and are not guaranteed. In addition, please consider the "Notes on technical specifications"