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Quartz Glass, UV-Grade Fused Silica

Synthetic quartz glass with high ultraviolet transmission

Special Properties

  • UV-grade glass with outstanding ultraviolet light transmittance
  • Enormous operating temperature range of up to 1000 °C
  • Low thermal expansion coefficient
  • Very good thermal shock resistance
  • High purity glass composition
  • Low fluorescence
  • Very good chemical strength
  • Completely free of soda

Typical Applications

  • UV-transparent optics
  • Glass windows for very high temperatures
  • UV-measurement technology
  • Glass substrates for thin film coatings
  • Space technology
  • Optical windows for ultraviolet applications
  • Microscope slides and coverslips with high UV-light transmissivity
  • High-power lighting applications
  • Semiconductor devices

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 utilized whenever a very high thermal strength and an excellent optical transmissivity of wavelengths below the visible spectrum is required. The very high UV-transparency cannot be outperformed by any other industrial grade glass. High purity fused silica window

The mentioned excellent thermal characteristics enable fused silica glass to be operated under very strong temperature loads. In addition, the small coefficient of expansion ensures an excellent heat shock resistance. Hence, amorphous quartz glass is often a base material for the fabrication of heat-resistant windows which must withstand high temperatures of up to 1000 °C without melting or breaking.

Likewise remarkable is the superb chemical stability of quartz glass. Its chemical strength is significantly higher than that of most other glass materials. The chemical durability of the glass against bases is top class. As well it is extremely resistant against saline solutions, acids and water.

Due to its exceptional purity, the material has very good electrical insulation properties. Electrical currents can flow essentially only by moving ionic impurities. Since these impurities are very small in quartz glass, the glass features a particularly high insulation resistance. The electrical properties, the huge operating temperature range as well as the high grade of purity make quartz glass material a perfect choice for numerous semiconductor applications and for the production of semiconductor devices.


The way from raw quartz glass blocks to quartz glass optics

Most of our quartz glass components are fabricated from large glass blocks, consisting of high quality non-crystalline fused silica. Such glass blocks are 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 in regards to low inclusions, as well as for an increased refractive index homogeneity. Our company is processing numerous quality quartz glass grades with different properties from nearly any well-known raw glass manufacturer worldwide, like Corning, Heraeus, Tosoh, SCHOTT, Saint Gobain, GE Quartz and many others. The fabrication of glass-windows and substrates, wafer components and coated optics based on these different glass grades is part of our manufacturing capabilities.

In order to request a quotation for optical windows, polished fused silica substrates or quartz glass microscope slides at any custom dimension, please use the button below. Please choose "UV-grade" glass to request optical grade fused silica for applications that require a high ultraviolet transmittance of > 80 % at 185 nm. Choose "sight glass" grade for applications that do not require such an enormous UV-transmissivity and whenever the optical properties and purity of the quartz glass are of secondary concern. These are cases, when you want to use the glass due to its low thermal expansion properties or only at increased operating temperatures. This material quality is usually used for sightglass windows:


Quotation for UV-grade
quartz glass

48h- Express Service icon

48-h Express Optics Service available

NEW in 2017! Within our express service the following fused silica thicknesses of UV-grade quartz glass 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 sight glass
grade quartz glass

48h- Express Service icon

48-h Express Optics Service available

NEW in 2017! Within our express service the following quartz glass thicknesses with sight glass grade are available: 1,00 mm ; 2,00 mm and 3,00 mm.



Transmittance of fused silica

Typical transmission of quartz glass
(synthetic fused silica)


Light Transmissivity

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

Refractive Index

  • nd = 1,4585 (fused silica)


  • 2,20 g/cm3


  • Homogeneity specifications per request
  • Index homogeneities of UV-quality materials down to ≤ 0,5 ppm possible on request

Inclusion Classes

Average Coefficient of Thermal Expansion

  • approximately 0,57 x 10-6/K


  • 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 and fused silica qualities. It is not practicable to provide all technical data about the many grades of quartz materials we process in our web site. For further detailed specifications, such as electrical characteristics, mechanical strength, index homogeneity, thermal properties 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 within 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"

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