Home / Products / Optical Glass / Quartz Glass - Fused Silica

Quartz Glass

Optical Grade Fused Silica with UV-Quality

Special Properties

  • Excellent ultraviolet transmission and optical quality
  • High-purity glass composition
  • Extremely heat-resistant
  • Low coefficient of thermal expansion
  • Crystal clear water-white appearance
  • Operating temperature up to 1000 °C
  • Very high thermal shock resistance
  • Outstanding chemical strength
  • Low fluorescence
  • High electrical insulation properties
  • Chemically inert
  • Made by a flame hydrolysis process

Typical Applications

  • Windows for ultraviolet and deep ultraviolet light (DUV)
  • Glass wafers for semiconductor technology
  • Substrates used for laser mirror coatings
  • Laser optics
  • UV-measuring instruments
  • Microscope slides and coverslips for medical applications
  • Industrial quartz products
  • High-temperature applications
  • Chemically resistant glass parts
  • Laboratory components
  • Space technology

Get a price quote

48h-Express Service 48-hour express service possible*


Related glass types

To help you choose the right type of quartz material, we have set up a website with FAQs about quartz glass.


Optical Quartz Glass – Synthetic Fused Silica

Quartz glass used for optics is a synthetically produced high-purity fused silica made by flame hydrolysis. The crystal-clear amorphous silicon dioxide material is virtually free of impurities and contains only silicon and oxygen. This unique type of quartz glass already enables UV transmission higher than 80% at a wavelength of 185 nm.

Quartz glass windowThe enormous operating temperature range and thermal load capacity of quartz glass are unparalleled. Silicon dioxide glass can operate permanently up to 1000 °C and is highly resistant to thermal shock. These outstanding thermal properties result from quartz glass's very low expansion coefficient.

As well, the chemical durability of this unique glass material is remarkable. It is particularly resistant to saline solutions, acids, and water. The chemical strength of quartz glass to bases surpasses almost all other glass materials.

Furthermore, its exceptional electrical performance makes quartz glass ideal for semiconductor technology. Since currents can only flow through mobile ionic impurities that are marginally present in quartz material, it has low conductivity and excellent electrical insulation resistance. These characteristics are essential for numerous electronics and semiconductor applications.


Quartz Glass Optics

We fabricate custom optics for the UV, visible, and infrared wavelength range mainly from large blocks, the so-called boules, and we can select the raw glass for inclusions and bubbles if necessary. Moreover, an index homogeneity down to ≤ 0,5 ppm is available if this parameter represents a critical requirement.
The first step to producing an optic from a boule is cutting the required material from the glass block. After this process, the quartz glass is shaped, finely ground, and polished according to the requirements. In this way, our company fabricates UV-transparent substrate glasses, glass wafers, microscope slides, and many other quartz glass items daily.


How can I obtain a price quote?

To request a quotation for windows, substrates, glass plates, or other parts made of optical quartz glass with individual dimensions, please select a thickness from the table or use the following button.


Get a price quote

48h-Express Service 48-hour express service possible*


Specifications & Properties

Transmittance spectrum of synthetic
fused silica in the ultraviolet to infrared range

Spectral curve of UV-grade quartz glass
Enlarge curve to show details

Glass thicknesses

As high-purity quartz glass is a block glass, there are no standard thicknesses. Consequently, the glass thickness needs to be specified and manufactured individually. To offer our customers good availability and the best possible service, we continually grind and polish the following glass thicknesses and tolerances. You can even order these within our 48-hour express service:

Click on a glass thickness to start an inquiry:

Glass Thickness (mm)


48h-Express Service
0,175 ±0,020
0,30 ±0,025
0,30 ±0,050
0,50 ±0,025
0,50 ±0,030
0,50 ±0,050
1,00 ±0,025
1,00 ±0,100
1,10 ±0,100
2,00 ±0,150
3,00 ±0,025
3,00 ±0,100
Other thicknesses are possible on demand.
*The glass thicknesses marked with "" are available in 48-hour express service.


Light Transmission

  • T > 80 % at 185 nm
    (UV-grade material = fused silica)

Refractive Index

  • nd = 1,4585


  • 2,20 g/cm3

Young's Modulus

  • 74 GPa (typical value)


  • Homogeneity classes per inquiry
  • Index homogeneity of the UV-class materials down to ≤ 0,5 ppm is possible on demand

Inclusion Classes

Glass Composition

  • Silicon dioxide (SiO2)

Operating Temperature

  • up to 1000 °C

Average Coefficient of Thermal Expansion

  • ≈ 0,57 × 10-6/K


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

Dielectric Constant

  • εr: 3,9 (500 MHz)


Fused Quartz Glass for Sight Glass Applications

Besides the quartz glass type described before, we also process less sophisticated quartz materials used for high temperatures, requiring only sight glass functionality. Since the inner material quality and the deep-UV transparency are of secondary concern in those cases, the less expensive Fused Quartz is the best choice for fabricating such items.

Unlike quartz glass, this glass is produced by melting natural quartz crystals. Hence, fused quartz is less pure than fused silica because it contains far more contaminants and can't offer fused silica's material purity, homogeneity, and optical performance. Therefore, it is typically only suitable for less demanding applications. Nevertheless, fused quartz has an almost identical coefficient of expansion, a similar heat resistance, and nearly the same good thermal properties as High-End glass. Besides, it also features virtually the same chemical strength as fused silica and still offers better UV transparency than most other glasses. Furthermore, it has the same crystal clear appearance as optical grade quartz glass and is significantly more economical than the sophisticated quartz materials described on this website.

So, this type of material is the best choice for fabricating sight glasses for high temperatures, lamp housings, UV-lighting systems and lamps, transparent furnace panes, pressure-resistant windows, and other industrial glass parts. You can find further details, specifications, and properties of this glass type in our Fused Quartz Glass spec sheet. Please also refer to our Quartz Glass FAQ page for help selecting the right glass for your application.

Our company processes raw materials from many leading manufacturers in the quartz glass industry (Corning, Heraeus, Tosoh, SCHOTT, Saint-Gobain Quartz, Shin-Etsu, GE Quartz, and many others). We are pleased to share detailed properties and information about the glass qualities we supply on request.


All given details and specifications are mean reference values and are not guaranteed. Please consider the "Notes on technical specifications".

© 1994 – 2023 Präzisions Glas & Optik GmbH

Last update 21.03.2023