Fused Quartz Overview

Fused Quartz is made using high quality, natural quartz powders with several fusion methods. Quartz material is stronger than glass, can be used at high temperatures (<1050°C) and has a high average transmission of over 80% from 260nm to 2500nm.

This material can have a variety of levels regarding quality and other attributes. The two main attributes for most optical applications involve the bubble content and OH (water) content. Fused quartz can have a variety of bubble content from very low to high as small air bubbles are trapped during the fusion process.

The OH content is determined by the manufacturing process and is important for infrared transmission. Flame-fused material always has higher water content. Typically, OH content below 10 ppm is considered appropriate for infrared applications.

The various qualities of fused quartz allow for use in a wide range of applications from semiconductor applications to lower precision window applications in hostile environments.

Characteristics of fused quartz include:

  • Extreme hardness
  • Large operating temperature range and shock resistivity
  • Available in materials with extensive optical transmission in the ultraviolet or the infrared spectrums
  • Permeability
  • Low coefficient of thermal expansion (CTE)
  • High chemical purity
  • High corrosion resistance
  • Excellent electrical insulation qualities
  • Low refractive index variations, can be controlled in up to 3 axis
  • Low birefringence values
  • Large size capabilities


Based upon customer demand, Sydor Optics offers Fused Quartz made from the following substrate materials. Of course, if you don’t see a material you need, please contact a Sales Engineer, who will gladly discuss additional options that may be available.