FSUV1 (Fused Silica)
FQVIS2 (Fused Quartz)
Fused Silica is the glassy form of quartz and is thus isotropic. It is tough and hard and has a very low expansion. Normal varieties contain water that gives strong absorption in the IR. Water-free varieties are available.
Vitreous silica is the generic term used to describe all types of silica glass, with producers referring to the material as either Fused Quartz or as Fused Silica. Originally, those terms were used to distinguish between transparent and opaque grades of the material. Fused Quartz products were those produced from quartz crystal into transparent ware, and Fused Silica described products manufactured from sand into opaque ware.
Today, however, advances in raw material beneficiation permit transparent fusions from sand as well as from crystal. Consequently, if naturally occurring crystalline silica (sand or rock) is melted, the material is simply called Fused Quartz. If the silicon dioxide is synthetically derived, however, the material is referred to as synthetic Fused Silica.
These materials are ultra pure, single component glasses (SiO2) with a unique combination of thermal, optical and mechanical properties, which make them the preferred materials for use in a variety of processes and applications where other materials are not suitable. The very high purity (over 99.9 %) ensures minimum contamination in process applications.
These materials can routinely withstand temperatures of over 1250 °C, and due to their very low coefficient of thermal expansion can be rapidly heated and cooled with virtually no risk of breakage due to thermal shock.
These materials are inert to most substances, including virtually all acids, allowing their use in arduous and hostile environments.
The dielectric properties and very high electrical receptivity of these materials over a wide range of temperatures, together with their low thermal conductivity allow their use as an electrical and thermal insulating material in a range of environments.
Fused Quartz is less expensive vitreous silica formed by fusing naturally occurring quartz crystal or lower grade synthetic stock material, the UV use is limited to 250 nm and this material is usually used for windows covering visible wavelengths.
Fused Silica is vitreous silica formed by fusing high purity synthetic material. The UV use can be reached about 160 nm.
FSUV1 (Fused Silica)Equivalent to Suprasil 1 and 2 (Heraeus), Spectrosil A and B (Saint-Gobain) and Corning 7940 (Corning), Dynasil 1100 and 4100 (Dynasil).
FQVIS2 (Fused Quartz)Equivalent to Homosil 1, 2 & 3 (Heraeus), Dynasil 1000 & 4000 and 5000 & 6000 (Dynasil)
UV grade Fused Silica (FSUV1) is synthetic amorphous silicon dioxide of extremely high purity. This non-crystalline, colorless silica glass combines a very low thermal expansion coefficient with good optical qualities, and excellent transmission in the ultraviolet. Transmission and homogeneity exceed those of crystalline quartz without the problems of orientation and temperature instability inherent in the crystalline form. Fused Silica is used for both transmissive and reflective optics, especially where high laser damage threshold is required.
FSUV1 is transparent in the ultraviolet and visible regions, and has no absorption bands in the 170 - 250 nm wavelength intervals. It has an intensive OH absorption band in the interval of wavelength 2600 - 2800 nm.
FSUV1 is used for optics operating in the deep UV and the visible wavelength range (laser lenses, windows, prisms, mirrors, etc.). It is practically free of bubbles and inclusions.
Optical Grade Fused Quartz (FQVIS2) provides good UV and visible transmission. It has almost the same physical and chemical properties with FSUV1. However only in thin & small sheet pieces, FQVIS2 is virtually bubble-free. Elements built from larger pieces will most likely contain bubbles, so application should not be sensitive to these inclusions. But in cases where simple light gathering and strong mechanical properties are the primary goals, FQVIS2 grade provides excellent performance at a low price.
Ideal Applications for FQVIS2:
- Condenser optics not concerned with scatter or distortion
- High temperature and pressure applications
- Optical flats, microscope slides and sight glasses