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Fused silica
Fused silica
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.
Fused
Silica includes
three
types: JGS1
(Ultraviolet
Grade
Fused
Silica),JGS2 (Optical
Grade
Fused Quartz), and JGS3 (Full Spectrum
Fused Silica).
Today
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.
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
250nm
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 160nm.
Ultraviolet Grade Fused Silica: JGS1
(China), equivalent to Suprasil 1 and 2 (Heraeus),
Spectrosil
A and B (Saint-Gobain) and
Corning 7940 (Corning), Dynasil 1100 and 4100
(Dynasil).
Optical Grade Fused Quartz:
JGS2 (China), equivalent to Homosil 1, 2 & 3
(Heraeus), Dynasil
1000 & 4000 and 5000
& 6000 (Dynasil)
Full Spectrum Fused
Silica: JGS3 (China), equivalent to Suprasil 300
(Heraeus).
Different Properties
Parameter Value
Maximum Size
Transmission Range(Medium
transmission ratio)
OH-
Content
Fluorescence (ex 254nm)
JGS1
<Φ200mm>
0.17~2.10um
(Tavg>90%)
1200 ppm
Virtually Free
JGS2
<Φ300mm>
0.26~2.10um (Tavg>85%)
150
ppm
Strong v-b
JGS3
<Φ200mm>
0.185~3.50um
(Tavg>85%)
5 ppm
Strong V-B