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Infrared IR optical
windows include the following optical materials: |
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Infrared Grade Fused Quartz Windows |
| Infrared transmitting
quartz polished optical windows and plates are used
to transmit from 350nm to 3.50 microns in the infrared
spectrum and are useful for their high temperature
resistance and stability in demanding environments.
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Optical Sapphire
(random) IR Windows. |
| Sapphire
polished windows and plates for infrared window
applications transmit from the visible @750nm to
the IR @ 5 microns. Sapphire is extremely hard and
scratch resistant which is why it is a useful window
in very hostile environments. It is used for its
mechanical and infrared properties and is widely
used as an (IR) infrared optical window |
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Optical Silicon
Windows |
| Silicon windows
either floatzone or optical grade transmits in the
infrared. Optical grade (monocrystaline or polycrystaline)
silicon is mainly used for the 3-5 microns range.
Floatzone silicon windows have higher transmission
at 9 microns and 1% higher at 3-5 microns. |
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Optical
Germanium IR Windows |
| Germanium
effective IR optical window operation ranges from
3-5 microns and 8-12 microns. Germanium is popular
for its high refraction, strength and thermal conductivity,
widely used in lasers and imaging systems. |
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Infrared Grade
Calcium Fluoride (CaF2) windows |
Calcium Fluoride
is good choice for optical windows in the 0.15 μm
- 9 μm range.
This material has found wide use in high power laser
optics due to its low absorption. Polished surfaces
are stable and will last several years under normal
conditions. Due to its low refractive index, Calcium
Fluoride can be used without anti-reflection coating. |
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Infrared Grade
Barium Fluoride (BaF2) windows |
| Barium Fluoride
, its transmission range is 0.2 μm - 11 μm. Polishing
is quicker than calcium fluoride using diamond pastes
but is less easy to obtain free of sleeks. Barium
fluoride is less resistant to attack by water than
Calcium Fluoride. Pronounced water attack occurs
at 500℃ , but the material can be used to 800 ℃
in a dry environment. The material is relatively
hard but is highly sensitive to thermal shock. |
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Infrared
Grade magnesium fluoride (MgF2) windows |
| Magnesium
Fluoride has excellent transmission in the UV to
NIR (120nm -6 um). MgF2 is relatively soft and somewhat
hygroscopic so polishing, coating and handling are
more critical than for Fused Silica windows. |
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Infrared
Grade Zinc Selenide (ZnSe) windows |
| Zinc Selenide
is used for optical windows, lenses, mirrors and
prisms particularly for infrared applications. The
transmission range is 0.5 μm - 22 μm. Used for high
power CO2-laser optics at 10.6 micronsZinc Selenide
is produced by synthesis from zinc vapour and H2Se
gas, forming as sheets on graphite susceptors. It
is microcrystalline in structure, the grain size
being controlled to produce maximum strength. Single
crystal ZnSe is available, but is not common but
has been reported as having lower absorption and
thus more effective for CO2 optics. |
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