CLEARTRAN®
Water-clear Form of Zinc Sulfide
CLEARTRAN®,
with its low absorption and scatter throughout its broad transmitting range,
is particularly well-suited for multi-spectral applications that require a
single aperture or beam path for several wavebands. For example, CLEARTRAN®
can be used in systems that have a visible camera, a mid- and long-wave detector
and a laser rangefinder or target designator. Additionally, CLEARTRAN®
has been supplied as external windows for military systems, and as thick apertures
for specialized sensor applications.
Summary:
Description
Advanced Materials' CLEARTRAN® (water
clear zinc sulfide) is a form of CVD ZINC SULFIDE® that is
modified by a post-deposition hot isostatic press. This process removes zinc
hydrides from the crystal lattice, normalizes crystal structure and purifies
the material, all contributing to single crystal like transmittance in the
visible through far infrared regions (0.4-14 microns).
CLEARTRAN® is chemically inert, non-hygroscopic,
highly pure, theoretically dense, and easily machined.
Available Forms
Custom diameters, rectangles, CNC-profiled blanks, generated
lens blanks, prisms and near-net shape domes can also be made to your specifications.
Sheet material is also available.
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Transmission
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| Optical Properties: |
| 10% transmission limits (t=6mm) |
0.37 - 14µm |
| Stress Birefringence |
< 40nm/cm |
| Forward Scatter (@ 0.6328µm) |
< 7 % cm-1 |
| Index of refraction inhomogeneity (Dn/n) |
| |
(ppm @ 0.6328µm) |
<20 |
| Thermo-optic coefficient, dn/dT(298-358K) |
| |
(1/K @ 0.6328µm) |
5.43 x 10-5 |
| (1/K @ 1.15µm) |
4.21 x 10-5 |
| (1/K @ 3.39µm) |
3.87 x 10-5 |
| Bulk absorption coefficient |
| |
(1/cm @ 1.3µm) |
6.0 x 10-4 |
| (1/cm @ 2.7µm) |
1.0 x 10-3 |
| (1/cm @ 3.8µm) |
6.0 x 10-4 |
| (1/cm @ 9.27µm) |
6.0 x 10-3 |
| (1/cm @ 10.6µm) |
2.0 x 10-1 |
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| Indices of
Refraction (n) |
| as a function of wavelength at room temperature (20°C)
|
| Wavelength (µ) |
n |
Wavelength (µ) |
n |
| 0.4047 |
2.54515 |
1.1287 |
2.28485 |
| 0.4358 |
2.48918 |
1.5296 |
2.27191 |
| 0.4678 |
2.44915 |
2.0581 |
2.26442 |
| 0.4800 |
2.43691 |
3.000 |
2.25772 |
| 0.5086 |
2.41279 |
3.500 |
2.25498 |
| 0.5461 |
2.38838 |
4.000 |
2.25231 |
| 0.5876 |
2.36789 |
4.500 |
2.24955 |
| 0.6438 |
2.34731 |
5.000 |
2.24661 |
| 0.6678 |
2.34033 |
8.000 |
2.22334 |
| 0.7065 |
2.33073 |
9.000 |
2.21290 |
| 0.7800 |
2.31669 |
10.000 |
2.20084 |
| 0.7948 |
2.31438 |
11.250 |
2.18317 |
| 0.8521 |
2.30659 |
12.000 |
2.17101 |
| 0.8943 |
2.30183 |
13.000 |
2.15252 |
| 1.0140 |
2.29165 |
|
|
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| Physical
Properites: |
| Crystal structure |
cubic |
| Grain size |
diameter |
20 - 35µm |
| Density |
(g cm-3@298K) |
4.09 |
| Resistivity |
( -cm) |
~1013 |
| Chemical Purity |
(%) |
99.9996 |
| Dielectric constant data is available from Rohm and
Haas. |
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| Thermal
Properties: |
| Coefficient of Thermal Expansion |
| |
(1/K @ 273 K) |
6.3 x 10-6 |
| (1/K @ 373 K) |
7.0 x 10-6 |
| (1/K @ 473 K) |
7.5 x 10-6 |
| (1/K @ 208 - 573K) |
6.5 x 10-6 |
| Thermal conductivity |
| - |
(J/K-m-s @ 298 K) |
27.2 |
| Heat Capacity |
(J/g-K @ 273 K) |
0.515 |
| |
(J/g-K @ 323 K) |
0.527 |
| (J/g-K @ 373 K) |
0.527 |
| Thermal Diffusivity |
m2/s |
1.3 x 10-5 |
| Maximum operating temperature will depend
on the environment |
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| Mechanical
Properties: |
| Hardness: |
Knoop, 50 gm load (kg mm-2) |
160 |
| |
Vickers, 1 kg load (kg mm-2) |
150 |
| Flexural Strength (modulus of rupture) |
| |
4 pt. loading (psi) |
10 x 103 |
| 4 pt. loading (MPa) |
60 |
| Disc. Bursting (MPa) |
50 |
| Fracture toughness (critical stress
intensity factor, KIC values) |
| |
(MPa ,
Vickers, 1 Kg) |
1.0 |
| Young's Modulus (elastic modulus) |
| |
(psi) |
10.8 x 106 |
| (GPa) |
74.5 |
| Poisson's ratio |
0.28 |
| Rain erosion resistance will depend
on the environment |
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