CVD ZINC SELENIDE®
Chemically
vapor deposited zinc selenide (CVD ZINC SELENIDE®) is the material
of choice for use as optical components in high powered CO2 lasers due to
its low bulk absorption at 10.6 microns. Its index of refraction homogeneity
and uniformity offers excellent optical performance for use as protective
windows or optical elements in high resolution forward looking infrared (FLIR)
thermal imaging equipment. This material has also been used as small windows
and lenses in medical and industrial applications, such as thermometry and
spectroscopy.
Summary:
Description
Advanced Materials’ CVD ZINC SELENIDE®
is chemically inert, non-hygroscopic, highly pure, theoretically dense and
easily machined. It has extremely low bulk losses due to absorption and scatter,
has a high resistance to thermal shock and is stable in virtually all environments.
Available Forms
Circular blanks and sheet material are available in
stock to meet your most urgent delivery requirements. Custom diameters, rectangles,
CNC-profiled blanks, generated lens blanks, prisms, and near-net shape domes
can also be made to your specifications.
Evaporative Source Material
Advanced Materials’ CVD ZINC SELENIDE®
is also available as an evaporative source material. It is supplied in specified
lump sizes (2-20mm), which to minimize surface contamination are hand selected
to be free from saw cut, abraded or polished edges.
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Transmission
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| Optical Properties |
| 10% transmission limits (t=6mm) |
0.5 - 22µm |
| Index of refraction inhomogeneity (Dn/n) |
| - |
(ppm @ 0.6328µm) |
<3 |
| Thermo-optic coefficient, dn/dT(298-358K) |
| |
(1/K @ 0.6328µm) |
1.07 x 10-4 |
| (1/K @ 1.15µm) |
7 x 10-5 |
| (1/K @ 3.39µm) |
6.2 x 10-5 |
| (1/K @ 10.6µm) |
6.1 x 10-5 |
| Bulk absorption coefficient |
| |
(1/cm @ 1.3µm) |
5.0 x 10-3 |
| (1/cm @ 2.7µm) |
7.0 x 10-4 |
| (1/cm @ 3.8µm) |
4.0 x 10-4 |
| (1/cm @ 5.25µm) |
4.0 x 10-4 |
| (1/cm @ 10.6µm) |
5.0 x 10-4 |
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| Indices of Refraction
(n) |
| as a function of wavelength at room
temperature (20°C) |
| Wavelength (µ) |
n |
Wavelength (µ) |
n |
| 0.54 |
2.6754 |
7.40 |
2.4201 |
| 0.58 |
2.6312 |
7.80 |
2.4183 |
| 0.62 |
2.5994 |
8.20 |
2.4163 |
| 0.66 |
2.5755 |
8.60 |
2.4143 |
| 0.70 |
2.5568 |
9.00 |
2.4122 |
| 0.74 |
2.4518 |
9.40 |
2.4100 |
| 0.78 |
2.5295 |
9.80 |
2.4077 |
| 0.82 |
2.5193 |
10.20 |
2.4053 |
| 0.86 |
2.5107 |
10.60 |
2.4028 |
| 0.90 |
2.5034 |
11.00 |
2.4001 |
| 0.94 |
2.4971 |
11.40 |
2.3974 |
| 0.98 |
2.4916 |
11.80 |
2.3945 |
| 1.00 |
2.4892 |
12.20 |
2.3915 |
| 1.40 |
2.4609 |
12.60 |
2.3883 |
| 1.80 |
2.4496 |
13.00 |
2.3850 |
| 2.20 |
2.4437 |
13.40 |
2.3816 |
| 2.60 |
2.4401 |
13.80 |
2.3781 |
| 3.00 |
2.4376 |
14.20 |
2.3744 |
| 3.40 |
2.4356 |
14.60 |
2.3705 |
| 3.80 |
2.4339 |
15.00 |
2.3665 |
| 4.20 |
2.4324 |
15.40 |
2.3623 |
| 4.60 |
2.4309 |
15.80 |
2.3579 |
| 5.00 |
2.4295 |
16.20 |
2.3534 |
| 5.40 |
2.4281 |
16.60 |
2.3487 |
| 5.80 |
2.4266 |
17.00 |
2.3438 |
| 6.20 |
2.4251 |
17.40 |
2.3387 |
| 6.60 |
2.4235 |
17.80 |
2.3333 |
| 7.00 |
2.4218 |
18.20 |
2.3278 |
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| Physical Properties
|
| Crystal structure |
cubic |
| Grain size |
diameter |
50 - 70µm |
| Density |
(g cm-3@298K) |
5.27 |
| Resistivity |
(W-cm) |
~1012 |
| 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) |
7.1 x 10-6 |
| (1/K @ 373 K) |
7.8 x 10-6 |
| (1/K @ 473 K) |
8.3 x 10-6 |
| Thermal conductivity |
| - |
(J/K-m-s @ 298 K) |
18.0 |
| Heat Capacity |
(J/g-K @ 298 K) |
0.339 |
| Maximum operating temperature will depend on
the environment |
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| Mechanical Properties |
| Hardness: |
Knoop, 50 gm load (kg mm-2) |
110 |
| - |
Vickers, 1 kg load (kg mm-2) |
112 |
| Flexural Strength (modulus of rupture) |
| - |
4 pt. loading (psi) |
8.0 x 103 |
| - |
4 pt. loading (MPa) |
55 |
| Fracture toughness (critical stress intensity factor, KIC
values) |
| - |
(MPa ,
Vickers, 100g) |
0.5 |
| Young's Modulus (elastic modulus) |
| -- |
(psi) |
9.75 x 106 |
| - |
(GPa) |
67.2 |
| Poisson's ratio |
0.28 |
| Rain erosion resistance will depend on the environment |
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