GaAs - Gallium Arsenide
American Photonics multispectral zinc sulfide is a form of CVD zinc sulfide that is subjected to a post-deposition hot isostatic process. This Removes zinc hydrides from the crystal lattice, normalizes crystal structure and purifies the material, thus creating a virtually clear substrate with high transmission and minimal scatter from 0.4 to 12 microns. When several wavebandsand a single crystal are required, multispectral zinc sulfide has become the material of choice.
APC can provide raw or generated blanks to most customer specificatons. Circular, square or rectangular geometries are available. See APC's capabilities with optical fabrication and film coatings for more details.
| Physical Properties | |
| Crystal structure | Cubic |
| Grain size (diameter) | 20-35 µm |
| Density (g cm-3 @298k) | 4.09 |
| Resitivity (Ωcm) | >1013 |
| Chemical Purity (%) | 99.996 |
| Dielectic constant data is available from Morton in technical bulletin #103 | |
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| Mechanical Properties | ||
| Hardness: | Knoop, 50gm load (kg mm-2) |
160 |
Vickers, 1kg load (kg mm-2) |
150 |
|
| Flexural Strength (modulus of rupture) | ||
4pt. loading (psi) |
10X10 |
|
4pt. loading (MPa) |
60 |
|
Disc. Bursting (MPa) |
50 |
|
| Fracture toughness (critical stress intensity factor, Kic values) | ||
| (MPa √m, Vicers, 1 Kg) | 1.0 |
|
| Young's modulus (elastic modulus) | ||
| (psi) | 10.8X10 |
|
| (GPa) | 74.5 |
|
| Poisson's ratio | 0.28 |
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| Rain erosion resistance will depend on the environment | ||
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| Thermal Properties | ||
| Coefficient of Thermal Expansions | ||
| (K1 @ 273K) | 6.3 X 10-6 | |
| (K1 @ 373K) | 7.0 X 10-6 | |
| (K1 @ 473K) | 7.5 X 10-6 | |
| (K1 @ 208-573 K)) | 6.5 X 10-6 | |
| Thermal Conductivity | ||
| JK-1m-1s-1 @298 K) | 27.2 | |
| Heat Capacity | ||
| Jg-1 K @ 273 K | 0.515 | |
| Jg-1 K @ 323 K | 0.527 | |
| Jg-1 K @373 K | 0.527 | |
| Thermal Diffusivity(m2s-1 | 1.3 X 10-5 | |
| Maximum operating temperature will depend on the environment | ||
| Optical Properties | ||
| 10% transmission limits (t=6mm) | 0.37 - 14µm | |
| Index of refraction in homogeneity (∆ n/n) | ||
| (ppm @ 0.6328 µm) | <20 | |
| Thermo-optic coefficient, dn/dt (298-358K) | ||
| (avg. values) | ||
| K -1 @ 0.6328 µm | 5.43 X 10-5 | |
| K -1 @ 0.1.15 µm | 4.21 X 10-5 | |
| K -1 @ 0.3.39 µm | 3.87X 10-5 | |
| Bulk absorbstion coefficient | ||
| (cm-1 @ 1.3 µm) | 6.0 X 10-1 | |
| (cm-1 @ 2.7 µm) | 1.0 X 10-1 | |
| (cm-1 @ 3.8 µm) | 6.0 X 10-1 | |
| (cm-1 @ 9.27 µm) | 6.0 X 10-1 | |
| (cm-1 @ 10.6 µm) | 2.0 X 10-1 | |