Material - Silicon (Si)
Monocrystalline Silicon Si is used as optical windows usually in (3 - 5) micron band and as substrates for production of optical mirrors.
Silicon Si is frequently used for laser mirrors because of its high thermal conductivity and low density. Silicon Si monocrystal is also useful as a transmitter in the 20 micron range. Si large blocks with polished faces are also employed as targets in neutron physics experiments.
Silicon is grown by Czochralski pulling techniques (CZ) and contains some oxygen which causes an absorption band at 5.8, 9.1 and 19.4 microns. To avoid this, Si monocrystalline material can be prepared by a Float-Zone (FZ) process. Optical silicon is generally lightly doped (5 to 40 Ohm*cm) for best transmission above 10 microns. Silicon has a further pass band 30 to 100 microns which is effective only in very high resistivity material.
Crystaltechno Ltd. manufactures from Silicon Si the following optics: blanks, windows, prisms, wedges, lenses and mirrors. These products are used for infrared applications.
Spectral Transmittance of FZ Silicon Uncoated Polished Window thickness 5mm for range (2.5 - 25) microns, (2.5 - 4.3) kOhm*cm.
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Crystaltechno Ltd. offers the manufacturing of silicon optics (in detail please see Catalog):
Perhaps you will find required Silicon Si optics at our stock, please see item Optical Crystals.
BASE PROPERTIES of Silicon Si
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PARAMETER |
|
VALUE |
|
|
|
|
|
|
| OPTICAL |
|
| |
Transmission Range |
|
1.2 to 15 microns |
|
| |
Refractive Index |
|
3.4223 at 5 microns |
|
| |
Reflection Loss |
|
51.0% at 5 µm (2 surfaces) |
|
| |
dn/dT |
|
160 x 10-6/K |
|
| |
dN/dµ = 0 |
|
10.4µm |
|
| |
Index of Absorption |
|
1 x 10-3 cm-1 at 3 microns |
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| PHYSICAL |
|
| |
Density |
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2.33 g/cm3 |
|
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Melting Point |
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1420° C |
|
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Thermal Conductivity |
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163.3 Wm-1K-1 at 273K |
|
| |
Thermal Expansion |
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4.15 x 10-6/°C |
|
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Hardness |
|
Knoop 1150 |
|
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Specific Heat Capacity |
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703 J/(kg K) |
|
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Dielectric Constant |
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13 at 10GHz |
|
| |
Young's Modulus (E) |
|
131 GPa |
|
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Shear Modulus (G) |
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79.9 GPa |
|
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Bulk Modulus (K) |
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102 GPa |
|
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Elastic Coefficients |
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C11=167 MPa, C12=65
MPa,
C44=80 MPa |
|
| |
Poisson Ratio |
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0.266 |
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| CHEMICAL |
|
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Solubility |
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Insoluble in water |
|
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Molecular Weight |
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28.09 |
|
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Class/Structure |
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Cubic diamond, Fd3m |
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REFRACTIVE INDEX of Silicon Si
| |
Wavelength, µm |
1.40 |
1.50 |
1.66 |
1.82 |
2.05 |
2.50 |
3.50-5.00 |
6.00-25.00 |
|
| |
Refractive Index |
3.49 |
3.48 |
3.47 |
3.46 |
3.45 |
3.44 |
3.43 |
3.42 |
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