|Materials||Silicon crystals||Diameter Range||~ 300mm|
|Thickness Tolerance||+/-0.1mm||Surface Quality||60/40 S/D|
|Parallelism||1 arc minute||Chamfer||0.3-0.5mmx45degree|
|Coating||AR/AR or DLC/AR|
|Transmission Range||1.2 to 15 μm||Refractive Index||3.4223 @ 5 μm (1) (2)|
|Reflection Loss||46.2% at 5 μm (2 surfaces)||Absorption Coefficient||0.01 cm-1 at 3 μm|
|Reststrahlen Peak||n/a||dn/dT||160 x 10-6 /°C (3)|
|dn/dμ = 0||10.4 μm||Density||2.33 g/cc|
|Melting Point||1420 °C||Thermal Conductivity||163.3 W m-1 K-1 at 273 K|
|Thermal Expansion||2.6 x 10-6 / at 20°C||Hardness||Knoop 1150|
|Specific Heat Capacity||703 J Kg-1 K-1||Dielectric Constant||13 at 10 GHz|
|Youngs Modulus (E)||131 GPa (4)||Shear Modulus (G)||79.9 GPa (4)|
|Bulk Modulus (K)||102 GPa||Elastic Coefficients||C11=167; C12=65; C44=80 (4)|
|Apparent Elastic Limit||124.1MPa (18000 psi)||Poisson Ratio||0.266 (4)|
|Solubility||Insoluble in Water||Molecular Weight||28.09|
|Class/Structure||Cubic diamond, Fd3m|
Hangzhou Shalom EO offers Silicon (Si) Windows made from optical grade silicon ( Czochralski or Float Zone Silicon) for IR applications. The wide transmission of silicon spans from NIR to LWIR. Due to their low thermal conductivity, Si windows perform greatly in laser systems. Additionally, with its low density (2.329 g/cm3, half that of Ge or ZnSe), silicon is ideal for weight-sensitive The Knoop Hardness of silicon is 1150, in fact, it is one of the hardest optical materials which are transparent to lights in the 1000-6000nm region.
The silicon crystal grown using the Czochralski method is particularly excellent for applications in MWIR (3-5μm) spectrum. After furnishing AR coating optimized for the wavelength range, the reflection of CZ silicon windows could be extremely low. However, CZ silicon has a strong absorption band at 9μm. During the production process, Float Zone silicon is deliberately doped with Nitrogen and purified to reduce its carbon and oxygen composition, attenuating the absorption at 9μm, therefore FZ silicon windows could be used in the LWIR (8-12μm) range.
In Shalom EO Silicon Windows are available in various custom dimensions, with a maximum diameter of 300mm. Coating options include DLC/AR coating and AR/AR coating.
1. Transmission curve of the Silicon windows (no coating)
2. Transmission curve of the Silicon windows with AR/AR coating at 3-5μm
3. Transmission of 0.5mm thickness FZ silicon windows without AR coating
4. Transmission of 0.5mm thickness FZ silicon windows with AR coating optimized at 8-12 micro