Silicon (Si) Windows

Maximum diameter 300mm
Window made of Czochralski or Float Zone Silicon
Transmission range 1.2-15μm
CZ silicon for MWIR (3-5μm) and FZ silicon for LWIR (8-12μm) applications
Coating options: DLC coating, AR coating
Low density for lightweight design, mechanical ruggedness, and Low cost

Curves All Inquire Us

Specifications:

Materials	Silicon crystals	Diameter Range	~ 300mm
Aperture	>90%	Dimension Tolerance	+0.0/-0.2mm
Thickness Tolerance	+/-0.1mm	Surface Quality	60/40 S/D
Parallelism	1 arc minute	Chamfer	0.3-0.5mmx45 degree
Coating	AR/AR or DLC/AR

Material Properties:

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. Silicon windows exhibit good transmission properties in the IR spectrum, in particular in the MWIR and LWIR spectral regions. Due to their high thermal conductivity, Si windows perform great for lasers. In addition, with its low density (2.329 g/cm3, half that of Ge or ZnSe), silicon is conducive to realizing weight-sensitive designs. Silicon features chemical/abrasion resistance, making silicon windows durable and suitable for use in challenging environments ((in fact, it is the hardest material that is transparent to 1000-1600nm light).

The silicon crystal grown using the Czochralski method is excellent for applications in the MWIR (3-5μm) spectrum. After depositing AR coating optimized for the wavelength range, the reflection of CZ silicon windows could be miniature. However, CZ silicon has a strong absorption band at 9μm. Whilst during the production process, Float Zone silicon is 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.

Shalom EO offers custom Silicon Windows. The Si windows are available in various custom dimensions, with a maximum diameter of 300mm. Coating options include DLC/AR coating and AR/AR coating.

Curves:

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