Silicon window has good thermal conductivity and low density, except as a slice of silicon window can also be made into silicon laser reflector, silicon lens, silicon flat convex lens, silicon double convex lens, silicon, silicon plane concave lens wedge Angle of window film, silicon films such as laser window, a variety of laser equipment and industrial applications, used in the infrared wavelengths of high precision instruments.
Silicon window plates are commonly used in the 1.2-8 muon near-infrared spectrum.
Silicon substrate density is small, the density of germanium material or zinc selenide material half, the weight is relatively light, silicon optical elements than germanium hardness is higher, commonly used in 3-5um band applications or 3-5 muon coating after anti-reflection film.
Silicon (Si) single crystals are commonly used as substrates for medium wave infrared optical Windows and optical filters of 3 to 5 microns. Due to their good thermal conductivity and low density, they are also commonly used for making laser reflectors or infrared temperature measurement and infrared optical lenses.
|Commercial Grade||Precision Grade||High Precision Grade|
|Parallelism||<3 arc min||<30 arc sec.||<2 arc sec.|
|BRD-GW-10 X1||10||1|| AR Coating@3-5um|
As a kind of nonmetallic element, Silicon is broadly used in semiconductor and optics. In semiconductor, Si is usually grown by Czachralski method and Float-zone process. Generally, the resistivity of Si grown by Czachralsik method(< 10 ohm/cm) is lower than that by Float-zone process(>10 ohm/cm). Besides, it can also be classified into N type(with Phos doped) and P type (with Boron doped) according to the conductivity. In infrared optics, we commonly use Float-zone(FZ) silicon which is much pure for the purpose of better transmittance. It is the most economical element for optics compared to Ge and other infrared materials like ZnSe, ZnS, etc. From fig. 1, we can see that the transmittance is generally the same between 3-8 um and arrives at the bottom at 9 um. With AR coatings, the transmittance can reach 95% and higher from Fig 2.
Melting point (℃)
Permittivity Static/high frame
Coefficient of thermal expansion (1/℃)
Elastic Modulus (Gpa)
Shear modulus of elasticity (Gpa)
Coefficient of thermal conductivity (J/k.m.s)
Specific heat capacity (J/g.k)
Young's modulus (Gpa)
C11=167 C11=65 C11=80
The range of transmission wavelength
The absorption coefficient (1/cm)
1.6 x 10--4
1.6 x 10-3@3000nm