optical window
optical window
Factory Custom K9 Optical Window Optical glass lens - Image 3

Factory Custom K9 Optical Window Optical glass lens

  • Material: BK7/K9, Sapphire, ZnSe, ZnS, Ge, Si, etc..
  • Dimension: 1.0mm-460mm
  • Thickness: 0.1mm-30mm
  • Surface Accuracy: lambda/20
  • Tolerance: +/-0.01mm
Category:

What is the K9 Optical window?

The K9 optical window is a transparent planar optical component made of high-quality K9 optical glass. It is widely used in various visible light and near-infrared optical systems.

It has excellent optical uniformity, high transmittance (from 350nm to 2000nm), low bubble and impurity content, as well as excellent processing performance. This material has a stable refractive index, a high Abbe number, and can effectively reduce chromatic aberration.

 BK7 and K9 are two common types of optical glass materials, which are widely used in optical components such as lenses, prisms, and window plates.

K9 is of the Chinese standard optical glass, while BK7 is the borosilicate glass of the German Schott brand. 

Specification about  the K9 optical window

 

Specification  

Data

 
Material K9 optical glass
Transmittance range 350 nm – 2000 nm(ultraviolet to near-infrared)
Density 2.51 g/cm³
Melting point 1400°C
Hardness (Mohs scale) ~5.5–6
Coefficient of thermal expansion 7.1 × 10⁻⁶ /K
Common surface quality 40-20 or higher

 

Advantages of the K9 Optical Window

  • High optical transparency:

Exhibits excellent transmittance within the wavelength range of 350nm to 2000nm, suitable for applications from ultraviolet to near-infrared.

  • Refractive index stability:

n_d ≈ 1.5168, reliable optical performance with low dispersion

  • Cost is moderate:

Compared to materials such as fused quartz, it has a more favorable price and offers high value for money. The K9 glass window is a common optical component.

  • Processability:

Suitable for cutting, grinding, polishing and coating processes

 

What is the material of optical window?

The selection of optical window materials is very diverse.

And the optical window materials include: calcium fluoride, barium fluoride, magnesium fluoride, lithium fluoride, germanium, silicon, zinc selenide, zinc sulfide, fused quartz, sapphire, and other materials.

Some common optical window materials include BK7 and K9.

N-BK7 and H-K9L are both borosilicate crown glasses. They share many similar characteristics.

However, N-bk7 was designed by Germany’s Schott. And H-K9L was produced by CDGM. It is a high-quality optical material.

 

Coatings of Optical Glass Windows

Optical windows can play a role in protecting the original structure in two physical environments.

Also, the coating on the window surface can increase the light transmittance. And common coatings include anti-reflective coating (AR) and scratch-resistant coating (AS).

Optical glass windows with coatings can enhance the light penetration ability and have the functions of waterproofing, dust-proofing and scratch-resistance.

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