Custom Potassium Chloride
Potassium chloride (KCl) is a crystalline material that is often used as a sputter window in CO2 lasers. It’s wide transmission band means it also has optical applications in the UV, visible, mid-wave and far-IR regions.
Below is a brief summary of potassium chloride’s optical properties, a full data sheet is available here.
Transmission range |
0.21 to 20µm |
Refractive Index |
1.45644 @ 10µm |
Density |
1.99 g/cm3 |
Melting Point |
776°C |
Hardness |
Knoop 7.2 <110>, 9.3 <100> with 200g indenter |
Knight Optical can supply a variety of potassium chloride optical components including windows and ground blanks. We can also provide uncoated and coated optics, with broadband antireflective (BBAR) coatings. Our typical manufacturing specifications are listed below, however we are always expanding our capabilities so if your requirements are not mentioned below please contact our technical sales team who will guide you through your enquiry.
Diameter |
< 5mm to 80mm |
Form error (@633nm) |
< 0.25 waves |
Centration /parallelism |
< 1 arc minute |
Scratch/dig |
< 40/20 |
Typical coatings |
BBAR @ 1-20µm DLC @ 1-20µm |
With our in-house state-of-the-art metrology laboratory you can be confident that your optical components will meet your requirements. You can find out more about our testing facilities here.
Additional Information
- Potassium chloride is grown via the Kyropoulos method , and cleaves easily.
- It is slightly more durable than potassium bromide but its transmission does not extend as far in the IR region.
Considerations
- KCl is extremely soft so care needs to be taken when handling. It is also very hygroscopic so needs to be kept in a moisture-free environment., or a protective coating should be applied to the exposed surface.
Typical Applications
Laser windows
- KCl is often used as a disposable protective window in CO2 laser systems due to its low refractive index, low absorption, and high damage threshold.
Our 2022/2023 Catalogue
Inside Knight Optical’s catalogue you’ll find details of the industries we serve as well as the many other services we can offer. It also showcases hundreds of our most popular products, supported by useful technical information, to help you choose the right part for your application.
Click below to view our digital catalogue now.