Broadband Infrared Crystal
Potassium Chloride (KCl)
Broad UV-to-IR transmission for FTIR and CO₂ laser window applications
Potassium Chloride (KCl) is a soft, synthetic alkali-halide crystal with broad optical transmission from the ultraviolet into the long-wave infrared. It is used for FTIR spectroscopy, infrared windows and CO₂ laser window applications where a wide spectral range is required. KCl is highly water soluble, so dry storage, careful handling and environmental protection are essential.
Is this material right for your application?
Use When:
Infrared transmission is required with slightly better durability than KBr
FTIR windows or prisms are used
Mechanical handling requirements are moderate
Laboratory conditions are dry
A balance between performance and cost is needed
Avoid When:
High humidity or moisture exposure is unavoidable
Mechanical robustness is critical
Extended outdoor operation is required
Consider Alternatives:
Potassium Bromide (KBr) – broader IR transmission
Sodium Chloride (NaCl) – cost-effective IR spectroscopy
ZnSe – durable IR windows for exposed systems
Explore Related Optical Materials
Sodium Chloride (NaCl)
Potassium Bromide (KBr)
Caesium Iodide (CsI)
Material specifications and frequently asked questions
FAQ
Q1. What wavelength range does KCl support?
A representative 2 mm KCl specimen transmits approximately from 0.18 to 25 µm.
Q2. Is KCl moisture-sensitive?
Yes. KCl is highly water soluble and requires dry handling and storage.
Q3. Where is KCl commonly used?
KCl is used for FTIR optics, infrared windows and CO₂ laser windows in controlled environments.
Q4. What are common alternatives to KCl?
KBr, NaCl and more durable IR materials can be considered depending on the wavelength and environment.
Softer than oxide glasses
Limited industrial durability
Suitable for dry environments only