Potassium Bromide (KBr)
Hygroscopic crystal with wide infrared transmission
IR Transmission Crystal
Potassium Bromide is a widely used infrared transmission material, particularly in FTIR spectroscopy. It offers broad mid-IR transmission and is commonly used for windows, prisms, and sample pellets. KBr is hygroscopic and must be protected from moisture, limiting its use to controlled laboratory environments.
Is this material right for your application?
Use When:
Avoid When:
Consider Alternatives:
Broad mid-IR transmission is required
FTIR spectroscopy is the primary application
Sample windows or pellets are used
Cost-effective IR materials are acceptable
The environment is dry and controlled
Moist or humid environments are present
Mechanical handling is frequent
Outdoor or exposed systems are involved
Long-term durability without encapsulation is required
Potassium Chloride (KCl) – slightly improved durability
Sodium Chloride (NaCl) – lower cost for basic IR work
ZnSe – non-hygroscopic IR optics
Key Properties
Optical
Broad mid-infrared transmission
Low refractive index
Mechanical
Soft and easily cleaved
Environmental
Highly hygroscopic
Laboratory-only suitability
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Frequently asked questions about Barium Fluoride specifications and use-cases
FAQ
Q1. What wavelength range does KBr support?
KBr transmits from ~250 nm to ~25 µm.
Q2. Is KBr hygroscopic?
Yes. KBr is highly hygroscopic.
Q3. Where is KBr commonly used?
FTIR spectroscopy windows and pellets.
Q4. What are common alternatives to KBr?
NaCl and CsI.
Extremely moisture sensitive
Soft and easily damaged
Best for controlled laboratory environments