Potassium Bromide
- KBr
Potassium Bromide (KBr) is a widely used infrared optical material valued for its broad mid-IR transmission, smooth refractive characteristics, and suitability for spectroscopic applications. KBr transmits from approximately 0.25 µm to 25 µm, covering the UV, visible, mid-IR, and far-infrared regions. This wide spectral range makes KBr ideal for FTIR windows, beamsplitters, prisms, gas-analysis systems, and other analytical instruments requiring deep mid-IR coverage.
KBr offers a low refractive index (~1.53 at 10 µm) and low dispersion, enabling high-quality infrared imaging and excellent compatibility with broadband IR systems. However, as a strongly hygroscopic material, KBr readily absorbs moisture and must be stored and operated in controlled low-humidity environments. Despite this limitation, its optical clarity and wide IR range make it a preferred material for laboratory spectroscopy, chemical analysis, and IR transmission studies.
At Global Optics UK, we manufacture and supply precision KBr windows, prisms, IR plates, and spectroscopy components, available uncoated or with protective coatings to reduce moisture sensitivity. Each optic is produced to strict surface-quality and dimensional tolerances, ensuring reliable performance in FTIR systems, gas-cell optics, mid-to-far IR detectors, and any application requiring broad-spectrum IR transmission and excellent optical uniformity.
Explore Related Optical Materials:
Potassium Chloride (KCl)
Cesium Iodide (Csl)
Barium Fluoride (BaF2)
FAQ
FAQ
Q: What is Potassium Bromide (KBr) used for?
A: KBr is widely used in FTIR spectroscopy, gas-analysis cells, environmental monitoring systems, and mid- to far-IR optics thanks to its very broad transmission range of ~0.25–25 µm.
Q: What makes KBr different from other infrared materials?
A: KBr offers exceptionally broad mid- and far-IR transparency with a low refractive index (~1.53). However, unlike non-hygroscopic materials, it is highly moisture-sensitive and must be stored and handled in dry conditions.
Q: Is Potassium Bromide hygroscopic?
A: Yes. KBr is strongly hygroscopic, meaning it rapidly absorbs moisture and requires sealed storage, desiccated environments, or protective window assemblies.
Q: Is KBr suitable for FTIR and analytical spectroscopy?
A: Absolutely. KBr is one of the most common materials for FTIR windows, beamsplitters, and gas-cell optics due to its broad and smooth transmission across the 2–25 µm region.
Q: What types of optical components can be made from KBr?
A: KBr is typically used for FTIR windows, prisms, plates, beamsplitters, and gas-cell components, particularly in analytical and environmental spectroscopy.
Q: How durable is Potassium Bromide?
A: Optically, KBr performs extremely well, but mechanically it is soft, easily scratched, and moisture-sensitive. It is usually used in protected assemblies or with careful laboratory handling.
Q: Can KBr optics be coated?
A: Yes — KBr windows can be supplied with specialised protective coatings or used in sealed/desiccated housings to improve durability and reduce moisture exposure.
Q: Is KBr safe to handle?
A: Yes, KBr is non-toxic, but it must be handled in dry conditions and protected from moisture to prevent degradation of the optical surfaces.
Q: Where can I obtain technical data for KBr?
A: Full technical specifications, datasheets, and material graphs for Potassium Bromide are available here.