Thallium
Bromo-Chloride
- KRS-6
KRS-6 (Thallium Bromo-Chloride, TlBrCl) is a specialised infrared optical material valued for its excellent transmission in the mid-IR to far-IR range, typically from 0.4 µm to 25 µm. This broad spectral coverage makes KRS-6 ideal for FTIR spectroscopy, thermal imaging, environmental monitoring systems, and broadband IR optical components that require efficient performance across both atmospheric windows.
With a moderate refractive index (~2.37 in the mid-IR) and smooth dispersion characteristics, KRS-6 delivers stable imaging and high clarity across long wavelengths. It is also non-hygroscopic, offering significantly greater durability and handling convenience compared with hygroscopic materials such as NaCl and KBr — making it reliable in humid or variable laboratory and field conditions.
At Global Optics UK, we manufacture and supply high-precision KRS-6 windows, prisms, ATR elements, and infrared components, available uncoated or with advanced IR anti-reflective or protective coatings. Each optic is fabricated to strict surface quality and dimensional tolerance standards, ensuring consistent performance for spectroscopy, thermal detection, IR sensing, and broadband analytical systems where stability, wide transmission, and mechanical reliability are essential.
Explore Related Optical Materials:
KRS-5
Zinc Selenide (ZnSe)
Germanium (Ge)
FAQ
FAQ
Q: What is KRS-6 used for?
A: KRS-6 is widely used in mid-infrared and far-infrared optical systems due to its broad transmission range from ~0.4 µm to 25 µm. It is commonly used for windows, beamsplitters, IR sensing optics, environmental monitoring instruments, and spectroscopy systems that require stable, non-hygroscopic materials.
Q: What makes KRS-6 different from KRS-5?
A: KRS-6 (TlBr/TlCl) and KRS-5 (TlBr/TlI) are similar IR halides, but KRS-6 offers slightly lower refractive index, improved mechanical stability, and better environmental robustness. It is also less malleable than KRS-5, giving it improved durability for optical windows and long-term sealed systems.
Q: Is KRS-6 hygroscopic?
A: No. KRS-6 is non-hygroscopic, meaning it does not absorb moisture. This makes it more durable and easier to handle than IR salts like NaCl, KBr, or CsI, which degrade quickly in humid environments.
Q: What is the refractive index of KRS-6?
A: The refractive index is typically around n ≈ 2.2–2.3 across the mid-IR, depending on wavelength. Its low dispersion makes KRS-6 suitable for broadband imaging and spectroscopy.
Q: What is the transmission range of KRS-6?
A: KRS-6 transmits efficiently from 0.4 µm to approximately 25 µm, covering visible, mid-IR, and far-IR wavelengths. This wide spectral coverage makes it ideal for FTIR, gas analysis, and environmental sensing.
Q: How mechanically durable is KRS-6?
A: KRS-6 is softer than materials like germanium or sapphire, but it is more mechanically stable and less flexible than KRS-5. It withstands moderate pressure and temperature cycling and is suitable for mounted optical components.
Q: Is KRS-6 safe to use?
A: KRS-6 contains thallium compounds and should be handled with care, avoiding abrasion or ingestion of dust. In solid, polished optical form it is stable and safe to use when normal laboratory handling procedures are followed.
Q: Can KRS-6 be coated?
A: Yes. KRS-6 can be supplied with custom anti-reflective (AR) coatings to improve transmission in specific IR bands. Protective coatings may also be applied to increase surface hardness.
Q: Where can I download the KRS-6 datasheet?
A: You can download the full KRS-6 Technical Datasheet here