Torr recently manufactured a bonded KRS-5 viewport for one of our customers.
KRS-5 is the short name for thallium bromo-iodide (TlBr42I58), it is one of the family of thallium halides. The KRS prefix is an abbreviation of “Kristalle aus dem Schmelz-fluss”, (crystals from the melt), it is a more commonly used material compared to KRS-6. Transmission starts around 580nm and extends to 40µm so it performs well as a deep IR material. It is widely used in spectroscopy to manufacture attenuated total reflection (ATR) prisms, windows, and lenses. It performs better than ZnSe at the longer wavelengths as ZnSe does not transmit past around 20µm. As it is non-hygroscopic it makes it a good alternative to materials like KBr, CsI, & AgCl. KRS-5 is poisonous, so great care must be taken when handling the material, it is harmful when in contact with the skin and can be fatal if ingested.
If you’d like more information about KRS-5 vacuum viewports or another other optical material, please contact us at email@example.com