H. H. Li. Refractive index of alkali halides and its wavelength and temperature derivatives. J. Phys. Chem. Ref. Data5, 329-528 (1976) and references therein. * Sellmeier formula is derived by critical analysis of experimental data from several sources.
Potassium iodide (KI) is a salt that is often used in the field of optics as an infrared-transparent material, particularly in the mid-IR range. With good transmission properties and low-cost production, it finds applications in windows and prisms for spectroscopic applications. KI is highly soluble in water and hygroscopic, making it sensitive to moisture and requiring stringent storage conditions. One notable drawback of KI is its relatively low mechanical strength, making it less ideal for applications requiring high durability. Nevertheless, its broad transmission range and high refractive index make it valuable for specific optical needs.