Sodium Chloride (NaCl) is commonly used for optical components in wide spectrum band from the ultraviolet to the infrared, since it is transparent over the entire range of wavelengths (about 0.25 µm to 16 µm).

Sodium Chloride can be used at temperatures up to 400 °C. The material is sensitive to thermal shock.

Sodium Chloride is hygroscopic and highly soluble in water. That's why it must be kept in a dry environment or protected against moisture degradation of polished surfaces. The material can be polished to a high standard under humidity controlled conditions.

Sodium Chloride is commonly used for optical windows, lenses, prisms and other optical items in the range from the ultraviolet to the infrared. It is one of the most useful materials for IR spectroscopic components and optical items for Fourier transform infrared (FTIR) spectroscopy. Due to its low absorption Sodium Chloride is mainly used in high power laser systems.