Thallium Bromoiodide (KRS-5)

Thallium Bromoiodide is widely used for optics when transmission to about 40µm is desired. KRS-5 is relatively insoluble in water and may be used in cells in contact with aqueous solutions.

KRS-5 is superior to the simple Bromide and Iodide Salts in that it is much harder. The top operating temperature is 200°C. The material does not cleave but will flow under pressure. The softness of the material limits the optical figure and surface quality that can be achieved in fabrication.

Property Specification
Transmission Range 0.6µm to 40µm
Density 7.371 gm/cc
Thermal Expansion 58 x 10-6 /°C
Surface Finish Generally a low scatter polish for the infrared (80-50 scratch-dig).
AR Coating Options Moisture Protection (specify wavelength of use).
Typical Applications Attenuated total reflection prisms, IR windows & lenses.
Products Manufactured Windows, Lenses, Wedges, Prism, Aspheric Lenses, Beamsplitters.

 

Wavelength (µm)
Index of Refraction (n)
2.0
2.395

4.0
2.382
6.0
2.378
8.0
2.375
10.0
2.371
12.0
2.366
14.0
2.364
16.0
2.355
20.0
2.341
22.0
2.332
24.0
2.323
26.0
2.312
28.0
2.301
30.0
2.289
32.0
2.275