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ALKOR Technologies - your CRYSTAL optics supplier.
Materials>>KCl windows

POTASSIUM CHLORIDE (KCl): KCl windows, KCl lenses

Alkor Technologies manufactures KCl optical elements: KCl windows, Drilled KCl windows, KCl wedges according to customer's specifications. The largest dimensions of KCl optics: Diameter 120 mm x 30 mm Thk.

Potassium Chloride is mainly used for CO2 laser protection windows as an inexpensive disposable material with a low refractive index.

Please send us your specifications and we will quote it within 24hrs.

KCl windows

KCl transmission

KCl transmittance. Sample thickness 10mm.

Potassium Chloride is used for infrared windows, lenses and prisms when transmission in the range 0.3-20µm is desired (transmission extends beyond that of Sodium Chloride).

Potassium Chloride is soluble in water and polished surfaces of KCl windows must be protected from moisture. KCl windows can be used at temperatures up to 400°C.

KCl properties

Chemical Formula KCl
Crystal Class Cubic
Lattice Constant, Å 6.29
Molecular Weight 74.55
Density, g/cm3 (20 °C) 1.98
Reflection Loss, % for two surfaces at 10 µm 6.8
Dielectric Constant for 106 Hz at 302 K 4.64
Melting Temperature, K 1050
Thermal Conductivity, W/(m K) at 315 K 6.7
Thermal Expansion, 1/K at 300 K 36.6 x 10-6
Specific Heat, cal/(g K) at 273 K 0.162
Debye Temperature, K 235
Bandgap, eV 8.5
Solubility, g/100 g H2O at 293 K 34.7
Knoop Hardness, kg/mm2 7.2[110], 9.3[100]
Young's Modulus, GPa 29.63
Rupture Modulus, GPa 0.0044
Shear Modulus, GPa 6.24
Bulk Modulus, GPa 17.36

KCl - Refractive index

µm No µm No µm No
0.185 1.8271 0.200 1.7187 0.251 1.5897
0.308 1.54136 0.410 1.50907 0.509 1.4962
0.671 1.48669 0.883 1.48142 0.982 1.4800
1.179 1.47831 2.357 1.47475 2.947 1.47383
3.536 1.47305 4.715 1.47112 5.000 1.47048
6.000 1.46842 7.000 1.466 8.000 1.4629
9.000 1.46002 10.00 1.45644 11.00 1.45244
12.00 1.44801 13.00 1.44313 14.00 1.43779
15.00 1.43197 16.00 1.42563 17.00 1.41877
18.00 1.41134 19.00 1.40333 20.00 1.39469
21.00 1.38538 22.00 1.37537 23.00 1.36461
24.00 1.35303 25.00 1.34059 26.00 1.32721
27.00 1.31281 28.00 1.29731