The 10.6-μm absorption of KCl

Abstract
The 10.6‐μm absorption in most KCl is shown to be dominated by a broad absorption band near 9.7 μm. The integrated absorption of this band decreases with increasing temperature. The temperature dependence is consistent with that to be expected from the dissociation of an absorbing pair. A KCl crystal has been measured whose 10.6‐μm absorption, 6.6±2×10−5 cm−1, is at the intrinsic multiphonon level.