Determination of the origin of the 10.6-μm absorption in CO2 laser window materials

Theoretical studies are presented which show that it should be possible to determine whether the absorption at 10. 6 μm in alkali halides is due to impurities or whether it is intrinsic. These studies show that the temperature dependence of the measured absorption should be very different for intrinsic multiphonon absorption as compared with defect-activated absorption.