Temperature and concentration quenching of mid-IR photoluminescence in iron doped ZnSe and ZnS laser crystals

Concentration dependences of the mid-IR kinetic of luminescence at 5E↔5T2 transition in Fe:ZnSe and Fe:ZnS laser samples were studied in 14–300 K temperature ranges. Radiation lifetime in Fe:ZnSe samples measured using low doped samples with iron concentration 0.1×1018 cm−3 was estimated to be 57 μs. The magnetic susceptibility for higher doped (CFe=38 and 112×1018 cm−3) Fe:ZnSe samples was found to consist of a paramagnetic Curie–Weiss behavior arising from the weakly interacting Fe2+ ions and a diamagnetic ZnSe contribution plus a temperature-independent, field-dependent contribution possibly arising from very small amounts of aggregated Fe.