Comparison of the emission properties of Ho³⁺ :KPb<sub>2 Cl ₅and Ho³⁺ :caf ₂ Crystals

Abstract

Most laser gain media are characterized by emission quenching in the mid-IR wavelength region as a result of the high phonon structure of such media. The need for  more emission in the mid-IR region has made the development of low phonon hosts a major research interest. In this work, we compared the infrared emission
 properties of Ho³⁺ doped low phonon halides (KPb_{2 Cl 5 ) with those of their fluoride counterparts. Results show 2 5 that mid-IR emission wavelengths that appeared in the  halide hosts were effectively quenched in the fluorides. Furthermore, the emission lifetimes of the halides did not vary significantly with temperature,  indicating that they  were not susceptible to much non-radiative decay as it was found in high phonon crystals.}

Keywords: Lasers, Fluorescence, Lifetime, Multi-phonon Relaxation, Radiative Decay, Mid-IR Emission Quenching.