Infrared Up-Conversion Emission Observed in Ho3+-Doped Potassium Lead Chloride

Abstract

In this work, we present the infrared emission properties of Ho³⁺ doped KPb₂Cl₅. Following optical excitation at 907nm, we observed several IR emission bands with center wavelengths at 1.064µm, 1.2µm, 1.33 µm, 1.67µm, 2.9µm and 3.9µm. While the 1.2µm, 1.67µm, 2.9µm and 3.9µm are from known energy transitions, the transitions leading to the 1.064µm and 1.33 µm emissions are not immediately obvious. Analysis of the transition mechanism suggests that these ‘unknown transitions’ are possible infrared up-conversion arising from excited state absorption.