Intensity‐dependent upconversion efficiencies of Er3+ions in heavy‐metal fluoride glass

摘要: The upconversion of infrared radiation to shorter wavelengths by Er3+ ions in heavy‐metal fluoride glasses, some doped with Yb3+, has been studied over a wide intensity range and for various excitation wavelengths. efficiency measured at room temperature varies linearly or quadratically saturates 100 W/cm2 higher, depending on emission wavelength. For 4 mol % ErF3 BaF2/ThF4, the 4I11/2 4I15/2 transition is 10% efficient 400 absorbed 1.5‐μm power, i.e., 4I13/2 excitation. A rate equation model Judd–Ofelt analysis data glasses just provide an understanding process while yielding values energy‐transfer rates excited‐state populations. These results could be used develop lasing as optical detectors.The detectors.