Normalized-lifetime thermal-lens method for the determination of luminescence quantum efficiency and thermo-optical coefficients: Application toNd3+-doped glasses

Abstract

We present a new method based on thermal lens ͑TL͒ technique to determine the fluorescence quantum efficiency, , and thermo-optical coefficients of fluorescent materials. These parameters can be obtained from the linear dependence of the TL signal with the experimental lifetimes of a set of samples with different luminescent ion concentrations. The method was applied in Nd 3+ -doped materials ͑Q-98 Phosphate, fluorozirconate, and fluoroindate͒. The obtained values are in agreement with those determined by other approaches based on TL methods and the ratio between experimental and radiative lifetime values ͑Judd-Ofelt theory͒. The method hereafter presented is very simple and does not require comparison with a reference sample or the use of multiple excitation wavelengths. In addition, the nature of concentration quenching taking into account the achieved and values and respective energy transfer microparameters, is discussed.

Effect of annealing and Nd concentration on the photoluminescence of Nd3+ ions coupled with silicon nanoparticles

“…8͒ as reported in glass matrices. 39,40 This is supported by the existence of Nd 2 O 3 nanocrystals in the FIG. 7.…”

Luminescent and thermo-optical properties of Nd3+-doped yttrium aluminoborate laser glasses

“…19 The fluorescence quenching effect is mainly due to ion-ion energy transfer processes involving nonradiative paths and is favored for high ionic concentrations. 28,29 This effect, less pronounced for Nd:YAlB glasses than for other borate glasses, might be attributed to some extent of substitution of Nd 3+ by Y 3+ preventing the Nd 3+ cluster formation. 17 For YAB crystal, low contents of rare-earth ions can be incorporated in Y 3+ sites without causing any distortion, but as the concentration is raised, increasing disorder leads to an emission band broadening ͑ϳ40 nm͒ and to a redshift of the emission peak from 1064 to 1062 nm.…”

“…In this sense, it is important to note that a main common feature of Nd 3+ doped materials, independently of the excitation wavelength, is that all emission bands originate from the 4 F 3/2 metastable state. 28 In other words, the relationship between ͓see Eq. ͑1͔͒ and has a simple form, 29 being given by =1 − ͗ em ͘ exc −1 , where ͗h em ͘ and h exc are the average emission and excitation energies, respectively.…”

Recent advances in lanthanide spectroscopy in Brazil

“…Jacinto et al [148] have reported a relatively simple method to determine emission quantum efficiency (η) and thermo-optical coefficients. This method does not require a direct comparison between the luminescence properties of reference and sample and is based on the normalized-lifetime thermal lens (TL) technique.…”