Effect of glass composition on Judd–Ofelt parameters and radiative decay rates of Er3+ in fluoride phosphate and phosphate glasses

Abstract We present a fluorescent emitter (rhodamine B) coupled to a dielectric or metallic interface as well as a metallic cavity to study their radiative decay processes. Supported by finite-difference time-domain (FDTD) simulations, we correlate the non-radiative and radiative decay rates with the absorption and scattering cross section efficiencies, respectively. On a single particle level, we use atomic force microscopy (AFM), scanning electron microscopy (SEM), scattering spectroscopy, fluorescence life time imaging (FLIM) and time-correlated single photon counting (TCSPC) to evaluate the enhanced fluorescence decay at the same location. With this study, we show a colloidal gain material, which can be integrated into lattices using existing directed self-assembled methods to study their coherent energy transfer.

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Role of the La/K Compositional Ratio in the Properties of Waveguides Written by Fs-Laser Induced Element Redistribution in Phosphate-Based Glasses

Materials ◽

10.3390/ma13061275 ◽

2020 ◽

Vol 13 (6) ◽

pp. 1275 ◽

Cited By ~ 1

Author(s):

Pedro Moreno-Zarate ◽

Francisco Muñoz ◽

Belen Sotillo ◽

Manuel Macias-Montero ◽

Julia Atienzar ◽

...

Keyword(s):

Refractive Index ◽

Glass Composition ◽

Near Field ◽

Phosphate Glasses ◽

Femtosecond Laser Irradiation ◽

Local Modification ◽

Fs Laser ◽

Index Contrast ◽

Element Redistribution ◽

Local Enrichment

The local modification of the composition of glasses by high repetition femtosecond laser irradiation is an attractive method for producing photonic devices. Recently, the successful production of waveguides with a refractive index contrast (Δn) above 10−2 by fs-laser writing has been demonstrated in phosphate glasses containing La2O3 and K2O modifiers. This large index contrast has been related to a local enrichment in lanthanum in the light guiding region accompanied by a depletion in potassium. In this work, we have studied the influence of the initial glass composition on the performance of waveguides that are produced by fs-laser induced element redistribution (FLIER) in phosphate-based samples with different La and K concentrations. We have analyzed the contribution to the electronic polarizability of the different glass constituents based on refractive index measurements of the untreated samples, and used it to estimate the expected index contrast caused by the experimentally measured local compositional changes in laser written guiding structures. These estimated values have been compared to experimental ones that are derived from near field images of the guided modes with an excellent agreement. Therefore, we have developed a method to estimate before-hand the expected index contrast in fs-laser written waveguides via FLIER for a given glass composition. The obtained results stress the importance of considering the contribution to the polarizability of all the moving species when computing the expected refractive index changes that are caused by FLIER processes.

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Effect of the Substitution Position on the Electronic and Solvatochromic Properties of Isocyanoaminonaphthalene (ICAN) Fluorophores

Molecules ◽

10.3390/molecules24132434 ◽

2019 ◽

Vol 24 (13) ◽

pp. 2434 ◽

Cited By ~ 2

Author(s):

Sándor Lajos Kovács ◽

Miklós Nagy ◽

Péter Pál Fehér ◽

Miklós Zsuga ◽

Sándor Kéki

Keyword(s):

Radiative Decay ◽

Fluorescence Emission ◽

Solvent Polarity ◽

Decay Rates ◽

Quantum Yields ◽

Time Resolved Fluorescence ◽

Solvatochromic Shift ◽

Fluorescence Emission Spectra ◽

Time Resolved ◽

Donor And Acceptor

The properties of 1,4-isocyanoaminonaphthalene (1,4-ICAN) and 2,6-isocyanoaminonaphthalene (2,6-ICAN) isomers are discussed in comparison with those of 1,5-isocyanoaminonaphthalene (1,5-ICAN), which exhibits a large positive solvatochromic shift similar to that of Prodan. In these isocyanoaminonaphthalene derivatives, the isocyano and the amine group serve as the donor and acceptor moieties, respectively. It was found that the positions of the donor and the acceptor groups in these naphthalene derivatives greatly influence the Stokes and solvatochromic shifts, which decrease in the following order: 1,5-ICAN > 2,6-ICAN > 1,4-ICAN. According to high-level quantum chemical calculations, this order is well correlated with the charge transfer character of these compounds upon excitation. Furthermore, unlike 1,5-ICAN, the 1,4-ICAN and 2,6-ICAN isomers showed relatively high quantum yields in water, that were determined to be 0.62 and 0.21, respectively. In addition, time-resolved fluorescence experiments revealed that both the radiative and non-radiative decay rates for these three ICAN isomers varied unusually with the solvent polarity parameter ET(30). The explanations of the influence of the solvent polarity on the resulting steady-state and time-resolved fluorescence emission spectra are also discussed.

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Parametric Calculations of Radiative Decay Rates for Magnetic Dipole and Electric Quadrupole Transitions in Tm IV, Yb V, and Er IV

Atoms ◽

10.3390/atoms6030052 ◽

2018 ◽

Vol 6 (3) ◽

pp. 52

Author(s):

Wan-Ü Tchang-Brillet ◽

Jean-François Wyart ◽

Ali Meftah ◽

Sofiane Ait Mammar

Keyword(s):

Magnetic Dipole ◽

Radiative Decay ◽

Transition Probabilities ◽

Energy Levels ◽

Electric Quadrupole ◽

Decay Rates ◽

Line Intensities ◽

Parametric Studies ◽

On Line ◽

Semi Empirical

Semi-empirical transition probabilities for magnetic dipole (M1) and electric quadrupole (E2) emission lines have been derived from parametric studies of experimental energy levels in Tm3+ (Tm IV), Yb4+ (Yb V), and Er3+ (Er IV), using Cowan codes. Results are compared with those existing from ab initio calculations or from more sophisticated semi-empirical calculations. Satisfactory agreements show that simple parametric calculations can provide good predictions on line intensities, provided that experimental levels are available, allowing reliable fits of energy parameters.

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