Frequency upconversion of orange light into blue light in Pr3+-doped fluoroindate glasses

Fluoroindate glasses co-doped with Pr3+/Er3+ for near-infrared luminescence applications

Fluoroindate glasses co-doped with Pr³⁺/Er³⁺ ions were synthesized and their near-infrared luminescence properties have been examined under selective excitation wavelengths. For the Pr³⁺/Er³⁺ co-doped glass samples several radiative and nonradiative relaxation channels and their mechanisms are proposed under direct excitation of Pr³⁺ and/or Er³⁺. The energy transfer processes between Pr³⁺ and Er³⁺ ions in fluoroindate glasses were identified. In particular, broadband near-infrared luminescence (FWHM = 278 nm) associated to the ¹G₄ → ³H₅ (Pr³⁺), ¹D₂ → ¹G₄ (Pr³⁺) and ⁴I_13/2 → ⁴I_15/2 (Er³⁺) transitions of rare earth ions in fluoroindate glass is successfully observed under direct excitation at 483 nm. Near-infrared luminescence spectra and their decays for glass samples co-doped with Pr³⁺/Er³⁺ are compared to the experimental results obtained for fluoroindate glasses singly doped with rare earth ions.

Frequency upconversion in Pr3+-Li2O-TeO2 binary glass by decay curve analysis

Using the decay curve analysis frequency upconversion under continuous wave NIR laser radiation ( approximately 890 nm) following the non-resonant excitation at higher energies than 1G4 level has been reported. The decay curve of the antistokes emission (3P0-->3H4) shows similar behavior as that of the stokes emission (3P0-->3H4) and does not show any rise time attributing to the excited state antistokes absorption assisted by phonon emission. The covalency, bonding parameters and nephalauxetic effect for the present system has also been determined.

Statistical approaches to the transient populations and to the macroscopic energy transfer rate for the upconversion phenomenon in monodoped amorphous solid

In this article, statistical approaches to the first and the second excited state transient populations and to the temporal macroscopic energy transfer rate for the upconversion process in amorphous solid generic systems monodoped with trivalent lanthanide ions are reached. The plots of the expressions show general tendencies reported in the literature. The derivation and the analysis of the formalism allowed us to fulfill our main objective, that is, to make a theoretical study about the microscopic and statistical mechanisms present in the phenomenon and their relation with the classic kinetic analysis. The study shows that the inclusion of the minimum possible radius between two optical centers in a solid affects the initial slopes of the decay curves of the luminescence from the intermediate state. We also corroborate that the usual treatment of experimental data using direct equations for the dynamics of the populations in laser pulsed excitation experiments falls in the mistake of not considering the temporality of the macroscopic energy transfer rate. Finally, physical explanations are formulated about this temporal behavior and about the main factors that generate the characteristic simple exponential decay loss of the luminescence from the intermediate state.

Optical properties and upconversion in Pr3+ doped in aluminum, barium, calcium fluoride glass--I

The absorption and the fluorescence spectra of Pr3+ ion doped in aluminum, barium, calcium fluoride (ABCF) glass have been studied. Judd-Ofelt theory has been used to derive the optical parameters, viz. the oscillator strength, transition probability, branching ratio, stimulated emission cross section, etc. A broadband upconversion has been observed at different wavelengths throughout the visible region when pumped with 810 nm radiation from a Ti-sapphire laser.