Transition probabilities of Er3+ ions in alumino-silicate glasses

Quantification of the resonant energy transfer processes in Er3+/Yb3+ co-doped Ca3Al2Si3O12 glasses

“…5, and Table 3, the fast component (τ 1 ) dominates the decay of the resonant manifolds. In the case of the most diluted sample, [Yb 3+ ] = 0.1 wt%, this time constant (τ 1 = 26 μs) is very close to the reported lifetime value for the 4 I 11/2 erbium manifold [25] (τ = 20 μs), indicating that, in diluted samples, in this temporal scale (t < 0.2 ms) the decay is governed by the spontaneous relaxation of 4 I 11/2 erbium level. A detailed inspection of the data reveals that also this fast component suffers a clear lengthening as the Yb 3+ concentration increases, suggesting that the time needed to activate the transfer processes depends on Yb 3+ concentration, being lower in samples with high Yb 3+ content.…”

“…As it is indicated in Fig. 1(b), considering the small energy gap between 4 I 9/2 and 4 I 11/2 erbium levels (ΔE ~ 2160 cm − 1 ) [25], the relaxation from the 4 I 9/2 level efficiently populates the 4 via multiphonon relaxation. In Er 3+ singly doped samples, the decay from this level is partially radiative to the ground state giving rise to the 4 I 11/2 → 4 I 15/2 emission band (λ emi ~ 1.0 μm) and partially non-radiative to the lower lying level 4 I 13/2 , from where the relaxation is basically radiative to the ground state, 4 I 13/2 → 4 I 15/2 transition (λ emi ~ 1.5 μm).…”

“…where P ij can be determined from the emission spectrum as the area of the i → j emission band (P ij ∝ ∫ I ij (λ) dλ). Taking into account the energy gap between the 2 F 5/2 and 2 F 7/2 ytterbium levels (ΔE ~ 10,000 cm − 1 ) and the gap law reported for Ca 3 Al 2 Si 3 O 12 glasses [25], it can be assumed that the multiphonon processes can be neglected in the relaxation of Yb 3+ ions; thus, A 2m = A 21 + W NR 21 ≈ A 21 . Under these conditions, eq.…”

Spectroscopy and Near-Infrared to Visible Upconversion of Er3+ Ions in Aluminosilicate Glasses Manufactured with Controlled Optical Transmission

“…The decay from the 4 I 13/2 level was found to behave like a perfect single exponential, whereas decays from 4 S 3/2 and 4 F 9/2 excited levels slightly deviated from a perfect exponential behavior. The observed lifetimes were in the same order of magnitude than those reported for other silicate and aluminosilicate glasses [10,11,32]. The fluorescence spectra at room temperature corresponding to the 4 I 13/2 → 4 I 15/2 transition were measured by exciting the samples at 802 nm.…”

“…In recent years rare-earth-doped glasses have been subject of intense research as host materials because of their significant optical properties, which make them adequate as infrared and upconversion lasers, optical amplifiers, and active photonic devices [1][2][3][4][5][6][7][8][9]. In particular, silicate and aluminosilicate glasses present excellent thermal and mechanical properties, and corrosion resistance to be used in practical applications [10][11][12][13][14][15][16][17]. In addition, their maximum phonon energy (~1050 cm −1 ) is much lower than that of phosphate and borate glasses,~1300 cm −1 and~1350 cm −1 , respectively, so that quantum efficiency is less influenced by multiphonon relaxation processes [16][17][18][19].…”