Dynamics of Tm–Ho energy transfer and deactivation of the F43 low level of thulium in fluorozirconate glasses

Abstract

The mechanism involved in the Tm 3ϩ ( 3 F 4 )→Ho 3ϩ ( 5 I 7 ) energy transfer and Tm 3ϩ ( 3 H 4 , 3 H 6 ) →Tm 3ϩ ( 3 F 4 , 3 F 4 ) cross relaxation as a function of the donor and acceptor concentrations was investigated in Tm-Ho-codoped fluorozirconate glasses. The experimental transfer rates were determined for the Tm→Ho energy transfer from the best fit of the acceptor luminescence decay using an expression which takes into account the Inokuti-Hirayama model and localized donor-to-acceptor interaction solution. The original acceptor solution derived from the InokutiHirayama model fits well the acceptor luminescence transient only for low-concentrated systems. The results showed that a fast excitation diffusion that occurs in a very short time (tӶ␥ Ϫ2 ) reduces the mean distance between an excited donor (D*) and the acceptor ͑A͒. A localized donor-to-acceptor interaction takes place, leading to an exponential decay of donors as an average of the microscopic rate equation solution of each D* -A pair separated by distance R that contributes in addition to the Inokuti-Hirayama solution. The observation that the experimental transfer rates were always much bigger than the one predicted by the diffusion model, in which the energy transfer process is assisted by excitation migration among donors state, reinforces the existence of a fast excitation diffusion among donor ions before the energy transfer to acceptor already observed in Yb:Er:ZBLAN. The fast excitation diffusion effect was observed to dominate both the Tm→Tm cross relaxation and Tm→Ho energy transfer ions from 3 H 4 and 3 F 4 thulium states, respectively.

Multicolor upconversion luminescence from RE3+-Yb3+ (RE=Er, Tm, Tb) codoped LaAlGe2O7 glasses

“…The LAG glass has relatively high T g and T x which shows the good thermal stability of the host glass. The high density and index of refraction are also consistent with other heavy metal oxide glasses [15][16][17][18]. The absorption and Fourier transform infrared spectra of blank LAG glass are shown in Fig.…”

Tm and Tm–Tb-doped germanate glasses for S-band amplifiers

“…This result is in agreement to what has been reported about the luminescence effects on the 3 F 4 state decay of Tm 3+ in (Tm:Ho) tellurite [5] and (Tm:Tb) chalcogenide [6] glasses, respectively. On the other hand, a residual luminescence from 3 F 4 excited state, corresponding to 25% of the Tm 3+ excited ions, remaining with the intrinsic lifetime of $8.9 ms in Tm(0.5 mol%):Ho(0.5 or 1 mol%):ZBLAN glass, has been observed [3]. C DA constant equal to 2.1 Â 10 À39 cm 6 s À1 was obtained for the Tm 3+ ( 3 F 4 )-Tb 3+ ( 7 F 0,1,2 ) energy transfer using the experimental value of g ¼ (52.5-10.8) ¼ 41.7 s À1/2 shown in Table 2 considering C A ¼ 0.2 mol%.…”

“…Because the energies of 5 I 7 and 7 F 0,1,2 levels of Ho 3+ and Tb 3+ , respectively, coincide with the energy of the 3 F 4 level, holmium and terbium ions may actuate as deactivator of the 3 F 4 lowest excited state of Tm 3+ to improve the population inversion of Tm 3+ ions in many luminescent solid materials. Besides the 3 H 4 and 3 F 4 fluorescence decay effects of Tm 3+ caused by Tb 3+ ions have been investigated in fluoroindate [2] and more recently in chalcogenide glass containing CsBr [6], a detailed investigation of the mechanisms of 3 set of rate equations, which can describe the system behavior under continuous pumping of the 3 H 4 state. In this work we investigated the time decay of 1470 and 1700 nm emissions of Tm 3+ in GLKZ glass singly doped with 0.1 mol% of thulium and doubly doped with terbium (0.1, 0.2, 0.4 and 0.8 mol%), due to its favorable optical properties such a wide transmission window (typically 300-5000 nm), high linear (1.65) and nonlinear refractive indices, good corrosion resistance and mechanical stability, and low cut-off phonon energy among oxide materials (800 cm À1 ).…”

“…To realize population inversion in Tm 3+ ions, Ho 3+ or Tb 3+ ions have been used to codoped the Tm-doped material to depopulate the 3 F 4 level of Tm 3+ in fluoroindate [2], fluorozirconate (ZBLAN) [3], fluorogermanate [4], tellurite [5] and chalcogenide [6] glasses. Because the energies of 5 I 7 and 7 F 0,1,2 levels of Ho 3+ and Tb 3+ , respectively, coincide with the energy of the 3 F 4 level, holmium and terbium ions may actuate as deactivator of the 3 F 4 lowest excited state of Tm 3+ to improve the population inversion of Tm 3+ ions in many luminescent solid materials.…”

"Investigação de Lasers de fluoreto dopados com Túlio e bombeados por diodo-Laser"

“…Para os dois comprimentos de onda usados, 685 e 960 nm, a polarização dos diodos era sigma. (64) onde ε é o parâmetro de acoplamento elétron-fônon, hω eff é a energia de fônon para a matriz usada e ΔE a diferença de energia a ser suprida por fonons. Porém os erros podem ser grandes, pois se considera apenas a diferença de energia entre uma transição e outra, sem se levar em conta a diferença de probabilidade para cada nível de energia.…”