Energy transfer processes in YAG:Er³⁺-Ce³⁺crystal

Spectral and kinetic peculiarities of the radiation trapping effect in doped materials

“…As noted above, a movable panel (19) with rigidly fixed upon it laser excitation source (1), focusing lens (2) and diaphragm (5) was introduced to the experimental setup which allowed to implement three sharply differing regimes of excitation and detection of luminescent signals. To provide more convenient experimental conditions for excitation and registration of the RT effect we used the input and output diaphragms with a hole diameter of 1 mm.…”

“…3) let us refer to the diagram of the energy levels of the first three multiplets of Er 3+ ions in the YAG matrix (Fig. 5) [17][18][19]22]. It is clear from that diagram that laser pumping at 970 nm transfers Er 3+ ions to the 4 I 11/2 excited state, from which the ions at room temperature transfer to Stark sublevels of the excited 4 I 13/2 state, mainly by the non-radiative relaxation.…”

“…The laser diode (1) with lens (3), reflecting plate (4) and the first diaphragm (5) are rigidly fixed on a single stage (19) which is able to move mechanically along the sample (6) and the second diaphragm (7). This allows to change the overlapping scope of the diaphragms, and thus, control the contributions from the directly and indirectly (through the effect of RT) excited regions of the sample in the recorded signals.…”

“…4 I 11/2 transition) with CW and pulsed laser radiations at 970 nm wavelength. Some preliminary results have been published previously [19,20].…”

Enhanced NIR emission in Ce3+/Er3+-doped YAG induced by Bi3+ doping

“…In Ce 3+ /Er 3+ co-doped YAG, excitation of Er 3+ occurs mainly via energy transfer from the Ce 3+ −5d to the 4 F 7/2 state of Er 3+ when pumped under 469-nm laser. After excitation of the Ce 3+ − 5d state, the electrons either relax radiatively to the 4f ground state, thereby producing broad band luminescence in the visible range, or transfer to the 4 F 7/2 level of Er 3+ [2,6] . Electrons at 4 F 7/2 level of Er 3+ ions experience fast nonradiative decay to the 4 I 13/2 level and then decay to the ground state, thereby emitting at 1531 nm.…”