Infrared-to-visible upconversion processes inPr3+/Yb3+-codoped

Rolindes Balda

¹

,

J. Fernández

²

,

A. Mendioroz

³

et al.

Abstract

In this work we report infrared-to-visible upconversion luminescence in the low-phonon-energy host material KPb 2 Cl 5 codoped with Pr 3ϩ and Yb 3ϩ ions. An orange luminescence from the 1 D 2 level, and less intense blue, green, and red emissions from the 3 P 0,1 levels of Pr 3ϩ have been observed under resonant excitation in the 1 G 4 level of Pr 3ϩ . As regards to Yb 3ϩ , when the 2 F 5/2 level is resonantly excited, the visible emissions are also present but the blue, green, and red emissions from 3 P 0,1 levels are enhanced if compared with the orange luminescence from level 1 D 2 . On the other hand, excitation at the high-energy wing of the 2 F 5/2 level originates emission only from 3 P 0,1 levels. The upconverted fluorescence from the 1 D 2 and 3 P 0,1 levels occurs by energy transfer upconversion and/or excited-state absorption processes depending on the excitation wavelength. The possible mechanisms which lead these processes are discussed.

Analysis of spectra of neat and lanthanide ion‐doped KPb2Cl5 excited by synchrotron radiation

“…Moreover, the occurrence of a Jahn-Teller effect cannot be envisaged in systems such as KPb 2 Cl 5 , where the static site symmetry of Pb 2þ is C 1 . The low-phonon host KPb 2 Cl 5 has attracted much attention due to its superior moisture resistance and ease of incorporation of lanthanide ions to give up- [16][17][18] or down- [19] conversion properties, infrared lasing [20][21][22][23] and antiStokes laser cooling [24,25]. The focus of many previous studies has therefore rested upon the characterization of lanthanide ion energy levels and spectral intensities in this host lattice and the site symmetries of the dopant ions [26][27][28][29].…”

Tb 3 + -doped KPb2Br5: Low-energy phonon mid-infrared laser crystal

“…6 Doping of rare-earth ions, such as Dy 3+ ,Nd 3+ ,Pr 3+ ,Yb 3+ ,Er 3+ , etc. [1][2][3][4][5][6][7][8][9][10] in KPb 2 Cl 5 have been reported by various workers in the recent past. The quenching of luminescence beyond 4 m is the limiting factor for room-temperature laser operation in the longer-wavelength region for the conventional hosts.…”

Rare-Earth-Doped Low Phonon Energy Halide Crystals for Mid-Infrared Laser Sources

“…In the near future, such systems will also be pumped at 4.6 m by means of high power quantum cascade laser (QCL) diodes for the emission at 5 m from the 3 H 5 level, particularly in KPb 2 Cl 5 because the pumping strategy involving ETU seems more favourable than in CsCdBr 3 , not only because of lower phonon energies but also because the one dimensional crystal structure of the latter compounds favours ion pairing of Pr 3+ [Amedzake et al, 2008;An & May, 2006;Balda et al, 2002Balda et al, , 2003Bluiett et al, 2008;Chukalina, 2004;Ferrier et al, 2009aFerrier et al, , 2009bGafurov et al, 2002;Guillot-Noël et al, 2004;Neukum et al, 1994;Rana & Kaseta, 1983]. Absorption and emission spectra recorded as a function of temperature at low temperature (10-50 K) over a broad spectral range allows for the determination of Pr 3+ ions crystal field sublevels dissolved in KPb 2 Cl 5 , and to match them with the eigenvalues of a parameterized crystal field model hamiltonian taking into account 74 sublevels of the 12 first multiplets.…”

“…Tm 3+ ions), and to exploit Yb 3+ -Pr 3+ energy transfer [Balda et al, 2003;Bluiett et al, 2008;Howse et al, 2010] thanks to high-powered low cost 980 nm (resp. 800 nm) diode pumping, but the high concentrations required remain hardly achievable in these compounds on the one hand, and the energy difference between laser and pumping wavelengths which would entail an important thermal load, on the other hand, lead us to consider another promising alternative : QCL diode pumping around 4.6 m (which delivers 1.8 W at room temperature [Bai et al, 2008]), that is, pumping directly in the emitting level.…”