Anti-Stokes laser cooling in Yb(3+)-doped KPb(2) Cl(5) crystal.
We report internal laser cooling in Yb(3+) -doped KPb(2)Cl(5) . From the quantum efficiency values measured in the heating and cooling regions by use of the photothermal deflection technique, we have obtained a room-temperature cooling efficiency of 0.2% in a sample doped with ~5x10(19)ions/cm(3) . Excitation spectra obtained under high irradiation fluences show an excess of fluorescence with regard to those obtained at low fluences, which agrees with the prediction of a model based on photon-ion-phonon interaction.
Mendioroz
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A
Fernández
J
J
Voda
M
M
Al-Saleh
M
M
Balda
R
R
García-Adeva
A J
AJ