title: Anti-Stokes laser cooling in Yb(3+)-doped KPb(2) Cl(5) crystal.
abstract: 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.
authors.forename: A
authors.initials: A
authors.lastname: Mendioroz
authors.forename: J
authors.initials: J
authors.lastname: Fernández
authors.forename: M
authors.initials: M
authors.lastname: Voda
authors.forename: M
authors.initials: M
authors.lastname: Al-Saleh
authors.forename: R
authors.initials: R
authors.lastname: Balda
authors.forename: A J
authors.initials: AJ
authors.lastname: García-Adeva