<title>Infrared-to-visible upconversion fluorescence and laser emission in rare-earth compounds</title>

Abstract

Infrared-tovisible upconversion in a variety of rare-earth compounds leads to strong fluorescence and also to laser emission in the visible upon excitation of the media by an appriopriate infrared beam. Usually, a diode laser operating at a wavelength of about 800 nm is used as a pumping source. Efficiency of the upconversion process strongly depends on temperature. The best results vere obtained at liquid nitrogen or lower temperatures. The reason for lowering temperatures is to depopulate the ground state manifold and to reduce the quenching of fluorescence by phonons.Upconversion based fluorescence and laser emission in rare-earth doped crystals (mainly -in erbium doped materials) a well as in stoichiometric erbium pentaphosphate are described. SPIE Vol. 2202/3 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/16/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx