Red-to-blue up-conversion spectroscopy of Tm 3+ in SrF 2 , CaF 2 , BaF 2 and CdF 2

Up-conversion emission phosphors based on doped silica glass ceramics prepared by sol–gel methods: control of silica glass ceramics containing anatase and rutile crystallites

“…5 Within such low phonon energy environments of halide host lattices, the REE ions (Pr 3z , Er 3z , Tm 3z ) can absorb two photons of different frequencies, and then efficiently generate red, green and blue radiation which is bright enough to be observed with the naked eye in ambient room light. [6][7][8] Up-conversion into the visible region stems from the stepwise absorption of two infrared photons of different wavelengths. As emission occurs only at the point of intersection of two crossed pump beams, then rastering them results in the formation of real 3D images.…”

Photon avalanche in Tm doped CdF2

“…We observed the anti-Stokes emissions arising from three main centres: a Tm3+ centre of cubic (Oh) symmetry, a (Tm3+, Na+) centre of orthorhombic (CzV) symmetry [6], and a centre, labeled A, the study of which is reported here. The A centre gives rise to the most intense emission (Fig.…”

“…The excitation spectrum of this fluorescence presents only one line at 15440 cm-' (3H4 4 'D2 transition). This line excites also a red fluorescence located at 14930 cm-] ('G4 + 3F4 transition) and an infrared fluorescence located at 12215 cm-' (lG4 h 3 H g transition), both being attributed to the Tm3+ (Oh) centre [6]. Many other emission lines (ID2 -+ 3F2, 3F3, 3H4; 'G4 --f 3F4, 3H5; and 3H4+ 3H6) arising from the A centre and being of weak intensity, were detected and used for the energy level diagram given in Table 1.…”

Morphology-dependent photoluminescence property of red-emitting LnOCl:Eu (Ln=La and Gd)

“…For instance, Y 2 O 3 :Eu and NaYF 4 :Yb, Er are wellknown UV-excited and IR-excited phosphors, respectively [5]. Up-conversion from IR radiation to visible light or ultraviolet radiation has been reported for several rare earths, Pr 3+ , Eu 3+ , Er 3+ , Ho 3+ , and Tm 3+ in many oxides, halides, and oxyhalide matrices [6][7][8]. Such studies have been focused to develop the solid-state up-conversion lasers based on rare earth-doped bulk materials and fibers.…”