Highly efficient upconversion emission and luminescence switching from Yb3+/Tm3+ co-doped water-free low silica calcium aluminosilicate glass

Blue Upconversion Emission in Germanate Glass Co‐Doped with Yb3+/Tm3+ Ions

“…Improvement of upconversion efficiency can be realized by the introduction of Yb 3+ ions as a sensitizing center at 980 nm. Co‐doping with Yb 3+ /Tm 3+ enables to achieve efficient blue emission produced in the course of phonon‐assisted energy transfer between ytterbium and thulium ions . The selection of a suitable glass system is a key factor in obtaining efficient upconversion emission.…”

“…Co-doping with Yb 3+ /Tm 3+ enables to achieve efficient blue emission produced in the course of phonon-assisted energy transfer between ytterbium and thu-lium ions. [7][8][9][10][11][12][13][14][15][16] The selection of a suitable glass system is a key factor in obtaining efficient upconversion emission. Among oxide glasses, germanate glasses have attracted a considerable interest for their combination of chemical durability, low phonon energies, and high transparency in a wide wavelength range.…”

Strong Influences of Melting Time and Tm3+ Concentration on Blue Up‐Conversion Photoluminescence for Tm3+/Yb3+ Co‐Doped TeO2–TlO0.5–ZnO Glass

“…This UCPL requires two kinds of optically active ions: the emitter of UCPL (e.g., Er 3+ , Eu 3+ , Tm 3+ , and so on) and energy donor (in cases, Yb 3+ ion is widely used.) . The sensitizer transfers the energy absorbed from excitation light to the activator, resulting in emission of higher energy light than excitation light.…”

“…The sensitizer transfers the energy absorbed from excitation light to the activator, resulting in emission of higher energy light than excitation light. Such a mechanism of UCPL is expected for applications to biolabels, display devices (3‐D display), sensors, and so on …”

“…The first and third steps of the energy transfers (see Fig. ) are in nonresonant type (energy difference is compensated by phonons) and the second is in resonant type . Yb 3+ ions have higher oscillator strength (several times higher than those of Tm 3+ ); thus, the most probable second step for Tm 3+ to rise up to 3 F 2,3 levels or 3 H 4 level (after nonradiative transition from 3 F 2,3 ) is resonant energy transfer from Yb 3+ to Tm 3+ ions ((Yb 3+ , Tm 3+ ): ( 2 F 5/2 , 3 F 4 )→( 2 F 7/2 , 3 F 2,3 )) as well as excited state absorption ( 3 F 4 → 3 F 2,3 by 975 nm).…”