Multicolor up conversion emission and color tunability in Yb 3+/Tm 3+/Ho 3+ triply doped heavy metal oxide glasses (original) (raw)
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Journal of Applied Physics, 2001
Efficient energy upconversion of cw radiation at 1.064 m into blue, red, and near infrared emission in Tm 3ϩ -doped Yb 3ϩ -sensitized 60TeO 2 -10GeO 2 -10K 2 O-10Li 2 O-10Nb 2 O 5 glasses is reported. Intense blue upconversion luminescence at 485 nm corresponding to the Tm 3ϩ 1 G 4 → 3 H 6 transition with a measured absolute power of 0.1 W for 800 mW excitation power at room temperature is observed. The experimental results also revealed a sevenfold enhancement in the upconversion efficiency when the sample was heated from room temperature to 235°C yielding 0.7 W of blue absolute fluorescence power for 800 mW pump power. High brightness emission around 800 nm ͑ 3 F 4 → 3 H 6 ͒ in addition to a less intense 655 nm ͑ 1 G 4 → 3 H 4 and 3 F 2,3 → 3 H 6 ͒ fluorescence is also recorded. The energy upconversion excitation mechanism for thulium emitting levels is assigned to multiphonon-assisted anti-Stokes excitation of the ytterbium-sensitizer followed by multiphonon-assisted sequential energy-transfer processes.
Infrared-to-green and blue upconversion in Tm[sup 3+]-doped TeO[sub 2]–PbO glass
Journal of Applied Physics, 2008
The infrared-to-visible upconversion ͑UC͒ in Tm 3+ -doped TeO 2 -PbO glass was investigated by exciting the samples with a Q-switched neodymium doped yttrium aluminum garnet laser operating at 1064 nm. UC emission bands at ϳ454, ϳ482, and ϳ518 nm corresponding, respectively, to the transitions 1 D 2 → 3 F 4 , 1 G 4 → 3 H 6 , and 1 D 2 → 3 H 5 were observed. Based on the dependence of the UC signals as a function of the Tm 3+ concentration and excitation intensity, we concluded that the generation of the UC emissions involves excited state absorption and cross relaxation among Tm 3+ ions.
Optical Materials, 2017
Yb 3þ , Er 3þ and Tm 3þ triply doped zinc-tellurite glass have been prepared containing up to 3.23 wt% of rare-earth ion oxides, were characterized by absorption spectroscopy, excitation, emission and upconversion spectra. Transparent and homogeneous glasses have been produced, managing the red, green and blue emission bands, in order to generate white light considering the human eye perception. The energy transfer (resonant or non-resonant) between those rare-earth ions provides a color balancing mechanism that maintains the operating point in the white region, generating warm white light, cool white light and artificial daylight through the increase of the 976/980 nm diode laser excitation power from 4 to 470 mW. A light source at 4000 K is obtained under the excitation at 980 nm with 15 mW, providing a white light environment that is comfortable to the human eye vision. The spectroscopic study presented in this work describes the white light generation by the triply-doped zinc-tellurite glass, ranging from blue, green and red, by controlling the laser excitation power and wavelength at 976/ 980 nm. Such white tuning provokes healthy effects on human health throughout the day, especially the circadian system.
Enhanced frequency upconversion and non-colour tunability in Er3+–Yb3+ codoped TeO2–WO3–b3O4 glasses
Springer, 2016
TeO2 –WO3 –Pb3O4 glasses codoped with Er3+ – Yb3+ ions have been prepared by melting and quenching process. Judd–Ofelt analysis has been performed to calculate the various radiative parameters viz., radiative lifetime , branching ratio and stimulated emission crosssections by using the absorption spectra. The nephelauxetic ratio, bonding and covalency parameters have been determined to get the information about the nature of bonding between the rare earth ions and neighbouring oxygen atoms. The near infrared (NIR) to visible frequency upconversion (UC) study upon excitations with 980 nm and 808 nm diode lasers has been performed. The variations observed in the UC emission intensity arising from the Er 3? ions have been explained on the basis of efficient energy transfer Yb3+ - Er3+ ions and back energy transfer Er3+-Yb3+ processes. On codoping with Yb 3? ions the intensity of the UC emission bands observed in the codoped glass upon excitation at 980 nm has been enhanced by many folds and explained on the basis of the oscillator strengths, UC emission crosssection and temporal evolution analysis. No tuning in the colour emitted from the codoped glass upon excitation at 980 nm is reported. The results suggested that the codoped glass may be suitable in making the NIR to visible upconverter and colour non-tunable optical devices.
White Upconversion in Yb 3+ /Tm 3+ /Ho 3+ Co-Doped Antimony-Germanate Glasses
Acta Physica Polonica A, 2013
In the paper the spectroscopic properties of antimonygermanate glass co-doped with Yb 3+ /Ho 3+ has been investigated. Fabricated Yb 3+ /Tm 3+ /Ho 3+ co-doped glass is characterised by the emission of simultaneous multicolour upconversion luminescence. Strong blue 1 G4 → 3 H6 (Tm 3+), green 5 F4 → 5 I8 (Ho 3+) and red 5 F5 → 5 I8 (Ho 3+) upconversion emission bands have been measured under 976 nm excitation at room temperature. Inuence of molar ratio of active ions and excitation power on the colour coordinates (CIE-1931) have been investigated.
White light generation in Tm3+/Ho3+/Yb3+ doped PbO-GeO2 glasses excited at 980 nm
Journal of Applied Physics, 2013
We report white light generation (WLG) in Tm 3þ /Ho 3þ /Yb 3þ doped PbO-GeO 2 glass under continuous-wave excitation at 980 nm. Intense blue (%477 nm), green (%545 nm), and red (% 658 nm) emissions were simultaneously observed at room temperature. The blue light is mainly due to the Tm 3þ transition 1 G 4 ! 3 H 6 . The green emission is due to the Ho 3þ transitions ( 5 S 2 , 5 F 4 ) ! 5 I 8 and the red luminescence is due to the Ho 3þ transition 5 F 5 ! 5 I 8 and transition 1 G 4 ! 3 F 4 associated to the Tm 3þ ions. Energy transfer processes from Yb 3þ to Ho 3þ and Yb 3þ to Tm 3þ ions were responsible for the WLG. Adjusting the relative concentration of the rare-earth (RE) ions, we could obtain emission in the white region of the CIE chromaticity diagram. The present results indicate that PbO-GeO 2 glass has large potential to be used for white displays. V C 2013 AIP Publishing LLC. [http://dx.
Visible up-conversion and near-infrared luminescence of Er 3þ /Yb 3þ co-doped SbPO 4 -GeO 2 glasses
Recent advances in glass chemistry have led to new multifunctional optical glasses of great technological importance. Glasses containing high amounts of antimony have been studied for use in nonlinear optics, near-infrared transmission, and as hosts for rare-earth ions in photonic devices. This work describes a luminescence study of Er 3þ and Er 3þ /Yb 3þ co-doping in a new SbPO 4-GeO 2 binary glass system. Near-infrared and visible up-conversion emissions were observed in the green and red regions, which are enhanced when the samples are co-doped with Yb 3þ. Near-infrared emissions have good quantum efficiency and full width half maximum of 61 nm. Visible up-conversion emissions are governed by two photons and described by excited state absorption, energy transfer and cross-relaxation processes.
Journal of Non-Crystalline Solids, 2008
The effect of Yb 3+ concentration on the frequency upconversion (UPC) of Er 3+ in PbO-GeO 2 -Ga 2 O 3 glasses is reported for the first time. Samples were prepared with 0.5 wt% of Er 2 O 3 and different concentrations of Yb 2 O 3 (1.0-5.0 wt%). The green (523 and 545 nm) and red (657 nm) emissions are observed under 980 nm diode laser excitation. The dependence of the frequency UPC emission intensity upon the excitation power was examined and the UPC mechanisms are discussed. An interesting characteristic of these glasses is the increase of the ratio of red to green emission, through an increase of the Yb 3+ concentration due to an efficient energy transfer from Yb 3+ to Er 3+ .
Visible up-conversion and near-infrared luminescence of Er3+/Yb3+ co-doped SbPO4-GeO2 glasses
Optical Materials, 2016
Recent advances in glass chemistry have led to new multifunctional optical glasses of great technological importance. Glasses containing high amounts of antimony have been studied for use in nonlinear optics, near-infrared transmission, and as hosts for rare-earth ions in photonic devices. This work describes a luminescence study of Er 3þ and Er 3þ /Yb 3þ co-doping in a new SbPO 4-GeO 2 binary glass system. Nearinfrared and visible up-conversion emissions were observed in the green and red regions, which are enhanced when the samples are co-doped with Yb 3þ. Near-infrared emissions have good quantum efficiency and full width half maximum of 61 nm. Visible up-conversion emissions are governed by two photons and described by excited state absorption, energy transfer and cross-relaxation processes.