Erbium-doped lead silicate glass has been investigated for near-infrared emission and up-conversion applications. Near-infrared emission due to 4I13/2→4I15/2 transition of Er3+ is relatively broad (70.5 nm) and long-lived (3.7 ms). Also, up-conversion luminescence spectra of Er3+ ions in lead silicate glass have been examined as a function of temperature. The relative intensities of luminescence bands corre-sponding to 2H11/2→4I15/2and4S3/2→4I15/2 transitions of Er3+ were determined with temperature. The fluorescence intensity ratio and temperature sensitivity were calculated. The maximum sensitivity for Er3+ doped lead silicate glass is close to 26.4 × 10−4K−1 at T = 590 K.
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Heavy metal lead borate glasses doped with rare earth ions were examined. The influence of heavy metal oxide PbO and activator concentration on luminescence properties of rare earth ions are discussed. Rare earth ions were limited to Eu3+, Dy3+ and Tb3+ which are emitting in the visible light. Increasing concentration of lead oxide in relation to boron oxide causes an increase in R (Eu3+), Y/B (Dy3+) and G/B (Tb3+) spectroscopic factors which correspond to the relative integrated luminescence intensities of 5D0-7F2/5D0-7F1, 4F9/2-6H13/2/4F9/2-6H15/2 and 5D4-7F5/5D4-7F6 transitions, respectively. Moreover, the influence of heavy metal oxide and activator concentration on luminescence decays from excited states of rare earth ions was examined in details.
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Heavy metal oxide and oxyfluoride lead silicate glasses doped with rare-earth ions were prepared. Next, they were heat treated in order to obtain transparent glass-ceramics. The rare-earths as optically active ions were limited to trivalent Eu3+ and Dy3+. Correlation between the local structure and the luminescence properties of Eu3+ and Dy3+ ions in the studied glass and glass-ceramic systems was examined using X-ray diffraction, FT-IR and optical measurements. Especially, the ratio of integrated emission intensity of the 5D0-7F2 transition to that of the 5D0-7F1 transition of Eu3+, defined as the luminescence intensity ratio R (Eu3+) as well as the ratio of integrated emission intensity of the 4F9/2-6H13/2 transition to that of the 4F9/2-6H15/2 transition of Dy3+, defined as the luminescence intensity ratio Y/B (Dy3+), have been analyzed in details. Their values are reduced due to part incorporation of rare-earth ions into cubic ?-PbF2 crystalline phase. The excitation and luminescence spectra of rare-earth ions in glass samples before and after heat treatment are presented and discussed in relation to potential application in optoelectronics.
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Oxyhalide lead borate glasses doped with rare earth ions have been studied before and after thermal treatment. The rare earths as optically active ions were limited to the Er3+ ions. Near-infrared luminescence due to the main 4I13/2–4I15/2 laser transition of Er3+ was registered. The introduction of PbX2 to the borate glass results in a reduction of spectral linewidth and an increase of luminescence lifetime of 4I13/2 state of Er3+ ions. The unusual large spectral linewidth for 4I13/2–4I15/2 transition of Er3+ in the oxide glass host was obtained, whereas the luminescence decay from 4I13/2 state is longer for a sample with PbF2 than PbCl2 and PbBr2. Heat treatment introduces transformation from a glass to transparent glass-ceramic (TGC). The coordination sphere around Er3+ ions is changed, giving important contribution to the luminescence characteristics. The spectroscopic consequence of this transformation is the increase of luminescence lifetime and the narrowing of spectral lines of Er3+.
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Oxychloroborate glasses containing Dy3+ ions in the B2O3–PbCl2–PbO–Al2O3–WO3 system were studied using X-ray diffraction, Raman, FT-IR, absorption, excitation and luminescence spectroscopy. The results concerning glass preparation, short-range order structure and optical properties are reported. X-ray diffraction analysis evidently indicates that the fully amorphous system was prepared. Coexistence of trigonal BO3 and tetrahedral BO4 units was evidenced by Raman and FT-IR spectroscopy. The electronic states belonging to the 4f9 configuration of trivalent Dy3+ were determined from the absorption and excitation spectra. The luminescence bands at 480, 573 and 662 nm were registered in oxychloride glasses, which correspond to transitions originating from the 4F9/2 state to the 6HJ/2 (J = 11, 13, 15) states of Dy3+.
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Oxyfluoride lead borate glasses singly doped with Nd3+ and Er3+ ions have been studied before and after thermal treatment. The orthorhombic PbF2 crystallites are formed during thermal treatment, which was evidenced by X-ray diffraction analysis. Near-infrared luminescence spectra at 1.06 žm and 1.53 žm have been registered for samples before and after annealing, which correspond to the main 4F3/2-4I11/2 and 4I13/2-4I15/2 laser transitions of Nd3+ and Er3+ ions, respectively. Luminescence decays from 4F3/2 state of Nd3+ and 4I13/2 state of Er3+ have been analyzed in detail. Contrary to Nd-doped samples, the luminescence lines obtained for Er-doped transparent oxyfluoride glass-ceramics are more intense and narrowed, whereas the luminescence decays from 4I13/2 state of Er3+ are slightly longer in comparison to precursor glasses.
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Energy transfer processes from Cr3+ to Nd3+ and NIR luminescence of Nd3+ ions at 1.06 žm in Cr-Nd co-doped lead borate glasses have been investigated. The spectroscopic investigation indicates that Cr3+ ions are located at strong-field and weak-field sites. Replacing PbO by PbF2 in lead borate glasses slightly influences the energy transfer processes between Cr3+ and Nd3+ and NIR luminescence of Nd3+ ions. The energy transfer process occurs in both oxide and oxyfluoride glass systems, which may be due to the thermally induced population of the 4T2 excited state of Cr3+ ions and the participation of lattice phonons.
W pracy omówiono metody otrzymywania grupy szkieł fluoroindo-wych domieszkowanych jonami wybranych lantanowców (Pr, Tm, Eu, Er, Ho). Celem było uzyskanie materiałów na źródła laserowe oraz wzmacniacze optyczne w zakresie średniej i dalekiej podczerwieni. Składy chemiczne wybranych zestawów przedstawiono w tablicy 1, a temperatury charakterystyczne tych szkieł (T oraz TJ przedstawiono w tablicy 2. Właściwości optyczne tej grupy szkieł jako matryc dla domieszkowania jonami lantanowców (szerokie pasmo transmisji, bardzo niskie tłumienie w średniej i dalekiej podczerwieni w porównaniu ze szkłami kwarcowymi) predestynują je zastosowań w telekomunikacji światłowodowej oraz medycynie. Ilustracją właściwości transmisyjnych szkieł fluoroindowych na tle szkieł fluorocyrkonowych jest rysunek 1 przedstawiający porównanie położenia krawędzi absorpcji tych szkieł od strony podczerwieni. Jony wybranych lantanowców (Tm, Pr) wykazują w tych szkłach znacznie wyższą wydajność kwantową lumi-nescencji i wysokie wartości czasów życia poziomów metastabilnych w porównaniu ze szkłami kwarcowymi (patrz tablica 3).
EN
The methods of fabrication of selected fluoroindate glasses doped with some lanthanide ions (Pr, Tm, Eu, Er, Ho) were discussed in the paper. The group of fluoroindate glasses were designed as laser sources and optical amplifiers in medium and far infrared range. Composition of the selected fluoride mixtures for glass fabrication have been presented in the table 1 whereas their specific temperatures (T and f) are shown in the table 2. Optical properties of these glasses as matrices for lanthanide ions doping (wide transmission band, low losses at medium and far IR range) allow to apply them in lightguide communication and micro-surgery. The illustration of advantageous fluoroindates transmission properties in comparison to fluorozirconates is figure 1 showing infrared absorption edge for fluoroindate and fluorozirconate glasses. Selected lanthanides ions (Tm, Pr) show in such the matrices much higher quantum yield and higher lifetimes of meta-stable levels than those in even high-purity silica glasses. Measured and calculated values (Judd-Ofelt approach) of radiative lifetimes and quantum yield for selected levels of lanthanide ions in fluoroindate glasses are shown in the table 3.
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Energy transfer processes in lead borate glasses doubly doped with Yb-Tm and Yb-Er have been investigated at room temperature under excitation of Yb at 975 nm. The non-resonant energy transfer from 2F5/2 state of Yb to 3H5 state of Tm results in up-converted emission at 850 nm due to the 3H4-3H6 transition of thulium ions. The nearly resonant transfer from 2F5/2 state of Yb to 4I11/2 state of Er results in green up-conversion and near-infrared emission, which correspond to the 4S3/2-4I15/2 and 4I13/2-4I15/2 transitions of erbium ions, respectively. High Yb concentration in both co-doped samples is required for optimal energy transfer efficiency (h > 90%). Results with the singly Yb-doped samples are also presented to clarify the energy transfer process.
Multicomponent fluoroindate glasses are promising materials for ultra-low loss mid-infrared optical fibers. Upon doping with rare earth ions, fibers are suitable for the development of blue lasers, tunable lasers, up-conversion lasers, high power laser materials and optical amplifiers for telecommunication systems. Characterization of glassy materials based on indium fluoride doped with Pr 3+ ions is reported using XRD, EPMA, DSC, IR and optical spectroscopy as well as their potential applications.
PL
Wieloskładnikowe szkła fluoroindowe są obiecującym materiałem do otrzymywania włókien optycznych mających zastosowanie w zakresie średniej podczerwieni. W wyniku aktywowania szkieł jonami ziem rzadkich stają się przydatne w konstrukcji lasera niebieskiego, konwertora promieniowania podczerwonego na światło widzialne, laserujących materiałów dużej mocy czy wzmacniaczy optycznych dla układów telekomunikacyjnych. W pracy przedstawiono charakterystykę szkieł opartych na fluorku indu domieszkowanych jonami prazeodymu. Badania przeprowadzono z zastosowaniem metod rentgenowskiej analizy fazowej (XRD), mikroanalizy rentgenowskiej (EPMA), różnicowej kalorymetrii skaningowej (DSC), spektroskopii w podczerwieni (R) i optycznej.
Structural and optical properties of lead borate systems with various PbO/B2O3 ratio in glass composition have been studied using X-ray diffraction, optical absorption and infrared spectroscopy. Increase of lead oxide concentration shifts light transparency in the direction of the longer wavelengths and considerably increases radiative transition rates. Coexistence of BO3 and BO4 units has been observed in PbO-B2O3-Al2O3-WO3 system.
PL
W pracy przedstawiono właściwości strukturalne i optyczne szkieł ołowiowo-boranowych o różnej zawartości w składzie tlenku ołowiu do tlenku boru. Badania przeprowadzono z zastosowaniem dyfrakcji rentgenowskiej, spektroskopii w podczerwieni i absorpcji światła. Ze wzrostem stężenia tlenku ołowiu przesuwa się zakres przepuszczalności światła w stronę dłuższych fal i zwiększają się w sposób znaczący szybkości przejść promienistych. Ponadto stwierdza się współistnienie grup BO3 i BO4 w badanym szkle.
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Results of X-ray diffraction (XRD), differential scanning calorymetry (DSC), electron probe microanalysis (EPMA) and optical absorption of InF3-based glasses are reported. Different concentrations of rare earth ions have been added to a base glass. XRD results show that no crystalline phases are formed. Characteristic temperatures were determined by DSC and values of glass stability parameters were calculated. Also, the effect of rare earth ions on the thermal stability of InF3-based glasses has been investigated. From the optical absorption measurements and Judd– Ofelt method the intensity parameters have been calculated. In consequence the trends of the intensity parameters are discussed as a function of the number of 4f electrons.
W artykule zaprezentowano właściwości spektroskopowe szkieł fluoroindowych domieszkowanych jonami europu. Na podstawie widm absorpcyjnych i emisyjnych wyznaczono charakterystyczne wielkości spektroskopowe badanych szkieł: parametry wiązania (beta i delta), parametry intensywności przejść Omega t, efektywne szerokości spektralne pasm emisyjnych delta nu eff, zmierzone i obliczone czasy życia tau, współczynniki rozgałęzienia luminescencji beta, współczynnik intensywności fluorescencji R, oraz wartości przekroju czynnego na emisję wymuszoną sigma em. Parametry spektroskopowe porównano z wartościami otrzymanymi dla szkieł fluorkowych i tlenkowych.
EN
Some spectroscopic properties of fluoroindate glasses doped with Eu3+ ions have been examined. From the absorption and emission spectra in the UV-VIS-NIR region, spectroscopic parameters such as bonding (beta and delta), Judd-Ofelt intensity parameters Omega t, effective linewidths delta nu eff, measured and calculated radiative lifetimes tau, branching ratios beta, fluorescence intensity ratio R and peak stimulated emission cross sections have been obtained and compared with similar results reported for fluoride and oxide glasses.
W pracy syntezowano szkła w złożonych układach wieloskładnikowych. Synteza prowadzona była w zaprojektowanej i wykonanej komorze do wytopów w atmosferze argonu, przy użyciu ultraczystych fluorków (zakupionych w Sigma Aldrich), w tyglu platynowym w temperaturze ~~850 stopni Celsjusza (w ciągu 1 h). Stop wylewano do podgrzanej do ~~250 stopni Celsjusza mosiężnej formy, wygrzewano w tej temperaturze, a następnie powoli chłodzono do temperatury pokojowej. Widma absorpcyjne rejestrowano przy pomocy spektrofotometru Varian Model 2300 UV-VIS-NIR. Próbki zawierające jony Eu i Tm wzbudzano za pomocą oscylatora parametrycznego (OPO) firmy Continuum Model Surelite I pompowanego trzecią harmoniczną lasera Nd:YAG firmy Continuum. Luminescencja z próbki analizowana była przez dwusiatkowy monochromator GDM-1000 firmy Carl Zeiss Jena i odbierana przez fotopowielacz. Sygnał z fotopowielacza podawany był na Boxcar Integrator Model SRS 250 firmy Stanford Research Systems. Przeprowadzona rentgenowska analiza fazowa, badania jednorodności składu chemicznego oraz pomiary właściwości optycznych wskazują na dobrą jakość uzyskanych szkieł.
EN
Rare earth elements doped fluoride glasses were formed in many elements systems. They were manufactured in dry box, in argon atmosphere with a use of ultrahigh purity fluorides (Sigma Aldrich) by melting their homogenised mixtures in a platinum crucible at ~~850 degrees centigrade. Liquid glass was poured to the preheated (250 degrees centigrade) brass mould then held at this temperature by 1 hour and then slowly cooled to the room temperature. XRD measurements showed a glassy structure of the resulted material, whereas EPMA measurements showed its chemical homogeneity. The understanding of the optical properties of rare earth ions in inorganic compouns is of great importance due to their potential technological applications, as, for example optical fibres, optical amplifiers, sensors and lasers. Fluoroindate glasses seem to be a particularly useful host for rare earth ions due to their optical quality and chemical stability. The studied fluoroindate glasses were based on indium fluoride InF3 as the network former and on various modifiers. Ideally, starting materials should be anhydrous fluorides of high purity. The samples obtained in this environment have good optical quality and chemical homogeneity. Optical absorption spectra have been recorded using Varian Model 2300 UV-VIS-NIR Spectrophotometer. Luminescence has been excited with a third harmonic of a Nd:YAG laser or with a Continuum Optical Parametric Oscillator. Luminescence spectra were recorded using a Stanford SRS 250 Boxcar Integrator connected to a personal computer. All spectroscopic measurements were carried out at room temperature.
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