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1

Erbium-doped lead silicate glass for near-infrared emission and temperature-dependent up-conversion applications

Pisarski W. A., Pisarska J., Lisiecki R., Ryba-Romanowski W.

Opto-Electronics Review

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2017

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Vol. 25, No. 3

238--241

EN

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.

2

Synthesis and optical spectroscopy of the lithium tetraborate glasses, doped with terbium and dysprosium

Padlyak B., Ryba-Romanowski W., Lisiecki R., Pieprzyk B., Drzewiecki A., Adamiv V., Burak Y., Teslyuk I.

Optica Applicata

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2012

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Vol. 42, nr 2

365-379

EN

A series of the Tb- and Dy-doped glasses with Li2O-2B2O3 (or Li2B4O7:Tb and Li2B4O7:Dy) composition were synthesised and their spectroscopic properties were investigated. The Li2B4O7:Tb and Li2B4O7:Dy glasses of high chemical purity and optical quality were obtained from corresponding polycrystalline compounds in the air using standard glass technology. The Tb and Dy impurities were added to Li2B4O7 composition in the form of Tb2O3 and Dy2O3 oxide compounds in amounts of 0.5 and 1.0 mol%. The electron paramagnetic resonance (EPR), luminescence excitation and emission spectra of the Li2B4O7:Tb and Li2B4O7:Dy glasses were investigated. On the basis of EPR and photoluminescence spectra analysis it was shown that the Tb and Dy impurities are incorporated in the Li2B4O7 glass network as Tb3+ (4f8, 7F6) and Dy3+ (4f9, 6H15/2) ions, exclusively. All observed transitions of the Tb3+ and Dy3+ centres in the luminescence excitation and emission spectra were identified. The luminescence kinetics shows single exponential decay for Tb3+ and Dy3+ centres in Li2B4O7 glasses. The lifetime values for main emission transitions of the Tb3+ and Dy3+ centres in the Li2B4O7 glasses containing 0.5 and 1.0 mol% Tb2O3 and Dy2O3 are determined at T = 300 K. Peculiarities of optical properties and local structure of the Tb3+ and Dy3+ centres in the Li2B4O7:Tb and Li2B4O7:Dy glasses as well as their potential applications have been discussed.

3

Thermal treatment effect on dynamics of luminescent states in oxyfluoride glass-ceramics doped with Pr3+ and Tb3+

Dominiak-Dzik G., Klimesz B., Ryba-Romanowski W.

Optica Applicata

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2010

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Vol. 40, nr 2

375--382

EN

The 50GeO2–(50–x–y)PbO–yPbF2–xLnF3 glass single doped with Pr3+ and Tb3+ ions was studied. The composition of the material was modified by varying the content of both PbF2 (y = 5, 10, 15 mol%) and LnF3 (x = 0.2 and 2 mol%). The differential thermal analysis (DTA) of as-melted samples was used to determine thermal characteristics. Optical techniques and kinetics measurements were used to monitor the effect of thermal treatment on spectroscopic properties and dynamics of luminescent states of optically-active ions in amorphous and two-phase systems. It was found that non-exponential decays of praseodymium luminescence in as-melted material become exponential or nearly exponential with corresponding longer lifetimes in thermally-treated samples. This effect was not so strong in the Tb3+-doped glass. The influence of the PbF2 content on luminescence dynamics was studied for samples doped with 2 mol% of Pr3+. It was observed that the increase of PbF2 content leads to lengthening of luminescence lifetime, e.g., the 1D2 lifetime increases from 4.1 to 45 ?s in 5 and 15 mol% of PbF2 as-melted samples, respectively.

4

Optical spectra and luminescence kinetics of the Sm3+ and Yb3+ centres in the lithium tetraborate glasses

Padlyak B., Ryba-Romanowski W., Lisiecki R., Adamiv V., Burak Y., Teslyuk I., Banaszak-Piechowska A.

Optica Applicata

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2010

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Vol. 40, nr 2

427--438

EN

Optical absorption, luminescence excitation, and emission spectra as well as luminescence kinetics of the Sm- and Yb-doped glasses with lithium tetraborate (Li2B4O7) composition were investigated and analysed. The Sm- and Yb-doped lithium tetraborate glasses of high optical quality were obtained in air from corresponding polycrystalline compounds according to standard glass synthesis technology. The Sm and Yb impurities were added to the Li2B4O7 compound in the form of Sm2O3 and Yb2O3 oxides in amount of 0.4 mol%. Using optical and electron paramagnetic resonance spectroscopy it was shown that the Sm and Yb impurities are incorporated into the lithium tetraborate glass network as Sm3+ (4f5, 6H5/2) and Yb3+ (4f13, 2F7/2) ions, exclusively. All of the observed transitions in the absorption and luminescence spectra of Sm3+ and Yb3+ centres were identified. The luminescence kinetics of the Sm3+ and Yb3+ centres in the Li2B4O7 glass are characterised by a single exponential decay. Decay constants for the main emission transitions of the Sm3+ and Yb3+ centres in the lithium tetraborate glass were obtained at T = 300 K. Incorporation peculiarities and optical spectra of Sm3+ and Yb3+ ions in the lithium tetraborate glass have been discussed in comparison with other borate glasses and crystals.

5

Influence of PbX2 (X = F, Cl, Br) content and thermal treatment on structure and optical properties of lead borate glasses doped with rare earth ions

Pisarska J., Lisiecki R., Dominiak-Dzik G., Ryba-Romanowski W., Goryczka T., Grobelny Ł., Pisarski W. A.

Optica Applicata

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2010

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Vol. 40, nr 2

351--358

EN

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+.

6

Optical spectroscopy and local structure of the Nd3+ luminescence centres in glasses of the CaO-Ga2O3-GeO2 system

Padlyak B., Ryba-Romanowski W., Lisiecki R.

Optica Applicata

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2008

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Vol. 38, nr 1

189-202

EN

Optical absorption and luminescence spectra as well as luminescence kinetics of the Nd3+ centres in glasses with Ca3Ga2Ge3O12:Nd composition, containing 0.2 and 1.0 wt% of the Nd2O3 were presented and analysed. The oscillator strengths and phenomenological intensity parameters omega t (omega 2, omega 4, and omega 6) were obtained using standard Judd-Ofelt theory. Calculated omega t parameters, radiative transitions rates, branching ratios and radiative lifetime for Nd3+ centres in the glass with Ca3Ga2Ge3O12 composition were analysed and compared with corresponding Nd3+ parameters in their crystalline analogue with garnet structure. Experimental lifetimes are compared with those calculated, and quantum efficiency of Nd3+ centres from 4F3/2 emitting level in the glass with Ca3Ga2Ge3O12 composition is estimated. Incorporation peculiarities and local structure of Nd3+ luminescence centres in the glass with Ca3Ga2Ge3O12 composition and corresponding Ca3Ga2Ge3O12:Nd3+ garnet laser crystals are considered. On the basis of extended X-ray absorption fine structure (EXAFS) spectra (L3-edge) of rare-earth elements analysis it has been shown that Nd3+ luminescence centres in the CaO-Ga2O3-GeO2 glass network occupy structural sites with the coordination number to oxygen N = 6.

7

Near-infrared luminescence of rare earth ions in oxyfluoride lead borate glasses and transparent glass-ceramic materials

Pisarska J., Ryba-Romanowski W., Dominiak-Dzik G., Goryczka T., Pisarski W.A.

Optica Applicata

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2008

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Vol. 38, nr 1

211-216

EN

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.

8

Nd3+ or Sm3+ doped oxyfluoride glass based on GeO2-PbO-PbF2. Synthesis and spectroscopic properties

Klimesz B., Dominiak-Dzik G., Ryba-Romanowski W.

Optica Applicata

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2005

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Vol. 35, nr 4

843-850

EN

Glasses with composition 50 GeO2-(45 - x)PbO-5 PbF2-x LnF3 (Ln = Nd or Sm, x = 0.2 and 2 mol%) were synthesised in the bulk form. Phase profiles and temperature characteristics were measured by differential thermal analysis (DTA); glass transition temperature Tg, as well as the b-PbF2 Tb and oxide glass crystallisation Tc temperatures have been derived for each individual system. A study of optical properties (absorption, emission) of the PbF2-Nd3+ and PbF2-Sm3+ was carried out. The oscillator strengths were obtained for several optical transitions and they have been used to calculate phenomenological intensity parameters W2, 4, 6. The probabilities of radiative transitions from fluorescent levels of Nd3+ and Sm3+ ions, as well as branching ratios and radiative lifetimes, were estimated on the basis of the Judd-Ofelt framework. The fluorescence dynamics of studied systems was measured. Experimental lifetimes were compared and discussed with those obtained with the Judd-Ofelt theory.

9

Energy transfer from Yb to X (X = Tm, Er) in lead borate glasses

Pisarska J., Ryba-Romanowski W., Dominiak-Dzik G., Goryczka T., Pisarski W.A.

Optica Applicata

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2005

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Vol. 35, nr 4

837-842

EN

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.

10

Physical properties of InF3-based glasses

Pisarska J., Ślęzok M., Żelechower M., Pisarski W. A., Goryczka T., Ryba-Romanowski W.

Optica Applicata

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2003

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Vol. 33, nr 1

133-139

EN

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.

11

Optical properties of fluoroindate glasses doped with rare earth ions.

Gabryś-Pisarska J., Żelechower M., Pisarski W.A., Gołąb S., Bałuka M., Ryba-Romanowski W.

Optica Applicata

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2000

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Vol. 30, nr 4

517-528

EN

Multicomponent indium based fluoride glass singly doped with europium, terbium, holmium and thulium has been investigated using methods of optical spectroscopy. Owing to low energy of phonons available in the glass matrix, the luminescent levels of rare earth ions are depopulated mainly by radiative transitions and nonradiative ion-ion interaction. The latter mechanism has been found to govern the relaxation dynamics of the /sup 5/D/sub 2/, /sup 5/D/sub 1/ levels of europium, the /sup 5/D/sub 3/ level of terbium, the /sup 5/S/sub 2/ level of holmium and the /sup 2/D/sub 5/, /sup 1/G/sub 4/ and /sup 3/H/sub 4/ levels of thulium when the activator concentration amounts to several mol%.

12

Wybrane właściwości fizykochemiczne i optyczne szkieł fluorkowych domieszkowanych jonami metali przejściowych

Pisarska J., Żelechower M., Ryba-Romanowski W., Mazurak Z.

Inżynieria Materiałowa

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2000

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R. XXI, nr 4

141-144

PL

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.

13

Optical absorption and luminescence of LiTaO₃:Cr and LiTaO₃:Cr, Nd crystals

Gołąb S., Sokólska I., Dominiak-Dzik G., Palatnikov M. N., Sidorov N. V., Biryukova I., Kalinnikov V. T., Ryba-Romanowski W.

Opto-Electronics Review

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1999

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Vol. 7, No. 2

145-147

EN

The interest in LiNbO₃ and LiTaO₃ crystals doped with transition metal or rare eartch ions is related to their potential applications as self-switching and self-frequency doubling laser materials. In the past considerable attention has been paid to LiNbO₃ crystals doped by variety of luminescent ions. In particular LiNbO₃:Cr was investigated recently by Macfarlane et al. [1]. Energy transfer between Cr³⁺ and Nd³⁺ in LiNbO₃ has been studied and discussed by Vergara et al. [2]. In this work we investigate spectroscopic properties of Cr³⁺ and Cr³⁺ - Nd³⁺ interaction in LiTaO₃ using optical absorption, luminescence and luminescence decay times at temperatures between 5 K and 300 K. Some preliminary data obtained with singly doped LiTaO₃:Cr at low activator concentration are given in our previous work [3]. Recorded spectra indicate that both the Cr³⁺ and Nd³⁺ are located in several non - equivalent sites that differ in the strength of the crystal field. Luminescence spectrum of Cr³⁺ consists of a broad band whose maximum and intensity depend on temperature. Below about 50 K an additional sharp band with four distinct components appears in the spectrum. The broad band attributed to the spin allowed ⁴T₂ - ⁴A₂ transition of Cr³⁺ ions overlaps two absorption bands of Nd³⁺ ions at about 810 nm and 890 nm making the Cr³⁺ - Nd³⁺ energy transfer process feasible. Results of measurements are discussed and compared to those obtained with LiNbO₃:Cr.