Optical Properties Of Tellurite Glasses Research Articles

Opto-Dielectric Properties of TeO2-Li2O-LiCl-Eu2O3 Glasses

Europium oxide (Eu2O3) doped lithium tellurite glasses were prepared via melt quenching method. The effects of Eu2O3 doping at varying concentrations on the physical, electrical and optical properties of tellurite glasses were determined. The physical properties utilizing density and molar volume are determined. Electrical and dielectric constant in the 0.01–10 MHz frequency range was monitored as a function of temperature (298–398 K). At room temperature, the conductivity and activation energy increase with an increase in Eu2O3 concentration. Small polaron hopping (SPH) is used to explain the conduction mechanism. The density of the localized state is found to decrease with increasing Eu2O3 concentration in the range of 21.3 to 17.3 eV−1 cm−3. Dielectric parameters which are dielectric constant and loss tangent are found to increase with the increase in the concentration of Eu2O3. To study the spectroscopic properties of fabricated glasses, absorption and emission spectroscopy have been performed. UV–vis-NIR absorption spectra of glass samples divulged two significant peaks. Under the excitation of a 393 nm laser diode, six emission bands were observed in the Eu3+ single-doped glasses of which the peak at 613 nm corresponding to the transition 5D0 → 7F2 is highly intense for such glasses. Increasing intensity ratio ranging from 1.13 to 2.13 with increased Eu2O3 concentration is attributed to the low symmetry environment around Eu3+ ions. The findings of the current study can be used in advanced functional optoelectronic applications.

Effect of Al2O3 concentration on fluorescence intensity ratio of Er3+/Yb3+ co-doped tellurite glasses for optical temperature sensors under 375 nm and 980 nm excitation

Alumina (Al2O3) is one of the most important ceramic materials. It has been used as a property modifier in different silica or tellurite glasses but its effect on the luminescent properties or on the fluorescence intensity ratio of Er3+/Yb3+ co-doped tellurite glasses has not been fully studied. In this work, the effect of the alumina on the structural, thermal and optical properties of tellurite glasses co-doped with Er3+ and Yb3+ ions was studied. It was observed that all the samples exhibit an amorphous structure but the glass transition temperature, thermal stability and band gap values increase with the alumina addition. Moreover, the luminescence behavior was studied in dependence of the temperature and specific attention was paid to the fluorescence intensity ratio (FIR) between 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions. The results indicate that the addition of alumina increases the rate of change of FIR versus temperature.

Optical Properties of Erbium-Doped Tellurite Glasses: A Review and Bibliometric Study

The aim of this paper is to review the optical properties of tellurite glasses doped by erbium and describe their bibliometric study about it. The research documents on of optical properties of tellurite glasses doped by erbium in the Scopus database are 115, start from 1999 until now. The visualization of the research assisted by VOSviewer software. There are three clusters: (1) red cluster for the optical properties begin from the fabrication process until the characterization of glasses based on the geometrical optics phenomena, (2) green cluster for the emission spectra until the analysis using McCumbers Theory, and (3) erbium-doped tellurite glasses optical properties based on energy transfer and XRD analysis on the blue cluster. Based on the Scopus documents, not too many researchers are concerned with researching erbium-doped tellurite glasses, never more than 12 documents per year. However, the researchers are consistent to explore further exploring the characteristics of the optical properties of glass exposed to erbium ion for laser applications.The research funding shows that the tellurite glasses doped by erbium are being developed for laser applications.

Modification in Structural Properties of Erbium-doped Zinc – Sodium Tellurite Glass: Effect of Bimetallic Cu/Ti Nanoparticles

The effect of bimetallic nanoparticles (NPs) on the structural and optical properties of tellurite glass doped with Cu/Ti NPs are reported. A series of glass with composition of (70–x–y) TeO2–20ZnO–9Na2O–1Er2O3–(x)CuO–(y)TiO2 (where x = 0.0, 0.1 and 0.04 mol%, y = 0.0, 0.1 and 0.04 mol%) are synthesized by using melt-quenching method. The structure and optical properties of tellurite glass containing Cu/Ti NPs are identified by using X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray (SEM-EDX) technique and Fourier Transform Infrared Spectroscopy (FTIR). XRD spectra show the nature of glass and the grain size. The SEM images shows the surface morphology and EDX spectra show the traces of C, O, Te, Na, Zn, Au, Er, Ti and Cu elements. FTIR spectra show the chemical bonding of constituent atom in glass matrix primarily the Zn2+ vibration, Cu (II)–O bonding, Te–O bending in term of TeO3 and TeO4 units, Cu–H stretching and O–H vibration of water group.

Effect of introduction of TiO2 and GeO2 oxides on thermal stability and 2 μm luminescence properties of tellurite glasses

Abstract In this paper, Tm3+ doped pure tellurite glass, TiO2 modified tellurite glass and TiO2/GeO2 co-modified tellurite glasses were prepared. The effects of the introduction of TiO2 and GeO2 oxides on the thermal, structural, optical properties of tellurite glasses were compared and analyzed intensively. Besides, the Judd-Ofelt intensity parameters and absorption and emission cross sections were calculated. DTA curves indicated the thermal stability of pure tellurite glass enhance obviously by GeO2 modification. The introduction of TiO2 and GeO2 oxides in tellurite glasses arise a series of variation on the absorbance, luminescence peak position and fluorescence intensity which have been explained and analyzed in detail. Based on the analysis, the addition of TiO2 in tellurite glass contributes to the improvement of 2 μm fluorescence performance, and the introduction of GeO2 has great advantages in enhancing the thermal stability of glass.

Effect of PbO on optical properties of tellurite glass

Abstract Binary (1 − x)(TeO2) − x(PbO), x = 0, 0.10, 0.15, 0.20, 0.25, 0.30 mol% glass system was fabricated using melt quenching method. X-ray diffraction (XRD) technique was employed to confirm the amorphous nature. The microanalysis of the major components was performed using energy dispersive EDX and X-ray spectrometry. Both the molar volume and the density were measured. FTIR and UV spectra were recorded at 400–4000 cm–1 and 220–800 nm, respectively. The optical band gap (Eopt), Urbach’s energy (Eu), index of refraction (n) were calculated using absorption spectrum fitting (ASF) and derivation of absorption spectrum fitting (DASF) methods. Molar refraction Rm and molecular polarizability α m have been calculated according to (ASF) method.

Samarium Concentration and Optical Correlation of Tellurite Glass

Modifying the structural and optical properties of inorganic glasses via controlled doping of various rare earth ions by inhibiting the quenching effect is a challenging task. We report the influence of samarium (Sm3+) ions concentration on enhanced optical properties of tellurite glass. A series of glasses with composition (0.80-x)TeO2 + 0.10Li2O + 0.10 Na2O + xSm2O3, where 0.0<x <0.03 mol% are prepared using melt quenching method and optical characterizations are performed. The XRD spectra confirm the amorphous nature of the glass. The Urbach energy decreases and the optical gap for both direcet and indirect transitions increases with the increse of samerium contents. The UV-Vis spectra comprised of eight absorption bands and PL spectra reveal four prominet peaks corresponding to various transitions from the ground state to the excited states of Sm3+ ion. The optical response shows significant enhancement with increasing concentration of samerium ions. Our detail experimental analyses may be useful for the development of tellurite glass based photonic devices. Keywords: Tellurite Glass, Sm3+ ions, Urbach Energy, Direct and Indirect Transition.

The influence of oxides on the optical properties of tellurite glasses

New tellurite glasses within composition 75TeO2–5WO3–15Nb2O5–5MxOy in mol%, where MxOy = (Na2O, Ag2O, ZnO, MgO, CuO, NiO, TiO2, MnO2), have been prepared using the conventional melt-quenching method. The optical properties of these glasses were estimated by measuring the ultraviolet–visible–near infrared (UV–vis–NIR) spectroscopy and linear refractive indices at different wavelengths. From the absorption edge studies, the values of the optical band gap (Eopt) and Urbach energy (ΔE) were evaluated. The density, molar volumes, molar refraction (Rm), molar polarizability (), metallization criterion (Mc), electronic polarizability of oxide ions (), and optical basicity (Λ) were estimated. Moreover, the nonlinear refractive index (n2), third-order nonlinear susceptibility (χ(3)), and nonlinear absorption coefficient (β) were observed. It was found that the linear and nonlinear refractive indexes increase with decreasing the optical energy gap.

Low-phonon tellurite glass co-doped with Tm3+/Ho3+ ions for optical fibre technology

In this paper the material and optical properties of tellurite glasses co-doped with Tm 3+ /Ho 3+ ions were investigated. Near infrared luminescence at the wavelength of 2060 nm ( 5 I 7 -> 5 I 8 ) in holmium ions was obtained as a result of energy transfer between Tm 3+ and Ho 3+ ions. The energy transfer (ET) between Tm 3+ -> Ho 3+ ions was investigated pumping at 795 nm. As a result of optimization of rare earth concentration the best efficiency of energy transfer in fabricated glasses was obtained for molar composition 0.2mol%Tm 2 O 3 : 0.2mol%Ho 2 O 3 . Full Text: PDF References H. Gebavi, D. Milanese, G. Liao, Q. Chen, M. Ferraris, M. Ivanda, O. Gamulin, S. Taccheo, "Spectroscopic investigation and optical characterization of novel highlythulium doped tellurite glasses", Journal of Non-Crystalline Solids, 355 (2009) 548-555. CrossRef B.M. Walsh, "Review of Tm and Ho materials; spectroscopy and lasers", Laser Physics, 19 (2009) 855-866. CrossRef S.D. Jackson, Y. Li, "High-power broadly tunable Ho3+-doped silica fibre laser", Electron. Lett, 40 (2004) 1474?1475 CrossRef M. Wang, L. Yi, G. Wang, L. Hu, J. Zhang, "2um emission performance in Ho3+ doped fluorophosphate glasses sensitized with Er3+ and Tm3+ under 800 nm excitation Solid State Communications", 149 (2009) 1216-1220. CrossRef H. Lin, Y.Y. Zhang, E.Y. Pun, "Fluorescence investigation of Ho3+ in Yb3+ sensitized mixed-alkali bismuth gallate glasses", Spectrochimica Acta. Part A, Molecular and biomolecular spectroscopy, 71 (2008) 1547-1550 CrossRef Q. Nie, X. Li, S. Dai, T. Xu, Z. Jin, X. Zhang, "Energy transfer and upconversion luminescence in Tm3+/Yb3+ co-doped lanthanum?zinc?lead?tellurite glasses", Journal of Luminescence, 128 (2008) 135-141. CrossRef X. Shen ,Q. Nie, T. Xu, T. Peng, Y. Gao, "Green and red upconversion emission and energy-transfer between Er3+ and Tm3+ ions in tellurite glasses", Physics Letters A332 (2004) 101?106 CrossRef T. Förster, "Zwischenmolekulare Energiewanderung und Fluoreszenz", Ann. Physik 6(2) (1948) 55-59 CrossRef

Investigations of thermal, structural and optical properties of tellurite glass with WO3 adding

Tellurite glasses with the molar composition (89-x) TeO2–10TiO2–1Nd2O3–xWO3 (x=0, 10 and 20mol%) were prepared by the conventional melt-quenching technique. The effects of WO3 concentration on the structural, thermal and optical properties of tellurite glasses have been discussed. From the differential scanning calorimetry measurements, thermal properties such as glass transition temperature Tg, crystallization temperature Tx, and thermal stability ΔT are estimated. It was found that ΔT increases with the increase of WO3 composition which can indicate a reinforcement of the glassy network. Both Raman and FTIR results show that the addition of WO3 induced a depolymerisation of tellurite glass since the Te–O–Te inter-chain linkages are progressively substituted by stronger Te–O–W bridges that are at the origin of the increase of the thermal stability of the glass.The optical band gap energy values corresponding to the direct and indirect allowed transitions and the Urbach energy values of the prepared tellurite glasses have been calculated from optical absorption edges. The results show an important decrease of the optical band gap with the increase of WO3 concentration. It was assigned to W6+ ions that could have a role as network modifier. The Urbach energy was found to decrease with WO3 compositions which suggest the possibility of long range order. The refractive index and extinction coefficient were obtained by spectroscopic ellipsometry. Higher values for the refractive index are recorded due to the high polarizability of non-bridging oxygen. It is observed also that the refractive index, n increases with increasing WO3 content. It is established that there is a trend by which the energy gap decreases with increasing refractive index and increasing the polarizability of the oxide ions. The complex dielectric function ε, relative to each sample, was estimated from regression analysis. The material studied here has potential application as optical fiber.

Optical properties of tellurite glasses elaborated within the TeO2–Tl2O–Ag2O and TeO2–ZnO–Ag2O ternary systems

The optical properties of glasses elaborated within the TeO2–Tl2O–Ag2O and TeO2–ZnO–Ag2O ternary systems are presented. The paper is articulated in two parts. The first part concerns the TeO2–Tl2O–Ag2O system, where the linear refractive index, the absorption coefficient and the optical band gap are measured as a function of the Ag2O content. From ellipsometry measurements, it is noticed that the linear refractive index n0 remains constant up to 5mol% in AgO0.5 and then slightly increases at higher concentrations (10mol%). Such evolution of the refractive index was related to the higher electronic polarizability of Ag+ cations compared to that of Te4+ cations, assuming that the electronic polarizability of O2− anions remains constant. The reduction in the optical band gap value is attributed for some part to the higher quantity of non-bridging oxygen atoms induced by the depolymerization of the glass. The third order non-linear optical properties (γ and Re(χ(3)) values) of these TeO2–Tl2O–Ag2O glasses are then extracted from Z-scan measurements. For glass compositions ranging from 0 to 10mol% in AgO0.5, the Re(χ(3)) value shifts from roughly 60 to more than 80 times that of silica, which testify to the excellent non-linear optical properties of such TeO2–Tl2O glasses containing silver (tellurite glasses possess intrinsic high optical non-linearity). The addition of Tl2O induces the depolymerization of the glass framework but, on the other hand, helps to maintain the amplitude of the optical non-linearity, through the presence of highly polarizable Tl-based entities. Here, below 5mol% in AgO0.5, it is believed that the activity of the electronic lone pair of Tl+ ions is inhibited. Over this limit, such lone pair would become active, explaining the clear increase of the Re(χ(3)) value. Finally, the second part of the paper is devoted to the study of photoluminescence properties of new TeO2–ZnO–Ag2O glasses. Indeed, probably due to the creation of Ag+–Tl+ pairs, there is absolutely no photoluminescence detected for glasses elaborated in the TeO2–Tl2O–Ag2O system. At the opposite, the temperature dependent photoluminescence properties of TeO2–ZnO–Ag2O glasses are reported. Under UV–visible excitation at 385nm, the samples emit orange light, with a broad emission wavelength peaking around 580–585nm. The nature of the light emitting centers is discussed and two main hypotheses are debated: the creation of Ag+–Ag+ or Ag+–Zn2+ pairs, with stronger arguments more in favor of the last one.

Study of thermal, structural and optical properties of tellurite glass with different TiO2 composition

Tellurite glasses with different TiO2 composition are elaborated and characterized. Differential Scanning Calorimetry (DSC) measurements show an improvement of the stability factor ΔT of the glass with the increase of TiO2 composition which can indicate a reinforcement of the network. Both Raman and FTIR results prove that the Te–O–Te inter-chain linkages are progressively substituted by stronger Te–O–Ti bridges that are at the origin of the increase of the thermal stability of the glass. However, for glasses with high TiO2 composition, some TiO4 polyhedron and crystalline phases of TiTe3O8 can be formed in the amorphous phase.It was found that TiO2 contributes in the highest extent to decrease the glass energy gap and to increase the refraction index due to Ti4+ that could have a role as network modifier. The Urbach energy Eu was found to decrease with TiO2 compositions which suggest the possibility of long range order locally arising from the formation of TiTe3O8 groups.

Effect of heat treatment on the structural and optical properties of tellurite glasses doped erbium

The 75TeO 2–20ZnO–4Na 2CO 3–1Er 2O 3 (in molar ratio) glass system was prepared by the conventional melt-quenching method. As such, the samples prepared were investigated by differential scanning calorimetry (DSC), X-ray diffractrometry (XRD), Raman spectroscopy and infrared luminescence. DSC analyses were carried out on our glass at different heating rates between 5 and 20 °C/min. The result of the annealing temperature on the spectroscopic properties of Er 3+ in tellurite glasses was discussed. The activation energy, for surface crystallization, was determined graphically from a Kissinger-type plot and had a value about 897.2 kJ/mol. Crystalline phases for both α-TeO 2, γ-TeO 2 and Zn 2Te 3O 8 system were determined by the XRD method and were confirmed by Raman spectroscopy characterizations after heat treatment. The effect of heat treatment on absorption spectra and luminescence properties in the tellurite glass was also investigated. With heat treatment, the ultraviolet absorption edge presented a redshift. As a result, the Judd–Ofelt (J–O) intensity parameters ( Ω 2, Ω 4, Ω 6) were determined. The spontaneous emission probabilities of some relevant transitions, the branching ratio and the radiative lifetimes of several excited states of Er 3+ were predicted using intensity J–O parameters. The near infrared emission that corresponds to Er 3+: 4I 13/2→ 4I 15/2 can be significantly enhanced after heat treatment. Notably, it is found that the luminescence lifetime in the present system is much longer than that in most other glasses and glass ceramics. A comparative study on luminescence performance suggests that the obtained glass ceramic is a promising material for Er 3+ doped fiber amplifiers.

The influence of ytterbium doping on the optical properties of tellurite glasses

AbstractThe goal of this work was to investigate the influence of rare earth ion Yb3+ doping on the thermal and optical properties of tellurite glass (TG) of the TeO2‐ZnO‐PbO‐La2O3 system. The reflectance, transmittance and ellipsometric measurements have been done. Decreasing of the refractive index of TG with the Yb3+ ion doping has been concluded. For determination of the refractive index variation in the bulk, the small angle light scatter (SALS) measurements have been carried out. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Thermal and optical properties of tellurite glasses doped erbium

Er3+-doped tellurite glasses with molar compositions of 75TeO2–20ZnO–(5 − x) Na2O–xEr2O3 (x = 0, 0.5, 1, 2, 3, and 4 mol%) have been elaborated from the melt-quenching method. The effects of Er2O3 concentration on the thermal stability and optical properties of tellurite glasses have been discussed. From the differential scanning calorimetry (DSC) profile, the glass transition temperature T g, and crystallization onset temperature T x are estimated. The thermal stability factor, defined as ∆T = T x − T g, was higher than 100 °C. It suggests that tellurite glass exhibits a good thermal stability and consequently is suitable to be a potential candidate for fiber drawing. Furthermore, the stability factor increases with Er2O3 concentration up to 2 mol% then presents a continue decrease suggesting of beginning of crystallization of highly doped tellurite glasses. The refractive index and extinction coefficient data were obtained by analyzing the experimental spectra of tanΨ and cos∆ measured by spectroscopic ellipsometry (SE). The complex dielectric functions (e = e1 + ie2) of the samples were estimated from regression analysis. The fundamental absorption edge has been identified from the optical absorption spectra and was analyzed in terms of the theory proposed by Davis and Mott. The values of optical band gap for direct and indirect allowed transitions have been determined. An important decrease of the optical band gap was found after Er doping. It was assigned to structural changes induced from the formation of non-bridging oxygen. The absorption coefficient just below the absorption edge varies exponentially with photon energy indicating the presence of Urbach’s tail. The origin of the Urbach energy is associated with the phonon-assisted indirect transitions.

Judd–Ofelt analysis and improvement of thermal and optical properties of tellurite glasses by adding P2O5

Abstract Er3+ and Er3+/Yb3+ co-doped tellurite glasses, suitable for developing optical fiber laser and amplifier, have been elaborated from the conventional melt-quenching method. Results of differential scanning calorimetry (DSC) measurements indicate a good thermal stability of tellurite glasses. The DSC measurements show an improvement of thermal stability of glass hosts after adding P2O5. Absorption spectrum from near infrared to visible was obtained and the Judd–Ofelt (J–O) intensity parameters (Ω2, Ω4, and Ω6) were determined. Spontaneous emission probabilities of some relevant transitions, branching ratio, and radiative lifetimes of several excited states of Er3+ have been predicted using intensity J–O parameters. Absorption cross-section and calculated emission cross-section, using the McCumber method, for the 4I13/2→4I15/2 transition, were determined and compared for the doped and co-doped glasses. Energy transfer (ET) and effect of changing concentration of P2O5 and Yb3+ ions on spectroscopic properties were investigated. It was found that the addition of P2O5 can increase the symmetry of the Er3+ ion. As a consequence, PL lifetime becomes more longer. The spectroscopic properties and the efficient infrared luminescence indicate that Er3+ doped TeO2–ZnO–Na2O–Er2O3 (TZNE) is a promising laser and amplifier materials and may be a potentially useful material for developing upconversion fiber optical devices.

Evaluation of the third-order nonlinear optical properties of tellurite glasses by thermally managed eclipse Z-scan

The third-order nonlinearity is measured for TeO2–ZnO–Na2O (TZN) glasses codoped with BaO, Nb2O5, and La2O3. The results for the sign and magnitude of the nonlinearity were obtained using a combination of the eclipse Z-scan with thermal nonlinearity managed Z-scan, whereas the Kerr shutter technique was employed to obtain the electronic time response of the nonlinearity, all performed with 76 MHz repetition rate 150 fs pulses at 800 nm. The results show a fast response (<200 fs) and a nonlinear refractive index varying from 1.5 to 3.5×10−15 cm2/W, depending upon glass composition. At the peak power level employed, nonlinear absorption was negligible. The results obtained are in good agreement with other tellurite compositions reported, confirming the electronic origin of the nonlinearity

Effect of ZnO and Bi 2O 3 addition on linear and non-linear optical properties of tellurite glasses

Glasses in the system TeO 2–Bi 2O 3–ZnO were studied with respect to their linear refractive indices and optical absorption in the UV–vis range. The third order non-linear refractive indices were measured using degenerated four wave mixing (DFWM). The optical Kerr susceptibilities calculated hereof were in the range from 5.49 to 6.58 × 10 −13 esu and hence 34–41 times larger than that of fused SiO 2. They are roughly proportional to values theoretically calculated by the theory of Lines.

Femtosecond nonlinear optical properties of tellurite glasses

The third-order nonlinear optical properties of tellurite glasses with different compositions were investigated in the femtosecond regime at 810nm. Using the I-scan technique, positive nonlinear refractive indices of ∼10−15cm2∕W were measured. The authors also determined that nonlinear absorption was negligible for all studied samples. This result, added to their good chemical stability, indicates that tellurite glasses are promising materials for ultrafast photonic applications.

The optical properties of tellurite glasses

The refractive index for a family of optical glasses (tellurite containing halide) has been analyzed. From the dielectric theory, the relationship between the refractive index and number of ions/unit volume (N/V) with polarizability α has been discussed. Halogen substitution resulted in a lower dielectric constant, along with lower density and lower refractive index. The reduced number of polarizable ions per unit volume was primarily responsible for the reduction in the dielectric constant, although reductions in electronic polarization also affected the dielectric properties.