Lead Niobium Germanate Research Articles

Replacement of glass-former B2O3 by GeO2 in amorphous host evidenced by optical methods

Two completely different glass-host matrices containing lead, i.e. borate and germanate glasses doped with erbium were studied. Replacement of glass-former B2O3 by GeO2 in amorphous host was evidenced by optical methods. The luminescence decay from the 4I13/2 upper laser state of Er3+ ions is relatively short, whereas up-converted emission signal is reduced definitely in borate glass containing lead due to its high B-O stretching vibrations. The results indicate that germanate glasses containing lead are promising for near-infrared luminescence and up-conversion applications. Full Text: PDF ReferencesR. Balda, A. Oleaga, J. Fernandez, J.M. Fdez-Navarro, "Spectroscopy and frequency upconversion of Er3+ ions in lead niobium germanate glasses", Opt. Mater. 24, 83 (2003). CrossRef H. Yamauchi, Y. Ohishi, "Spectroscopic properties of Er3+-doped PbO?Ga2O3?GeO2 glass for optical amplifiers", Opt. Mater. 27, 679 (2005). CrossRef W.A. Pisarski, Ł. Grobelny, J. Pisarska, R. Lisiecki, W. Ryba-Romanowski, "Spectroscopic properties of Yb3+ and Er3+ ions in heavy metal glasses", J. Alloys Compd. 509, 8088 (2011). CrossRef M.B. Saisudha, J. Ramakrishna, "Effect of host glass on the optical absorption properties of Nd3+, Sm3+, and Dy3+ in lead borate glasses", Phys. Rev. B 53, 6186 (1996). CrossRef C.K. Jayasankar, V. Venkatramu, S. Surendra Babu, P. Babu, "Luminescence properties of Dy3+ ions in a variety of borate and fluoroborate glasses containing lithium, zinc, and lead", J. Alloys Compd. 374, 22 (2004). CrossRef W.A. Pisarski et al. "Luminescence spectroscopy of rare earth-doped oxychloride lead borate glasses", J. Lumin. 131, 649 (2011). CrossRef M. Kochanowicz, W. Mazerski, J. Żmojda, K. Czajkowski, D. Dorosz, "Green upconversion emission in tellurite optical fibre codoped with Yb3+/Er3+", Phot. Lett. Poland 5, 35 (2013). CrossRef J. Dorosz, "Novel constructions of optical fibers doped with rare ? earth ions", Ceramics 86 (2005). CrossRef J. Żmojda, D. Dorosz, M. Kochanowicz, J. Dorosz, "Spectroscopic properties of Yb3+/Er3+ - doped antimony-phosphate glasses for fiber amplifiers", Phot. Lett. Poland 2, 76 (2010). CrossRef J. Dorosz, R. S. Romaniuk, "Development of Optical Fiber Technology in Poland", INTL J. Electron. Telecom. 57, 191 (2011). CrossRef Q.Y. Zhang et al. "Effects of PbF2 doping on structure and spectroscopic properties of Ga2O3?GeO2?Bi2O3?PbO glasses doped with rare earths", J. Appl. Phys. 99, 033510 (2006) CrossRef W.A. Pisarski, G. Dominiak-Dzik, W. Ryba-Romanowski, J. Pisarska, "Role of PbO substitution by PbF2 on structural behavior and luminescence of rare earth-doped lead borate glass", J. Alloys Compd. 451, 220 (2008). CrossRef M. Sołtys, J. Pisarska, L. Żur, T. Goryczka, W.A. Pisarski, "Influence of M2O3 (M = Al, Ga) glass modifiers on structure, thermal and spectroscopic properties of rare earth ions in lead phosphate based systems", Proc. SPIE 9228, 92280A (2014). CrossRef J. Janek, J. Pisarska, W.A. Pisarski, "Rare earth doped lead-free germanate glasses for modern photonics", Phot. Lett. Poland 6, 71 (2014). CrossRef W.A. Pisarski et al. "Infrared-to-visible conversion luminescence of Er3+ ions in lead borate transparent glass-ceramics", Opt. Mater. 31, 1781 (2009). CrossRef J. Pisarska, L. Żur, W.A. Pisarski, "Optical spectroscopy of Dy3+ ions in heavy metal lead-based glasses and glass?ceramics", J. Mol. Struct. 993, 160 (2011). CrossRef L. Żur, M. Sołtys, J. Pisarska, W.A. Pisarski, "Absorption and luminescence properties of terbium ions in heavy metal glasses", J. Alloys Compd. 578, 512 (2013). CrossRef W.A. Pisarski, L. Żur, M. Kowal, J. Pisarska, "Enhancement and quenching photoluminescence effects for rare earth ? Doped lead bismuth gallate glasses", J. Alloys Compd. 651, 565 (2015). CrossRef M. Shojiya, Y. Kawamoto, K. Kadono, "Judd?Ofelt parameters and multiphonon relaxation of Ho3+ ions in ZnCl2-based glass", J. Appl. Phys. 89, 4944 (2001). CrossRef

Rare earth doped lead-free germanate glasses for modern photonics

Lead-free germanate glasses doped with rare earth ions were synthesized and next studied using excitation and luminescence spectroscopy. Rare earths were limited to Pr 3+ , Eu 3+ and Er 3+ ions. Several luminescence bands correspond to transitions originating from the 3 P 0 and 1 D 2 states of Pr 3+ , the 5 D 0 state of Eu 3+ , the 4 S 3/2 , 4 F 9/2 and 4 I 13/2 states of Er3+ , respectively. The relatively long lifetime for the upper 4 I 13/2 laser state of Er 3+ suggest that lead-free germanate glasses are promising materials for near-infrared optical amplifiers. Full Text: PDF References M. Yamane and Y. Asahara, Glasses for photonics (Cambridge University Press 2000). CrossRef A. Jha et al, "Rare-earth ion doped TeO2 and GeO2 glasses as laser materials", Prog. Mater. Sci. 57, 1426 (2012). CrossRef J.S. Wang, E.M. Vogel, E. Snitzer, "Tellurite glass: a new candidate for fiber devices", Opt. Mater. 3, 187 (1994). CrossRef J. Dorosz, "Optical Fibers Technology", Ceramics 86 (2005). J. Dorosz, R.S. Romaniuk, "Development of Optical Fiber Technology in Poland", INTL J. Electron. Telecom. 57, 191 (2011). CrossRef M. Kochanowicz, W. Mazerski, J. Żmojda, K. Czajkowski, D. Dorosz, "Green upconversion emission in tellurite optical fibre codoped with Yb3+/Er3+", Phot. Lett. Poland 5, 35 (2013). CrossRef J. Żmojda, D. Dorosz, M. Kochanowicz, J. Dorosz, "Spectroscopic properties of Yb3+/Er3+ - doped antimony-phosphate glasses for fiber amplifiers", Phot. Lett. Poland 2, 76 (2010). CrossRef H. Lin, E.Y.B. Pun, B.J. Chen, Y.Y. Zhang, "Rare-earth ion doped lead- and cadmium-free bismuthate glasses", J. Appl. Phys. 103, 056103 (2008). CrossRef S.S. Bayya, G.D. Chin, J.S. Sanghera, I.D. Aggarwal, "Germanate glass as a window for high energy laser systems", Opt. Express 14, 11687 (2006). CrossRef J.M. Jewell, P.L. Higby, I.D. Aggarwal, "Properties of BaO–R2O3– Ga2O3–GeO2 (R = Y, Al, La, and Gd) Glasses", J. Am. Ceram. Soc. 77, 697 (1994). CrossRef R.R. Xu, Y. Tian, M. Wang, L.L. Hu, J.J. Zhang, "Spectroscopic properties of 1.8 μm emission of thulium ions in germanate glass", Appl. Phys. B 102, 109 (2011). CrossRef R. Xu, Y. Tian, L. Hu, J. Zhang, "Broadband 2 μm emission and energy-transfer properties of thulium-doped oxyfluoride germanate glass fiber", Appl. Phys. B 104, 839 (2011). CrossRef V.K. Tikhomirov, S.A. Tikhomirova, "Hypersensitive transition 3P0 → 3F2 of Pr3+ related to the polarizability and structure of glass host", J. Non-Cryst. Solids 274, 50 (2000). CrossRef R. Balda, A. Oleaga, J. Fernandez, J.M. Fdez-Navarro, "Spectroscopy and frequency upconversion of Er3+ ions in lead niobium germanate glasses", Opt. Mater. 24, 83 (2003). CrossRef H. Yamauchi, Y. Ohishi, "Spectroscopic properties of Er3+-doped PbO–Ga2O3–GeO2 glass for optical amplifiers", Opt. Mater. 27, 679 (2005). CrossRef W.A. Pisarski, Ł. Grobelny, J. Pisarska, R. Lisiecki, and W. Ryba-Romanowski, "Spectroscopic properties of Yb3+ and Er3+ ions in heavy metal glasses", J. Alloys Compd. 509, 8088 (2011). CrossRef

Structural origin of the nonlinear optical properties of lead niobium germanate film glasses

The structural origin of the nonlinear optical susceptibility (/χ(3)/) of lead-niobium-germanate film glasses with large Nb2O5 contents has been investigated. /χ(3)/ shows a strong enhancement with the Nb content in the films with /χ(3)/ values close to 2 × 10−11 esu at 800 nm for a Nb content as high as 0.71. Boling-Glass-Owyoung and Lines’ semiempirical models predict accurately the values of /χ(3)/ for transparent bulk glasses but not for film glasses. This discrepancy is related to the remarkable structural differences between them. Raman spectroscopy suggests the formation of a three-dimensional (3D) structure of [NbO6] octahedra in the case of film glasses having large Nb contents, while X-ray photoelectron spectroscopy shows that a significant fraction of these units contain Nb4+ ions. The combination of a 3D structure of [NbO6] with the presence of Nb4+ polarons and their migration through electron intervalence transfer is proposed as the origin of the observed enhancement of /χ(3)/ in the film glasses.

Upconversion emission in Er3+-doped lead niobium germanate thin-film glasses produced by pulsed laser deposition

Thin films of Er3+-doped lead–niobium germanate have been produced by pulsed laser deposition from Er3+-doped 25PbO2–25Nb2O5–50GeO2 (mol%) transparent glasses with an Er content in the range 0.5–3 wt%. The room-temperature infrared to visible upconversion properties of these thin films have been investigated under 800-nm laser excitation. An energy transfer upconversion mechanism has been identified to be responsible for the population of the 4S3/2:2H11/2 excited level, from which an intense green emission occurs. A rate equation analysis supports the proposed mechanism.

Influence of surface effects on the performance of lead–niobium–germanate optical waveguides

Lead–niobium–germanate planar waveguides have been produced by pulsed laser deposition. The composition of the waveguides is found to be relatively weakly dependent on the laser fluence, while their surface morphology is affected dramatically. Smooth surfaces are obtained for a narrow fluence range centered at 2.0 J/cm 2, while particulates having typical diameters of <0.5 μm or droplets with typical diameters of <10 μm are observed at lower and higher fluences, respectively. The refractive index of the waveguides increases with fluence up to 2.1 at 2.0 J/cm 2, which is close to the value of the bulk glass, and remains constant at higher fluences. Propagation losses show instead a minimum (≈6.5 dB/cm) at 2.0 J/cm 2. The characteristics of the ablation process that leads to the ejection of solid particulates or molten droplets as well as the increase of the waveguides density on increasing the fluence are discussed to be responsible for the observed optical behavior.

Effect of concentration on the infrared emissions of Tm3+ ions in lead niobium germanate glasses

Abstract In this work, we have studied the effect of concentration on the 3 H 4 → 3 F 4 and 3 F 4 → 3 H 6 emissions of Tm 3+ -doped lead–niobium–germanate glasses (GeO 2 –PbO–Nb 2 O 5 ) for different Tm 3+ concentrations (0.1, 0.2, 0.5, 1, 2, and 3 wt%) and at different temperatures between 10 K and 295 K. The emission spectra obtained under 798 nm excitation reveal the existence of energy transfer via cross-relaxation among Tm 3+ . As a result, the intensity of the infrared 3 H 4 → 3 F 4 emission at 1474 nm decreases in relation to that of emission at 1820 nm, as concentration increases. The non-exponential character of the decays from the 3 H 4 level with increasing concentration, together with the dependence of the quenching rate on Tm 3+ concentration, indicate the presence of a dipole–dipole quenching process in the framework of a diffusion-limited regime. The self-quenching of the 3 F 4 → 3 H 6 emission at 1820 nm can be attributed to limited diffusion within the active centers.

Optical spectroscopy of Tm3+ ions in GeO2–PbO–Nb2O5 glasses

Abstract In this work, we report the optical properties of Tm 3+ doped lead–niobium–germanate glasses (GeO 2 –PbO–Nb 2 O 5 ) for different Tm 3+ concentrations ranging between 0.5 and 3 wt%. Judd–Ofelt intensity parameters have been determined to calculate the radiative transition probabilities and radiative lifetimes of excited states. Luminescence spectra and lifetimes were measured under 798 nm excitation. The infrared emissions at 1474 nm and 1820 nm have been characterized at room temperature for all concentrations. In this glass the infrared emission corresponding to the 3 H 4 → 3 F 4 transition is broader by nearly 40 nm if compared to fluoride glasses used for S-band amplifiers. The stimulated emission cross-sections have been determined from the line shape of the emission spectra and the lifetimes of levels 3 H 4 and 3 F 4 respectively.

Energy transfer studies in Eu3+-doped lead–niobium–germanate glasses

The spectral migration of energy among Eu 3+ ions in lead-niobium-germanate glass (60GeO 2 -25PbO-15Nb205) with different Eu 3+ concentrations (0.5, 1, 3, and 5 mol%) has been investigated at low temperature by using time-resolved fluorescence line narrowing (TRFLN) spectroscopy. The spectral features of the time-resolved fluorescence line-narrowed 5 D 0 → 7 F 0 emission spectra under resonant excitation at different wavelengths along the 7 F 0 → 5 D 0 transition as a function of time, excitation wavelength, and concentration reveal the existence of energy migration between discrete regions of the inhomogeneous broadened spectral profile. The analysis of the time evolution of the 5 D 0 → 7 F 0 emission shows that the electronic mechanism responsible for the ion-ion interaction can be identified as a dipole-dipole energy transfer process.

Infrared-to-visible upconversion of Er^3+ ions in GeO_2–PbO–Nb_2O_5 glasses

We report the infrared-to-visible upconversion luminescence of Er3+-doped lead–niobium–germanate glasses (GeO2–PbO–Nb2O5) with different Er2O3 concentrations (0.5, 1, 2, and 3 wt.%) under continuous-wave and pulsed-laser excitation in the near-infrared region inside the 4I9/2 level. Intense green emission due to the (2H11/2, 4S3/2)→4I15/2 transitions was observed at room temperature together with a weak red emission corresponding to the 4F9/2→4I15/2 transition. These upconversion emissions are attributed to a two-photon process. The time evolution of the green emission from the 4S3/2 level indicates that energy-transfer upconversion and excited-state absorption are responsible for the upconversion luminescence. The increase of the weak red emission with increasing Er2O3 concentration, together with its temporal behavior under infrared excitation, suggests that for Er2O3 concentrations higher than 1 wt.%, the upconverted red emission is the result of multiphonon relaxation from the 4S3/2 level and energy-transfer processes.

Infrared to visible upconversion of Er3+ and Er3+/Yb3+ codoped lead–niobium–germanate glasses

Abstract Infrared-to-visible upconversion processes have been investigated in Er 3+ -doped and Er 3+ /Yb 3+ codoped lead–niobium–germanate glass (55GeO 2 –25PbO–20Nb 2 O 5 ) with a fixed 0.5 mol% Er 3+ concentration and different Yb 3+ concentrations ranging from 0 to 2 mol%. Visible emissions at 526, 547, and 660 nm corresponding to the 2 H 11/2 → 4 I 15/2 , 4 S 3/2 → 4 I 15/2 , and 4 F 9/2 → 4 I 15/2 transitions were observed under continuous wave excitation at 978 nm. The quadratic pump power dependence of these emissions indicates a two photon upconversion process. An enhancement of the visible upconversion fluorescence in Er 3+ /Yb 3+ codoped samples is confirmed due to efficient energy transfer from Yb 3+ to Er 3+ ions.

Laser action and upconversion of Nd3+ in lead–niobium–germanate bulk glass

Laser action together with upconversion processes which produce green, orange, and red emissions in Nd3+-doped lead–niobium–germanate bulk glass (60GeO2–25PbO–15Nb2O5) have been investigated. The upconversion processes were conducted in such a way that the dynamics of the visible fluorescence was analyzed under lasing and non-lasing conditions. The features present in the time resolved upconverted emission show the existence of excited state absorption of both pump radiation and laser emission.

Spectroscopy and frequency upconversion of Er3+ ions in lead niobium germanate glasses

Abstract In this work we report the optical properties and upconversion luminescence of Er 3+ ions in lead–niobium–germanate glass (GeO 2 –PbO–Nb 2 O 5 ) suitable for use in optical waveguide devices. The optical properties of Er 3+ ions have been established in terms of absorption and emission spectra and lifetime measurements in the visible and infrared regions. The 1.5 μm emission cross-section has been determined from the line shape of the emission spectrum and the calculated emission probability for the 4 I 13/2 level. Upconversion emissions at 529, 548, and 653 nm have been obtained under infrared excitation at 803 nm in the 4 I 9/2 level and compared with those obtained under one photon excitation. Pumping power measurements were also carried out. The possible excitation mechanisms responsible for this upconversion luminescence are discussed.