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Zhao Q, Hao Q, Luo Y, Li X, Cui S, Tan F, Yu C, Peng GD. Photo-induced bleaching and thermally stimulated recovery of BAC-P in Bi-doped phosphosilicate fibers. OPTICS LETTERS 2020; 45:5389-5392. [PMID: 33001901 DOI: 10.1364/ol.404179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
The first results of the study on photobleaching and thermally induced recovery in Bi-doped phosphosilicate fiber have been presented. It was revealed that the rate of bleaching of phosphor-related Bi active center (BAC-P) becomes slower with the decrease of photon energy. The quadratic dependence of the bleaching rate of BAC-P on laser power is obtained under 532 nm laser irradiation. The effect of temperature on the bleaching dynamics of BAC-P is also investigated under 532 nm radiation, suggesting a thermally aggravated bleaching process upon heating at certain temperatures (≥300∘C). Furthermore, the thermal recovery of bleached Bi-doped silica-based fiber (BDF) is investigated and a 13% increase of luminescence is achieved upon thermal quenching for 5 min at 400ºC. The underlying mechanism of photobleaching and thermo-stimulated recovery process of BAC-P is also discussed.
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Hongisto M, Veber A, Petit Y, Cardinal T, Danto S, Jubera V, Petit L. Radiation-Induced Defects and Effects in Germanate and Tellurite Glasses. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E3846. [PMID: 32878282 PMCID: PMC7504562 DOI: 10.3390/ma13173846] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/24/2020] [Accepted: 08/25/2020] [Indexed: 01/13/2023]
Abstract
This review focuses on the radiation-induced changes in germanate and tellurite glasses. These glasses have been of great interest due to their remarkable potential for photonics, in terms of extended transmission window in the mid-infrared, ability of rare-earth loading suitable with a laser, and amplification in the near- and mid-infrared or high nonlinear optical properties. Here, we summarize information about possible radiation-induced defects, mechanisms of their formation, and the influence of the glass composition on this process. Special attention is paid to laser-induced structural modification of these glasses, including possible mechanisms of the laser-glass interaction, laser-induced crystallization, and waveguide writing. It is shown that these methods can be used for photostructuring of the glass and have great potential for practical applications.
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Affiliation(s)
- Mikko Hongisto
- Photonics Laboratory, Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland; (A.V.); (L.P.)
- CNRS, University of Bordeaux, Bordeaux INP, ICMCB, UMR 5026, F-33600 Pessac, France; (Y.P.); (T.C.); (S.D.); (V.J.)
| | - Alexander Veber
- Photonics Laboratory, Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland; (A.V.); (L.P.)
| | - Yannick Petit
- CNRS, University of Bordeaux, Bordeaux INP, ICMCB, UMR 5026, F-33600 Pessac, France; (Y.P.); (T.C.); (S.D.); (V.J.)
| | - Thierry Cardinal
- CNRS, University of Bordeaux, Bordeaux INP, ICMCB, UMR 5026, F-33600 Pessac, France; (Y.P.); (T.C.); (S.D.); (V.J.)
| | - Sylvain Danto
- CNRS, University of Bordeaux, Bordeaux INP, ICMCB, UMR 5026, F-33600 Pessac, France; (Y.P.); (T.C.); (S.D.); (V.J.)
| | - Veronique Jubera
- CNRS, University of Bordeaux, Bordeaux INP, ICMCB, UMR 5026, F-33600 Pessac, France; (Y.P.); (T.C.); (S.D.); (V.J.)
| | - Laeticia Petit
- Photonics Laboratory, Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland; (A.V.); (L.P.)
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Bradley D, Khandaker M, Alanazi A. Irradiated glass and thermoluminescence yield: Dosimetric utility reviewed. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2020.108680] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Bradley D, Siti Shafiqah A, Siti Rozaila Z, Sabtu SN, Abdul Sani S, Alanazi AH, Jafari S, Amouzad Mahdiraji G, Mahamd Adikan F, Maah M, Nisbet A, Tamchek N, Abdul Rashid H, Alkhorayef M, Alzimami K. Developments in production of silica-based thermoluminescence dosimeters. Radiat Phys Chem Oxf Engl 1993 2017. [DOI: 10.1016/j.radphyschem.2016.01.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Ha NN, Giang NT, Thuy TTT, Trung NN, Dung ND, Saeed S, Gregorkiewicz T. Single phase Si1-xGex nanocrystals and the shifting of the E1 direct energy transition. NANOTECHNOLOGY 2015; 26:375701. [PMID: 26303286 DOI: 10.1088/0957-4484/26/37/375701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report preparation and characterization of Si1-xGex alloys with varied composition x of a large range from 0-1. The materials have been obtained by co-sputtering, followed by a heat treatment process at 600, 800, and 1000 °C for 30 min in a nitrogen gas atmosphere. X-ray diffraction data have revealed the formation of single-phase nanoparticles in the face-centered cubic (FCC) structure of Si1-xGex alloys. We found that lattice constant a of the Si1-xGex alloys increased linearly with the composition parameter x. Average diameters of the single-phase nanoparticles were estimated to be between 3-10 nm. Further evidence of FCC single-phase [Formula: see text] nanoparticles has been obtained by high resolution transmission electron microscopy. From absorption spectra, the gradual shift of the direct phononless transition identified for the E1 point in the Brillouin zone of bulk Ge is observed in single-phase Si1-xGex nanoparticles as a function of the composition parameter x.
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Affiliation(s)
- Ngo Ngoc Ha
- International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No.1 Dai Co Viet, Hanoi, Vietnam
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Gunawardena DS, Mat-Sharif KA, Tamchek N, Lai MH, Omar NYM, Emami SD, Muhamad-Yasin SZ, Zulkifli MI, Yusoff Z, Abdul-Rashid HA, Lim KS, Ahmad H. Photosensitivity of gallium-doped silica core fiber to 193 nm ArF excimer laser. APPLIED OPTICS 2015; 54:5508-5512. [PMID: 26192853 DOI: 10.1364/ao.54.005508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Grating inscription in a Ga-doped silica core fiber (~5 wt. % Ga) has been demonstrated using ArF (193 nm) and KrF (248 nm) excimer lasers. In a comparative study with germanosilicate fiber with similar Ge concentration, a Ga-doped silica core fiber shows greater photosensitivity to an ArF excimer laser due to the higher absorbance in the region of 190-195 nm. In addition, the photosensitivity of a Ga-doped silica core fiber has been greatly enhanced with hydrogenation. Ga-doped fibers are potential photosensitive fibers for fiber Bragg grating production with an ArF excimer laser.
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Siti Shafiqah A, Amin Y, Md Nor R, Tamchek N, Bradley D. Enhanced TL response due to radiation induced defects in Ge-doped silica preforms. Radiat Phys Chem Oxf Engl 1993 2015. [DOI: 10.1016/j.radphyschem.2015.02.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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8
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Richard N, Martin-Samos L, Girard S, Ruini A, Boukenter A, Ouerdane Y, Meunier JP. Oxygen deficient centers in silica: optical properties within many-body perturbation theory. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:335502. [PMID: 23877003 DOI: 10.1088/0953-8984/25/33/335502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The electronic and optical properties of neutral oxygen vacancies, also called oxygen deficient centers (ODC(I)s), have been investigated in pure and germanium doped silica (both amorphous and α-quartz) through first-principles calculations. By means of density functional theory and many-body perturbation theory (GW approximation and the solution of the Bethe-Salpeter equation), we obtain the atomic and electronic structures as well as the optical absorption spectra of pure and Ge-doped silica in the presence of ODCs (SiODC(I)s and GeODC(I)s); our study allows us to interpret and explain the very nature of the optical features in experimental absorption spectra. The theoretical optical absorption signatures of these defects show excellent agreement with experiments for the SiODC(I)s, i.e. two absorption bands arise around 7.6 eV due to transitions between the defect levels. Our theoretical results also explain the experimental difficulty in measuring the GeODC(I) absorption band in Ge-doped silica, which was in fact tentatively assigned to a broad and very weak absorption signature, located between 7.5 and 8.5 eV. The influence of Ge-doping induced disorder on the nature of the defect-related optical transitions is discussed. We find that even if the atomic and electronic structures of SiODC(I) and GeODC(I) defects are relatively similar, the slight network distortion induced by the presence of the Ge atom, together with the increase in the Ge-Si bond asymmetry, completely changes the nature of the optical absorption edge.
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Affiliation(s)
- N Richard
- CEA, DAM, DIF, Bruyères-le-Châtel, F-91297 Arpajon Cedex, France.
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9
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Origlio G, Cannas M, Girard S, Boscaino R, Boukenter A, Ouerdane Y. Influence of the drawing process on the defect generation in multistep-index germanium-doped optical fibers. OPTICS LETTERS 2009; 34:2282-2284. [PMID: 19649071 DOI: 10.1364/ol.34.002282] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Variation of germanium lone pair center (GLPC) concentration in germanosilicate multistep-index optical fibers and preforms was studied using confocal microscopy luminescence technique. The experimental results provide evidence that in the central core region ([Ge] approximately 11 wt.%) of our specific canonical samples the ratio [GLPC]/[Ge] is five times larger in fiber than in preforms. The relative influence of the glass composition and of the drawing process on the generation efficiency of the GLPC defects that drive the glass photosensitivity is discussed. The radial distribution of these defects suggests a possible enhancement of the defect creation related to the internal stress of the fiber core.
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Affiliation(s)
- G Origlio
- Laboratoire H. Curien, UMR CNRS 5516, Université Jean Monnet, 18 rue du Pr.Benoît Lauras 42000, Saint-Etienne, France.
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Messina F, Cannas M, Boscaino R. Generation of defects in amorphous SiO(2) assisted by two-step absorption on impurity sites. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2008; 20:275210. [PMID: 21694371 DOI: 10.1088/0953-8984/20/27/275210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Generation of the Si dangling bond defect in amorphous SiO(2) (E' centre) induced by tunable pulsed UV laser radiation was investigated by in situ optical absorption measurements. The defect generation efficiency peaks when the photon energy equals ∼5.1 eV, it depends quadratically on laser intensity and is correlated with the native linear absorption due to Ge impurities. We propose a model in which the generation of E' is assisted by a two-step absorption process occurring on Ge impurity sites.
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Affiliation(s)
- F Messina
- Dipartimento di Scienze Fisiche ed Astronomiche, Università di Palermo, Via Archirafi 36, I-90123 Palermo, Italy
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11
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Zyubin AS, Mebel AM, Lin SH. Optical Properties of Oxygen Vacancies in Germanium Oxides: Quantum Chemical Modeling of Photoexcitation and Photoluminescence. J Phys Chem A 2007; 111:9479-85. [PMID: 17629254 DOI: 10.1021/jp072314f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Photoabsorption and photoluminescence properties of single and double oxygen vacancy (OV and DOV) defects in quartz-like germanium oxide have been investigated by high-level ab initio calculations. It has been found that photoabsorption for these systems occurs at lower energies as compared to the analogous defects in SiO(2). For OV, the lowest electronic excitations with high oscillator strengths have energies of 6.7-7.0 eV, whereas for DOV, the lowest-energy photoabsorption band is calculated to be in the range of 5.5-5.9 eV. Significant geometry relaxation and large Stokes shift are inherent for these excited states and, as a result, their photoluminescence bands are predicted to peak at 3.1-3.3 eV for OV and at 2.6 eV for DOV. The double oxygen vacancy is suggested to be the most suitable candidate for generating bright blue photoluminescence observed experimentally for substoichiometric quartz-like GeO(2) nanowires, as the calculated optical properties of DOV are in close agreement with the features found in experiment.
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Affiliation(s)
- A S Zyubin
- Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 106, Taiwan.
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Ho CKF, Pal R, Djie HS, Pita K, Ngo NQ, Osipowicz T. Optical and physical properties of solgel-derived GeO2:SiO2 films in photonic applications. APPLIED OPTICS 2007; 46:4397-406. [PMID: 17579694 DOI: 10.1364/ao.46.004397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The functionality of optical components relies heavily on the composition-dependent properties of germanosilicate materials, which include the refractive index, photosensitivity, and microstructural properties. Recent studies and parallel developments are presented of germanosilicate films with composition x of Ge content (i.e., xGeO(2):(1-x)SiO(2)) that were synthesized by the solgel process for various integrated photonic applications undertaken. The following novel aspects are discussed with respect to the effect of composition of the glassy films (0.05</=x</=0.40): determination of spectral optical properties, UV imprinting of optical waveguides with relatively large index change (Dn), and quantum-well intermixing enhancement observed in InGaAs(P)/InP quantum-well optical devices. The implications of the results are discussed.
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Affiliation(s)
- Charles K F Ho
- Photonics Research Centre, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798
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Mestanza SNM, Rodriguez E, Frateschi NC. The effect of Ge implantation dose on the optical properties of Ge nanocrystals in SiO(2). NANOTECHNOLOGY 2006; 17:4548-4553. [PMID: 21727576 DOI: 10.1088/0957-4484/17/18/004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Ge nanocrystallites (Ge-nc) embedded in a SiO(2) matrix are investigated using Raman spectroscopy, photoluminescence and Fourier transform infrared spectroscopy. The samples were prepared by ion implantation with different implantation doses (0.5, 0.8, 1, 2, 3 and 4) × 10(16) cm(-2) using 250 keV energy. After implantation, the samples were annealed at 1000 °C in a forming gas atmosphere for 1 h. All samples show a broad Raman spectrum centred at w≈304 cm(-1) with a slight shift depending on the implantation doses. The Raman intensity also depends on the Ge(74+) dose. A maximum photoluminescence intensity is observed for the sample implanted at room temperature with a dose of 2 × 10(16) cm(-2) at 3.2 eV. Infrared spectroscopy shows that the SiO(2) films moved off stoichiometry due to Ge(74+) ion implantation, and Ge oxides are formed in it. This result is shown as a reduction of GeO(x) at exactly the dose corresponding to the maximum blue-violet PL emission and the largest Raman emission at 304 cm(-1). Finally, the Raman spectra were fitted with a theoretical expression to evaluate the average size, full-width at half-maximum (FWHM) and dispersion of Ge-nc size.
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Affiliation(s)
- S N M Mestanza
- Center for Semiconductor Components, State University of Campinas, PO Box 6061, CEP 13083-870, Campinas, SP, Brazil
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14
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Self-alignment of Ge nano-particles in laser induced Bragg grating in Ge–B–SiO2 film. J Photochem Photobiol A Chem 2006. [DOI: 10.1016/j.jphotochem.2006.05.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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15
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Zyubin AS, Mebel AM, Lin SH. Photoluminescence of oxygen-deficient defects in germanium oxides: A quantum chemical study. J Chem Phys 2006; 125:64701. [PMID: 16942299 DOI: 10.1063/1.2238866] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The photoabsorption and photoluminescence (PL) properties of the surface E(') center, -GeX(3), and the combined E(')-center-oxygen vacancy, X(3)Ge-GeX(2), defects in substoichiometric germanium oxides have been investigated by high-level ab initio calculations, including complete active space self-consistent field, multireference configuration interaction, and symmetry-adapted cluster configuration interaction methods. Both defects have been shown to give rise to photoabsorption bands between 4 and 6 eV. Geometry relaxation is significant and the Stokes shifts are large for all calculated excited states. A removal of an electron from the Ge-Ge bond leads to its destruction, whereas the creation of an electron hole at lone pairs of O atoms results in elongations of the Ge-O-Ge bonds in the corresponding bridges. Most often, deexcitations of excited electronic states proceed radiationlessly, through crossing points of their potential energy surfaces with those of the lower states. The -GeX(3) defect is able to generate several PL bands in the UV ( approximately 3 eV) and IR (1.2-1.4 and 0.5-0.6 eV) spectral ranges, whereas the X(3)Ge-GeX(2) defect gives only one red/orange PL band at 2.0-2.1 eV. No intense PL band was found in the blue spectral region of 2.5-2.7 eV, and the two defects are not likely to contribute to the intense blue photoluminescence observed for GeO(2) nanowires.
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Affiliation(s)
- A S Zyubin
- Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 106, Taiwan
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Zyubin AS, Mebel AM, Lin SH. Photoluminescence of oxygen-containing surface defects in germanium oxides: A theoretical study. J Chem Phys 2005; 123:044701. [PMID: 16095378 DOI: 10.1063/1.1940027] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Photoabsorption and photoluminescence properties of nonbridging oxygen -O-Ge[triple bond](NBO), -OO-Ge[triple bond] (peroxy radical), O=Ge=, and (O2)Ge= defects in germanium oxides have been investigated by high-level ab initio calculations. Geometry optimization for excited electronic states of model clusters simulating these defects was carried out at the complete-active-space self-consistent-field level, and relative energies were calculated by various methods including time-dependent density-functional theory, outer-valence Green's functions, equation-of-motion coupled cluster theory with single and double excitations, symmetry-adapted cluster configuration interaction, multireference second-order perturbation theory, and multireference configuration interaction. The results demonstrate that the considered excited states of the aforementioned defects normally exhibit large Stokes shifts and that, with few exceptions, UV photoabsorption is accompanied by red or IR photoluminescence.
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Affiliation(s)
- A S Zyubin
- Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 106, Taiwan
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Laser-induced ultraviolet absorption and refractive index changes in Ge–B–SiO2 planar waveguides by inductively coupled plasma-enhanced chemical vapor deposition. Chem Phys Lett 2003. [DOI: 10.1016/j.cplett.2003.08.076] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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18
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Takahashi M, Sakoh A, Ichii K, Tokuda Y, Yoko T, Nishii J. Photosensitive GeO2-SiO2 films for ultraviolet laser writing of channel waveguides and bragg gratings with Cr-loaded waveguide structure. APPLIED OPTICS 2003; 42:4594-4598. [PMID: 12916627 DOI: 10.1364/ao.42.004594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Irradiation with intense ultraviolet laser pulses induced a large refractive-index change in 30GeO2-70SiO2 waveguide-grade thin films prepared by the plasma-enhanced chemical vapor deposition method, which contained a large amount of photoactive Ge2+ defects. The maximum index change in the as-deposited films by KrF and XeF excimer laser irradiation was estimated to be 1.2 x 10(-3) and 0.28 x 10(-3), respectively. These results clearly indicate that the photorefractivity of GeO2-SiO2 glasses is due to a Ge2+ defect in origin. The channel waveguide and the planar Bragg gratings were directly written in the photoactive Ge(2+)-enriched GeOs-SiO2 thin films by pulsed ultraviolet laser irradiation with a Cr-metal-loaded-type waveguide structure.
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Affiliation(s)
- Masahide Takahashi
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
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19
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Low optical loss germanosilicate planar waveguides by low-pressure inductively coupled plasma-enhanced chemical vapor deposition. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(02)01837-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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20
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Raghavachari K, Ricci D, Pacchioni G. Optical properties of point defects in SiO2 from time-dependent density functional theory. J Chem Phys 2002. [DOI: 10.1063/1.1423664] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Cristoni S, Armelao L, Gross S, Seraglia R, Tondello E, Traldi P. Study of polycondensation reactions of Ge(OEt)(4) and Ge(OEt)(4)/Si(OEt)(4) by electrospray ionization mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2002; 16:733-737. [PMID: 11921254 DOI: 10.1002/rcm.619] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Uchino T, Takahashi M, Yoko T. Structure and formation mechanism of Ge E (') center from divalent defects in Ge-doped SiO2 glass. PHYSICAL REVIEW LETTERS 2000; 84:1475-1478. [PMID: 11017546 DOI: 10.1103/physrevlett.84.1475] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/1999] [Indexed: 05/23/2023]
Abstract
We have performed ab initio quantum-chemical calculations on clusters of atoms modeling a divalent Ge defect in Ge-doped SiO (2) glasses. It has been found that the divalent Ge defect interacts with a nearby GeO (4) tetrahedron, forming complex structural units that are responsible for the observed photoabsorption band at approximately 5 eV. We have shown that these structural units can be transformed into two equivalent Ge E' centers by way of the positively charged defect center.
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Affiliation(s)
- T Uchino
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
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25
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Hosono H, Nishii J. High photosensitivity and nanometer-scale phase separation in GeO(2)-SiO(2) glass thin films. OPTICS LETTERS 1999; 24:1352-1354. [PMID: 18079801 DOI: 10.1364/ol.24.001352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Amorphous xGeO(2)-(1-x)SiO(2) thin films exhibit large negative index changes (4-8%) in the high GeO(2) region (x>~0.25) on irradiation with ArF laser pulses. The sign of the index change is opposite the low GeO(2) region X<0.25, and the magnitude of the index change is larger by an order of magnitude than that reported so far. Cross-sectional transmission electron microscope observation has revealed that nanometer-scale phase separation is induced in these highly photosensitive glasses by irradiation with ArF excimer laser light pulses or electron beams. This is a first finding of microphase separation in SiO(2)-GeO(2) glasses by irradiation and provides an essential constraint on the modeling of photonic effects induced by irradiation in these glasses.
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Brambilla G, Pruneri V, Reekie L, Payne DN. Enhanced photosensitivity in germanosilicate fibers exposed to CO2 laser radiation. OPTICS LETTERS 1999; 24:1023-1025. [PMID: 18073928 DOI: 10.1364/ol.24.001023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report a novel method to increase the UV photosensitivity of GeO(2): SiO(2) optical fibers based on exposure to CO(2) laser irradiation before grating writing. Fibers treated with a CO(2) laser can produce gratings with refractive-index modulation two times greater and a Bragg wavelength that can be 2 nm longer than those of untreated fibers. Experiments on GeO(2): SiO(2) preform samples treated with a CO(2) laser in a way similar to the fibers showed a marked increase of the 242-nm absorption band, which is associated with an increase of germanium oxygen-deficient centers and is believed to be responsible for the higher photorefractive response.
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Nishii J, Yamanaka H. Bragg gratings printed upon thin glass films by excimer laser irradiation and selective chemical etching. APPLIED OPTICS 1997; 36:6852-6856. [PMID: 18259555 DOI: 10.1364/ao.36.006852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Photon-induced property changes of sputter-deposited GeO(2)-SiO(2) thin glass films were investigated. Irradiation with ArF laser pulses induced the changes in refractive index of -10% and volume of +30% in the film without ablation. A Bragg grating with a positive sinusoid wave pattern was printed upon the film by irradiation with ArF excimer laser pulses through a phase mask. The irradiated area could be quickly etched by a HF solution. The ratio of etching rate of irradiated area to unirradiated area was higher than 30. A Bragg grating with a surface relief pattern was successfully formed on the film by irradiation with excimer laser pulses followed by chemical etching. Diffraction efficiency of the gratings increased by 25 times with the etching.
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Affiliation(s)
- J Nishii
- Department of Optical Materials, Osaka National Research Institute, Agency of Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka 563, Japan
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Crivelli B, Martini M, Meinardi F, Paleari A, Spinolo G. Photoinduced conversion of optically active defects in germanium-doped silica. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:16637-16640. [PMID: 9985788 DOI: 10.1103/physrevb.54.16637] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Continenza A. All-electron study of the electronic properties of quartz with Al substitutional impurity. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:13687-13693. [PMID: 9985283 DOI: 10.1103/physrevb.54.13687] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Davis KM, Miura K, Sugimoto N, Hirao K. Writing waveguides in glass with a femtosecond laser. OPTICS LETTERS 1996; 21:1729-31. [PMID: 19881782 DOI: 10.1364/ol.21.001729] [Citation(s) in RCA: 527] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
With the goal of being able to create optical devices for the telecommunications industry, we investigated the effects of 810-nm, femtosecond laser radiation on various glasses. By focusing the laser beam through a microscope objective, we successfully wrote transparent, but visible, round-elliptical damage lines inside highsilica, borate, soda lime silicate, and f luorozirconate (ZBLAN) bulk glasses. Microellipsometer measurements of the damaged region in the pure and Ge-doped silica glasses showed a 0.01-0.035 refractive-index increase, depending on the radiation dose. The formation of several defects, including Si E' or Ge E' centers, nonbridging oxygen hole centers, and peroxy radicals, was also detected. These results suggest that multiphoton interactions occur in the glasses and that it may be possible to write three-dimensional optical circuits in bulk glasses with such a focused laser beam technique.
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Nishii J, Yamanaka H, Hosono H, Kawazoe H. Preparation of Bragg gratings in sputter-deposited GeO(2)-SiO(2) glasses by excimer-laser irradiation. OPTICS LETTERS 1996; 21:1360-1362. [PMID: 19876352 DOI: 10.1364/ol.21.001360] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
GeO(2) - SiO(2) thin glass films were prepared by the rfsputtering deposition method. Changes in the refractive index of -3% and in the volume of +18% were induced in the film by irradiation with excimer-laser pulses. Bragg gratings a (periodic surface-relief pattern with a sinusoidal wave) have been written in the film by irradiation through a phase mask.
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Dianov EM, Starodubov DS. Efficient photobleaching of 390-nm luminescence in germanosilicate preforms by the third harmonic of a Nd:YAG laser. OPTICS LETTERS 1996; 21:635-637. [PMID: 19876108 DOI: 10.1364/ol.21.000635] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Permanent photobleaching of blue luminescence with a maximum at ~390 nm in Ge-doped fiber preforms by exposure to the third harmonic (354 nm) of a Nd:YAG laser has been observed. The experimental results show that photodestruction of a germanium oxygen-deficient center can occur without photoionization.
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Hosono H, Kawazoe H, Nishii J. Defect formation in SiO2:GeO2 glasses studied by irradiation with excimer laser light. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:R11921-R11923. [PMID: 9982887 DOI: 10.1103/physrevb.53.r11921] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Fujimaki M, Yagi K, Ohki Y, Nishikawa H, Awazu K. Laser-power dependence of absorption changes in Ge-doped SiO2 glass induced by a KrF excimer laser. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:9859-9862. [PMID: 9982547 DOI: 10.1103/physrevb.53.9859] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Bagratashvili VN, Popov VK, Tsypina SI, Chernov PV, Rybaltovskii AO. Oscillator strengths of UV absorption and luminescence for oxygen-deficient centers in germanosilicate fibers. OPTICS LETTERS 1995; 20:1619-1621. [PMID: 19862102 DOI: 10.1364/ol.20.001619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The time-resolved measurements of triplet and singlet luminescence from germanium oxygen-deficient centers (GODC's) in germanosilicate fibers excited by short UV laser pulses are used to determine the cross section of UV absorption of GODC's at lambda = 248 nm (sigma = 5 x 10(-18) cm(2)), the oscillator strength of UV absorption (f(abs) = 0.027), and UV luminescence (f(lum) = 0.031). The basis for these measurements is the direct luminescence detection of lifetimes of electronically excited states of GODC's, the saturation of triplet luminescence signals, and the analysis of the rate equations that govern the laser photoexcitation and relaxation processes in GODC's.
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Nishii J, Fukumi K, Yamanaka H, Kawamura K, Hosono H, Kawazoe H. Photochemical reactions in GeO2-SiO2 glasses induced by ultraviolet irradiation: Comparison between Hg lamp and excimer laser. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:1661-1665. [PMID: 9981229 DOI: 10.1103/physrevb.52.1661] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Nishii J, Kitamura N, Yamanaka H, Hosono H, Kawazoe H. Ultraviolet-radiation-induced chemical reactions through one and two-photon absorption processes in GeO(2)-SiO(2) glasses. OPTICS LETTERS 1995; 20:1184-1186. [PMID: 19859466 DOI: 10.1364/ol.20.001184] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Photochemical reactions in 10 GeO(2)-90 SiO(2) glass induced by irradiation with excimer lasers (KrF, 5.0 eV, XeCl, 4.0 eV) and a Hg lamp (4.9 eV) were examined. The irradiation with excimer lasers generated two types of paramagnetic defect, an electron-trapped center associated with fourfold coordinated Ge ions and a self-trapped hole center on bridging oxygen. Taking the optical band gap (~7.1 eV) of the glass obtained in this work and the power density of laser pulses [10-90 mJ/(cm(2) pulse), pulse duration 20 ns] into account, we concluded that these centers were formed by band-to-band excitation by two-photon absorption process. On the other hand, the lamp illumination ( 16 mW/cm(2)) caused the formation of Ge E' centers from preexisting oxygen-vacancy-type defects by the one-photon absorption process. These two kinds of reaction proceed independently, depending on the power densities of UV beams, at least in our experimental condition.
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Albert J, Malo B, Bilodeau F, Johnson DC, Hill KO, Hibino Y, Kawachi M. Photosensitivity in Ge-doped silica optical waveguides and fibers with 193-nm light from an ArF excimer laser. OPTICS LETTERS 1994; 19:387-389. [PMID: 19829650 DOI: 10.1364/ol.19.000387] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Photosensitivity in optical fibers and waveguides has been associated with the bleaching of an absorption band located near 5.0 eV (or 242 nm). We present new results for Bragg grating formation and UV bleaching experiments carried out using 193-nm light from an ArF excimer laser instead of the usual laser sources operating near 242 or 248 nm.
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Chiang KS, Sceats MG, Wong D. Ultraviolet photolytic-induced changes in optical fibers: the thermal expansion coefficient. OPTICS LETTERS 1993; 18:965-967. [PMID: 19823260 DOI: 10.1364/ol.18.000965] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We show that recent experimental results of Wong et al. [Opt. Lett. 17, 1773 (1992)] on the effect of UV photolytic processing on the birefringence of elliptical-core fibers arise from a 15-30% reduction of the coefficient of thermal expansion of the germanosilicate core. An explanation based on reconfiguration of the glass network to minimize the stress energy during UV processing is proposed.
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Tsai TE, Friebele EJ, Griscom DL. Thermal stability of photoinduced gratings and paramagnetic centers in Ge- and Ge/P-doped silica optical fibers. OPTICS LETTERS 1993; 18:935-937. [PMID: 19823250 DOI: 10.1364/ol.18.000935] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The electron-spin-resonance spectra of paramagnetic defects in Ge/P-doped silica fibers prepared with second-harmonic generation (SHG) are compared with those induced in Ge- and Ge/P-doped silica preforms by 5-eV photons. Among the defects observed, the thermal stability of Ge E'-type centers is similar to that of photoinduced Bragg grating efficiency but not of SHG efficiency. The isochronal anneal curves of the Ge(l) and Ge(2) centers in, Ge/P-doped silica correlate well with SHG efficiency, but the agreement is not nearly so good in silica containing only Ge. Only the thermal behavior of photoinduced Ge E'(d1) centers is similar to that of SHG efficiency in both materials, albeit only in the initial stages of annealing.
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