Bi-doped Glasses Research Articles

GeO2 influence on the formation of near-infrared emitting centers in Bi-doped multicomponent silicate glasses

A meaningful increase in the number of NIR emission centers was experimentally observed in bismuth-doped multicomponent silicate glasses additionally doped with germanium dioxide. The emission and excitation spectra of the glass sets were monitored and compared with the spectra of radiative oxygen-deficient centers in vitreous silica and germania.

Regulation of structure rigidity for improvement of the thermal stability of near-infrared luminescence in Bi-doped borate glasses

The effect of heat-treatment on the near-infrared (NIR) luminescence properties was studied in Bi-doped borate glasses. The luminescence intensity generally decreases with the increase of temperature, and the thermal stability can be improved by nearly 4.5 times with addition of 5 mol% La2O3. Collaborative studies by using steady photoluminescence (PL) and photoluminescence excitation (PLE) spectra, luminescence decay curve, differential thermal analysis (DTA), Raman spectra and X-ray diffraction (XRD) indicate that the luminescence decrement is associated with the agglomeration of Bi active centers during heat-treatment. The improvement of the thermal stability of NIR luminescence with the addition of La2O3 is benefited from the enhancement of structure rigidity due to the strong cationic field strength of La3+. The results not only provide valuable guidance for suppressing performance degradation of Bi-doped glass during fiber drawing process, but also present an effective way to control the luminescence properties of main group elements in glasses from the perspective of glass structure.

Absorption and Emission Properties of Bismuth-Doped Silicate Glass

Single Bi-doped and M/Bi co-doped silicate glass (M=Al, Y, La) were prepared and broadband NIR emission were observed when the glass samples were pumped by 514 nm and 808 nm LD, respectively. The absorption intensity and emission intensity of the Y/Bi co-doped glass and La/Bi co-doped glass decrease obviously compared to single Bi-doped glass. The absorption intensity in the region of 600-1100 nm and the NIR emission intensity pumped by an 808 nm LD were remarkably enhanced by the introduction of Al2O3 into the Bi-doped silicate glass. It is suggested that the Al/Bi co-doped silicate glass might be very useful for broadband fiber amplifiers and widely tunable lasers.

Upconversion luminescence in bismuth-doped germano-silicate glass optical fiber

We report, for the first time, a broadband upconversion emission (800–1000 nm) in Bi-doped germano-silicate glass optical fibers with excitation in the range of 1515–1585 nm, which can explain the low laser efficiency at wavelengths longer than 1500 nm. The mechanism responsible for the emission is two-step upconversion process. The origin of this upconversion luminescence is discussed and new energy transition schemes are proposed. • We fabricated bismuth-doped germane-silicate glass optical fibers. • New upconversion emission band was observed by pumping around 1.5 μm. • Both emissions at 837 and 945 nm depend quadratically on the incident power. • Two-step upconversion process and new energy transition scheme was proposed.

Enhanced broadband near-infrared luminescence in Bi-doped glasses by co-doping with Ag

Enhanced broadband near-infrared luminescence has been observed in Bi-doped oxyfluoride glasses excited from UV to near-infrared regions with the addition of AgCl. Enhancement factors depend greatly on excitation wavelength and maximal enhancement factor over three times occurs at the excitation wavelength around 320, 640, and 800 nm. Ag species play dual functions. The mechanism of the enhancement is discussed in depth combing the energy transfer from Ag+, molecular-like, nonplasmonic Ag species, Bi3+ and Bi2+ to near-infrared bismuth active centers, and the redox reaction of Bi species with Ag species. These results offer a valuable way to enhance the near-infrared luminescence efficiency of Bi-doped glasses, and the dual functions of Ag species may also be employed to enhance luminescence of rare-earth and transition metal ions doped materials.

On the analogy between photoluminescence and carrier-type reversal in Bi- and Pb-doped glasses

Reaction order in Bi-doped oxide glasses depends on the optical basicity of the glass host. Red and NIR photoluminescence (PL) bands result from Bi(2+) and Bin clusters, respectively. Very similar centers are present in Bi- and Pb-doped oxide and chalcogenide glasses. Bi-implanted and Bi melt-doped chalcogenide glasses display new PL bands, indicating that new Bi centers are formed. Bi-related PL bands have been observed in glasses with very similar compositions to those in which carrier-type reversal has been observed, indicating that these phenomena are related to the same Bi centers, which we suggest are interstitial Bi(2+) and Bi clusters.

Multifunctional tunable ultra-broadband visible and near-infrared luminescence from bismuth-doped germanate glasses

Here, we present three facile approaches to achieve wavelength tunable luminescence in the same host material with single dopant, i.e., by modulating doping level, preparation temperature, and atmosphere. Based on these methods, ultra-broadband tunable near-infrared luminescence with the largest full width at half maximum of about 500 nm covering the whole windows of optical communication has been obtained in bismuth-doped germanate glasses. Wavelength tunable luminescence is also observed with the change of excitation wavelength. Systematical strategy was followed to approach the physical origin of the near-infrared luminescence and we proposed that three different bismuth active centers contribute to the near-infrared luminescence in the germanate glasses. A comprehensive explanation for the tunable luminescence is given, combining the concentration, energy transfer, and chemical equilibrium of these active centers in the glasses. With the increase of melting temperatures and the increase of reducing extent of the preparation atmosphere, bismuth species transform from Bi3+ to Bi2+, Bi+, Bi0 and bismuth clusters, and then to bismuth colloid. Of particular interest is that red tunable luminescence was also observed by modulating doping level, preparation atmosphere, and excitation wavelength. Besides, the trapped-electron centers in germanate glasses can interact with bismuth species of high valence states leading to the formation of bismuth active centers of low valence states and the decrease of trapped-electron centers. This tunable ultra-broadband luminescence is helpful for a better understanding of the origin of the near-infrared luminescence in Bi-doped glasses and may have potential applications in varieties of optical devices.

Amplification in Extended Transmission Bands Using Bismuth-Doped Optical Fibers

Bismuth-doped optical glasses emit NIR luminescence in an ultrabroad spectral region of 1000-2000 nm. It makes Bi-doped glasses and glass optical fibers a promising active medium for the creation of Bi-doped fiber lasers and broadband optical amplifiers for this spectral region. Since the first fabrication of Bi-doped fibers in 2005 a large number of papers devoted to the development of Bi-doped fiber lasers and optical amplifiers have been published. It has been shown that Bi-doped fibers are a new breakthrough in active laser materials.

Nanocrystal-enhanced near-IR emission in the bismuth-doped chalcogenide glasses

Bismuth (Bi)-doped materials have attracted a great deal of attention because of their broadband nearinfrared (near-IR) emission around the wavelength utilized in telecommunications. In this study, broad near-IR emission band from 1 100 to 1 650 nm is generated in the Bi-doped 90GeS2-10Ga2S3 glass and glass-ceramics under 820 nm of light excitation. Based on the analysis of the absorption and emission spectra, the origin of this broadband emission is ascribed to the Bi2-2 dimers. The precipitation of \β-GeS2 nanocrystals drastically enhances the emission intensity and lifetime of Bi-doped chalcogenide glass.

Coordination Structure around Bi Ion in Bi-doped Phosphate Glasses

Coordination Structure around Bi Ion in Bi-doped Phosphate Glasses

Effects of sefl-reduction of glass matrix on the broadband near infrared emissions from Bi-doped alkali earth aluminoborosilicate glasses

We report the effects of self-reduction of glass matrix on the broadband near infrared (NIR) emissions from Bi-doped alkali earth aluminoborosilicate glasses. Bi2O3 -doped as well as Eu2O3, -doped as a comparison, 35SiO2-25AlPO4-12.5Al2O3-12.5B2O3-15RO (R=Ca,Sr,Ba) glasses were prepared in air. Results show that the self-reduction process of Eu3+→Eu2+ occurs in this glass matrix. Meanwhile the intensity of NIR emission peaked at about 1300nm increases with the increase in the radius of alkali earth ions, while the intensity of both NIR emission peaked at about 1100nm and the red emission from Bi2+decreases. Then the origins of infrared-emitting bismuth centers were discussed according to the correlation of the conversion of Bi ions with the size of alkali earth ions. The results of this work is helpful for understanding the nature of Bi-NIR-emission and may be a guide for the selection of composition of high performance Bi-doped glass.

Enhanced broadband near-infrared luminescence of Bi-doped oxyfluoride glasses

Broadband near-infrared luminescence covering 900 to 1600 nm has been observed in Bi-doped oxyfluoride silicate glasses. The partial substitution of fluoride for oxide in Bi-doped silicate glasses leads to an increase of the intensity and lifetime of the near-infrared luminescence and blue-shift of the near-infrared emission peaks. Both Bi-doped silicate and oxyfluoride silicate glasses show visible luminescence with blue, green, orange and red emission bands when excited by ultra-violet light. Careful investigation on the luminescence properties indicates that the change of near-infrared luminescence is related to optical basicity, phonon energy of the glass matrix and crystal field around Bi active centers. These results offer a valuable way to control the luminescence properties of Bi-doped materials and may find some applications in fiber amplifier and fiber laser.

Broadband near-infrared luminescence and energy transfer in Bi singly-doped and Bi/Yb co-doped titanate glasses

Super-broadband near-infrared (NIR) emission from 1100 nm to 1600 nm is observed in Bi-doped titanate glasses at the excitation of 808 nm laser diode (LD). The effects of Bi content on the optical spectra are investigated. It is also found that the Bi-related emission intensity can be enhanced by Yb3+ co-doping at the excitation of 980 nm LD. It should be ascribed to the energy transfer from Yb3+ to active Bi ions. The energy transfer processes are studied based on the Inokuti-Hirayama (I-H) model, and the energy transfer of electric dipole-dipole interaction is confirmed to be dominant in Bi/Yb co-doped glasses.

Broadband NIR luminescence of Bi-doped Li2O-Al2O3-SiO2 glass-ceramics

Transparent Bi-doped Li2O-Al2O3-SiO2 (LAS) glass-ceramics are prepared by controlled nucleation and crystallization of glasses with TiO2 worked as nucleating agents. The presence of β-eucryptite (LiAlSiO4) crystalline phase can be indicated by X-ray diffraction analyses. Enhanced near infrared luminescence in the range of 1000~1550nm with FWHM over 270nm is observed from Bi-doped LiAlSiO4 glass-ceramics compared with initial glass. Blue emission centered at 425nm in glass and glass-ceramics could be ascribed to the emission band of the Bi3+ ions (3P1–1S0). Based on optical basicity theory, the broad infrared luminescence from the Bi-doped LAS glass and glass-ceramics can be derived from low valence Bi ions. The possible mechanism of the enhancement of near infrared (NIR) fluorescence is also discussed in this manuscript.

Laser-assisted production of Bi-doped silica glasses

We have presented a novel method for production of Bi-doped silica glasses based on laser melting of precursor materials. The obtained glasses possessed strong near-infrared broadband photoluminescence between 900 and 1700nm with lifetime about 300μs. The effect of Bi concentration was discussed. According to XPS data, there are two different valence states of Bi ions, which can be related to Bi3+ and Bi in a lower positive oxidation state.

Excitation wavelength-dependent near-infrared luminescence from Bi-doped silica glass

We report on excitation wavelength-dependent near-infrared luminescence from Bi-doped silica glass prepared by chemical vapor deposition technique. The peak position of the emission bands shows a complex change between 1120nm and 1270nm with increasing excitation wavelength from 280nm to 980nm. This behavior can be well explained by existence of two kinds of Bi active centers, Bi0 and Bi+, which contribute to the NIR emissions at 1120nm and 1267nm, respectively.

Superbroad near-to-mid-infrared luminescence from Bi_5 ^3+ in Bi_5(AlCl_4)_3

Superbroad near-to-mid infrared (NIR-MIR) photoluminescence was observed from Bi5(AlCl4)3 at room temperature, spanning the spectral range of about 1000 to 4000 nm. On the basis of structural considerations and dynamic analyses, Bi5(3+) clusters were identified as the optically active species, inherently differing from the species which is typically believed to be active in NIR-emitting Bi-doped glasses. In comparison to most other NIR-luminescent Bi-doped materials, the MIR-part of the luminescence spectrum is still present at room temperature. Emission intensity and excited state lifetime were found to exhibit abnormal temperature dependence, where the former increases with temperature up to a critical value of about 150 K. This behavior is related to a temperature-dependent overlap between ground state and excited states. The observed stabilization of MIR photoemission at room temperature may be a starting point for the development of Bi-based NIR-MIR light sources with superbroad emission spectrum, where Bi5(3+) or similar polycationic species act as optical gain medium.

Preparation and near-infrared luminescence properties of Bi-doped BaO-B2O3glasses

Bi-doped BaO-B2O3 glasses are prepared by the melting method. Visible and infrared luminescence spectra, fluorescence decay curve and Raman scattering spectra are measured. NIR emissions, not only one broadband emission peak but also several emission peaks, appear in Bi-doped BaO-B2O3 glass under 808 nm LD pumping. The effect of the network structure of BaO-B2O3 glass on the NIR emission is discussed, and the mechanism for the emission is investigated preliminarily.

Bi-doped germanium niobate glasses with near-infrared broad-band emission

The Bi2O3 doped glasses with concentrations of (0.9-x) GeO2-xNb2O5-0.1BaO (x=0.04, 0.07, 0.1) glasses are prepared by the conventional melting method. The differential thermal analysis (DTA) curves, the absorption spectra, the fluorescence decay curve and the X-ray photoelectron spectra are measured. The difference between glass crystallization onset temperature and transition temperature (Tx-Tg) of the glasses is up to 200℃ from the DTA curve. Absorption peaks at 500, 700, and 1000 nm are observed. The absorption edges show a red-shift with the increase of Nb2O5 content x. The emission band at 1300 nm with the full width at half maximum near 200 nm is observed under the excitation of 808 nm laser. The fluorescence intensity increases with the increase of the concentration of Bi2O3. The fluorescence intensity reaches a maximal value when the concentration of Bi2O3 is about 0.01. The peaks of binding energy in XPS are located at 159.6 and 164.7 eV respectively. The binding energy peaks are located between those of Bi3+ and Bi5+ by comparing with those of Bi2O3 (Bi3+) and NaBiO3 (Bi5+). According to the XPS results, one may conclude that Bi3+ and Bi5+ ions co-exist in the glass. The near infrared broadband emission may be assigned to Bi5+ ion based on the results of emission spectra and X-ray photoelectron spectra. The broadband intensity is gradually weakened as the Nb2O5 content x increases from 0.04 to 0.1. As GeO2 is substituted by Nb2O5, complex NbGe defects are formed and the lower valence state of Bi ions will be inevitably formed to compensate the extra electric charge from Nb5+, thus resulting in the inhibition of Bi5+ and weakening the fluorescence aforementioned.

Broadband tunable near-infrared emission of Bi-doped composite germanosilicate glasses

Download options Please wait... Article information DOI https://doi.org/10.1039/C2JM15606G Article type Paper Submitted 02 Nov 2011 Accepted 12 Dec 2011 First published 06 Jan 2012 Download Citation J. Mater. Chem., 2012,22, 3154-3159 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Broadband tunable near-infrared emission of Bi-doped composite germanosilicate glasses N. Zhang, J. Qiu, G. Dong, Z. Yang, Q. Zhang and M. Peng, J. Mater. Chem., 2012, 22, 3154 DOI: 10.1039/C2JM15606G To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Search articles by author Na Zhang Jianrong Qiu Guoping Dong Zhongmin Yang Qinyuan Zhang Mingying Peng