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Attenuation spectra of SM-1 (red curve) and SM-2 (blue curve) YFs. Inset demonstrates the spectral details originated from other than Yb 3+ features.
Source publication
New zirconia-germano-alumino silicate, nano-particles based, Ytterbium doped fibers are obtained through the conventional modified chemical vapour deposition and solution doping techniques. The start fiber preforms are characterized by means of electron micro probe, energy dispersive x-ray, and electron diffraction analyses, revealing the presence...
Context in source publication
Context 1
... absorption spectra of fiber samples SM-1 and SM-2 are presented in Fig. 7. Experimentally, these spectra were obtained using a white-light source with a fiber output utilized as a probe beam and an optical spectrum analyzer (OSA) with a 0.5 nm resolution. The lengths of the fiber samples were chosen to be 140 (SM-1) and 100 (SM-2) cm. It is seen that the measured spectra are quite similar in the appearance ...
Citations
... Fibers fabricated via the latter approach are called glass-ceramic (GC) fibers. Attempts to in-situ grow the NCs during preform fabrication via phase separation effects [14] can be understood as a variation thereof. So far, the vast majority of reported NC doped fibers were GC fibers, an assessment that can also be found in recent reviews [15][16][17]. ...
SiO2 fibers doped with rare-earth-doped nanocrystals are promising to overcome the strong SiO2 multi-phonon quenching and could yield novel laser gain materials. So far, no attention has been paid to the question how well the nanocrystals can suppress the quenching depending on the properties of the SiO2 host glass. Here, a novel analytical model was applied to study the impact of the glass purity and composition on the quenching efficiency. Only a few experimentally accessible material and design parameters are required to compute the average quenching rate inside the nanocrystals. It is demonstrated that sufficiently low levels of quenching can only be expected for SiO2 free of impurities or dopants that increase the multi-phonon absorption. This indicates that high-purity aluminosilicate glasses, in contrast to phosphosilicate and borosilicate glasses, are ideal hosts.
... In combination with MCVD, commercial powders [11] as well as co-precipitated precursors [13] can be used. Alternative methods of nanostructures formation in various oxide systems during preform thermal annealing have also been published [22][23][24][25]. ...
Efficient holmium fiber lasers have been studied as attractive laser sources operating around 2.1 μm. We report on holmium-doped silica fibers prepared by the modified chemical vapor deposition in combination with either a solution-doping method or a nanoparticle-doping method. A set of 15 fibers with various compositions was characterized and compared with respect to their fluorescence lifetime, laser slope efficiency and laser threshold. This set of fibers in wide concentration ranges allowed us to assess reliably the influence of material composition and the influence of doping method. The best-performance fibers exhibited slope efficiency 83.1%, laser threshold 155 mW and a record value of upper laser level lifetime of 1.35 ms. These results were achieved in fibers with holmium concentration lower than 800 molar ppm and Al/Ho molar ratio greater than 70. Significant differences between fibers prepared by solution doping and nanoparticle doping were not observed. The behavior of
$\text{Al}_2 \text{O}_3$
nanoparticles during fiber preparation is discussed in details.
... [546][547][548][549][550] A growing body of literature now exists with respect to vapor deposited, phase separated (glass ceramic) optical fibers. Representative examples include nano-phase separated yttria-alumino-silica (YAS) glass optical fibers doped with bismuth 551 or Yb 2 O 3 , 227 Yb-and Er-doped zirconia-silicate optical fibers 228,552 and multicomponent silicates 553 and titanates. 554 A second approach to "nanoparticle" doping involves the suspension of nanoparticles into a solution that subsequently is solution doped into the porous silica preform soot per convention. ...
Over the past two decades, fiber laser technologies have matured to such an extent that they have captured a large portion of the commercial laser marketplace. Yet, there still is a seemingly unquenchable thirst for ever greater optical power to levels where certain deleterious light-matter interactions that limit continued power scaling become significant. In the past decade or so, the industry has focused mainly on waveguide engineering to overcome many of these hurdles. However, there is an emerging body of work emphasizing the enabling role of the material. In an effort to underpin these developments, this paper reviews the relevance of the material in high power fiber laser technologies. As the durable material-of-choice for the application, the discussion will mainly be limited to silicate host glasses. The discussion presented herein follows an outward path, starting with the trivalent rare earth ions and their spectroscopic properties. The ion then is placed into a host, whose impact on the spectroscopy is reviewed. Finally, adverse interactions between the laser lightwave and the host are discussed, and novel composition glass fiber design and fabrication methodologies are presented. With deference to the symbiosis required between material and waveguide engineering in active fiber development, this review will emphasize the former. Specifically, where appropriate, materials-based paths to the enhancement of laser performance will be underscored.
... Also, any doping can provide a rearrangement of SiO 4 and PO 4 tetrahedron units of the glass network [38,39]. This effect is similar to the impact of the phase-separated nanosized RE-rich areas in the glass bulk [40]. ...
Mixed barium‐strontium Nd:phosphate glasses of composition: 58P2O5–13K2O–8Al2O3–4B2O3–2.5La2 O3–2SiO2–0.5Nd2O3–12(Ba1–xO/SrxO) with a different degree of molar substitution x were prepared. Optical properties of these glasses were examined by UV–Vis-IR and photoluminescence (PL) spectroscopies. Considering IR spectra, it was suggested a certain contribution of oxygen defects in the optical properties of glasses. UV–Vis absorbance and PL emission spectra owing to the internal f–f electron transitions of Nd3+ ions were shown a complex character of electronic processes. The result of a comprehensive analysis of the optical scattering indicatrices has revealed non-monotonic variations of the scattering efficiency against the ratio of Sr to Ba that is correlated with the suggested content of the oxygen defects in the mixed glasses. A cubic nonlinear optical (NLO) response under the pulsed laser radiation self-action at 1064 nm shows that the self-defocusing effect increases with the molar fraction of Ba. For a continuous wave laser excitation at 1064 nm, the most efficient NLO refractive response with Re(χ(3)) = 2.9 × 10−3 esu was obtained in the pure strontium Nd:phosphate glass, being classified as a promising for NLO applications.
... Recently, nanostructured optical fibers obtained by incorporation nanoparticles in an amorphous matrix attracted much attention (Kir'yanov et al. 2011;Hamzaoui et al. 2012). The presence of nanoparticles induces nonlinear optical properties and offers potential for optical amplification. ...
Sol-gel technique is very flexible, simple, and low-cost method to fabricate photonic structures having applications in various field. During sol-gel synthesis, compounds with well-controlled composition can be obtained as thin films, powders, or monoliths. Obtained materials can then be used to prepare photonic structures such as waveguides, photonic crystals, coatings, and bulk glasses. The present chapter is focused on the recent results of different research groups working in the field; some results obtained by the authors in sol-gel-derived photonic structures are also presented. In particular, the silica-tin dioxide system is described. The consideration is mainly focused, but not only, on the spectroscopic properties of rare earth-activated materials that due to the light emission can be used in some specific application such as sensing, biomedical diagnostic, energy conversion, telecommunication, lighting, and photon management. © Springer International Publishing AG, part of Springer Nature 2018.
... Recently, nanostructured optical fibers obtained by incorporation nanoparticles in an amorphous matrix attracted much attention (Kir'yanov et al. 2011;Hamzaoui et al. 2012). The presence of nanoparticles induces nonlinear optical properties and offers potential for optical amplification. ...
Sol–gel technique is very flexible, simple, and low-cost method to fabricate photonic structures having applications in various field. During sol–gel synthesis, compounds with well-controlled composition can be obtained as thin films, powders, or monoliths. Obtained materials can then be used to prepare photonic structures such as waveguides, photonic crystals, coatings, and bulk glasses. The present chapter is focused on the recent results of different research groups working in the field; some results obtained by the authors in sol–gel-derived photonic structures are also presented. In particular, the silica–tin dioxide system is described. The consideration is mainly focused, but not only, on the spectroscopic properties of rare earth-activated materials that due to the light emission can be used in some specific application such as sensing, biomedical diagnostic, energy conversion, telecommunication, lighting, and photon management.
... Different research groups around the world have reported results on Er-doped optical fiber using various codopant namely Ca, Mg, Sr, Zr, Bi, etc. [12][13][14][15][16][17][18] in order to tune the spectral properties of RE-doped preform/fiber and to achieve enhanced RE solubility. Similarly, Yb has been doped into modified silica host glass by various groups [19][20][21][22] where the host glass doped with Al or P is further modified by adding minor quantities of dopants like, Y, La, etc. In this context, Ba has been used as modifier in the fabrication of different silicate glass containing RE ions [23,24]; very recently highly BaO-doped silica glass has been fabricated through molten core method to investigate brillouin spectra of the same [25] and Ba-doping level in pure silica glass has been determined using MCVD-solution doping technique [26]. ...
Barium has been established as an alternate codopant other than conventional aluminum or phosphorous for fabrication of rare-earth- (RE) doped optical fiber through modified chemical vapor deposition (MCVD) coupled with solution doping technique. Different optical and material characterization results of our fabricated fibers indicate potential application as amplifier and laser. The amplifier performance of Er-doped fiber and lasing as well as photo darkening (PD) experiment of Yb-doped fiber doped with BaO is presented where Ba serves as an alternate candidate for enhancement of RE solubility in silica glass.
... Different research groups around the world have reported results on Er-doped optical fiber using various codopant namely Ca, Mg, Sr, Zr, Bi, etc. [12][13][14][15][16][17][18] in order to tune the spectral properties of RE-doped preform/fiber and to achieve enhanced RE solubility. Similarly, Yb has been doped into modified silica host glass by various groups [19][20][21][22] where the host glass doped with Al or P is further modified by adding minor quantities of dopants like, Y, La, etc. In this context, Ba has been used as modifier in the fabrication of different silicate glass containing RE ions [23,24]; very recently highly BaO-doped silica glass has been fabricated through molten core method to investigate brillouin spectra of the same [25] and Ba-doping level in pure silica glass has been determined using MCVD-solution doping technique [26]. ...
The present invention provides a method of making rare earth (RE) doped optical fiber using BaO as co-dopant instead of Al or P commonly used for incorporation of the RE in silica glass by MCVD and solution doping technique. The method comprises deposition of particulate layer of GeO2 doped SiO2 with or without small P2O5 for formation of the core and solution doping by soaking the porous soot layer into an aqueous solution of RE and Ba containing salt. This is followed by dehydration and sintering of the soaked deposit, collapsing at a high temperature to produce the preform and drawing of fibers of appropriate dimension. The use of Ba-oxide enables to eliminate unwanted core-clad interface defect which is common in case of Al doped fibers. The fibers also show good RE uniformity, relatively low optical loss in the 0.6-1.6 μm wavelength region and good optical properties suitable for their application in amplifiers, fiber lasers and sensor devices.
... The main target at this is keeping high optical efficiency of an Ytterbium (Yb) doped fiber system, the highest as compared to other rare-earth doped ones, and in the meantime diminishing photodarkening (PD), a detrimental effect known as seriously deteriorating output characteristics of fiber lasers and amplifiers. For instance, we recently attempted to approach these goals by fabricating and investigating a row of novel Yb doped fibers[1]–[3]. As a continuation of the research, we found interesting to develop and study one more type of Yb doped fibers based on lanthano-alumino-silicate (LAS) glass. ...
Novel lanthano-alumino-silicate optical fibers doped with ytterbium (Yb) in a wide concentration range are obtained
through the conventional modified chemical vapor deposition process and solution doping technique. The featuring fibers’ characteristics are determined, applying a routine that involves the spectroscopic, nonlinear-optical, and laser methods as well as photodarkening tests. Special attention is paid to address thoroughly the effect of Yb3+ concentration upon the fibers’ properties.
... Ces recherches présentent à chaque fois des nanoparticules cristallines [1]. L'équipe du CGCRI (Calcutta, Inde) étudie également des nanoparticules d'ytterbium réalisées in-situ par MCVD [2][3][4]. Ils obtiennent des nanoparticules cristallines. ...
... Une seconde voie consiste a créer les nanoparticules in-situ grâce aux traitements thermiques appliqués lors de la réalisation de la préforme. Les premières observations on été faites dans notre laboratoire puis étudiées par l'équipe de M.C. Paul [2][3][4] de l'institut de recherche verre et céramique de Kolkata (Inde) après une collaboration. ...
Erbium-doped optical fibres are commonly used to realize amplifiers. To control and modify erbium spectroscopic properties in these silica-based optical fibres, we study an original way that consists in encapsulating ions into oxide nanoparticles obtained in-situ, directly during MCVD process. The modification of the erbium local environment allows to modify spectroscopic properties. These nanoparticles appear during the fabrication with the incorporation of a nucleation agent. Thermal cycles necessary to the preform fabrication ensure therefore to activate a spontaneous phase separation.This thesis aims to study the effect of different fabrication parameters, such as nucleating agent concentration in the doping solution or consolidation and collapsing phases, on the nanoparticle characteristics and erbium spectroscopic properties. In this manus- cript, this study of the different parameters is organised in two axes : material composition and thermal cycles. Nanoparticles have mainly been characterised by Scanning Electron Microscopy (SEM). Erbium spectroscopy has been analysed by means of emission spectrum measurements as well as measurements of the 1,5μm fluorescence lifetime. Spectroscopic modifications, i.e. emission spectrum broadening of 40 until 60%, have only been obtained for fibres that exhibit particles with high mean diameters ( 50nm). Transparency criteria could only be satisfied while manipulating particle density.
