Aluminosilicate Fibers Research Articles

Monolithic silica fiber laser operating at 585 nm.

We report, to the best of our knowledge, the first monolithic silica fiber laser operating in the visible. The laser cavity is based on a dysprosium-doped aluminosilicate fiber bounded by a pair of fiber Bragg gratings operating at 585 nm. The yellow laser signal reaches a record output power of 147 mW. Although the pump irradiation causes photodarkening, significant reduction of the photoinduced absorption losses is demonstrated via a photobleaching process with visible light.

Preparation of aluminosilicate fiber-SiBOC composite foams for thermal protection applications

ABSTRACT In this study, aluminosilicate fiber-embedded SiBOC matrix composite foams are realised by a simple, cost-effective and easily scalable method. Aluminosilicate wool is transformed into a compressible preform using polyvinyl alcohol as a binder. The preforms are impregnated with methylvinylborosiloxane (MVBS), followed by heat treatment at 1400°C in an inert atmosphere. The composite foam’s density, compressive strength and thermal conductivity are modulated in the ranges 0.71–0.46 g/cc, 0.79–0.39 MPa and 0.21–0.13 Wm−1K−1, respectively, by varying MVBS concentration from 29 to 54 wt.%. While the incorporation of aluminosilicate fibers was observed to lower the thermal conductivity of the composite foams, it did not contribute to their compressive strength. Exposure of the foams to air at 1300°C for 90 min didn’t change their density, while it increased the compressive strength by up to 46% due to improved fiber-matrix adhesion and rounding of cracks.

Preparation and optical properties of thulium doped lanthanum aluminum silicate glass photonic crystal fiber

Lanthanum aluminum silicate glass has excellent optical properties, such as high solubility of rare earth ions, good thermal stability, and excellent physicochemical properties. Some of its physicochemical properties are similar to those of silica glass, so it is easy to combine with silica glass to fabricate special optical fibers. It is considered to be an ideal laser glass matrix material. In this paper, a series of Tm<sup>3+</sup> doped lanthanum aluminum silicate glasses with different concentrations for <i>x</i>Tm<sub>2</sub>O<sub>3</sub>-(70–<i>x</i>)SiO<sub>2</sub>-21Al<sub>2</sub>O<sub>3</sub>-9La<sub>2</sub>O<sub>3</sub> (<i>x</i> = 0.2%, 0.4%, 0.6%, 0.8%, 1%, mole fraction) are successfully developed by the traditional high-temperature melting method. Using thulium-doped lanthanum aluminum silicate glass as the fiber core, thulium-doped double-cladding photonic crystal optical fibers are prepared by the stack-and-draw technique and rod in tube method. The core diameter of the thulium-doped lanthanum aluminosilicate glass double-clad photonic crystal fiber is as long as 21.7 μm, the inner cladding diameter is about 119.3 μm, and the outer diameter is about 236.8 μm. The optical properties of thulium-doped lanthanum aluminum silicate glass and its optical fiber are studied experimentally. Under the excitation of a 793 nm laser, the fluorescence bandwidth of thulium-doped lanthanum aluminum silicate glass reaches 223 nm in a wavelength range of 1550–2050 nm. The fiber laser constructed with thulium-doped lanthanum alumino-silicate glass fiber achieves a laser operating at around 2 μm. The fiber laser resonant cavity consists of a pair of dichroic mirrors. The front dichroic mirror has high transmittance for light at 793 nm and high reflectivity (99.9%) for the light within a wavelength range of 1850–2050 nm. The back dichroic mirror has high reflectivity (99.9%) for light at 793 nm and high transmittance (~ 15%) at 2050 nm. Under the experimental conditions in our laboratory, the laser power reaches 253 mW. The highest slope efficiency is 9.67%, which is close to that of the thulium-doped glass fiber laser reported in the literature. It is also found that the central wavelength of fiber laser is shifted toward the longer wavelength with the increase of the optical fiber's length. These results suggest that thulium-doped lanthanum aluminum silicate glass and thulium-doped photonic crystal fiber are suitable for 2-μm fiber laser.

(INVITED) Bi-doped optical fibers and fiber amplifiers

Bismuth (Bi)-doped aluminosilicate, phosphosilicate, germanosilicate and high (⩾50 mol%) germanosilicate fibers have shown luminescence around 1.15 μm, 1.3 μm, 1.45 μm and 1.7 μm, respectively. Bi-doped fibers have paved the way for developing optical amplifiers and fiber lasers in the wavelength region of 1150–1500 nm and 1600–1700 nm, where it can serve a wide range of applications in astronomy, imaging, medicine and advanced optical communications. However, spectroscopic study is required to understand the nature of near-infrared (NIR)-emitting Bi active centers (BACs) to improve the efficiency of Bi-doped fiber amplifiers and lasers. In this paper, we review the luminescence properties of Bi-doped glasses as well as Bi-doped fibers with aluminosilicate, phosphosilicate, and germanosilicate glass hosts. Absorption and emission cross-sections of Bi-doped phosphosilicate fibers are reported. In addition, we review the current state of the art of Bi-doped fiber amplifiers development in the second telecom window (O-band) and in the E-band and S-band for the next-generation high-capacity optical communications.

KW-level, narrow-linewidth linearly polarized all-fiber amplifier based on homemade Yb-doped aluminosilicate polarization-maintaining fiber

In this work, we demonstrate a homemade 20/400 µm polarization-maintaining ytterbium-doped fiber (PMYDF) with a stress birefringence value of 4.2 × 10−4. The core concentrations of Yb2O3 and Al2O3 were 0.79 wt% and 0.83 wt% respectively. The cladding absorption at 976 nm was measured to be 1.5 dB/m. The PMYDF exhibited a polarization extinction ratio (PER) of 18 dB over meter-long fiber lengths, favoring linearly polarized laser amplification. By applying the PMYDF in the amplifier, an output power of 1247 W was achieved with a 3 dB spectral linewidth of 87 pm under the pumping of 976 nm lasers, corresponding to a slope efficiency of 83.1 %. With a high polarization capability, this 20/400 µm PMYDF exhibits great potential for application in high-power, narrow linewidth, linearly polarized fiber lasers.

Interfacial reaction and interface mechanical behaviors of the 2.5D aluminosilicate fiber reinforced ZrO2 composites

The interfacial reaction and interface mechanical behaviors were carefully studied in the 2.5D aluminosilicate fiber reinforced ZrO2 (ASf/ZrO2) composites which had been prepared by polymer impregnation and pyrolysis. The study confirmed that the interfacial reactions can be attributed to the contact of Si-OH with Zr-OH groups and the diffusion of Si4+ in ZrO2 matrix. A chemical bonding significantly formed between the fiber and the matrix. The investigation showed that the interfacial bonding strength enhanced slowly from 113.13 ± 4.83 MPa to 153.01 ± 11.35 MPa with the temperature increasing from 800 °C to 1000 °C, which could be attributed to the interfacial reaction and the great radial compressive stress. At 1100 °C, the interfacial bonding strength declined to 142.11 ± 6.66 MPa. The reason of the decrease could be the shear damage of the interfacial bonding induced by the axial residual stress which were − 476.52 ± 12.47 MPa and 492.57 ± 12.90 MPa in the fiber and in the matrix, respectively.

Influence of drying method on the migration of the binder and the properties of a high-temperature filter based on aluminosilicate fibers

Ceramic filter elements based on aluminosilicate fibers were produced by vacuum forming, using various drying methods. Microwave drying and freezing followed by drying have been used as methods to reduce binder migration. The microstructure of the obtained filter elements, tensile strength and aerodynamic resistance were analyzed. The obtained characteristics were compared with the characteristics of filter elements made using convective drying. Ill. 6. Ref. 33. Tab.

Stable broadband fiber-coupled near infrared light sources based on a bismuth heavily doped aluminosilicate optical fiber

Bismuth centers doped in glasses and crystals exhibit broadband near-infrared luminescence covering a spectral range from ∼1100 nm to ∼1800 nm, which could not be easily achieved with rare-earth ions. The luminescence between ∼1100 nm and 1250 nm of bismuth-doped aluminosilicate optical fibers depends on the concentration of Al3+ dopants and the bismuth active center. Nevertheless, conventional bismuth-doped aluminosilicate optical fiber fabricated by modified chemical vapour deposition exhibits strong quenching effect for near-infrared luminescence, which limits the optical gain per unit length for the optical fiber. As an alternative, using Bi-doped fiber preforms obtained from a nano-porous glass route, we have demonstrated the fabrication of bismuth-doped aluminosilicate optical fibers with Bi concentration of ∼5000 ppm without quenching. Here, we report a stable and reliable spontaneous emission spanning across 1070 nm–1250 nm with center wavelength of ∼1160 nm and 3-dB spectral bandwidth of ∼81 nm in this aluminosilicate bismuth-doped optical fiber. The spectral result could be promising for application in tunable and ultrafast fiber lasers.

Er:YAG/Yb:YAG nanopowders‐derived Er/Yb co‐doped yttrium aluminosilicate (YAS) fibers fabricated by UV‐curable nanocomposites for 1.5‐µm single‐frequency fiber lasers

AbstractThe rare‐earth (RE)‐doped yttrium aluminosilicate (YAS) glass fibers have demonstrated their unique advantages in single‐frequency lasers due to their high solubility of RE ions and high gain per unit length. However, the RE‐doped YAS fiber is usually fabricated by RE:YAG crystal or ceramic rods and melting‐in‐tube method, which depend heavily on RE:YAG crystal or ceramic rods and, thus, cannot adjust the fiber compositions effectively; there is little research on the multiple RE ions co‐doped YAS fiber deriving from RE:YAG crystal or ceramic rods. In present work, we developed a novel method to fabricate Er/Yb co‐doped YAS fibers efficiently. The Er:YAG and Yb:YAG nanopowders were fabricated by the coprecipitation method, and then the nanopowders were dispersed into liquid organic resin to form a novel UV‐curable nanocomposite, after curing, debinding, purifying, and drawing process, an Er/Yb co‐doped YAS fibers was fabricated, the absorption coefficients of the fiber was measured to be 17 dB/cm at 976 nm (2F7/2ground level to2F5/2level of Yb and4I15/2ground level to4I11/2level of Er) and 3.2 dB/cm at 1530 nm (4I15/2ground level to the high states of4I13/2of Er). A 1.5‐µm single‐frequency laser was constructed with the 2‐cm Er/Yb co‐doped YAS fiber. The longitudinal mode spacing was calculated to be 2.2 GHz with an effective cavity length of 4.5 cm, and the spectral signal‐to‐noise ratio was higher than 60 dB. To the best of our knowledge, it is the first time that Er/Yb co‐doped YAS fibers are fabricated using the UV‐curable nanocomposites. It indicates that this proposed technology is critical for the fabrication of various types of RE ions co‐doped YAS fibers and their applications in single‐frequency fiber lasers.

3D Laser Engineering of Molten Core Optical Fibers: Toward a New Generation of Harsh Environment Sensing Devices

AbstractAluminosilicate glasses offer wide‐ranging potential as enabling materials for a new generation of optical devices operating in harsh environments. In this work, a nonconventional manufacturing process, the molten core method, is employed to fabricate and study sapphire (Al2O3) and YAG (yttrium aluminum garnet) derived all‐glass silicate optical fibers in which a femtosecond (fs) laser is used to imprint oriented nanostructures inside the fiber cores. Both writing kinetics and thermal stability of the laser‐modified regions are investigated over a wide temperature range (20–1200 °C). The laser‐imprinted modifications in these high alumina‐content fibers exhibit improved thermal stability with respect to commercial pure silica and GeO2‐doped silica analogs. Furthermore, optical devices in the form of Rayleigh backscattering and fiber Bragg grating sensors are fabricated to demonstrate the high‐temperature sensitivity and stability of these nonconventional fibers. This functionalization of aluminosilicate fibers by fs‐laser direct writing opens the door to a new generation of optical devices suitable for high‐temperature operation.

Influence of drying process on the aluminosilicate fiber hot gases filter element properties

The influence of drying process on the properties of ceramic filter elements for industrial high-temperature gases purification was studied. Filter elements were based on aluminosilicate fiber manufactured via vacuum filtration with the following molding and machining of the workpiece, it's treatment with a colloidal silicon oxide sol binder, and drying with the employment of various processes. Convective drying (CD), microwave drying (MWD) and filter element freezing followed by convective drying (FCD) processes were employed to study the related binder migration and its effect on filter properties. Diffusional redistribution of the binder through the thickness of the filter element's wall decreases in the series CD→FCD→MWD with the accordingly observed improvement of the structural uniformity and mechanical strength of the filters. The tensile strength of samples dehydrated via convective drying, freezing followed by convective drying and microwave drying, all of which then heat-treated at 1000 °C (the assumed maximum operating temperature), is 0.35 MPa, 0.57 MPa and 0.48 MPa, respectively. The pressure drop measured at the specific air flow of 100 m3/m2 is respectively 700Pa, 490Pa and 410Pa.

Anti-Stokes fluorescence cooling of nanoparticle-doped silica fibers.

The first observation of cooling by anti-Stokes pumping in nanoparticle-doped silica fibers is reported. Four Yb-doped fibers fabricated using conventional modified chemical vapor deposition (MCVD) techniques were evaluated, namely, an aluminosilicate fiber and three fibers in which the Yb ions were encapsulated in CaF2, SrF2, or BaF2 nanoparticles. The nanoparticles, which oxidize during preform processing, provide a modified chemical environment for the Yb3+ ions that is beneficial to cooling. When pumped at the near-optimum cooling wavelength of 1040 nm at atmospheric pressure, the fibers experienced a maximum measured temperature drop of 20.5 mK (aluminosilicate fiber), 26.2 mK (CaF2 fiber), and 16.7 mK (SrF2 fiber). The BaF2 fiber did not cool but warmed slightly. The three fibers that cooled had a cooling efficiency comparable to that of the best previously reported Yb-doped silica fiber that cooled. Data analysis shows that this efficiency is explained by the fibers' high critical quenching concentration and low residual absorptive loss (linked to sub-ppm OH contamination). This study demonstrates the large untapped potential of nanoparticle doping in the current search for silicate compositions that produce optimum anti-Stokes cooling.

Sound absorption characteristics of aluminosilicate fibers

Sound absorption characteristics of aluminosilicate fibers

Fabrication of yttrium aluminosilicate fibers with high Yb3+ doping from Yb:YAG ceramic nanopowders and its application in single-frequency fiber lasers

A yttrium aluminosilicate fiber with a Yb doping concentration of 4.53 wt.% was fabricated by powder-in-tube method, in which the preform core was Yb:YAG ceramic nanopowders synthesized by co-precipitation method. Compared with the method of using YAG crystal rod as fiber core, the fiber composition design can be more flexible and a series of crystal rod processing technology can be circumvented. The absorption coefficient of the Yb-doped YAS fibers was measured 28.4 dB/cm at 976 nm. A single-frequency fiber laser was constructed with the YAS fiber length of 1cm. To our knowledge, this is the first time that rare earth (RE) doped YAS fiber prepared by powder-in-tube method was used in fiber laser.

A high emissivity coating with a sacrificial interface layer on ceramic fiber fabric for high temperature application

The reaction or tight bonding between thermal insulation coating and the base ceramic fiber cloth is the main reason of the cloth embrittlement and failure. In this paper, the sacrificial interface layer is applied on aluminosilicate fiber cloth to inhibit the reaction between SiC-MoSi2-SiB6 high emissive coating and the cloth. The sacrificial interface layer will be pyrolyzed at high temperature. The obtained space effectively prevents the glass formed by oxidation or melting of high emissive coating from contacting or reaction with the fibers in the cloth. The influence of different thickness of the middle layer and external coating on the micro morphology and mechanical properties of the fiber cloth was comprehensively compared and studied. The reusable performance of the coating was evaluated. The tensile strength of the fiber cloth with the optimized interface layer and external coating is about 40 MPa after heat treatment at 1300 °C for 1 h, which is 71.2% higher than that of the bare cloth; the tensile strength of the sample with only the outer coating and no intermediate layer is only 10 MPa after heat treatment at 1200 °C for 1 h. The bonding strength of the coating will not be obviously reduced by the application of sacrificial interface layer. By means of the interface layer the thermal shock resistance of the coating is improved. After 10 thermal shock cycles, the coating with a suitable interface layer is not cracking and spalling, and the bonding strength of it is as high as 125 kPa, the tensile strength is still as high as 20 MPa.

OXIDE-CONTAINING MINERAL FIBERS: TYPES, METHODS OF PRODUCTION, APPLICATION AND MANUFACTURERS (REVIEW)

The article provides an overview of mineral oxide fibers of various chemical composition: aluminosilicate, alumina, silica, bio-soluble, zirconium oxide fibers and others. Methods for producing discrete and continuous fibers, such as spinning fibers from melts, sol-gel technology, spinning from solutions of metal salts, etc., are described. filtration for alumino-silicate and bio-soluble fibers; thermal insulation up to 1600 or 2000 C and reinforcement of composites used in the aerospace and defense industries for alumina fibers and fibers based on zirconium dioxide, etc. Producers of mineral oxide-containing fibers and products based on them abroad and in Russia are represented.

Super Electrical Insulating Materials Based on Honeycomb‐Inspired Nanostructure: High Electrical Strength and Low Permittivity and Dielectric Loss

AbstractThe high breakdown field strength is the most important index to evaluate the performance of insulating materials. It is theoretically found that the breakdown field strength of dielectric samples can be significantly improved by up to 1–2 orders of magnitude by constructing nanopore structures. Thus, bridged silsesquioxane super electrical insulating materials (BSSEIM) are developed with nanosized pore structures and their extremely high electrical insulation performance is realized. The results indicate that the breakdown field strength of the BSSEIM is dramatically higher than aluminosilicate fiber insulating materials (ASFIM) by 570.5% for dry samples and 118.1% for oil‐impregnated samples. Specifically, the prepared BSSEIM samples have excellent dielectric performances with permittivity and dielectric losses that are only 51.3% and 1.1% of ASFIM, which are significantly lower than most existing insulating materials. Finally, the theoretical analysis indicates that the nanopore structures can effectively limit the scale of the head size for an electron avalanche and significantly reduce the number of effective gas molecules by dividing the gas into nanounits. This significantly inhibits the ionization of gas molecules and improves the breakdown field strength of samples. This discovery overturns previous understandings of traditional insulating materials and opens an avenue toward super electrical insulating materials.

Comparative study of γ-radiation resistance between Yb/Ce/F and Yb/P doped aluminosilicate fibers

To quantitatively compare the radiation resistance of Ytterbium/Cerium/Fluorine(Yb/Ce/F)-codoped aluminosilicate and Yb-doped aluminophosphosilicate fibers in an ionizing radiation environment, we fabricated these two kinds of samples by applying the modified chemical vapor deposition system combined with chelate precursor doping technique. When the radiation dose accumulated to 200 Gy, the radiation-induced transmission attenuation of Yb-doped aluminophosphosilicate fiber is approximately 2.8 times that of the Yb/Ce/F-codoped aluminosilicate fiber. At this dose level, the slope efficiency of Yb/Ce/F-codoped sample decreased to 1/2 of the non-radiated efficiency value, while the other sample dropped to 1/20. The results demonstrate that Yb/Ce/F-codoped fibers are much more suitable for application in a radiated environment.

Fabrication of superwetting, anti-icing nickel-cobalt carbonate hydroxide coated-aluminosilicate fiber paper for oil-water separation

Fabricating low-cost and high-efficiency oil-water separation superwetting materials for the demand of oil spilling treatment remains a great challenge. Herein, a superwetting aluminosilicate fiber paper decorated by flower-like nickel-cobalt carbonate hydroxide (NiCo-CH) nanostructures was prepared via the hydrothermal method and chemical modification with stearic acid (SA) or 1H, 1H, 2H, 2H-Perfluoroalkyltriethoxysilane (FAS-17). The superhydrophilic multi-layers nanoflowers combing with nanoflakes were uniformly distributed on the surface of aluminosilicate fiber. The superhydrophilic aluminosilicate fiber was then modified by the SA to obtain the superhydrophobic aluminosilicate fiber (SA-NiCo-CH@Al 2 SiO 5 FP). The SA-NiCo-CH@Al 2 SiO 5 FP revealed high separation efficiency (> 95.4%) for both light oils and heavy oils, and high oil flux (417 L m −2 h −1 –71,656 L m −2 h −1 ). Furthermore, the SA-NiCo-CH@Al 2 SiO 5 FP can also remain superhydrophobicity under various harsh conditions, such as dust, sand impact, acid or alkali, and low-temperature environments. This study revealed an inexpensive and simple-fabricated multifunctional superwetting material, which provides promising avenue for future applications in oil-water separation.

Correlation between viscoelasticity of aluminosilicate melts and elastic properties of melt-spun fibers

Aluminosilicate fibers via melt-spinning process have great potential for industrial applications (e.g. refractory, insulation, and reinforcement). While the viscoelastic properties of the melts obviously have relation with the conditions for the melt-spinning process and fiber properties, such dependencies remain poorly understood. Herein, we report the viscoelastic properties of aluminosilicate melts at 800-1450°C, which requires sophisticated measuring system due to the stiffening of melts at lower temperature. Afterward, we analyzed how the high temperature rheological properties influences the melt-spun fiber properties. Interestingly, the elastic moduli of fibers were observed proportional to the reciprocal of shear moduli of the melts at the solid-liquid transient temperature. The results suggest that the shear modulus of the aluminosilicate melt feasibly influences the elastic recovery of melt-fiber during quenching, and impacts the fiber elastic property consequently. The results shows a clear relation between rheological properties of melt and the elastic properties of the specific form of solidified ceramic, fibers.