[Show abstract][Hide abstract] ABSTRACT: Glass materials with high emission characteristics and low content of limiting impurities are required for creation of devices for middle infrared (mid-IR) fiber optics. The paper presents the results of preparation of high-purity Pr3+-doped GaxGeySbzSe1-(x+y+z) (x=3÷4, y=20÷26, z=5÷11) glasses. The multi-stage technique for synthesis of these glasses is developed. It is based on chemical distillation purification of glass components and the transport reaction for purification of gallium. Transmitting, as well as thermal and luminescent properties of glasses are investigated. The content of limiting impurities of oxygen, carbon and hydrogen in the glass samples was ≤0.2 ppm wt. The 1300-3000 ppm wt Pr;bsupesup-doped Ga-Ge-Sb-Se bulk glasses exhibit an intensive photoluminescence in the spectral range of 3.5-5.5 μm.
Full-text · Article · Feb 2016 · Journal of Luminescence
[Show abstract][Hide abstract] ABSTRACT: Glass samples of [GeSx]90I10 (x = 1.5, 1.7, 2.0, 2.3, 2.45, 2.6) compositions were prepared, and some their thermal, optical properties as well as tendency to crystallization were investigated. The compositional dependences of glass transition temperature, volume fraction of crystallized phase and activation energy of glass formation (Eg) have nonmonotonic character with a maximum for [GeS2.0]90I10 glass. Glasses of 85.8GeS2–14.2GeI4 and [GeS1.5]90I10 compositions are identified as promising for preparation of optical fiber. For the first time, Ge–S–I glass fibers were produced. Minimum optical losses in 85.8GeS2–14.2GeI4 glass fiber were 2.7 dB/m at a wavelength of 5.1 μm, and that in [GeS1.5]90I10 glass fiber were 14.5 dB/m at 5.5 μm.
[Show abstract][Hide abstract] ABSTRACT: Ge-S-I glasses having iodine content of 4.0-22.1 at.% and the x(S)/x(Ge) ratio of 1.7-2.1 were prepared by melting and subsequent cooling of the products of thermal decomposition of Ge2S3I2. The maximum temperature of synthesis was 550 °C, and the homogenization duration of the glass-forming melt at 750 °C was 1 h. The compositions and properties of the resulting glasses and the impurity content in samples obtained under different conditions of Ge2S3I2 decomposition were investigated. The purest samples of prepared glasses were characterized by high optical transparency in the spectral range of 2-10 μ m and the low content of impurities: silicon (0.1 ppm wt), metals (b0.5 ppm wt) and hydrogen in the form of S-H bonds (0.02 ppm wt).
No preview · Article · Dec 2015 · Journal of Non-Crystalline Solids
[Show abstract][Hide abstract] ABSTRACT: This paper examines a mathematical diffusion model for the purification of substances by distillation. We present the dependences of the separation factor - a quantitative characteristic of the degree of purification of substances - and the effective separation coefficient on the Peclet number, vaporization rate, and sampling ratio. For selenium containing barium impurities, we determine the equilibrium separation coefficient and diffusion coefficient of the solute from experimental data.
No preview · Article · Nov 2015 · Inorganic Materials
[Show abstract][Hide abstract] ABSTRACT: GeSx:Bi glasses have been found to be promising materials for production of new broadband fiber amplifiers and the fiber lasers. However, these glasses were instable to crystallization that hinders drawing out the optical fibers. The processes of the phase formation and interphase distribution of bismuth between different phases used as an activation ion have been studied by means of XRD, DTA and EDX techniques under varying of temperature and composition of GeSx:Bi (1 < x < 2) glasses. The limits of glass stability for the synthesis technique used were established to correspond to 1.3 < x < 1.6 concentration range. The dopant (Bi) was shown not to be incorporated into germanium sulfide crystals lattice. A reversible process of metallic bismuth formation and its subsequent dissolution was observed during thermal treatment of the glasses under 'heating-cooling-heating' mode. The crystallization of GeS, α-GeS2, β-GeS2 within 1.25 ≤ x ≤ 1.9 ranges at 25 to 550 °C has been described.
No preview · Article · Nov 2015 · Journal of Non-Crystalline Solids
[Show description][Hide description] DESCRIPTION: Ultrapurification of monogermane 72GeН4 with the content of the main isotope 99.953 at % was carried
out by the method of low-temperature rectification. The nature and content of molecular impurities in
monogermane samples were determined by the method of chromato-mass-spectrometry. By the results
of analysis the content of each of 50 impurities, referring to the classes of volatile inorganic hydrides,
hydrocarbons, chlorine- and fluoro-hydrocarbons, alcohols, ethers, alkyl- and chloro-germanes, in the
rectificate does not exceed 1×10-5 mol.%. The mostly high content (mol. %) is of carbon dioxide (3×10-5), of
di- and trigermane (10-2–10-4).
[Show abstract][Hide abstract] ABSTRACT: Arsenic selenide glass with the low content of residual impurities (hydrogen ≤0.02 ppm wt, oxygen <0.1 ppm wt, carbon <0.5 ppm wt, silicon ≤0.1 ppm wt, and metals 0.01-0.1 ppm wt) is prepared. The effect of the method for producing arsenic selenide on the content of limited impurities and the optical transmission in the mid-IR range is investigated. Optical fibers of high-purity As30Se70-As40Se60 glass compositions are drawn. The minimum optical loss in unclad As35Se65 glass fiber of diameter 200 μm is 70 dB/km at wavelengths of 2.7 and 3.8 μm. The minimum optical loss in core-clad As40Se60/As38Se62 glass fiber is 67 dB/km in the 6-6.5 μm spectral range, which is the best result for the core-clad As-Se glass fibers.
No preview · Article · Oct 2015 · Optical Materials
[Show abstract][Hide abstract] ABSTRACT: Chalcogenide glass fibers have attractive properties (e.g. wide transparent window, high optical non-linearity) and numerous potential applications in the mid-infrared (MIR) region. Low optical loss is desired and important in the development of these fibers. Ge-As-Se glass has a large glass-forming range to provide versatility of choice from continuously varying physical properties. Recently, broadband MIR supercontinuum generation has been achieved in chalcogenide fibers by using Ge-As-Se glass in the core/clad. structure. In the shaping of chalcogenide glass optical fiber preforms, extrusion is a useful technique. This work reports glass properties (viscosity-temperature curve and glass transition) and optical losses of Ge-As-Se fiber fabricated from an extruded preform. A robust cutback method of fiber loss measurement is developed and the corresponding error calculation discussed. MIR light is propagated through 52 meters of a fiber, which has the lowest loss yet reported for Ge-As-Se fiber of 83 ± 2 dB/km at 6.60 μm wavelength. The fiber baseline loss is 83-90 dB/km across 5.6-6.8 μm, a Se-H impurity absorption band of 1.4 dB/m at 4.5 μm wavelength is superposed and other impurity bands (e.g. O-H, As-O, Ge-O) are ≤ 20 dB/km. Optical losses of fiber fabricated from different positions of the extruded preform are investigated.
Full-text · Article · Aug 2015 · Optical Materials Express
[Show abstract][Hide abstract] ABSTRACT: Data are presented on the influence of silver and sodium ions on the refractive index and structure of TeO2-WO3-La2O3 glasses. Using ellipsometry, we have obtained dispersion dependences of the refractive index of the tellurite glasses. Structural changes in the glass network have been assessed using the Wemple-DiDomenico model. Increasing the mole fraction of Na2O from 3 to 12% increases the refractive index of the glasses by 4%, whereas increasing the mole fraction of Ag2O from 5 to 12% at Na2O content of 3% increases the refractive index by 1%.
No preview · Article · Aug 2015 · Inorganic Materials
[Show abstract][Hide abstract] ABSTRACT: We have investigated the coprecipitation of tellurium(IV) and tungsten(VI) compounds through the addition of aqueous ammonia to a mixture of a tellurium dioxide solution in hydrochloric acid and tungstic acid. We have revealed general trends in the distribution of macrocomponents between the precipitate and solution and demonstrated the feasibility of proportional tellurium(IV) and tungsten(VI) precipitation in the pH range from 2 to 7.
No preview · Article · Jun 2015 · Inorganic Materials
[Show abstract][Hide abstract] ABSTRACT: We have investigated the coprecipitation of tellurium(IV), molybdenum(VI), and lanthanum(III) hydroxides from hydrochloric acid solutions of compounds of these elements and found conditions under which the precipitate was identical in composition to the starting solution of macrocomponents.
No preview · Article · Jun 2015 · Inorganic Materials
[Show abstract][Hide abstract] ABSTRACT: The glass samples of the Ge-S-I system were synthesized by plasma-enhanced chemical vapor deposition (PECVD) in a low-temperature non-equilibrium RF-plasma discharge. The vapors of S and GeI4 were the initial substances. The process was carried out in a flowing quartz reactor at the walls temperature of 300-500 °C and the total pressure range of 1.9-22.8 Torr. The phase and the elemental compositions of the deposited glassy batches were investigated. The glasses obtained by melting of the solid reaction products were homogenized in the evacuated quartz glass ampoule and they were studied by DSC, X-ray microanalysis, and atomic emission spectroscopy. The proposed method allows to prepare the glasses of the system Ge-S-I with Si content less than 3 ⋅ 10−5 wt.%.
[Show abstract][Hide abstract] ABSTRACT: Precipitates of tellurium(IV), molybdenum(VI), and bismuth(III) compounds of controlled composition have been obtained by precipitation from hydrochloric acid solutions of tellurium dioxide, ammonium heptamolybdate, and dibismuth trioxide. We have examined the general aspects of the macrocomponent distribution between the precipitate and solution and found conditions of a sufficiently complete tellurium(IV), molybdenum(VI), and bismuth(III) precipitation in a weakly acidic medium. After drying and calcination, the precipitates thus obtained were used as starting mixtures for the preparation of TeO2-MoO3-Bi2O3 glasses.
No preview · Article · Mar 2015 · Inorganic Materials
[Show abstract][Hide abstract] ABSTRACT: We have prepared (TeO2)0.80(MoO3)0.20 tellurite glass samples containing 0.02-0.5 wt % nickel and investigated their optical transmission in the range 450-2800 nm. The transmission spectra of the glasses contain absorption bands centered at 810 and 1320 nm. From the composition dependence of the absorption coefficient, we have evaluated the specific absorption coefficient of Ni2+ in the range 600-2800 nm. It has been found to be 20.6 ± 0.4 cm−1/wt % at the maximum of the 1320-nm absorption band.
No preview · Article · Mar 2015 · Inorganic Materials
[Show abstract][Hide abstract] ABSTRACT: Glass samples of the GeS2-GeI4 system with iodine content of 5, 8, 10, 12 and 15 at.% are prepared by reacting germanium tetraiodide, germanium and sulfur in the evacuated silica-glass ampoules. The glass samples are characterized by high transparency in the spectral range of 0.55-10 μm. Regularities of changes in optical and thermal properties of the glasses depending on the iodine content are established. Transmission edges of samples are determined and impurity absorption bands are identified. The optimal iodine content in the Ge-S-I glasses for optical applications is determined to be equal to 10-12 at.%. Temperatures of glass transition, the onset of crystallization and starting of weight reduction of samples are determined. Chemical and phase compositions of the products of glass crystallization when heated up to 650 °C are investigated.
No preview · Article · Feb 2015 · Optical Materials
[Show abstract][Hide abstract] ABSTRACT: The methods of preparation of chalcogenide glasses for infrared fiber optics with low content of limiting impurities have been developed. The methods are based on solidification of glass-forming melts prepared by melting the initial high-purity elements in evacuated silica ampoule and purified additionally with chemical and distillation procedures. The effect of impurities (oxygen, hydrogen, carbon, sulfur, inclusions) on optical transmission of glasses was determined. The optical, thermal and crystallization properties of glasses were studied. Chalcogenide glass-based, low loss, multimode and single-mode optical fibers are produced with technical and operation characteristics sufficient for a number of cutting-edge applications. Factors affecting the optical absorption of glasses and optical fibers are analyzed.
[Show abstract][Hide abstract] ABSTRACT: This paper describes a 3D laser ultramicroscopy technique and apparatus for the nondestructive characterization of heterophase inclusions in bulk high-purity materials for fiber and power optics. In this technique, the concentration and size of inclusions undetectable by optical microscopy are determined using CCD detection of the light scattered by them in a direction normal to the incident laser beam at wavelengths from 0.63 to 0.98 μm. The detection limit of the technique in terms of inclusion size is n × (10–100) nm, the range of detectable number concentrations is 1–1011 cm−3, and the scan depth in the sample is ∼1 cm. Its performance has been evaluated using test systems. The potential of the technique is illustrated by the dispersion analysis of promising materials for IR fiber-optic applications.
No preview · Article · Dec 2014 · Inorganic Materials
[Show abstract][Hide abstract] ABSTRACT: Glass samples of the Ge–Sb–Se–I system were prepared by reacting germanium tetraiodide and antimony triiodide with selenium in a set-up which provides selective removal of iodine from the melt. Thermodynamic modeling of purification reactions of the components is shown. The glasses are analyzed by X-ray spectral microanalysis, differential scanning calorimetry, IR spectroscopy, Raman scattering spectroscopy, and laser mass spectrometry. In the purest examples of these glasses, the content of residual impurities is: hydrogen—0.1 ppm mol, silicon—0.02 ppm wt., and transition metals—less than 0.5 ppm wt.
No preview · Article · Nov 2014 · Journal of Non-Crystalline Solids