Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C3/00—Glass compositions
  • C03C3/32—Non-oxide glass compositions, e.g. binary or ternary halides, sulfides or nitrides of germanium, selenium or tellurium
  • C03C3/325—Fluoride glasses

Definitions

• the present invention relates to fluorinated glasses which can be used in optics, in particular in the infrared, and which can be used to manufacture optical fibers.
• fluoride glasses include the optical transmission in technical areas, such as for e - *> the, are telecommunications, fiber optic sensors, 1 stru ⁇ - ntation infrared and uses medical, especially laser surgery.
• conventional fluorinated glasses which belong to the family of fluorozirconates or to the family of fluoroaluminates, have infrared transmission limits around - + micrometers.
• REPLACEMENT SHEET extended Composition rules allowing the value of the maximum transmissible wavelength to be increased are known. Light, small and very charged cations must be excluded, for example Li, Ti, Zr, Nb, Al. This condition is encountered in several families of fluoride glasses, such as those based on the fluorides of scandium, thorium, gallium and indium. In particular, fluoroindate glasses appear promising because they have the lowest phonon energy. Glasses of fluoroindates are mentioned in document FR-A-2 478 618 and document EP-A-0 036 373. Many studies have been carried out since and reference will be made more particularly to the article "Fluoroindate glasses" by M Poulain, M. Poulain, Y. Messaddeq and A. Soufiane, published in the book “Solid state optical materials” in the "Ceramic transactions” series of the American Ceramic Society, published in 1992.
• the simplest glasses of fluoroindates are binary compositions, such as InF Stamm-BaF 2 .
• the compositions serving as a basis for the manufacture of bulk samples most often combine InF , with various divalent fluorides, such as BaF 9 , PbF Directory, SrF, -,, CdF Facility, CaF 2 , ⁇ n > ⁇ 2 '
• divalent fluorides such as BaF 9 , PbF Directory, SrF, -,, CdF Approach, CaF 2 , ⁇ n > ⁇ 2 '
• yttrium fluoride stabilized InF intercept -BaF 2 that lanthanum fluoride could be incorporated in limited proportion and that the glasses of fluorogallates were usually miscible with glasses of fluoroindicates.
• thorium fluoride the vitrifying ability of which is well known, also makes it possible to increase the stability of fluoroindate glasses and to decrease the quantity of indium fluoride necessary to
• fluoroindate glasses of increased stability are known, the compositions of which are as follows:
• composition adjustments were made to the first two glasses, BIZYbT and IZBS, particularly tions of InF resortby GaF Deposit, of YbF, by YFreteor LuF.-, of ThF, by ZrF, or HfF ,, of ZnF 2 by nF. posting of BaF 2 by PbF Facility, and SrF 2 by CdF context.
• These tests which have been described in the literature, would have made it possible to obtain massive samples with a thickness close to one centimeter. However, they do not allow the drawing of satisfactory optical fibers. In various laboratories, a devitrification of the surface has been demonstrated, inducing numerous mechanical and optical defects.
• certain compositions which are reputed to be favorable contain thorium in a significant amount. Thorium being naturally radioactive imposes precautions for use which are conceived on a laboratory scale, but which are difficult to envisage in an industrial environment.
• An object of the present invention is to give compositions of fluoroindate glasses which tend to devitri ⁇ fication lower than compositions of fluoroindates previously known.
• the fluoroindate glass is stabilized by the addition of tin fluoride and / or antimony fluoride in a proportion not exceeding 8% by mole.
• fluoride glass is obtained by partially replacing indium by gallium, or zinc by manganese, in a proportion not exceeding 20 mol%, the two substances being able to be independent or associated.
• Gallium helping to slightly increase the phonon energy should preferably be avoided when seeking maximum infrared transmission at long wavelengths.
• Manganese can be substituted for zinc because Frequently observes similar vitrification domains with the fluorides of these two elements. This substitution may possibly lead to additional stabilization of the glass, but it results in a deterioration of the transmission in the near ultraviolet and the vitreous samples then appear yellowish.
• the fluoroindate glass has the molar composition which lies within the following limits: 2 to 12% of GdF 3
• the yttric rare earths include, in addition to ytrium, the following elements: Lu, Yb, Er, Ho, Tm, Dy and Tb, and that the ceric rare earths include: Ce, Pr, Nd and Sm.
• magnesium fluoride was used as a stabilizer for fluoroindate glasses.
• a particularly demonstrative example is provided by the existence of ternary glasses in the InF Stamm-BaF 2 ⁇ MgF 2 system which can be poured under a thickness greater than 2 mm. The ternary diagram of FIG.
• fluoride glass has the molar composition which is situated within the following limits:
• YF 3 or of rare earths yttriques 0 to 12% of a fluoride belong to the group of alkaline fluorides, LaF Stammand ceric rare earths, A1F.-, ZrF ⁇ ,, HfF ,, ThF ,.
• fluorinated glass contains both magnesium and gadolinium, as stabilizing elements, in an overall proportion of between 2 and 20 mol%, the other constituents obeying the same rules as above.
• fluoride glass contains: 2 to 6% of GdF 3 38 to 42% of InF 3 + GaF. - 15 to 25% of SrF 2 + PbF 2 + CF 2
• M' Zr, Hf, Th.
• magnesium a light element, is less favorable than indium for infrared transmission because it tends to move the absorption boundary multiphonon towards weaker wavelengths. Furthermore, magnesium tends to increase the resistance of glass to corrosion by humidity and to increase its mechanical resistance.
• lithium which appears in the list of additives which can be incorporated within the limit of 12 mol%.
• the contribution of these cations to the multiphonon absorption boundary becomes proportionally lower as the wavelength decreases.
• the reduction in infrared transparency linked to the introduction of magnesium or lithium into the composition of the glass may be less significant between 5 and 6 micrometers than around 8 micrometers.
• FIG. 1 is the ternary diagram of the InF_-BaF Stamm-MgF ? , already mentioned
• FIG. 2 is the diagram of the complex system InF_-GaF Stamm-GdF heap of Example 4 below
• FIG. 3 is a diagram representing a spectral loss curve.
• vitreous samples thicker than 10 mm was prepared on the basis of the same nominal composition, but substituting: 3% of dF 3 and PrF 3 for SrF 2 2 at 12% from GaF 3 to InF 3 2 to 5% of CdF 2 to ZnF 2 2 to 8% of PbF 2 to SrF 2
• GaF History, GdF.- the diagram of which is shown in FIG. 2. Inside limit 3, there is the glass formation zone increased stability. Limit 4 corresponds to the composition range for which glasses can be obtained by cooling faster under a thickness of several millimeters.
• Samples of glasses based on indium fluoride stabilized by gadolinium fluoride or magnesium fluoride were synthesized in thicknesses greater than 10 mm for various compositions which are collated in Table B below.
• characteristic physical values are also given, such as the density, the glass transition temperature T, the temperature at the start of crystallization T, and the maximum temperature of the peak. of crystallization under standard measurement conditions.
• Fibers doped with Nd and Pr ions have the expected absorption and emission characteristics for these rare earths in a fluorinated matrix. They are suitable for mounting laser emission or optical amplification.
• ThF4 10 YbF3 5 SBF3 317 1.517 3 13 CdF2 10 ThF4 10 YbF3 5 SbF3 302 1.526 2 10 ThF4 6 YF3 5 SbF3 318 1.515 2 5 CdF2 10 ThF4 Î0 YbF3 5 SbF3 318 1.522 2 10 ThF4 10 YF3 1.5 Sb3 10 ThF4 10 YF3 5 SbF3 326 1.503 2 5 ThF4 2.5 CdF2 308 1.507 3 12 9 ThF4 10 YbF3 4 MnF2 338 1 * 509

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• General Chemical & Material Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Glass Compositions (AREA)

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• 1992
  • 1992-03-20 FR FR9203568A patent/FR2688778B1/fr not_active Expired - Fee Related
• 1993
  • 1993-03-19 EP EP93920543A patent/EP0590147A1/fr not_active Withdrawn
  • 1993-03-19 US US08/425,214 patent/US5480845A/en not_active Expired - Fee Related
  • 1993-03-19 JP JP5516334A patent/JPH06509317A/ja active Pending
  • 1993-03-19 CA CA002103244A patent/CA2103244A1/fr not_active Abandoned
  • 1993-03-19 WO PCT/FR1993/000283 patent/WO1993019014A1/fr not_active Application Discontinuation
  • 1993-03-19 AU AU37575/93A patent/AU662620B2/en not_active Ceased

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