Abstract:
The invention relates to a method allowing cost-effective production of doped quartz glass, particularly laser-active quartz glass, that is improved with regard to the homogeneity of the doping material distribution, in that a suspension is provided comprising SiO2 particles and an initial compound for at least one doping material in an aqueous fluid, the fluid being removed under formation of a doped intermediate product comprising particles of the doping material or particles of the precursor substance or the doping material, and the doped quartz glass is formed by sintering the doped intermediate product, wherein at least part of the particles of the doping material or the particles of the precursor substance of the same is generated in the suspension as a precipitate of a pH-value-controlled precipitation reaction of the initial compound.
Abstract:
An optically active glass and an optical fiber comprising such glass, having reduced photodarkening properties are provided. The optically active glass is mainly composed of silica representing from about 50 to 98 mol % of the glass. It also includes at least one active ion, such as a rear-earth ion, which induces a photodarkening effect in optical properties of the glass. Moreover, the glass includes an effective amount of phosphorus oxide providing the photodarkening reducing effect, preferably in an amount of from about 1 to 30 mol %. A method for reducing a photodarkening effect in optical properties of an optically active glass including the step of introducing phosphorus oxide to the glass is also provided.
Abstract:
An optical fiber including: (i) a silica based, rare earth doped core having a first index of refraction n1; and (ii) at least one silica based cladding surrounding the core and having a second index of refraction n2, such that n1>n2, said cladding having a plurality of stress rods and a plurality of air holes extending longitudinally through the length of said optical fiber; wherein said optical fiber supports a single polarization mode or poses-polarization maintaining properties within the operating wavelength range.
Abstract:
A method produces a glass body that contains a reduced amount of OH groups in the metallic-oxide-containing glass layer and that has a reduced amount of transmission loss due to OH groups when the glass body is transformed into an optical fiber. The production method produces an optical glass body. An optical fiber contains the optical glass body in at least one part of its region for guiding a lightwave. The production method includes the following steps: (a) introducing into a glass pipe a gas containing an organometallic compound and a glass-forming material; (b) decomposing the organometallic compound into an organic constituent and a metallic constituent; (c) heating and oxidizing the metallic constituent so that produced glass particles containing a metallic oxide are deposited on the inner surface of the glass pipe to form a glass-particle-deposited layer; and (d) consolidating the deposited layer to form a metallic-oxide-containing glass layer.
Abstract:
The present invention concerns a preform for an optical fiber, an optical fiber so obtained and methods for making the same. The fiber is characterized in that porous glass doped with at least one dopant is used. Resulting fibers can be used to make high attenuation fibers.
Abstract:
A new class of nanostructured RE-doped SiO2-base materials that display superior fluorescence properties is provided. In particular, high gain combined with a broad and flat spectral band width is observed in material composed of a high fraction of a nano-dispersed metastable silicate phase in a glassy SiO2 matrix, produced by partial devitrification (crystallization) of several glassy Al2O3/Er2O3- and Y2O3/Er2O3-doped SiO2 compositions. Also, a highly deconvoluted spectral emission, with several prominent peaks, is observed in completely devitrified material, consisting of a uniform nano-dispersion of an equilibrium silicate phase in a crystobalite SiO2 matrix. Such enhanced fluorescence properties were observed in heat treated nanopowders prepared by vapor-phase, solgel, rapid solidification, and spray-pyrolysis methods.
Abstract translation:提供了一类新型的具有优异荧光性能的纳米结构的RE掺杂SiO 2基体材料。 特别地,在通过部分失透反应产生的玻璃状SiO 2基体中的高分数纳米分散的亚稳态硅酸盐相组成的材料中观察到具有宽的和平坦的光谱带宽的高增益( 几个玻璃状的Al 2 O 3 / O 2 O 3 - 和Y 2的结晶, O 3组成的二氧化硅组合物。 此外,在完全失透的材料中观察到具有几个突出的峰的高度去卷积的光谱发射,由平底硅酸盐相在均匀的SiO 2基体中的均匀的纳米分散体组成。 在通过气相,溶胶凝胶,快速凝固和喷雾热解方法制备的热处理纳米粉末中观察到这种增强的荧光性质。
Abstract:
The present invention discloses a process for making rare earth (RE) doped optical fibre by using RE oxide coated silica nanoparticles as the precursor materia, more particularly the method of the present invention involves preparation of stable dispersions (sol) of RE oxide coated silica nanoparticles at ambient temperature and applying a thin coating on the inner surface of silica glass tube following dip coating technique or any other conventional methods, of the said silica sol containing suitable dopants selected from Ge, Al, P, etc., the coated tubes were further processed into optical preforms by following MCVD technique and fiberised in desired configuration, the novelty lies in eliminating the step of the formation of porous soot layer at high temperature by CVD process inside a fused silica glass tube for formation of the core and also in the elemination of the incorporation of the rare earth ions into the porous soot layer following the solution doping technique or other conventional methods, the direct addition of RE oxides in the sol eliminates the formation of microcrystalites and clusters of rare earth ions and prevents change in composition including variation of RE concentration in the core which results in increase in the reproducibility and reliability of the process to a great extent, further the addition of Ge(OET)4 at ambient temperature in the silica sol reduces the quantity of GeCl4 which is required at high temperature to achieve the desired Numerical Aperture.
Abstract:
A co-doped silicate optical waveguide having a core including silica, and oxides of aluminum, germanium, erbium and thulium. The composition concentrations are: Er from 15 ppm to 3000 ppm; Al from 0.5 mol % to 12 mol %; Tm from 15 ppm to 10000 ppm; and Ge from 1 mol % to 20 mol %. In a specific embodiment, the concentration of Er is from 150 ppm to 1500 ppm; Al is from 2 mol % to 8 mol %; and Tm is from 15 ppm to 3000 ppm. A boron-less cladding surrounds the core.
Abstract:
A method and apparatus are disclosed for the manufacture of an optical fiber preform having incorporated therein a comparatively high concentration of rare earth dopant material, and which thus can be drawn and processed into an optical fiber having low numerical aperture, low core attenuation, and high pumping power absorption. The high concentrations of rare earth dopant material are accomplished through either the “hybrid vapor processing” (HVP) method or a “hybrid liquid processing” (HLP) method, each capable of being practiced in combination or independently of one another. The HVP method involves the vaporization of a rare earth halogen by the exposure thereof to a sufficiently elevated temperature, independently, or contemporaneously with the transport of the resultant rare earth halogen laden vapor, into a glass forming oxidation reaction zone on a flowing stream of essentially an unreactive inert gas, such as helium. According to the HLP method, a first amount of rare earth dopant is provided according to the HVP method and/or other vapor source of rare earth dopant which is mixed with glass forming vapors to form a deposited soot layer on the internal surface of a glass tube. The soot-deposited tube is then impregnated with a dopant solution which may be formulated with a second amount of rare earth dopant. The tube is then thermally collapsed resulting in an optical preform with a an enhanced amount of incorporated first and second amounts of rare earth dopant.
Abstract:
A fusion splice including a first optical fiber having a first MFD and a first MFD expansion rate. The splice further includes a second fiber having a second MFD and a second MFD expansion rate, wherein the second MFD is lower than the first MFD. The second fiber comprises a core, a cladding radially surrounding the core, and a zone of high-concentration of fluorine between the core and the cladding. The rate of MFD expansion of the first fiber is less than the rate of MFD expansion of the second fiber during the fusion splicing operation.