Abstract: A radar system includes a transmitting element adapted to transmit a radar signal, a receiving element adapted to receive a reflected signal of the radar signal being transmitted by the transmitting element, and a radome covering the transmitting element and the receiving element and having an inner surface and an outer surface. The inner surface of the radome faces the transmitting element and the receiving element. The radome comprises a recess being located at the inner surface.

Abstract: An article including a glass having that includes SiO2, Al2O3, and B2O3 and least one of Li2O, Na2O, K2O, MgO, CaO, SrO, BaO, SnO2, ZnO, La2O3, F, and Fe2O3, wherein the glass includes a dielectric constant of about 10 or less and/or a loss tangent of about 0.01 or less, both as measured with signals at 10 GHz.

Abstract: The present invention relates to fiber glass strands, yarns, fabrics, composites, prepregs, laminates, fiber-metal laminates, and other products incorporating glass fibers formed from glass compositions. The glass fibers, in some embodiments, are incorporated into composites that can be used in reinforcement applications. Glass fibers formed from some embodiments of the glass compositions can have certain desirable properties that can include, for example, desirable electrical properties (e.g. low Dk) or desirable mechanical properties (e.g., specific strength).

Abstract: Provided is an image guide fiber that improves image quality while preventing a manufacturing problem. The image guide fiber according to the present disclosure has a numerical aperture NA in the range of 0.70 to 0.90. A linear thermal expansion coefficient difference ??, which is a value obtained by subtracting a linear thermal expansion coefficient ?2 at from 100 to 300° C. of clad glass, from a linear thermal expansion coefficient ?1 at from 100 to 300° C. of core glass, is in the range of ?3×10?7° C. to 15×10?7/° C. A glass-transition temperature Tg1 of the core glass is higher than a glass-transition temperature Tg2 of the clad glass. A core occupancy area ratio is 25% or more. A pixel density is 0.1 pixel/?m2 or more.

Abstract: Systems and methods are provided for mechanically encapsulating an infrared transmitting optical fiber, removing any power coupled to the cladding of the infrared optical fiber, and bridging the thermal properties between the optical fiber and the mechanical ferrule used. Embodiments of the present disclosure have several advantages over prior systems. For example, in an embodiment, the transmitting ferrule does not require epoxy to mount the fiber to the ferrule, isolates the front face of the fiber, and allows for high power to be incident on the connector without damage by reducing the thermal induced stress and managing any stray light coupled to the core.

Abstract: A security element for marking, authenticating or identifying objects or living beings, such as people, animals or plants is provided that includes one or more layers of materials that are arranged next to or on top of each other or that overlap, which have security markings. At least one layer of the security element has, at least regionally, a crackle pattern in form of tears or cracks, nicks, wear areas or shrinkages and possible impurities, which can be scanned and detected together or separately as security features. A method for producing such a security element and to a use thereof for authenticating a person or an object, or for authorizing, triggering, continuing, carrying out and ending an action is also provided.

Abstract: An optical device for generating a frequency comb includes an optical source and a first waveguide comprising a nonlinear optical medium operable to mix at least two input optical waves to generate a plurality of first optical waves. The optical device also includes a second waveguide concatenated to the first waveguide and characterized by a first dispersion characteristics and operable to compress the waveforms of the plurality of first optical waves and to reduce a frequency chirp introduced by the first waveguide. The optical device additionally includes a third waveguide concatenated to the second waveguide. The third waveguide comprises a nonlinear optical medium and is operable to mix the plurality of first optical waves to generate a plurality of second optical waves and to increase a total number of second optical waves with respect to a total number of first optical waves.

Abstract: An IR supercontinuum source for generating supercontinuum in the MIR or possibly LWIR spectral bands comprises a supercontinuum fiber formed from a heavy metal oxide host glass having low optical loss and high non-linearity over the spectral band that is stable, strong and chemically durable. The supercontinuum fiber is suitably a depressed inner clad fiber configured to support only single transverse spatial mode propagation of the pump signal and supercontinuum. The source suitably includes a tapered depressed inner clad fiber to couple the pump signal into the supercontinuum fiber. The source may be configured as an “all-fiber” source.

Abstract: Alkali-doped boroaluminosilicate glasses are provided. The glasses include the network formers SiO2, B2O3, and Al2O3. The glass may, in some embodiments, have a Young's modulus of less than about 65 GPa and/or a coefficient of thermal expansion of less than about 40×10?7/° C. The glass may be used as a cover glass for electronic devices, a color filter substrate, a thin film transistor substrate, or an outer clad layer for a glass laminate.

Abstract: Intermediate to high CTE glass compositions and laminates formed from the same are described. The glasses described herein have properties, such as liquidus viscosity or liquidus temperature, which make them particularly well suited for use in fusion forming processes, such as the fusion down draw process and/or the fusion lamination process. Further, the glass composition may be used in a laminated glass article, such as a laminated glass article formed by a fusion laminate process, to provide strengthened laminates via clad compression as a result of CTE mismatch between the core glass and clad glass.

Abstract: An optical waveguide having a cladding layer formed of high-purity glass, or a cladding layer formed of high-purity isotope-proportion modified glass, and with a core of high-purity isotope-proportion-modified glass with the index of refraction of the core glass greater than the index of refraction of the cladding glass, said high-purity isotope-proportion-modified core material having a Si-29-isotope proportion at most 4.447% Si-29 (atom/atom) of all silicon atoms in said core, or at least 4.90% of Si-29 (atom/atom) atoms in said core, or having a Ge-73 isotope proportion of at most 7.2% Ge-73 (atom/atom) of all germanium atoms in said core, or at least 8.18% of Ge-73 (atom/atom) of Germanium atoms in said core region.

Abstract: Glasses are provided that are highly transparent and have very good resistance to solarisation. The resistance to solarisation is favoured to a special extent by the production method. The concentrations of reduced polyvalent ion species are reduced by targeted use of bubbling with an oxidising gas. Methods for producing glasses and to the uses thereof, particularly as core glasses in optical waveguides, are also provided.

Abstract: Various embodiments described herein comprise a laser and/or an amplifier system including a doped gain fiber having ytterbium ions in a phosphosilicate glass. Various embodiments described herein increase pump absorption to at least about 1000 dB/m-9000 dB/m. The use of these gain fibers provide for increased peak-powers and/or pulse energies. The various embodiments of the doped gain fiber having ytterbium ions in a phosphosilicate glass exhibit reduced photo-darkening levels compared to photo-darkening levels obtainable with equivalent doping levels of an ytterbium doped silica fiber.

Abstract: A tellurium oxide glass that is stable, strong and chemically durable exhibits low optical loss from the UV band well into the MIR band. Unwanted absorption mechanisms in the MIR band are removed or reduced so that the glass formulation exhibits optical performance as close as possible to the theoretical limit of a tellurium oxide glass. The glass formulation only includes glass constituents that provide the intermediate, modifiers and any halides (for OH— reduction) whose inherent absorption wavelength is longer than that of Tellurium (IV) oxide. The glass formulation is substantially free of Sodium Oxide and any other passive glass constituent including hydroxyl whose inherent absorption wavelength is shorter than that of Tellurium (IV) oxide. The glass formulation preferably includes only a small residual amount of halide.

Abstract: Provided is a method for manufacturing an optical fiber that is inserted into an insertion portion of an endoscope and guides light, wherein inside an upright fiber drawing furnace, inside a hollow clad tube including a clad glass having a viscosity ?1 of 5.0<Log ?1<7.0 at a temperature at which a viscosity ?2 of a core glass becomes Log ?2=3.5, the core glass in a fluidized state runs down by gravity, whereby the core glass and the clad glass are integrated.

Abstract: An endoscope includes an insertion portion including an image pickup section, an illumination section, and a light guide inserted inside the insertion portion, the light guide including a plurality of fibers made of a glass not containing lead, the plurality of fibers guiding illuminating light from a light source apparatus to the illumination section, the light guide having a numerical aperture of 0.46 to 0.90. A core glass of a fiber have a refractive index nd of 1.56 to 1.74, and a composition of (A) 20 to 55 wt % SiO2, (B1) 0 to 4.0 wt % B2O3, (B2) neither P2O5 nor GeO2 contained, (C) 25 to 72 wt % (BaO+SrO+La2O3+Lu2O3+Ta2O5+Gd2O3+WO3), (D) 0 to 30 wt % ZnO, (E) no Al2O3 contained, (F) no ZrO2 contained, (G) neither PbO nor As2O3 contained, (H) 0 to 15 wt % (Na2O+K2O), (I) 0 to 0.050 wt % Sb2O3 and (J) 0.26 to 1.63 wt % (Na2SO4+K2SO4).

Abstract: A glass for a light guide fiber GA1 is used in a core of a fiber 10 of a light guide, and has a refractive index nd between 1.56 and 1.74. The glass for a light guide fiber GA1 has the following composition: (A) SiO2: 20 to 55 wt %, (B11) B2O3: 0 to 2.0 wt %, (B2) does not contain P2O5 and GeO2, (C1) (BaO+SrO+La2O3+Lu2O3+Ta2O5+Gd2O3+WO3): 39 to 46 wt %, (D1) ZnO: 4 to 16 wt %, (E) does not contain Al2O3, (F) does not contain ZrO2, (G) does not contain PbO and As2O3, (H1) (Na2O+K2O): 4 to 10 wt %, (I) Sb2O3: 0 to 0.050 wt %, and (J1) (Na2SO4+K2SO4): 0.32 to 0.78 wt %.

Abstract: IR-transmitting alkaline earth selenogallo- and/or selenoindo-germanate glasses that are capable of hosting luminescent rare earth dopants. The relatively high Ga and/or In content of most compositions serves to eliminate the typical clustering tendency of rare earth dopants in chalcogenide glasses, resulting in improved luminescence.

Abstract: An amplifying optical fiber includes a core containing oxides of elements selected from the group consisting of silicon, germanium, phosphorus, bismuth, aluminum, gallium with a concentration of bismuth oxide of 10-4-5 mol %, a total concentration of silicon and germanium oxides of 70-99.8999 mol %, a total concentration of aluminum and gallium oxides of 0.1-20 mol % wherein both aluminum and gallium oxide are present and a ratio of aluminum oxide to gallium oxide is at least two, and a concentration of phosphorus oxide from 0 to 10 mol %, and provides a maximum optical gain at least 10 times greater than the nonresonant loss factor in the optical fiber. An outside oxide glass cladding comprises fused silica. The core has an absorption band in the 1000 nm region, pumping to which region provides an increased efficiency of power conversion of pump light into luminescence light in the 1000-1700 nm range.

Abstract: Provided are an amorphous polyamide resin composition having high transparency, and is excellent in heat resistance and stiffness, and a molded product thereof. The glass filler contains, expressed in terms of oxides by mass %, 68 to 74% of silicon dioxide (SiO2), 2 to 5% of aluminum oxide (Al2O3), 2 to 5% of boron oxide (B2O3), 2 to 10% of calcium oxide (CaO), 0 to 5% of zinc oxide (ZnO), 0 to 5% of strontium oxide (SrO), 0 to 1% of barium oxide (BaO), 1 to 5% of magnesium oxide (MgO), 0 to 5% of lithium oxide (Li2O), 5 to 12% of sodium oxide (Na2O), and 0 to 10% of potassium oxide (K2O), where a total amount of lithium oxide (Li2O), sodium oxide (Na2O), and potassium oxide (K2O) is 8 to 12%.

Abstract: Disclosed is an optical fiber that includes a central core that is suitable for transmitting and amplifying an optical signal and an inner optical cladding that is suitable for confining the optical signal transmitted within the central core. The central core is formed from a core matrix that contains silica-based nanoparticles doped with at least one rare earth element. The disclosed optical fiber can be used with limited optical losses even in an environment with strong ionizing radiation.

Abstract: An ytterbium-doped optical fiber of the present invention includes: a core which contains ytterbium, aluminum, and phosphorus and does not contain germanium; and a cladding which surrounds this core. The ytterbium concentration in the core in terms of ytterbium oxide is 0.09 to 0.68 mole percent. The molar ratio between the phosphorus concentration in the core in terms of diphosphorus pentoxide and the above ytterbium concentration in terms of ytterbium oxide is 3 to 30. The molar ratio between the aluminum concentration in the core in terms of aluminum oxide and the above ytterbium concentration in terms of ytterbium oxide is 3 to 32. The molar ratio between the above aluminum concentration in terms of aluminum oxide and the above phosphorus concentration in terms of diphosphorus pentoxide is 1 to 2.5.

Abstract: An optical glass has a refractive index (nd) of 1.60 or over and excellent transmittance and internal quality. The optical glass comprises 0.1-4 mass % of Ta2O5 to total mass of glass calculated on oxide basis, has ratio of 0.95<Ta2O5/(Ta2O5+(ZrO2)+TiO2+Nb2O5+WO3)×5)?1.00, and further comprises SiO2+B2O3+Al2O3+BaO in a total amount of 81% or over.

Abstract: A glass for a light guide fiber GA1 is used in a core of a fiber 10 of a light guide, and has a refractive index nd between 1.56 and 1.74. The glass for a light guide fiber GA1 has the following composition: (A) SiO2: 20 to 55 wt %, (B11) B2O3: 0 to 2.0 wt %, (B2) does not contain P2O5 and GeO2, (C1) (BaO+SrO+La2O3+Lu2O3+Ta2O3+Gd2O3+WO3): 39 to 46 wt %, (D1) ZnO: 4 to 16 wt %, (E) does not contain Al2O3, (F) does not contain ZrO2, (G) does not contain PbO and As2O3, (H1) (Na2O+K2O): 4 to 10 wt %, (I1) Sb2O3: 0.001 to 0.010 wt %, and (J1) (Na2SO4+K2SO4): 0.32 to 0.78 wt %.

Abstract: Zirconium-containing BaO- and PbO-free X-ray opaque glasses having a refractive index nd of about 1.518 to about 1.533 and a high X-ray opacity with an aluminum equivalent thickness of at least about 180% are provided. Such glasses are based on a SiO2—Al2O3—B2O3 system with additions of K2O, ZrO2, and one or both of La2O3 and Cs2O. Such glasses may be used, in particular, as dental glasses or as optical glasses.

Abstract: A method of manufacturing a fluorine-containing optical fiber base material through a sintering process includes dehydrating a porous glass stack by heating it under a chlorine-based gas atmosphere, adding fluorine into the porous glass stack by heating it under a fluorine source gas atmosphere, and making the porous glass stack transparent by heating it under a fluorine source gas atmosphere at a higher temperature than a temperature at which the porous glass stack is heated in the adding. Here, process temperatures in the dehydrating, adding and making are T1, T2 and T3 (K) respectively, concentrations of the fluorine source gas in the adding and making are C2 and C3 (%) respectively, a parameter Q is represented by the formula: Q=C2×exp(?T2/T1)+C3×exp(?T2/T1), and the process temperatures and the concentrations of the fluorine source gas satisfy the relation Q>0.14.

Abstract: Provided is optical glass that does not contain lead, which is an environmental pollutant. The optical glass is ideal for the transmission of light even after being exposed to X-rays, and has a high refractive index. The optical glass comprises, by mass% in terms of oxide versus the glass total mass, 1.0% to 60.0% of an SiO2 component, and one or more selected from the group consisting of an La2O3 component, ZrO2 component, TiO2 component, Nb2O5 component, and Ta2O5 as essential components. The optical glass has a refractive index (nd) of 1.50 or greater, and has a light intensity recovery rate of 45% or greater when the glass having been irradiated with X-rays with a dose of 2.5 Gy is irradiated with light of a xenon lamp for 11 hours.

Abstract: A clad glass composition that is excellent in devitrification resistance and that prevents the whole mother glass rod from devitrifying by preventing a core glass composition from devitrifying in forming a mother glass rod using a concentric crucible drawing method, is provided. The clad glass composition forms a clad of a mother glass rod for a gradient-index rod lens having a core/clad structure.

Abstract: Provided is an erbium doped optical fiber (EDF) for amplification which allows an easy estimation of the amplification performance and high production stability. The fiber includes a core and a cladding. The core is mainly made of silica glass and doped with erbium at a concentration of 500 wtppm or more and 2500 wtppm or less. In the fiber, the cutoff wavelength is 850 nm or more and 1450 nm or less, the mode field diameter is 4.5 ?m or more and 6.5 ?m or less, the polarization mode dispersion is not more than 0.1 ps per 10 m, the coordination number of oxygen elements around an erbium element in the core is one or more and eight or less, and the bond length between erbium and oxygen is 0.225 nm or more and 0.235 or less.

Abstract: To provide a light-amplifying glass capable of increasing absorption of Yb3+. A light-amplifying glass to be used for amplifying light having a wavelength of 1.0 to 1.2 ?m, which comprises, as represented by mol % based on the following oxides, from 30 to 55% of Bi2O3, from 25 to 50% of either one, or both in total, of SiO2 and B2O3, from 12 to 27% of either one, or both in total, of Al2O3 and Ga2O3, from 0 to 4% of La2O3 and from 0.1 to 4% of Yb2O3 and which contains substantially no Er2O3. An optical waveguide having such a light-amplifying glass as a core.

Abstract: Provided is an optical fiber for amplification and an optical fiber amplifier for use in L-band, in which optical fiber the increase of transmission loss and the degradation of hydrogen-resistant characteristic can be restrained. The optical fiber is basically made of silica glass and comprises: a core region doped with erbium and P element of 2 wt % to 5 wt % concentration, Ge not being added thereto; and a cladding region enclosing the core region and doped with F element, wherein the optical fiber has a gain at least in a wavelength range of 1570 to 1620 nm. The optical fiber amplifier comprises: the optical fiber; a pump light source for outputting the pump light capable of exciting a rare-earth element added to the core region of the optical fiber; and an optical coupler for introducing into the optical fiber the pump light having been output from the pump light source.

Abstract: To provide a light-amplifying glass capable of increasing absorption of Yb3+. A light-amplifying glass to be used for amplifying light having a wavelength of 1.0 to 1.2 ?m, which comprises, as represented by mol % based on the following oxides, from 30 to 55% of Bi2O3, from 25 to 50% of either one, or both in total, of SiO2 and B2O3, from 12 to 27% of either one, or both in total, of Al2O3 and Ga2O3, from 0 to 4% of La2O3 and from 0.1 to 4% of Yb2O3 and which contains substantially no Er2O3. An optical waveguide having such a light-amplifying glass as a core.

Abstract: An optical glass has a refractive index (nd) of 1.60 or over and excellent transmittance and internal quality. The optical glass comprises 0.1-4 mass % of Ta2O5 to total mass of glass calculated on oxide basis, has ratio of 0.95<Ta2O5/(Ta2O5+(ZrO2)+TiO2+Nb2O5+WO3)×5)?1.00, and further comprises SiO2+B2O3+Al2O3+BaO in a total amount of 81% or over.

Abstract: A process for producing an optical glass fiber from crystal-glass phase material. In one embodiment, the process includes the step of providing a molten crystal-glass phase material in a container, wherein the temperature of the molten crystal-glass phase material is at or above the melting temperature of the molten crystal-glass phase material, Tm, to allow the molten crystal-glass phase material is in liquid phase. The process further includes the step of cooling the molten crystal-glass phase material such that the temperature of the molten crystal-glass phase material, T1, is reduced to below Tm to cause the molten crystal-glass phase material to be changed from the liquid phase to a viscous melt.

Abstract: The present invention relates to amorphous thin films and methods of manufacturing the same. These amorphous thin films contain zirconium oxide (ZrO2), preferably at a concentration of at least 30 mol %, and other metal oxides and have surprisingly good mechanical and optical properties. In some embodiments of the present invention, the thin films may be further processed to obtain fluorinated glasses containing the same metal elements as the metal oxides.

Abstract: This invention pertains to a chalcogenide glass of low optical loss that can be on the order of 30 dB/km or lower, and to a process for preparing the chalcogenide glass.

Abstract: A method of producing a large mode area optical preform includes selecting a preexisting rod and at least one preexisting outer tube. The rod and tube are selected so that a difference between respective indices of refraction is uniform and lies within the desired range, and a ratio between respective rod and tube diameters is within the desired range after the rod is inserted into the tube and both are thermally treated. The predetermined ranges are selected to provide mass production of a large mode area fiber with the desired physical and geometrical characteristics.

Abstract: An optical member comprising OD-doped silica glass, optionally doped with fluorine. The optical member is particularly advantageous for use in connection with radiation having a wavelength shorter than about 248 nm. In certain embodiments the optical member can be advantageously used for wavelength as short as about 157 nm.

Abstract: A glass filler for a polycarbonate resin, whereby the refractive index of the glass filler can be improved to the same level as a polycarbonate resin, and the transparency of a molded product after reinforced with such a filler can be maintained without coloration, and a polycarbonate resin composition employing such a filler, are provided.

Abstract: A glass composition for glass fiber comprises, by mass percentage in terms of oxide, 60 to 75% SiO2, 0 to 10% Al2O3, 0 to 20% B2O3, 5 to 15% Li2O+Na2O+K2O, 0 to 10% MgO+CaO+SrO+BaO+ZnO, 0 to 10% TiO2 and 0 to 10% Zr02. A glass fiber consists of the above glass composition for glass fiber. A process for producing a glass fiber comprises the steps of melting the above glass composition in a heat-resistant vessel and continuously drawing out the molten glass through a heat-resistant nozzle so as to form a glass fiber; coating the surface thereof with a chemical; and continuously reeling the coated glass fiber. A composite material is obtained by compositing the glass fiber with an organic resin.

Abstract: A known method for producing a hollow cylinder of synthetic quartz glass comprises the steps of: (a) providing an inner tube of synthetic quartz glass having an inner bore defined by an inner wall, (b) cladding the inner tube (3?) with an SiO2 soot layer (4?), and (c) sintering the SiO2 soot layer with formation of the hollow cylinder. Starting therefrom, to indicate a method in which on the one hand the sintering process is completed before the hollow cylinder is further processed together with the core rod, and in which on the other hand a complicated machining of the inner bore of the hollow cylinder of quartz glass is not required, the invention suggests that during sintering the surface temperature of the inner wall of the inner tube should be kept below the softening temperature.

Abstract: A chalcogenide glass composition composed of arsenic (As), selenium (Se), sulfur (S), and antimony (Sb) is presented. The composition includes arsenic in the range from 25% to 45% by weight relative to the total weight of the composition, selenium in the range from 40% to 65% by weight relative to the total weight of the composition, sulfur in the range from 2% to 15% by weight relative to the total weight of the composition, and antimony in the range from 0% to 15% by weight relative to the total weight of the composition. The variability of constituents on a weight basis is greater than the related arts, thus facilitating a broader range of design options. The glass composition is preferred to have a thermal expansion coefficient of about 23.6×10?6/° C., a temperature coefficient of refractive index less than about 1×10?6/° C., a glass transition temperature less than 200 degrees Celsius, and/or a glass softening temperature less than 250 degrees Celsius.

Abstract: To improve a known method for making a quartz glass tube as a semifinished product for the manufacture of optical fibers, the tube comprising an inner fluorine-doped quartz glass layer and an outer quartz glass layer, so as to achieve inexpensive manufacture and improved dimensional stability of the quartz glass tube, it is suggested according to the invention that the quartz glass of the inner layer should be produced in a first plasma deposition process with formation of an inner layer having a wall thickness of at least 1.5 mm, with a fluorine content of at least 1.5% by wt. being set in the quartz glass, and that the quartz glass of the outer layer should be produced in a second plasma deposition process and deposited directly or indirectly on the inner layer with formation of a composite tube, and that the composite tube should be elongated into the quartz glass tube.

Abstract: A method of producing an optical fiber preform by heating a glass preform that has a glass rod and a silica glass porous body and includes a valid portion and invalid portions, comprising: heating the glass preform while moving the glass preform along its axial direction relative to a heater; stopping the relative movement or decreasing a speed of the relative movement when an invalid portion positioned at a tail end reaches a vicinity of the heater; heating the invalid portion for a predetermined time while maintaining a temperature at which the silica glass porous body can be vitrified; decreasing the heating temperature to a temperature determined by adding 200° C. to an annealing point of a silica glass; and removing the glass preform to the outside of the heating furnace without increasing the heating temperature to the temperature at which the silica glass porous body is vitrified.

Abstract: The present invention provides a clad glass composition that is excellent in devitrification resistance and that prevents the whole mother glass rod from devitrifying by preventing a core glass composition from devitrifying in forming a mother glass rod using a concentric crucible drawing method. The clad glass composition forms a clad of a mother glass rod for a gradient-index rod lens having a core/clad structure. The clad glass composition includes the following components, indicated by mol %: 45 to 65% SiO2; 0.5 to 10% TiO2; 0 to 15% B2O3; 0 to 7% Al2O3; 0.1 to 10% Bi2O3; 0 to 5% Li2O; 5 to 30% Na2O; 0 to 10% K2O; 0 to 15% MgO; 0 to 10% CaO; 0 to 10% SrO; 0.

Abstract: A method for manufacturing a polarization-maintaining optical fiber is provided. The method includes (a) making a fiber preform by providing in an over-cladding tube: a core rod having an inner core and a cladding surrounding the inner core; at least one stress-applying part (SAP) disposed adjacent to the core rod along an outer periphery of the cladding thereof and having a coefficient of thermal expansion different from that of the cladding; inner filler rods arranged along the outer periphery of the core rod at positions where the SAP is not disposed and having a coefficient of thermal expansion different from that of the SAP; and a plurality of outer filler rods arranged adjacent the over-cladding tube between the over-cladding tube and inner filler rods, SAP and core rod, and consisting of a same material as the over-cladding tube; and (b) drawing the fiber preform to obtain the optical fiber.

Abstract: A core glass and a fiber-optic light guide made from it are described. The core glass is in the alkali-zinc-silicate system and contains, in Mol % on an oxide basis: 54.5-65, SiO2; 18.5-30, ZnO; 8-20, ? alkali oxides; 0.5-3, La2O3; 2-5, ZrO2; 0.02-5, HfO2; 2.02-5, ?ZrO2+HfO2; 0.4-6, BaO; 0-6, SrO; 0-2, MgO; 0-2, CaO; 0.4-6, ? alkaline earth oxides; 0.5-3, Li2O, but no more Li2O than 25% of the ? alkali oxides; >58.5, ? SiO2+ZrO2+HfO2. A molar ratio of Na2O/K2O is from 1/1.1 to 1/0.3. A molar ratio of ZnO to BaO is greater than 3.5.

Abstract: The invention relates to vitreous compositions, in particular of the vitroceramic type, transparent to infrared, production and uses thereof. Said compositions comprise in mol. %: Ge 5-40, Ga<1, S+Se 40-85, Sb+As 4-40, MX 2-25, Ln 0-6, adjuncts 0-30, where M=at least one alkaline metal, selected from Rb, Cs, Na, K and Zn, X=at least one atom of chlorine, bromine or iodine, Ln=at least one rare earth and adjunct=at least one additive comprising at least one metal and/or at least one metal salt with the sum of all molar percentages of the components present in said composition being 100.

Abstract: An optical fiber according to Tran U.S. Pat. No. 5,274,728 is improved by chemically etching the surface of the GeO2-based glass perform with an acid solution based on a mixture of HNO3 and water.

Abstract: The present invention provides a glass composition that exhibits a fluorescence function and an optical amplification function in a wide wavelength range. This glass composition includes a bismuth oxide, a silicon oxide, an aluminum oxide, and a divalent metal oxide, and the glass composition emits fluorescence in an infrared wavelength region through irradiation of excitation light, with bismuth contained in the bismuth oxide functioning as a fluorescent source.