Optical fibre and optical transmission system

FIELD: optics.

SUBSTANCE: invention relates to optical fibres. Optical fibre with low attenuation is proposed, which is made with possibility to use as optical transmission line in optical access network, it is glass optical fibre, based on quartz, and includes core, comprising central axis, optical cladding, surrounding core, and protective cover surrounding optical cladding. Core contains GeO2 and has relative difference of index of refraction Δcore, based on optical cladding, greater or equal to 0.35 % or less or equal to 0.50 %, and has volume v of index of refraction greater or equal to 0.045 µm2 and less or equal to 0.095 µm2. Protective cover has relative difference of index of refraction ΔJ, greater or equal to 0.03 % and less or equal to 0.20 %. Core glass has fictitious temperature greater or equal to 1,400 °C and less or equal to 1,590 °C. Residual tension in core is compression stress with absolute value greater or equal to 5 MPa.

EFFECT: technical result is reduction of losses in optical fibre, when used as optical transmission line in optical access network.

22 cl, 6 dwg



Same patents:

FIELD: measurement equipment.

SUBSTANCE: invention relates to fibre-optic temperature sensors. A sensitive element is made in the form of a fibre from luminescent glass that includes neutral molecular clusters of silver and ions of rare-earth metal.

EFFECT: increase of temperature sensitivity of a sensor.

3 dwg

FIELD: physics, optics.

SUBSTANCE: invention relates to fibre optics. This optical fibre comprises core without Ge and with central area, first ring area, second ring area doped with fluorine and shell. Profile of optical fibre relative refraction ratio is selected to allow attenuation not over 0.175 dB/km in wavelength of 1550 nm. Additionally, this fibre comprises primary coating with modulus of elasticity lower than 1.0 MPa and secondary coating with said modulus over 1200 MPa.

EFFECT: larger efficient area and lower attenuation.

20 cl, 14 tbl, 23 dwg

FIELD: chemistry.

SUBSTANCE: dry, deuterium-containing gases, for example dimethylsulphoxide D6 vapours, are introduced into a tube of a fibrous light guide workpiece. Alloying of precipitable layers of a glass core and envelope with small additions of deuterium is carried out both in the process of the layer precipitation and at high-temperature tube compression.

EFFECT: reduction of the light guide optical loss and mass loss of workpieces, reduction of thereof production process duration.

2 cl, 1 tbl

FIELD: physics, optics.

SUBSTANCE: invention relates to single-mode optical fibres having a low attenuation coefficient. The optical waveguide fibre includes a core and a cladding. The core includes an alpha-profile, where alpha (α) is greater than 2.5 and less than 3.0. The core and cladding provide the fibre with an attenuation coefficient of less than 0.331 dB/km at wavelength of 1310 nm, attenuation coefficient of less than 0.328 dB/km at wavelength of 1383 nm, attenuation coefficient of less than 0.270 dB/km at wavelength of 1410 nm and attenuation coefficient of less than 0.190 dB/km at wavelength of 1550 nm. Also provided is a method of producing the optical fibre.

EFFECT: reduced attenuation coefficient and bending loss.

5 cl, 8 dwg, 5 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of obtaining workpieces from silver halides and their solid solutions for fibrous infrared lightguides, which includes application on silver halide crystal-core of crystalline shell of crystalline silver halide with refraction index lower than in crystal-core, and thermal processing. Shell on crystal-core is applied by ion-exchange diffusion in ion-exchange source, as the latter taken is finely disperse silver halide powder with coarseness 1-20 mcm, diffusion is carried out at temperature, close to melting temperature of crystal-core in atmosphere of mixture of vapours of halides, included into composition of crystal material and powder, taken in equal ratio under pressure 0.2-0.5 atm.

EFFECT: method makes it possible to reduce optic loss of lightduides, operating in infrared spectrum range.

2 ex

FIELD: physics.

SUBSTANCE: fibre-optic guide is obtained by chemical deposition of quartz glass from a mixture of starting gaseous reagents. The optic guide has a core of undoped quartz glass with low content of chlorine in the glass of the core due to considerable excess of oxygen O2 relative to silicon tetrachloride SiCl4 during manufacture.

EFFECT: providing high radiation resistance of an optic guide in the near infrared range by suppressing radiation-induced light absorption.

32 cl, 7 dwg

FIELD: measurement equipment.

SUBSTANCE: invention relates to a sensor system comprising a wave guide. A diffraction lattice is available on a part of the wave guide. Also the wave guide comprises a coating, including polymer. Polymer comprises a chain, where an aromatic group and a chemical group are present, being selected from a group of sulfonyl groups, carbonyl groups, carbonate groups, fluorocarbon groups, siloxane groups, pyridine groups and amide groups.

EFFECT: high stiffness and high temperature resistance.

18 cl, 2 tbl, 7 dwg

FIELD: physics.

SUBSTANCE: photonic crystal waveguide with a hexagonal shape comprises cladding and a hollow core in which a multilayer of capillaries is inserted. The period and diameter of channels of the multilayer of capillaries is close or much smaller than the radiation wavelength of the required spectral range. The diameter of capillaries of the cladding is always greater than the diameter of channels of the multilayer.

EFFECT: enabling selection of spectral components with a width smaller than 200 nm from optical radiation flux of a wideband source within the entire visible wavelength range.

2 cl, 10 dwg

FIELD: physics, optics.

SUBSTANCE: invention relates to fibre-optic engineering and can be used in producing microstructured fibre light guides used in optical amplifiers, lasers, spectral filters and telecommunication networks. A method of producing microstructured fibre light guides from a workpiece in which the upper end is sealed. The light guides are drawn from the lower heated end of the workpiece. To control and vary structural and physical parameters of the obtained microstructured fibre light guides, temperature of the upper part of the workpiece from the sealed end to the entrance of the furnace is controlled by an additional heater. To obtain microstructured fibre light guides with a constant external diameter, but with optical parameters which vary according to a given law along the light guide, temperature of the additional heater is varied according to a given law when drawing the light guide or a given constant temperature profile is created in the light guide.

EFFECT: wider field of use of the method owing to the possibility of producing long light guides with stable internal structural parameters, high reproducibility, easy monitoring and control of parameters of the light guides and producing a light guide structure with openings of different sizes.

3 cl, 6 dwg

FIELD: radio engineering, communication.

SUBSTANCE: apparatus has a dielectric waveguide in form of a hollow cylinder with openings in the wall for inlet of fibre-optic links lying at a distance δ from each other. Leads of the fibre-optic links are placed in a cylinder bushing made of waveguide material. The bushing is tightly fit into the cavity of the waveguide and protrudes from the waveguide by a distance h. An optical lens is placed coaxially opposite the bushing. The distances δ and h are selected to be comparable with the given wavelength λ of radio-frequency radiation. To ensure coaxiality of the fibre-optic link and the optical axis of the lens, the waveguide is placed such that coaxiality can be adjusted. To protect information radio-wave radiation from spurious reflection, the waveguide is placed in a pipe made of porous dielectric material with low permittivity.

EFFECT: invention improvement.

3 cl, 2 dwg

FIELD: optical cable and optical fiber manufacture.

SUBSTANCE: branded optical fiber has optical-fiber core, marking layers, and dyed layer. Set of marking layers composed of small definite-size droplets of marking dye are disposed at intervals along optical fiber core, on its surface. Dyed layer is applied to marking layers and to optical-fiber core on areas covered with marking layers. Specified thickness of dyed layer is not less than or equal to 2 μm and not more than or equal to 10 μm. Specified thickness of marking layers is not less than or equal to 0.5 μm and not more than or equal to 2.5 μm. Specified length of marking layers is not less than or equal to 1 mm and not more than or equal to 15 mm. Interval between marking layers should be specified between 1 and 200 mm. Specified volumetric efficiency of marking layers should be mot over or equal to 20%. Specified diameter of small droplets should be not less than or equal to 10 μm. and not less than or equal to 10 μm. Optical cable has plurality of branded fibers disposed in forming tube covered with plastic jacket.

EFFECT: enhanced identifying ability and reduced laying loss.

18 cl, 11 dwg

FIELD: the invention refers to the technology of creation of fiber-optic light-pipes.

SUBSTANCE: it may be used in the fields where conditions of the work demand protection of the light-pipe from diffusion of admixtures from without. Longitudinal cavities are created in a glass shell and these cavities are filled with gas not influencing on optical losses in the light-pipe. In quality of gas helium or heavy hydrogen is used. The diffusion of gas from the cavities of the light-pipe from without prevents diffusion of hydrogen from the environment inside the light-pipe to its light leading core of the light-pipe not to hinder propagation of light along the core. The core of the light-pipe may be single-mode or multi-mode, out of plain quartz glass or out of quartz glass alloyed with oxides of germanium, phosphorous, aluminum, boron. The cavities may be filled with gas not only from the end-face of the light-pipe but also from the outside through unsealed cavities in a definite place of the light-pipe.

EFFECT: possibility to work in atmosphere containing hydrogen at increased temperatures without additional optical losses connected with hydrogen.

10 cl, 5 dwg

FIELD: physics.

SUBSTANCE: molecular hydrogen or deuterium inclusion concentration is maintained within 1·1019 to 5·1021cm-3 range in core and shell of fiber light guide. During light guide operation molecular hydrogen or deuterium is fed under pressure not less than 1 MPa to a cavity formed in the shell and/or protection coating. Medium for molecular hydrogen or deuterium spill prevention or impediment from the cavity through light guide end surfaces is provided.

EFFECT: enhanced light guide resistance to nuclear or ionising radiation by molecular hydrogen or deuterium concentration regulation (replenishment along reduction) in light guide glass during operation.

42 cl, 8 dwg

FIELD: physics.

SUBSTANCE: length of beats Lbt is measured when optical fibre is wound on a coil. The average bond length Lb is measured when the optical fibre is in form of an optical cable. Polarisation modal dispersion (PMD) is calculated when the optical fibre is in form of optical cable, using equation (1) for the section of the optical fibre for which there is no connection between polarisation modes, and using equation (2) for all lengths of optical fibre; where λ - is the optical wavelength and C - is speed of light. The optical fibre has a core and a fibre shield around the core, in which polarisation modal dispersion, measured using the method of measuring polarisation modal dispersion (PMD) of optical fibre, is equal to or less than The fibre optical cable, in which there are several covered optical fibres, has a protective layer around the optical fibre and is placed side by side. The covered optical fibres are put into the cable shield.

EFFECT: design of a method of measuring polarisation modal dispersion of optical fibre, through which polarisation modal dispersion of optical fibre can be evaluated after assembling into an optical cable, when the fibre is wound into a coil for transportation.

15 cl, 8 dwg

FIELD: physics.

SUBSTANCE: present invention pertains to fibre-optic communications systems, and particularly to single-mode bi-layered crystalline infrared light waveguides for 5-30 mcm spectrum range. The light waveguide comprises a core and a shell. The core, with diameter of 15-45 mcm, is made from solid solutions of silver chloride and silver bromide, doped with univalent thallium iodide, with the following ratio of ingredients, in wt %: silver chloride 19.5-15.0; silver bromide 80.0-82.0; univalent thallium iodide 0.5-3.0. The shell, with diameter of 0.7-1.0 mm, is made from solid solutions of silver chloride and silver bromide, with the following ratio of ingredients, in wt %: silver chloride 19.0-21.0; silver bromide 81.0-79.0.

EFFECT: obtaining a single-mode bi-layered crystalline infrared light waveguide for transmitting electromagnetic radiation in the middle and far infrared band (5-30 mcm).

FIELD: physics.

SUBSTANCE: present invention pertains to fibre-optic communications systems and is aimed at transmitting information along single-mode crystalline infrared light waveguides in a wide spectral range. The single-mode crystalline infrared light waveguide comprises a core and a shell, and is based on solid solutions of silver chloride and silver bromide. The core has diameter of 20-110 mcm and with its ingredients in the following ratio, in wt %: silver chloride 19.0-21.0; silver bromide 81.0-79.0. The shell contains the same ingredients at the following ratio, in wt %: silver chloride 25.0-35.0; silver bromide 75.0-65.0.

EFFECT: design of light waveguides which work in a wide spectral range (3-30 mcm).

1 dwg

FIELD: physics, optics.

SUBSTANCE: invention relates to multimode fiber with refractive index distribution profile. The proposed multimode comprises light conducting core with one or more layers of cladding, that features, at least, 1Gbit/s capacity in the range of wave widths of, at least, 100 nm in spectral range comprising 1300 nm-wanelength and allowing aforesaid capacity over the fiber length of, at least, 1000 m. The method of producing above fiber comprises applying glass layers, with doping impurities or without them, onto the substrate inner side by gas plating using the mix of chemically active gases to produce a semi-finished product with preset refractive index distribution profile. Aforesaid semi-finished product is now drawn to make a multimode optical fiber by heating up one end of the semi-finished product. The concentration of one doping impurity in light-conducting core is adjusted so that the concentration of doping impurity on the fiber axis is lower than that of the aforesaid light conducting core.

EFFECT: method of producing optical fiber with preset refractive index distribution profile.

32 cl, 6 dwg

FIELD: production processes.

SUBSTANCE: invention refers to guided-wave and fibre optics, and can be used for fabrication of long-period fibre grids. Method of manufacturing corrugated optic fibres consists in the fact that fibre is submerged vertically into 5-30% solution of organic polymer in organic solvent and is vertically removed from solution; the procedure is repeated for 1-5 times, after that, fibre is dried. When fibre is removed vertically from solution, drops of solution flow down the fibre, and at the same time, solution is partially dried. Due to effects of self-organisation of drops, they are located at regular intervals along fibre. After fibre is completely dried, at the location of drops there formed are thickenings forming a corrugation.

EFFECT: simplifying manufacturing procedure of long-period fibre grids, enlarging range of materials for fibre grids.

2 dwg

FIELD: physics; optics.

SUBSTANCE: invention relates to a system of optical devices with optical fibre made through fusion. The proposed optical system with optical fibre which is made through fusion includes at least one optical component containing optical fibres and at least one other optical component which interacts with light passing through the said optical fibres, which include a glass core with the following composition: La2O3 - 1-23 mol %, ZrO2 - 1-10 mol %, WO3 ≥ 2.5 mol %, ZnO - 1-15 mol %, BaO - 0-9 mol %, B2O3 - 20-70 mol %, Ta2O5 - 0-3 mol %, CaO - 0-7 mol %, PbO - 6-35 mol %, SiO2 - 0-40 mol %, As2O3 and/or Sb2O3 - 0-0.1 mol %, Nb2O5 - 0-3 mol % and Al2O3 - 0-8 mol %. The glass core essentially does not contain CdO and is characterised by refraction index of at least 1.8, and coefficient of thermal expansion CTE ≥ approximately 74×10-7.

EFFECT: increased refraction index and improved dispersion characteristics.

32 cl, 3 tbl

FIELD: technological processes.

SUBSTANCE: method includes twisting of stock around axis with speed of 0.5…1 rotation per second and simultaneous longitudinal stretching with speed of 0.1…1 mm/s. In the first version stock is represented a solution of polymer with concentration of 50…80%, and produced fibre is soaked with polymer dissolvent for 2…15 s and dried. In the second version stock is represented by polymer melt, and produced fibre is heated for 5…10 s to the temperature that exceeds temperature of polymer softening by 5…10°C and cooled down to room temperature. Method makes it possible to form helical corrugations on polymer fibre with period from 50 micrometre to 1 mm and height of corrugation from 1 to 20 micrometre.

EFFECT: simplified technology of manufacturing and expanded nomenclature of materials and geometric characteristics of helical long-period fibre grids.

2 cl, 5 dwg, 2 ex