Infrared light guide with large mode field diameter. RU patent 2506615.
| Single-mode double-layer crystalline infrared light-guide / 2504806 Invention relaters to fibre-optic communication systems and specifically to single-mode double-layered crystalline infrared light-guides for the 2-50 mcm spectral range. The light-guide comprises a core and a cladding. The 10-250 mcm diameter core is made of silver bromide-based crystals containing a solid solution of monovalent thallium bromide-iodide, with the following ratio of components, wt %: silver bromide 98.8-65.0; solid solution 1.2-35.0. The 0.6-1.1 mm diameter cladding is made of crystals based on the same material, with the following ratio of components, wt %: silver bromide 99.0-69.5; solid solution 1.0-30.5. |
 Bend-insensitive single-mode optical fibre / 2489740Single-mode optical fibre includes, from the centre to the periphery, a central core, an intermediate cladding, a cladding with depressed channels and an outer optical cladding. The central core has a radius r1 and a positive refractive index difference Δn1 with the optical cladding. The intermediate cladding has a radius r2 and a positive refractive index difference Δn2<Δn1 with the optical cladding. The cladding with depressed channels has a radius r3 and a negative refractive index difference Δn3 with the optical cladding. The optical fibre has a mode field diameter (MFD) between 8.6 mcm and 9.5 mcm at wavelength of 1310 nm, and at wavelength of 1550 nm, the bire has bending losses less than 0.25×10-3 dB/turn for a radius of curvature of 15 mm. The fibre length needed for attenuation of the LP11 mode to each 19.3 dB at wavelength of 1260 nm is less than 90 m. |
 Testing method of light-emitting diodes with inaccessible emission input/output edge / 2477847Testing method of light-emitting diodes with an inaccessible emission input/output edge consists in introduction of sounding emission to an accessible edge at least of one LED and recording of reflected emission by means of a photoreceiver through the same edge of LED. First, a reflecting colour coat is applied to inaccessible LED edge, or it is installed tightly or with a gap to the reflecting colour surface; LED sounding is performed using white light; recording of reflected emission is performed with the photoreceiver with colour CCD-matrix, and then, integrity or defectiveness of LED is determined visually as per the colour of the image of accessible LED edge or as per the colour grade parameter of that image, which is determined by means of a PC. |
 Radiation-proof light guide for fibre-optic gyroscope / 2472188Light guide has a protective and hardening coating, an external quartz protective cladding; a depressive cladding; a light-guide core consisting of quarts glass, loading rods which guide linear birefringence in the light-guide core and the depressive cladding. The light guide additionally includes a second depressive cladding between the protective quartz cladding and the external boundary of the first depressive cladding in a region which is free from the loading rods. Radiation-proof properties are achieved by making the "Panda" light guide core from pure quartz glass. |
 High birefringence, linear polarisation supporting radiation-resistant fibre-optic guide (versions) / 2469363According to the first version of the device, the light guide has a core with a high refraction index owing to doping of quartz glass and bending regions lying symmetrically about the diameter of the light guide which form birefringence. According to the second version of the device, the light guide has a core with a high refraction index owing to doping of quartz glass and having a elliptic shape in the cross-section. The dopant used is nitrogen in concentration range of 0.01-10 atom %. |
 Birefringent microstructured fibre-optic guide with low mode field asymmetry / 2465622Device is made from solid transparent material. The device has in the central part a core with an elliptical or circular shape, formed by surrounding it with longitudinal holes. The holes surround the core in one layer. Two holes have a larger distance between them compared with the other holes. There is an additional hole opposite said holes. The light guide can also have one or more additional layers of holes around said layer, wherein in each layer, the holes lie equidistant from the nearest two holes of the previous layer. The cross-section of the light guide has not more than one plane of symmetry which passes through the axis of the light guide. |
 Fibre spark and electric arc sensor / 2459222Designs of a sensor sensitive element are proposed, which comprises at least one optical fibre with a polymer coating with addition of a fluorescent substance, a cylindrical lens and a cylindrical reflector, and also a sensitive element in the form of a fibre with a corrugated periodical polymer coating. |
 Apparatus for producing optical fibre and method of producing optical fibre / 2445279Invention can be used to produce optical fibre by drawing optical fibre from an optical fibre workpiece. The apparatus has a unit for forming optical fibre without cladding, a coating unit, a first direction changer and a winding apparatus. The first direction changer, which first changes the direction of movement of the optical fibre, is a rotating component having an outer surface which is formed around its axis of rotation and is in contact with optical fibre coming out of the coating unit. When viewed in the cross-section, which includes the axis of rotation, the outer surface has a flat shape with predetermined width, wherein the optical fibre is allowed to freely move in the direction of the width of the outer surface. According to the method of producing optical fibre, the contact angle, which is centralised relative the axis of rotation, between the first direction changer and the optical fibre ranges from 10° to 80°. |
 Method of making birefringent microstructured optical fibre / 2437129According to the method, at least 4 grooves which are pairwise symmetric about a plane which passes through the longitudinal axis of rotation of the workpiece rod are obtained on the entire length of the workpiece rod. The structure of a fibre core, dimensions of which are determined by dimensions of an inscribed elllipse, is obtained in the cross-section. The workpiece rod and a quartz tube are fused in a non-working region and drawn into a pre-workpiece. The pre-workpiece is cut into pieces in which inner channels are etched. The inner and outer surfaces are washed and dried and then welded up on both ends. The pieces of the pre-workpieces are collected with a capillary quartz tube having a welded tubular holder. Pieces of the pre-workpiece and the capillary tube are fused on the side opposite the tubular holder. A preform is obtained as a result, which is drawn into an optical fibre coated with a protective reinforcing coating. |
 Method of making large-size optical fibre workpiece / 2427013Optical fibre workpiece is made by depositing mass of porous quartz glass onto the periphery of a glass rod. The mass of the porous quartz glass is vitrified via thermal treatment of the glass workpiece. The workpiece has a part which is suitable for stretching until optical fibre is obtained, and defective part on both ends of the suitable part. During vitrification, part of the mass of the porous quartz glass in the defective part shifts along the axial direction of the glass rod. When the mass of the porous quartz glass shifts, tension between the glass rod and the mass of the porous quartz glass relaxes. |
 Optical fiber and fiber-optic cable for its manufacture / 2256204Branded 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. |
 Fiber-optic light-pipe with increased steadfastness to diffusion of molecules from the environment / 2314556It 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. |
 Fiber light guide resistant to nuclear and/or ionising radiation (versions), microstructure fiber light guide resistant to nuclear and/or ionising radiation, and method for molecular hydrogen or deuterium concentration regulation in fiber light guide / 2337385Molecular 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. |
 Optical fibre and method of measuring polarisation modal dispersion of optical fibre / 2339982Length 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. |
| Single-mode bi-layered crystalline infrared light waveguide / 2340920 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. |
 Single-mode crystalline infrared light waveguide / 2340921Present 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. |
 Multimode fiber with refractive index distribution profile, optical communication system incorporating aforesaid fiber and method of its production / 2356076Invention 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. |
 Method of manufacturing corrugated optic fibres / 2379719Invention 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. |
 System of optical devices with optical fibre made through fusion / 2383907Invention 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. |
 Method for manufacturing of helical long-period fibre grid (versions) / 2392646Method 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. |
FIELD: physics, optics.
SUBSTANCE: invention relates to infrared light guides with a large mode field diameter. The light guide has a core and cladding which consists of rods arranged in a hexagonal order. The 98-112 mcm diameter core is made of silver bromide-based crystals containing a solid solution of monovalent thallium bromide-iodide (TIBr0.46I0.54), with the following ratio of components, wt %: silver bromide - 91.0-61.0; solid solution (TIBr0.46I0.54) - 9.0-39.0. The cladding contains rods with diameter of 42-48 mcm with distance of 70-80 mcm between centres thereof, with the following ratio of components thereof, wt %: silver bromide 92.0-64.5; solid solution (TIBr0.46I0.54) 8.0-35.5.
EFFECT: enabling operation at wavelength of 10,6 mcm, enabling propagation of only one lower-order mode within the fundamental band gap.
The invention relates to the infrared (IR) single mode fibers with a large diameter of the field of fashion, needed for the manufacture of fiber lasers and sensors, amplifiers, fiber-optic cables of medium and far infrared range of the spectrum, intended for molecular analysis in various areas of technology.
Distribution of radiation in a single-mode fiber is concentrated in the small diameter of the core of the great length of the fiber. This increases the nonlinear-optical effects and distortion of the spectrum of the pulse. Nonlinearity of the fiber can be reduced by increasing the diameter of the field of fashion and reducing the length of the fiber [Semenov .., Egorova OLGA, Kosolapov A.F. and other Fibers with a photonic band gap and the large diameter of the field of fashion. Scientific and technical journal «Foton-Express». 2009. №6. P.25-26].
Known nanostructured crystal fibers with the fundamental optical losses at wavelengths of 7-12 mm [Б LN., Б A.L., E.M. Dianov, V.N., N.V. Nanostructured crystal fibers with the fundamental optical losses at wavelengths of 7-12 microns. Scientific and technical journal «Foton-Express». 2011. №6. S.204-205]. Diameter of nanostructured fiber 500 microns, length 20 m, the composition 50AgCl - 50AgBr. But this fiber is a multimode.
Known nano - and microcrystalline IR optical fibers on the basis of crystals of solid solutions Ag 1-x, Tl x Br 1-y I y ; Ag 1-x, Tl x Cl y I z Br 1-y-z [Chazov A. I. Zhukova L.V., Korsakov A.S., Wroblewski DS., Korsakov E.A. Research and development of nano - and microcrystalline IR optical fibers. Scientific and technical journal «Foton-Express». 2011. №6. .200-201]. But the authors do not indicate the structure of a fiber, i.e. the ratio of the diameter of inserts (rods) to the distance between them, and their relationship with the size of the field of fashion. In addition, the fundamental characteristics of the fiber - numerical aperture, the diameter of the field of fashion, the difference between the refractive indices of the materials inserts (rods) and the matrix.
The closest technical solution is a light guide with a photonic band gap and the large diameter of the field of fashion [Semenov .., Egorova OLGA, Kosolapov A.F. and other Fibers with a photonic band gap and the large diameter of the field of fashion. Scientific and technical journal «Foton-Express». 2009. №6. P.25-26]. Shell fiber consists of quartz glass, which are located in order rods doped quartz glass core, like shell, consists only of pure quartz glass. To obtain the large diameter of the field of fashion, the authors used the ratio of (less than 0.4) diameter rods (elements) of the shell (d) to the distance between them (B). This allows for a small numerical aperture of the core at the large diameter of the field of fashion. But such fibers work in the near infrared range of the spectrum, i.e. from 0.8 to 1.6 microns (see Fig.2 [Semenov .., Egorova OLGA, Kosolapov A.F. and other Fibers with a photonic band gap and the large diameter of the field of fashion. Scientific and technical journal «Foton-Express». 2009. №6. P.25-26]).
The objective of the invention is to obtain infrared optical fibers to work at a wavelength of 10.6 microns with a large diameter of the field of fashion, the core and the cladding made of crystals on the basis of AgBr containing solid solution (TlBr 0,46 I 0,54 ), and cores made of the same crystals, but with different content.
The problem is solved by the fact that the infrared light guide with a large diameter of the field of fashion has a core diameter of 98-112 microns made of crystals on the basis of silver bromide containing solid solution bromide and iodide monovalent thallium (TlBr 0,46 I 0,54 ) with the following component ratio, mass%:
silver bromide
91,0-61,0
solid solution (TlBr 0,46 I 0,54 )
9,0-39,0and in the shell, made of the same crystals and the same chemical composition, diameter rods are 42-48 microns 70-80 microns between their centres and composition with the following ratio , wt.%:
silver bromide
92,0-64,5
solid solution (TlBr 0,46 I 0,54 )
8,0-35,5In waveguides of this structure and composition extends only one mode is of a lower order within the fundamental band gap.
Advantages over the prototype:
1. New fiber is designed to operate at a wavelength of 10.6 microns (CO2 laser), and in the prototype - 0.8 to 1.6 microns.
2. The new structure of the fiber, namely diameter rods from 42 to 48 microns, located in a shell on the distance between their centers of 70 to 80 microns, can receive a large diameter of the field of fashion - 98-112 microns while maintaining a singlemode work.
3. Due to certain chemical composition of the core, shell and located in a shell rods mode fiber is completely single-mode fibers within the fundamental band gap.
Example 1
To work at a wavelength of 10.6 microns manufactured IR-optical fiber with a core diameter 98 microns composition, wt.%:
silver bromide
91,0solid solution (TlBr 0,46 I 0,54 )
9,0Shell fiber has the same composition. It placed in order rods with a diameter of 42 microns on the distance between their centres 70 microns, which are made of crystals composition, wt.%:
silver bromide
92,0solid solution (TlBr 0,46 I 0,54 )
8,0The ratio of the diameter of rods to the distance between their centers is
. The difference between the refractive indices of the core and inserts is C = =0,006. Numerical aperture NA=0,12, angle of electromagnetic radiation in optical fibre - 14 degrees with a normalized frequency V=1,95. Held shooting end of the fiber; radiation at the output of core has the appearance of a Gaussian function that indicates the distribution of one fundamental mode, i.e. confirms single-mode fiber at a wavelength of 10.6 microns.
Example 2
Manufactured by extrusion fiber with a core diameter 105 microns. The core and shell have the composition,% Mas.:
silver bromide
78,0solid solution (TlBr 0,46 I 0,54 )
22,0In shell placed rods with a diameter of 45 microns on the distance between their centers of 75 microns and composition, wt.%:
silver bromide
79,7solid solution (TlBr 0,46 I 0,54 )
20,3Fundamental characteristics of the fiber following: C = =0,005, NA=0.11, the angle of the light guide - 13 degrees with a V=2,11 and the ratio of the diameter of rods to the distance between their centers is
. Fiber operates at a wavelength of 10.6 microns; apply one fashion of a lower order, which confirms the single mode operation.
Example 3
Retrieved fiber with a core diameter of 112 microns to work at a wavelength of 10.6 microns. The core has the following composition,% Mas.:
silver bromide
61,0solid solution (TlBr 0,46 I 0,54 )
39,0Shell provided the crystalline matrix of the same composition, and that core, which in order placed rods with a diameter of 48 microns with a distance of 80 microns between their centers. The rods have the composition,% Mas.:
silver bromide
64,5solid solution (TlBr 0,46 I 0,54 )
35,5Light conductor has the following fundamental characteristics:
difference between the refractive indices C = =0,003, the numerical aperture NA=0,10, the angle of the light guide - 13 degrees with a V=2,20. The ratio of the diameter of rods to the distance between their centers is
. When shooting the end face of the fiber electromagnetic radiation in the transverse its profile is subordinate to the Gaussian law energy distribution, which confirms the single mode operation crystalline infrared fiber.
In the manufacture of infrared light guide with the composition of the core and cladding less than 9 wt.% or more than 39% Mas. solid solution (TlBr 0,46 I 0,54 ) in silver, as well as the manufacture of rods with diameter less than 42 microns or more than 48 microns and the distance between their centers of less than 70 microns or more than 80 microns and composition, respectively, less than 8 wt.% or more of 35.5% Mas. solid solution (TlBr 0,46 I 0,54 ) in silver cannot be reached singlemode IR light guide.
The technical result allows to receive infrared light guide with a large diameter of the field of fashion (98-112 microns), which is achieved by placing in a matrix of a certain composition rods with different composition and diameter 42-48 microns with the distance of 70-80 microns between their centers. Due to this structure, and you can receive a small numerical aperture of the core at the large diameter of the field of fashion. IR-fiber single-mode is when you work at a wavelength of 10.6 microns (CO2 laser) within the fundamental band gap.
Infrared light guide with a large diameter of the field of fashion, including the core and shell, consisting of rods located in order, characterized in that the core of the fiber diameter 98-112 microns is made of crystals on the basis of silver bromide containing solid solution bromide and iodide monovalent thallium (TlBr 0,46 I 0,54 ) with the following component ratio, mass%:
silver bromide
91,0-61,0
solid solution (TlBr 0,46 I 0,54 )
9,0-39,0and in the shell, made of the same crystals and the same chemical composition, diameter rods are 42-48 microns 70-80 microns between their centres and composition with the following component ratio, mass.%:
silver bromide
92,0-64,5
solid solution (TlBr 0,46 I 0,54 )
8,0-35,5