Method of obtaining crystalline workpieces from silver halides and their solid solutions for infrared fibrous lightguides
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.
The invention relates to the field of materials transparent in the infrared spectral range 0.4 to 40 μm, namely crystals of silver halides which can be used for the manufacture of optical elements, infrared, laser, acousto-optic and fiber-optic technology.
A method of obtaining crystalline pieces of silver halides for the extrusion of fibers. From a crystal of silver halide mechanically cutting a workpiece of a given size, heated and extruded through the die plate, the light guide (U.S. Patent No. 5182790, publ. 26.01.1993, IPC C30B 15/24, NPK 385/141).
The disadvantage of this method is to obtain a fiber with high optical losses due to the insecurity of the boundaries of the fiber environment. Such a fiber is exposed to heat and ultraviolet dissociation of silver halides. The outer polymer shell such fibers only protects from mechanical influences and does not reduce optical loss.
An object of the invention is the reduction of optical losses of the optical fibers operating in the infrared region of the spectrum.
A method of obtaining crystalline pieces of silver halides and their solid solutions for the extrusion of the fibre, in which the billet for extrusion is made of two parts - the crystal heart is eveny and shell, made in the form of a hollow cylinder made of a material with a smaller refractive index than the refractive index of the core material. Before extrusion of the two parts assembled in type design "rod in the tube", is heated and mechanically compresses to improve the contact rod and the inner surface of the tube. The extrusion is carried out at a heating to the softening pieces and high pressure. Get a blank shell of the fibre (I. S. young, W. F. Golovanov, G. C. Polyakov "single Crystals of silver halides for fiber optics". Surface x-ray, synchronous and neutron studies. 2003, No. 7, S. 22-25).
The disadvantage of a relatively high optical loss in the fiber, related to the fact that the contact surface of the core-shell is not optical and clean, there are always mechanical impurities: organic material, the pores of the shell.
The technical result of the claimed method is the reduction of optical loss of the fiber.
The technical result is achieved that the way to get pieces of silver halides and their solid solutions for fiber infrared optical fibers, comprising applying to the crystal core of the silver halide crystal shell of crystalline silver halide indicator prelo the population, less than crystal-core, and heat-treated according to the invention the shell on the crystal core is applied by ion diffusion in the ion source, which take the fine powder of the silver halide particle size of 1-20 μm, the diffusion is carried out at a temperature close to the melting point of the crystal core, in an atmosphere of a mixture of vapor of the halogen included in the composition of the crystal and powder, taken in equal proportions at a pressure of 0.2-0.5 ATM.
The essence of the method lies in the fact that, by subjecting the ion-exchange diffusion crystal of silver halide in an ion source, which take crystalline fine powder of silver halide particle size of 1-20 μm, with a smaller refractive index in the crystal core is formed a radial gradient of chemical composition, resulting in a gain radial gradient layer of refractive index in the crystal of silver halide, which prevents the light output outside of the workpiece and, therefore, optical loss.
When used as an ion vapor source halides of silver, due to the low concentration of ions in the gas phase, in the crystalline core is not formed, the gradient of the chemical composition.
Use as an ion source of the melt is of halogenide silver is impossible, as the temperature of the melt of silver halide with a refractive index lower than that of the crystalline core, significantly above the temperature of melting of the core. The location of the core in the melt leads to its destruction.
The process of diffusion at low temperature reduces the rate of diffusion and productivity of the process.
The dispersion of powder of silver halide than 20 microns violates the integrity and uniformity of the resulting gradient layer. The dispersion of less than 1 μm is difficult and complicates the work of creating a gradient layer due to toxicity and explosive powder.
Conducting ion diffusion at the melting temperature close to the melting point of the crystal of silver halide in the air or in vacuum, it is impossible due to the dissociation of silver halide, and therefore it is impossible to obtain a gradient layer of refractive index in the crystal. Formed by the decomposition of fine metal colloidal silver reduces the spectral transmittance of the crystal at 90-99%, and formed in the gas phase halogen enough to suppress dissociation.
To suppress the dissociation of the halide of the silver diffusion process leads to a mixture of vapor of the halogen contained in the composition of the solid solution of silver halide is, taken in equal proportions at a pressure of 0.2-0.5 ATM. Pressure of the mixture of Halogens in the gas phase 0.1 ATM is not enough to suppress the dissociation of the silver halides. To create more pressure 0.5 ATM impractical due to increased corrosion damage of the equipment elements.
Examples of the method
Example 1. In a glass container of heat-resistant borosilicate glass download cylindrical crystal of silver bromide with a diameter of 25 mm, length 100 mm, the refractive index of which is within the working range of wavelengths (0.4 to 12 microns) is 2.21 are 2,30. Crystal fall asleep from all sides and mechanically compacted fine powder of silver chloride. The dispersion of powder of silver chloride is 10.0 μm. The refractive index 1,90-2,00. The container is filled with a mixture of vapors of the Halogens chlorine and bromine in the ratio of 1:1 at a pressure of 0.3 ATM and sealed. A sealed container is heated to a temperature of 410°C and kept at this temperature for 200 hours. From chilled to room temperature container retrieve the crystal, cut off the ends. End surface of the grind, Polish and measure optical and chemical characteristics. Measurement of the gradient of the chemical composition of the resulting sample is carried out by a chemical method on the content of chlorine and bromine with an accuracy of ±2% by successive removal of layers of the crystal is and from forming to the center. The chemical composition of the layers of the cylindrical workpiece adjacent to the forming amounted to 20% of silver bromide - 80% of silver chloride to 95% of silver bromide and 5% of silver chloride on the axis of the crystal. The refractive index of the workpiece, as measured by x-ray microanalyzer "Comebax" (accuracy ±1,5%), amounted to 2.29 from along the axis of the workpiece to 2.10 along. From the obtained crystalline workpiece by extrusion made of polycrystalline fiber diameter of 1.0 mm, the optical loss which amounted to 0.05 dB/m For comparison, extruded from the original billet silver bromide fiber with a shell of silver chloride (core/shell - 0,5/0,5 mm) optical loss was 0.3 dB/m
Example 2. In a glass container of heat-resistant borosilicate glass download cylindrical crystal of a solid solution of chloride - bromide of silver composition: 25% of the mass. silver chloride - 75% of the mass. bromide silver with a diameter of 18 mm, a length of 100 mm, a refractive index which is within the working range of wavelengths (0.4 to 12 microns) is 2,18-2,19. Crystal fall asleep from all sides and mechanically compacted fine powder of silver chloride. The dispersion of powder of silver chloride is of 20.0 μm. The refractive index 1,90-2,00. The container is filled with a mixture of vapors of the Halogens chlorine and bromine in the ratio of 1:1 while allowing the attachment of 0.4 ATM and sealed. A sealed container is heated to a temperature of 400°C and kept at this temperature for 200 hours. From chilled to room temperature container retrieve the crystal, cut off the ends. End surface of the grind, Polish and measure optical and chemical characteristics. Measurement of the gradient of the chemical composition of the resulting sample is carried out by a chemical method on the content of chlorine and bromine with an accuracy of ±2% by successive removal of layers of crystal from forming to the center. The chemical composition of the layers of the cylindrical workpiece adjacent to the forming amounted to 60% of silver bromide - 40% of silver chloride to 70% of silver bromide - 30% of silver chloride on the axis of the crystal. The refractive index of the workpiece, as measured by x-ray microanalyzer "Comebax" (accuracy ±1,5%), ranged from 2,20 axis of the workpiece to 2.09 along. From the obtained crystalline workpiece by extrusion made of polycrystalline fiber diameter of 1.0 mm, the optical loss which amounted to 0.01 dB/m For comparison, extruded from the original piece chloride - bromide of silver composition: 25% of the mass. silver chloride - 75% of the mass. bromide silver fiber with a shell of silver chloride (core/shell - 0,5/0,5 mm) optical loss was 0.3 dB/m
As seen from the above examples, the proposed JV the property allows you to create crystal billet for extrusion of the fibre with a radial gradient of refractive index is non-defective, exposed to the possibility of contamination of the inner surface design of the rod in the tube", which greatly reduces the optical loss in extruded optical fiber.
The way to get pieces of silver halides and their solid solutions for fiber infrared optical fibers, comprising applying to the crystal core of the silver halide crystal shell of crystalline silver halide with a refractive index lower than that of the crystal core, and heat treatment, characterized in that the shell on the crystal core is applied by ion diffusion in the ion source, which take the fine powder of the silver halide particle size of 1-20 μm, the diffusion is carried out at a temperature close to the melting point of the crystal core, in the atmosphere of a vapor mixture of halogen, included in the material composition of the crystal and powder, taken in equal proportions at a pressure of 0.2-0.5 ATM.
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
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: physics, optics.
SUBSTANCE: invention relates to fibre-optics and can be used in making anisotropic single-mode fibre light guides. The method involves making a cylindrical workpiece by MCVD method, which has a core, a low-viscosity tensive cladding and a structural cladding. Two grooves are made at diametrically opposite sides of the workpiece, followed by high-temperature rounding of the workpiece and drawing of the fibre. The structural cladding consists of quartz glass doped with P2O5 and/or B2O3 and/or F additives in an amount which enables to lower the compression and rounding temperature by 100-150°C.
EFFECT: longer outer diameter of the workpiece, low mass transfer of the quartz glass and high efficiency of the process.
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.
SUBSTANCE: 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.
EFFECT: expanding the operating spectral range of the light-guide in the long-wave region to 50 mcm and high light resistance.
SUBSTANCE: single-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.
EFFECT: fibre can be used in difficult operating conditions, for example miniature optical boxes.
15 cl, 2 dwg
FIELD: measurement equipment.
SUBSTANCE: testing 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.
EFFECT: providing the possibility of enlarging the application field of LED testing method with one accessible emission input/output edge to LEDs of small length; increasing the capacity of the testing process and its technical simplification.
2 cl, 4 dwg
SUBSTANCE: multilayered coating contains three successive layers with an even thickness: a lower mirror metal radio-reflecting skin-layer of pure aluminium, an intermediate protective thermoregulatory dielectric layer of zirconium dioxide and an upper protective wear-resistant highly strong diamond-like carbon layer.
EFFECT: provision of the operation in extreme conditions of open space due to the application of a thin substrate-envelope from a polymer composite material.
3 cl, 1 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to a monocrystal with a garnet-type structure to be used in optical communication and laser processing devices. This monocrystal is described by general formula (Tb3-xScx)(Sc2-yAly)Al3O12-z, where 0<x<0.1; 0≤y≤0.2; 0≤z≤0/.3.
EFFECT: translucent monocrystal that can inhibit cracking at cutting.
5 cl, 3 dwg, 1 tbl, 5 ex
SUBSTANCE: invention relates to an immersion liquid which can be used in optical instrument-making for investigating optical parameters of inorganic materials and optical components, including large, irregularly shaped articles. The immersion liquid for optical investigation contains 97-99 wt % meta-bis(meta-phenoxyphenoxy)benzene and 1-3 wt % 2-naphthol. To reduce viscosity and surface tension, the immersion liquid may further contain 0.1-3 wt % dibutyl sebacate per 100 wt % of said composition.
EFFECT: disclosed immersion liquid is nontoxic, has a good refraction index nD>1,6 and high adhesion to inorganic optical materials, which enables to deposit on the entire surface of the investigated substrate or part thereof a thin immersion layer and use thereof for effective quality control of large optical articles without immersion in a cell with an immersion liquid.
2 cl, 2 dwg, 2 tbl, 2 ex
FIELD: physics, optics.
SUBSTANCE: invention relates to visible light absorbers, particularly novel azo compound monomers, particularly suitable for use in materials for implantable ophthalmic lens materials. The ophthalmic device material includes an azo compound, a device forming acrylic monomer and a cross-linking agent. The ophthalmic device is made from the ophthalmic device material and is in the form of intraocular lenses, contact lenses, keratoprostheses and corneal inlays or rings.
EFFECT: azo compounds are suitable for use as monomers which absorb part of the visible light spectrum (about 380-495 nm).
17 cl, 6 dwg, 3 tbl
SUBSTANCE: free form ophthalmic lens comprises a first optical zone portion comprising multiple voxels of polymerised crosslinkable material containing a photoabsorptive component. The optical zone portion comprises a first area having a first refraction index and a second area having a second refraction index; and a second portion comprising a layered volume of crosslinkable material polymerised beyond the gel point of the crosslinkable material.
EFFECT: obtaining ophthalmic lenses with a free form surface and areas with different refraction indices, which enable to correct vision by changing the focal distance.
18 cl, 19 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to production of sandwiched materials used in thin-film instruments and devices. Proposed levelling film comprises levelling ply containing binding polymer resin and inorganic filler as components, at least, on one side of transparent polymer substrate. Note here that the number of foreign particles with mean diameter of 20-100 mcm on levelling air surface does not exceed 5 per m2.
EFFECT: decreased amount of linear defects at production of thin-film transistor on film surface.
3 cl, 1 tbl, 3 ex, 2 dwg
FIELD: physics, optics.
SUBSTANCE: group of inventions relates to producing a terbium aluminium garnet monocrystal which can be used as a Faraday rotator for optical insulators. In the terbium aluminium garnet monocrystal, a portion of aluminium is at least replaced with scandium and a portion of at least aluminium or terbium is replaced with at least one component selected from a group consisting of thulium, ytterbium and yttrium, wherein the garnet monocrystal has the general formula (Tb3-x-zSczMx) (Sc2-yMy) Al3O12 (1), where M represents at least one component selected from a group consisting of Tm, Yb and Y, and x, y and z satisfy the following relationship: 0<x+y≤0.30 and 0≤z≤0.30.
EFFECT: present monocrystal has a high light transmission factor in a wide wavelength range and a wide Faraday rotation angle with cracking-resistance.
8 cl, 3 dwg, 1 tbl, 12 ex
SUBSTANCE: invention relates to polymers for producing ionic silicone hydrogels suitable for making ophthalmic devices. Disclosed are polymers obtained from reactive components comprising at least one silicone-containing component which includes at least one trimethylsilyl group and at least one ionic component comprising at least one anionic group, which is a carboxylic acid-containing component. Also disclosed is a contact lens made from the disclosed polymers.
EFFECT: disclosed polymers demonstrate improved thermal stability and desirable protein uptake.
24 cl, 5 dwg, 10 tbl, 18 ex
SUBSTANCE: invention refers to ophthalmic devices and methods for preparing them. What is presented is a soft silicone hydrogel contact lens which possesses an ability to deliver a hydrophobic comfort-maintaining agent (phospholipid, glycolipid, glyceroglycolipid, sphingolipid, sphingoglycolipid, fatty alcohol containing 8 to 36 carbon atoms, or a mixture thereof) into the user's eye gradually releasing it from a polymer matrix consisting of hydrophobic chains formed of a silicon monomer or macromere, and hydrophilic chains formed of a hydrophilic monomer or macromere when in use. What is also presented is a method for making the above contact lens.
EFFECT: in the presented soft silicone contact lens, the hydrophobic comfort-maintaining agent is not covalently bond to the polymer matrix wherein it is distributed and can be released from the soft hydrogel contact lens into the user's eye when in use reliably for a long period of time and thereby reinforcing and stabilising a lipid layer of the lachrymal fluid film and reducing eye dryness.
16 cl, 2 tbl, 7 ex
FIELD: physics, optics.
SUBSTANCE: device has a base and a plurality of convex and concave structural elements arranged on the surface of the base with spacing which is equal to or less than the wavelength of visible light. The structural elements form a plurality of tracks and form a structure of a quadrangular or quasi-quadrangular array. In one version, each structural element has the shape of an elliptical or truncated elliptical cone, the long axis of which is parallel to the track. In another version, the ratio ((2r/P1)×100) of the diameter 2r to the spacing P1 is 127% or higher, where P1 is the spacing between structural elements on the same track, and 2r is the diameter of the lower surface of the structural element in the direction of the track. The method is carried out by forming a resist layer on the peripheral surface of a columnar or cylindrical standard mould, forming latent images via interrupted irradiation of the resist layer with a laser beam while rotating the standard mould with relative displacement of the laser beam spot parallel to its central axis, forming a resist structure via development thereof and forming structural elements by etching using the resist structure as a mask.
EFFECT: improved antireflection characteristics.
12 cl, 6 tbl, 67 dwg
SUBSTANCE: method of obtaining a material for a high temperature mass-sensitive piezoresonance sensor based on a monocrystal of lanthanum-gallium aluminium tantalate, the composition of which corresponds to formula La3Ta0.5Ga5.5-xAlxO14, where x=0.1-0.3, characterised by the electric resistance not less than 109 Ohm at a temperature of 20-600°C, includes growing of monocrystals from a melt of oxides its component constituents in an atmosphere of an oxidiser-containing inert gas, and additional annealing in air at a temperature of 1050-1150°C for 41-43 hours.
EFFECT: increase of exploitation properties, such as the electric resistance of the material itself, increased by more than an order, and extension of the work temperature range to room temperature.
4 cl, 2 dwg, 5 tbl