Microstructured multicore optical fibre (MMOF), a device and the fabrication method of a device for independent addressing of the cores of microstructured multicore optical fibre

Abstract

Microstructured multicore optical fibre with a microstructure area, in which, at least two basic cells are embedded, where each of them contains a core, preferably made of glass, specifically including doped silica glass or polymer, together with the surrounding it longitudinal areas with lower refraction index vs. that of the cladding, which areas may adopt the shape of holes, filled with gas, in particular with the air or a fluid or a polymer or spaces of another glass with doping allowing to reduce refractive index (further referred to as holes), embedded in a matrix of glass, in particular of silica glass or polymer. The refraction index of the holes is decreased vs. that of the matrix of glass, in particular of silica glass or polymer. The basic cell is characterised by the diameter of D2 core, the diameter of D3 core and the distance between adjacent holes, corresponding to lattice constant A. The centres of the holes are localised on the vertices and the middle points of the sides of the hexagon, the centre of which is designated by the core; the length of side c of the hexagon, created by the centres of holes, is equal to the preferably doubled lattice constant A. The juxtaposed, at least, two basic cells are surrounded by the cladding, preferably made of glass, in particular of silica glass or polymer. A Device for addressing cores of the multicore optical fibre a fabrication method of the device for addressing cores is also disclosed.

Claims

1. A microstructured, multicore optical fibre, comprising: a microstructure area in which a plurality of basic cells is embedded, each one of the plurality of basic cells includes a core, the core made of a core material that is glass or doped silica glass or polymer, surrounding each core is a plurality of longitudinal holes having a refractive index that is lower than that of a cladding surrounding the plurality of basic cells and each core of the plurality of basic cells, wherein the plurality of longitudinal holes are filled with air, fluid, polymer, or glass having a doping to reduce the refractive index of the glass, and wherein the plurality of basic cells is located in a matrix of either silica glass or polymer, wherein the refractive index of the filled longitudinal holes is less than a refractive index of the matrix, and wherein each one of the plurality of basic cells is characterized by a diameter of the core, a hole diameter of each of the plurality of longitudinal holes, and a distance between adjacent ones of the plurality of longitudinal holes, corresponding to a lattice constant Λ, wherein centers of the longitudinal holes are located on vertices and middle points of sides of a hexagon having a center which is occupied by one of the cores, wherein the cladding is comprised of silica glass or polymer.

2. The microstructured, multicore optical fibre according to claim 1, wherein a first basic cell of the plurality of basic cells is located at a geometric centre of the microstructured, multicore optical fibre, while the other of the plurality of basic cells adjoins the first basic cell at sides or vertices of the hexagon of the first basic cell.

3. The microstructured, multicore optical fibre according to claim 1 or 2, wherein a length of a side c of the hexagon, is twice the lattice constant Λ.

4. The microstructured, multicore optical fibre according to claim 1, wherein the plurality of basic cells share some of the plurality of longitudinal holes.

5. The microstructured, multicore optical fibre according to claim 1, wherein the plurality of basic cells includes a central basic cell, and wherein others of the plurality of basic cells surround the central basic cell in a first ring, wherein the cores of each of the plurality of basic cells forming the first ring are located in correspondence with vertices of a hexagon and the distance between adjacent basic cells forming the hexagon is three or four times the lattice constant Λ.

6. The microstructured, multicore optical fibre according to claim 5, further comprising a subsequent ring of basic cells around the first ring having cores located at six times the lattice constant Λ apart.

7. The microstructured, multicore optical fibre according to claim 1, wherein a difference between the refractive indices of the core material of each core of the plurality of basic cells and the cladding material is Δ=5.63.Math.10.sup.−3±2.9.Math.10.sup.−3 for light wavelength λ=1550 nm.

8. The microstructured, multicore optical fibre according to claim 1, wherein the lattice constant Λ is equal to (7.8±3.6) μm, each fibre core of the plurality of basic cells has the diameter equal to 0.7+/−0.46 that of the lattice constant Λ, the diameters of the longitudinal holes is equal to 0.7+/−0.3 that of the lattice constant Λ, and the cladding diameter is equal to the lattice constant times 13 plus 50 μm+/−20.

9. The microstructured, multicore optical fibre according to claim 1, wherein the core of each of the plurality of basic cells is doped with ions of rare earths.

10. The microstructured, multicore optical fibre according to claim 9, wherein each core is doped with erbium at a level from 3.Math.10.sup.18/cm.sup.−3 to 120.Math.10.sup.18/cm.sup.−3, wherein a difference between a refractive index of the cores and a refractive index of the cladding amounts to $\Delta =2.5*{10}^{-2}\frac{+1.6*10-2}{-2.1*10-2}$ for light of wavelength of λ=1550 nm.

11. The microstructured, multicore optical fibre, according to claim 8 or 9 or 10, wherein the lattice constant Λ is equal to 7.8+/−3.6 μm, a diameter of the cores is equal to 0.5+/−0.46 that of the lattice constant Λ, a diameter of the longitudinal holes is equal to 0.6+/−0.3 that of the lattice constant Λ, and the cladding diameter is equal to the lattice constant Λ multiplied by 13, plus 50 μm+/−20.

12. The microstructured, multicore optical fibre according to claim 9, wherein the plurality of basic cells is surrounded by a ring of additional longitudinal holes.

13. The microstructured, multicore optical fibre, according to claim 12, wherein the ring of additional longitudinal holes forms a hexagon around the plurality of basic cells.

14. The microstructured, multicore optical fibre, according to claim 12, wherein the ring of additional longitudinal holes is arranged in a circle.

15. The microstructured, multicore optical fibre, according to claim 1, wherein the plurality of basic cells includes a central basic cell with the other of the plurality of basic cells surrounding the central basic cell, and wherein the other of the plurality of basic cells are only partially surrounded by longitudinal holes.

16. The microstructured, multicore optical fibre, according to claim 15, wherein the longitudinal holes partially surrounding the other of the plurality of basic cells have varying diameters.

17. The microstructured, multicore optical fibre, according to claim 1, further comprising at least one marker hole outside of the plurality of longitudinal holes that has a refractive index that is different from a refractive index of the plurality of longitudinal holes.

18. A device for addressing cores of a microstructured, multicore optical fibre, comprising a plurality of single-core, single-mode optical fibres, arranged in parallel in a capillary, wherein the number of single-core, single-mode optical fibres is equal to or less than a number of cores in the multistructured, multi-core optical fibre and wherein each one of the single-core, single-mode optical fibres is respectively joined to one of the cores of the multistructured, multi core optical fibre such that a cross section of each of the single-core, single-mode optical fibres in the capillary is parallel with a cross section of the respective core of the microstructured, multi-core optical fibre to which the single-core, single-mode fibre is joined, wherein, the capillary is made of a material that is susceptible to being tapered and changed in dimension upon application of heat and longitudinal tension.

19. A device, according to claim 18, wherein when the number of single-core, single-mode optical fibres is less than the number of cores in the microstructured, multicore optical fibre, the capillary further comprises glass rods in a number equal to a difference between the number of cores in the microstructured, multicore optical fibre and the number of single-core, single-mode optical fibres.

20. A device, according to claim 19, wherein the glass rods act as a filling in the device.

21. A device, according to claim 18, wherein the capillary is made of undoped silica glass.

22. A device, according to claim 18, wherein the capillary is made of polymer.

23. A method of fabrication of a device for independent addressing of the cores of a microstructured, multicore optical fibre, comprising: analyzing a structure of the microstructured, multicore optical fibre and determining a number of cores of the microstructured, multicore optical fibre, a diameter of each of the cores and or less than for each core, a distance between the core and each other core; measuring a diameter of a plurality of single-mode optical fibres, including cladding, with which the microstructured, multicore optical fibre is to be connected, and determining a scale of tapering of each one of the plurality of the single-mode optical fibres; removing the cladding of each of the single-mode optical fibres to expose a fragment and cleaning a surface exposed on each fragment of the single-mode optical fibres created by removing the cladding; etching, with hydrofluoric acid, the exposed and cleaned fragments of the single-mode optical fibres; tapering of each of the single-mode optical fibres according to a calculated scale of tapering, so that each one of single-mode fibres is tapered to match the diameter of a respective one of the cores of the microstructured, multicore optical fibre; tapering a capillary to allow for insertion of the single-mode optical fibres and glass rods, so that the inserted single-mode optical fibres and glass rods have limited freedom of movement; laying the single-mode optical fibres and glass rods in the capillary; tapering and clamping the single-mode optical fibres and glass rods in the capillary by heating and tensing; cleaving the capillary including the single-mode fibres and glass rods at a right angle to a longitudinal axis of the capillary with a cleaver, and polishing a surface of the capillary at a point where it was cleaved; cleaving the microstructured, multicore optical fibre to create a surface and polishing the surface; positioning the capillary and the microstructured, multicore optical fibre together and welding the cores of the microstructured, multicore optical fibre to respective ones of the plurality of single-mode cores; and splicing cores of the microstructured, multicore optical fibre with respective ones of the single-mode cores in the capillary.

24. The method of fabrication, according to claim 23, wherein the tapering of the capillary and its internal structure is made in such a way that the capillary with laid optical fibres clamped on the internal structure.

25. The method of fabrication, according to claim 23 or 24, wherein, when the diameters of single-mode optical fibres are substantially larger than the distance among the cores of the microstructured, multicore fibre the tapering and etching are changed in the sequence of technological operations.

26. The method of fabrication, according to claim 23, wherein, when the cores of the microstructured, multicore optical fibre have diameters that differ from the diameters of the cores of single-mode optical fibres, the tapering is continued till equalization of the diameters of the cores of single-mode optical fibres in the structure in the capillary with the diameters of the cores of the multi core optical fibre.

27. The method of fabrication, according to claim 23, wherein positioning the microstructured, multicore optical fibre and the capillary is done in such a way that light is delivered to one of the cores of the multi core optical fibre or to a single-mode optical fibre, while during welding, a connection formed by the welding is checked based on power transfer to one of the single-mode optical fibres in the capillary from the microstructured, multicore optical fibre.

Description

(1) The microstructured optical fibre, according to the invention, has been presented on the drawings, where

(2) FIG. 1 presents the cross-section of the optical fibre, according to this invention in a preferable example of fabrication,

(3) FIG. 2 presents other, advantageous variants of layout of the basic cells,

(4) FIG. 3 presents the cross-section of the optical fibre in another, preferable example of fabrication,

(5) FIG. 4 presents the cross-section of the optical fibre in another, preferable example of fabrication

(6) FIG. 5 presents the cross-section of the optical fibre in another, preferable example of fabrication,

(7) FIG. 6 presents the cross-section of the optical fibre in another, preferable example of fabrication,

(8) FIG. 7 presents the optical fibre, according to the invention, with an additional cladding,

(9) FIG. 8 presents the optical fibre, according to the invention, with an additional cladding in another configuration of the additional cladding,

(10) FIG. 9 presents the optical fibre, according to the invention, with an additional cladding in another configuration of the additional cladding,

(11) FIG. 10 presents the cross-section of single-mode optical fibres, located in the capillary,

(12) FIG. 11 presents a schematic juxtaposition of multicore optical fibre with the capillary, together with the internal optical fibre structure,

(13) FIG. 12 presents a diagram of guidance system with the use of microstructured multicore optical fibre, according to the invention, in a preferable example of fabrication,

(14) FIG. 13 presents a diagram of guidance system with the use of microstructured multicore optical fibre, according to the invention, in another preferable example of fabrication,

(15) FIG. 14 presents a diagram of guidance system with the use of microstructured multicore optical fibre, according to the invention, in another preferable example of fabrication,

(16) FIG. 15 presents the optical fibre, according to the invention, with preferable location of markers (6.1),

(17) FIG. 16 presents the optical fibre, according to the invention, with preferable example of fabrication and with another preferable location of marker.

EXAMPLE I

(18) Microstructured, multicore optical fibre, according to invention and intended for transmission, further: microstructured multicore guidance optical fibre, according to the invention, includes an area with microstructure, in which basic cells are embedded, out of which, each of them includes a core of doped silica glass with surrounding it, longitudinal holes, filled with the air, (further: the holes), located in the matrix of silica glass.

(19) The difference between the refraction indices of the core material and the cladding material (both internal and outer) amounts to Δ=5.2.Math.10.sup.−3±0.5.Math.10.sup.−3 for the light wavelength of λ=1550 nm.

(20) The basic cell is characterised by D2 core diameter, D3 hole diameter and the lattice constant Λ, corresponding to the distance between the centres of adjacent holes. The centres of the holes are located on the vertices and the middle points of the sides of the hexagon, the centre of which is designated by the core; the length of side c of the hexagon, made of the axes of the holes, equals the double value of the lattice constant Λ. The basic cells, juxtaposed within the microstructure area, are covered with the outer cladding.

(21) The first basic cell of the structure is located at the geometric centre of the multicore optical fibre, while the other basic cells adhere to it with their sides. The other basic cells, mutually juxtaposed, share the core surrounding holes.

(22) The basic cells, surrounding the basic cell, located in the geometric centre of the optical fibre, constitute the, so-called, first ring. The cores of the first ring are located on the vertices of the hexagon, side b of which equals the tripled value of the lattice constant, multiplied by a, where a=⅔.Math.√3.

(23) The geometric parameters of optical fibre are determined in the following way:

(24) D1 outer diameter of the cladding 4.1 is (146.4±5) μm;

(25) D2 core diameters 2.1 are (8.2±0.5) μm;

(26) D3 hole diameters 3.1 are (7.7±0.2) μm;

(27) The lattice constant Λ is (8.2±0.5) μm.

(28) In this example of fabrication, the diameter of the cores of the multicore optical fibre equals approximately the diameter of the core of standard single-mode optical fibre.

(29) The device for addressing cores of microstructured, multicore guidance optical fibre, according to this invention, includes seven standard single-mode optical fibres, enclosed in the capillary and connected via the microstructured multicore optical fibre, according to the invention. The cross-sections of the optical fibres in the capillary are parallel to the cross-section of multicore optical fibre.

(30) The capillary is fabricated of material, susceptible to changes of geometric dimensions under the influence of temperature, combined with longitudinal tension. The capillary is fabricated of undoped silica glass.

(31) The method of fabrication of the device for addressing cores consists in: 1. an analysis of the structure of multicore optical fibre and determination of the number of cores of the multicore optical fibre, the diameter of cores and the distances among them. 2. measurement of the diameters of the cores S.1 and of the claddings of single-mode optical fibres S.2, with which the multicore optical fibre is connected, and the scale of tapering of the single-mode optical fibres is determined. 3. removal of the cladding of single-mode optical fibres and cleaning their surface. 4. etching, preferably with hydrofluoric acid, the exposed and cleaned fragments of the single-mode optical fibres, the alignment of the cores of the multicore optical fibre was possible with the cores of the single-mode optical fibre. 5. tapering of single-mode optical fibres, according to the calculated scale of tapering, allowing to achieve the diameters of their cores equal to the dimensions of the diameters of the cores of the multicore optical fibre. 6. preparation of a capillary S.3 by its tapering to the size, allowing for insertion of single-mode optical fibres and glass rods, so that the inserted elements had no freedom of movement or that their movement was limited 7. laying of single-mode optical fibres and glass rods in the capillary. 8. tapering and clamping of the laid and spliced structure in the capillary by its heating and tensing, while the multicore optical fibre is also tapered. 9. cleaving the capillary with the laid and spliced structure under right angle to the axis of the longitudinal capillary, with a cleaver for optical fibres with various outer diameters and internal structures, with a possibility of controlled stretching of the fibre. 10. cleaving the multicore optical fibre 11. orientation of the capillary vs. the multicore optical fibre, together with the structure, laid and welded in its inside 12. connection of the multicore optical fibre with the capillary and the structure in its inside by splicing.

(32) While connecting the multicore optical fibre with seven cores with standard single-mode optical fibres (7), it is necessary to determine: the number of cores of the multicore optical fibre, core diameter of the multicore optical fibre (8.2 μm), the distance among the cores of the multicore optical fibre (approx. 28 μm). The diameter of the cladding of single-mode optical fibre is determined (approx. 125 μm), as well as the diameter of the cladding of the multicore optical fibre (approx. 146 μm).

(33) Etching is carried out at 21° C. with the use of hydrofluoric acid in 40% concentration. The etching rate at, approximately 63 μm/h, allows to achieve the required diameter of single-mode optical fibre of 28 μm within approximately 46 minutes.

(34) The capillary with initial internal diameter of 200 μm and the outer diameter of 286 μm is tapered to corresponding diameters of 89 μm and 127 μm, respectively.

(35) The etched single-mode optical fibres are laid in the capillary, tapered to 89 μm/127 um, till the moment of laying seven optical fibres in one capillary.

(36) The tapering of the capillary and its internal structure is performed in such a way that the capillary, together with the laid optical fibres, clamped on the internal structure. Accordingly, the capillary is tapered, together with the etched single-mode optical fibres, from the 89/127 μm size down to the 72 μm/103 μm size.

(37) Since during the tapering process of the capillary and its internal, welded structure, the optical fibre cores have also decreased their diameter (down to 7 μm), as well as the distances between cores decreased to 24 μm, the multicore optical fibre should also be tapered. The multicore optical fibre is tapered till the core diameters achieve the value of about 7 μm (i.e., to the cladding diameter of approx. 125 μm).

(38) After the capillary is cleaved, together with the welded in its inside and etched optical fibres, and after cleaving of the tapered multicore optical fibres, the orientation of the multicore fibre and of the structure in the capillary is carried out in such a way that light is delivered to one of the external cores of the multicore optical fibres and, during splicing, is checked what part of power has transferred to one of the single-mode optical fibres in the capillary.

(39) The tapering of single-mode optical fibres, capillaries and capillaries with laid and welded structures, is done by means of a Vytran GPX-3400 filament splicer, used for processing/connecting of optical fibre elements.

(40) During splicing, depending on the diameter of the multicore optical fibre and the geometry of the capillary with its internal structure, the heating power of the glass processing platform is selected, so that the obtained connection was mechanically durable and with low optical losses. The pre-set values of the optical fibre element processing/connecting for the Vytran GPX-3400 glass processing platform are as follows:

(41) TABLE-US-00001 Distance of the Delay shifting of optical Distance among Power Splicing before fibres on one optical fibres before [W] time [s] splicing [s] another [μm] splicing [μm] 60 7 0.2 14 8

(42) The way of signal transmission with the use of the microstructured, multicore guidance optical fibre, according to this invention, using the spatial multiplication, is an alternative for the disclosed transmission systems. The method of transmission with the use of multicore optical fibre is such that the microstructured multicore guidance optical fibre, according to this invention, is used as the main guidance medium. The problem of addressing cores in the multicore optical fibre is solved with the use of the device and technique for independent addressing of the cores of the microstructured multicore optical fibre, according to the invention.

(43) In case of small transmission distances (see FIG. 12), over which, no need for amplification occurs, the microstructured multicore guidance optical fibre, according to this invention, 1 is placed between two devices for addressing cores 3 and 4, out of which, one allows to deliver signal by means of transmitters 5 and standard single-mode optical fibres 2 to particular cores, while the second device 4 allows to receive the signal from particular cores and direct it to receivers 6 via standard single-mode optical fibres 2.

(44) When the transmission distance requires signal amplification, it is arranged in the following way (see FIG. 13). The signal from transmitters 5 is guided via single-mode optical fibres 2 to core addressing device 3. Then the signal is guided via microstructured optical fibre, according to the invention 1. On the distance, where amplification is required, an amplification module is installed 7, possible for multiple repetition within one telecommunication line. After light amplification by module 7, the signal is guided farther on via the microstructured multicore guidance optical fibre, according to this invention. Signals from particular cores are directed to single mode optical fibres 2 with the use of the core addressing device 4. In this way, the signals are delivered to receivers 6. The amplifying module 7 consists of two devices for addressing cores 4′ and 3, out of which, the first one 4′ directs the signal from particular cores of the microstructured multicore optical fibre, according to the invention 1 to single-mode optical fibres 2, while the second one 3′ delivers the signal from optical fibres 2 to the cores of the microstructured multicore optical fibre 1. In the amplifying module 7, on the line of signal guidance via single-mode optical fibres 2, there is an integrated, optical fibre amplifying element 8. Such an element 8 may be, for example, a commercially available erbium-doped fiber amplifier (EDFA).

EXAMPLE II

(45) Microstructured, multicore optical fibre, according to invention includes an area with microstructure, in which basic cells are embedded, out of which, each of them includes a core of doped silica glass with surrounding it, longitudinal holes, filled with the air, (further: the holes), located in the matrix of silica glass.

(46) The difference between the refraction indices of the core material and the cladding material (both internal and outer) amounts to Δ=5.2.Math.10.sup.−3±0.5.Math.10.sup.−3 for the light wavelength of λ=1550 nm.

(47) The basic cell is characterised by D2 core diameter, D3 hole diameter and the lattice constant Λ, corresponding to the distance between the centres of adjacent holes. The centres of the holes are located on the vertices and the middle points of the sides of the hexagon, the center of which is designated by the core; the length of side c of the hexagon, made of the axes of the holes, equals the double value of the lattice constant Λ. The basic cells, juxtaposed within the microstructure area, are covered with the outer cladding.

(48) The first basic cell of the structure is located at the geometric centre of the multicore optical fibre, while the other basic cells adhere to it with their sides. The other basic cells, mutually juxtaposed, share the core surrounding holes.

(49) The basic cells, surrounding the basic cell, located in the geometric centre of the optical fibre, constitute the, so-called, first ring. The cores of the first ring are located on the vertices of the hexagon, side b of which equals the tripled value of the lattice constant, multiplied by a, where a=⅔.Math.√3.

(50) The geometric parameters of optical fibre are determined in the following way:

(51) D1 outer diameter of the cladding 4.1 is (125±5) μm;

(52) D2 core diameters 2.1 are (7±0.5) μm;

(53) D3 hole diameters 3.1 are (6.6±0.2) μm;

(54) The lattice constant Λ is (7±0.5) μm

(55) In the example of fabrication, the diameter of the cladding of the multicore fibre equals approximately the cladding diameter of standard single-mode optical fibre.

(56) The microstructured active multicore optical fibre, according to the invention, includes an area of microstructure within which basic cells are located, each of them with a core of silica glass, together with the surrounding it twelve longitudinal holes filled with the air, further: the holes, located in the matrix of silica glass. The difference between the refraction indices of the core material and the cladding material (internal and outer) is 2.5*10.sup.−2±0.5.Math.10.sup.−2 for the light wavelength of λ=1550 nm. Whereby, the core is doped with erbium, at the level from approx. 20.Math.10.sup.18/cm.sup.−3 to approx. 100.Math.10.sup.18/cm.sup.−3.

(57) The basic cell is characterised by D2 core diameter, D3 hole diameter and the distance between the holes, corresponding to the lattice constant Λ.

(58) The centres of the holes are localised on the vertices and the middle points of the sides of the hexagon, the centre of which is designated by the core; the length of side c of the hexagon, created by the axes of holes, is equal to the doubled network constant Λ. The basic cells, located within the area of microstructure, are surrounded by the outer cladding.

(59) The first basic cell of the structure is preferably located at the geometrical centre of the multicore optical fibre, while the other basic cells adhere to the first basic cell with their sides or vertices. The other basic cells, mutually juxtaposed, possess common, core surrounding holes.

(60) The basic cells, surrounding the basic cell, located at the geometric centre of the optical fibre, constitute the, so-called, first ring. The cores of the first ring are located on the vertices of the hexagon, side b of which equals the tripled value of the lattice constant, multiplied by a, where a=⅔.Math.√3.

(61) The optical fibre, according to the invention, has got an additional cladding by locating an additional group of holes around the area of the microstructure, made by the basic cells.

(62) The holes, being part of the outer microstructured cladding in the optical fibre with an additional cladding are located on the circle with D4 radius. Whereby, it is preferable D5 hole diameters of the outer microstructured cladding are lower in size from the network constant Λ. The holes in the outer microstructured cladding demonstrated the circle shape of the their cross-section and are located in a distance from the fibre edge of, at least, 30 μm.

(63) The dimensions of the seven-core optical fibre with an additional cladding are as follows: D1 outer diameter of the cladding 4.1 is (151±5) μm; D2 core diameters 2.1 are (2.9±0.5) μm; D3 hole diameters 3.1 are (5.5±0.5) μm; The lattice constant Λ is (7±0.5) D4 radius of the additional cladding (90±2) μm; D5 diameters of the holes 5.1 making the additional cladding (6+0.5) μm.

(64) The device for core addressing of the microstructured multicore optical fibre, according to the invention has got seven, placed in the capillary, standard single-mode optical fibres, connected with the microstructured multicore optical fibre, according to the invention. The cross-sections of the optical fibres in the capillary are parallel with the cross-section of the multicore optical fibre.

(65) The capillary is fabricated of material susceptible to changes of geometric dimensions under the influence of temperature, associated with longitudinal tension. The capillary is fabricated of undoped silica glass.

(66) The method of fabrication the core ad dressing device (the 1-12 sequence of actions) is identical with that in Example I). While connecting the multicore optical fibre with seven cores with standard single-mode optical fibres, the following parameters are defined: 1 the number of cores of the multicore optical fibre (7), core diameter of the multicore optical fibre (7 μm), the distance among the cores of the multicore optical fibre (approx. 24 μm). The diameter of the cladding of single-mode optical fibre is determined (approx. 125 μm), as well as the diameter of the cladding of the multicore optical fibre (approx. 125 μm).

(67) Etching is carried out at 21° C. with the use of hydrofluoric acid in 20% concentration. The etching rate at, approximately 15 μm/h, allows to achieve the required diameter of single-mode optical fibre of 28 μm within approximately 158 minutes.

(68) The capillary with initial internal diameter of 200 μm and the outer diameter of 286 μm is tapered to corresponding diameters of 89 μm and 127 μm, respectively.

(69) The etched single-mode optical fibres are laid in the capillary, tapered to 89 μm/127 um, till the moment of laying seven optical fibres in one capillary

(70) The tapering of the capillary and its internal structure is performed in such a way that the capillary, together with the laid optical fibres, clamped on the internal structure. Accordingly, the capillary is tapered, together with the etched single-mode optical fibres, from the 89/127 μm size down to the 72 μm/103 μm size.

(71) After the capillary is cleaved, together with the welded in its inside and etched optical fibres, and after cutting of the tapered multicore optical fibres, the orientation of the multicore fibre and of the structure in the capillary is carried out in such a way that light is delivered to one of the external cores of the multicore optical fibres and, during splicing, is checked what part of power has transferred to one of the single-mode optical fibres in the capillary.

(72) The tapering of single-mode optical fibres, capillaries and capillaries with laid and welded structures, is done by means of a Vytran GPX-3400 filament splicer, used for processing/connecting of optical fibre elements.

(73) During splicing, depending on the diameter of the multicore optical fibre and the geometry of the capillary with its internal structure, the heating power of the glass processing platform is selected, so that the obtained connection was mechanically durable and with low optical losses. The pre-set values of the optical fibre element processing/connecting for the Vytran GPX-3400 filament splicer are as follows:

(74) TABLE-US-00002 Distance of the shifting of optical Distance among Power Splicing Delay before fibres on one optical fibres before [W] time [s] splicing [s] another [μm] splicing [μm] 58 7 0.2 14 8

(75) The way of signal transmission with the use of the microstructured, multicore guidance optical fibre, according to this invention, using the spatial multiplication, is an alternative for the disclosed transmission systems. The method of transmission with the use of multicore optical fibre is such that the microstructured multicore guidance optical fibre, according to this invention, is used as the main guidance medium. The problem of addressing cores in the multicore optical fibre is solved with the use of the device and technique for independent addressing of the cores of the microstructured multicore optical fibre, according to the invention.

(76) When the transmission distance requires signal amplification, it is arranged in the following way (see FIG. 14).

(77) During transmission, pumping takes place directly to the microstructured, active, multicore optical fibre, according to the invention in the variant with additional cladding. Whereby, pumping can be carried out as lateral pumping or pumping from the front of the microstructured, active multicore optical fibre, according to the invention in the variant with additional cladding The technologies of lateral and frontal pumping have been disclosed and do not require any modification for the application in this variant of guidance system. The variant of the guidance system with direct pumping is characteristic in that the signal from transmitters 5 is guided via standard, single-mode optical fibres 2 to the device of independent core addressing 3, according to the invention. The signal is then guided via the microstructured multicore optical fibre, according to the invention 1.

(78) In case of signal transmission over a distance, after which signal amplification is necessary, an amplification module 7 is used (also cyclically within one telecommunication line). Within element 9, pumping takes place into the microstructured active multicore optical fibre, according to the invention, in the variant with an additional cladding 1′, disclosed technologies with the use of pumping optical fibre(s) 10 and the spliced connection of optical fibre 1′ with the transmission optical fibre 1. Specifically, the side from which the active fibre is pumped, is not important for the functional essence of the invention. The signal is amplified in the microstructured, active, multicore optical fibre, according to the invention, in the variant with additional cladding 1′; this optical fibre is connected via the spliced connection 11 with the microstructured, multicore optical fibre, according to the invention 1. The signal, guided via the optical fibre 1 is then directed to the device of independent core addressing, according to the invention 4, after which step, signals from particular cores are transmitted via standard optical fibres 2 to receivers 6.