ARCHITECTURE FOR ELECTROMAGNETIC WAVEGUIDE

Abstract

An electromagnetic waveguide, such as an optical fibre, including a hollow central core surrounded by a microstructured sheath formed by an assembly of elementary cells, the microstructured sheath also including at least two elementary cells, at least one intermediate element connecting the elementary cells, the intermediate element having a cross-section with an area less than or equal to 50% of the cross-sectional area of each of the cells that it connects, the intermediate element having a refractive index less than or equal to the refractive index of each of the elementary cells that it connects.

Claims

1. An electromagnetic waveguide, such as an optical fibre, comprising: a hollow central core surrounded by a microstructured sheath formed by an assembly of elementary cells, the microstructured sheath comprising, between at least two elementary cells, at least one intermediate element connecting said elementary cells such that said at least two elementary cells are connected by said intermediate element only, said intermediate element having a cross section the area of which is less than or equal to 50% of the cross-sectional area of each of said cells that it connects, said intermediate element having a refractive index less than or equal to the refractive index of each of said elementary cells that it connects, said intermediate element having a tubular structure comprising a wall surrounding a central zone.

2. The waveguide according to claim 1, characterized in that the intermediate element has a cross section the area of which is less than or equal to 30% of the cross-sectional area of each of said cells that it connects.

3. The waveguide according to claim 1, characterized in that at least one of the elementary cells connected by the intermediate element includes a peripheral wall surrounding a central zone, the thickness of the wall of said intermediate element being less than 50% of the thickness of said elementary cell or each one of said elementary cells that it connects.

4. The waveguide according to claim 1, characterized in that at least one elementary cell is exclusively connected to any other elementary cell by at least one intermediate element.

5. The waveguide according to claim 1, characterized in that at least one intermediate element connects two elementary cells only.

6. The waveguide according to claim 1, characterized in that at least one intermediate element connects three adjacent elementary cells.

7. The waveguide according to claim 1, characterized in that each elementary cell is connected to one other elementary cell only by an intermediate element.

8. The waveguide according to claim 1, characterized in that at least one elementary cell is constituted by a single cell.

9. The waveguide according to claim 1, characterized in that at least one elementary cell is a cell, called hybrid, constituted by at least one first cell inserted in at least one second cell.

10. The waveguide according to claim 9, characterized in that at least one hybrid elementary cell comprises an intermediate element between the first and the second cell.

11. The waveguide according to claim 1, characterized in that the microstructured sheath comprises: a first peripheral ring, comprising a first series of elementary cells; and a second, concentric ring, inscribed within said first peripheral ring, comprising a second series of elementary cells.

12. The waveguide according to claim 11, characterized in that each elementary cell of the second ring is connected to at least one elementary cell of the first ring, by at least one intermediate element.

13. The waveguide according to claim 1, characterized in that it comprises: at least one jacket enclosing the microstructured sheath; and at least one intermediate element between at least one elementary cell and said jacket.

14. A device for guiding an electromagnetic wave utilizing an electromagnetic waveguide according to claim 1.

15. The device according to claim 14, characterized in that it is a micro-machining device using a laser wave, said device comprising at least one said waveguide, provided to be passed through by said laser wave.

16. The device according to claim 14, characterized in that it is a telecommunications device emitting and/or receiving at least one electromagnetic wave, said device comprising at least one said waveguide, provided to be passed through by said electromagnetic wave.

Description

DESCRIPTION OF THE FIGURES AND EMBODIMENTS

[0082] Other advantages and characteristics will become apparent on examining the detailed description of an embodiment that is in no way limitative, and from the attached drawings, in which:

[0083] FIG. 1 is a diagrammatic representation of an example of two elementary cells connected by an intermediate element, and capable of being utilized in a waveguide according to the invention;

[0084] FIG. 2 is a diagrammatic representation of an example hybrid cell capable of being utilized in a waveguide according to the invention;

[0085] FIG. 3 is a diagrammatic representation of an example of three elementary cells connected by one and the same intermediate element, and capable of being utilized in a waveguide according to the invention;

[0086] FIG. 4 is a diagrammatic representation of an example elementary cell connected to two other elementary cells by intermediate elements, and capable of being utilized in a waveguide according to the invention;

[0087] FIG. 5 is a diagrammatic representation of an example elementary cell connected to two other elementary cells by intermediate elements, and capable of being utilized in a waveguide according to the invention;

[0088] FIG. 6 is a diagrammatic representation of example shapes of elementary cells capable of being utilized in a waveguide according to the invention;

[0089] FIG. 7 is a diagrammatic representation of example shapes of intermediate elements capable of being utilized in a waveguide according to the invention;

[0090] FIG. 8 is a diagrammatic representation of a non-limitative embodiment example of an electromagnetic waveguide according to the invention;

[0091] FIG. 9 is a diagrammatic representation of another non-limitative embodiment example of an electromagnetic waveguide according to the invention;

[0092] FIG. 10 is a diagrammatic representation of another non-limitative embodiment example of an electromagnetic waveguide according to the invention;

[0093] FIG. 11 is a diagrammatic representation of another non-limitative embodiment example of an electromagnetic waveguide according to the invention; and

[0094] FIG. 12 is a very diagrammatic representation of a non-limitative embodiment example of a device for guiding an electromagnetic wave utilizing an electromagnetic waveguide according to the invention.

[0095] It is well understood that the embodiments that will be described hereinafter are in no way limitative. Variants of the invention can be envisaged in particular comprising only a selection of the characteristics described hereinafter, in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention with respect to the state of the prior art. This selection comprises at least one, preferably functional, characteristic without structural details, or with only a part of the structural details if this part alone is sufficient to confer a technical advantage or to differentiate the invention with respect to the state of the prior art.

[0096] In the figures, elements common to several figures retain the same reference.

[0097] FIG. 1 is a diagrammatic representation of an example of two elementary cells connected by an intermediate element, and capable of being utilized in a waveguide according to the invention.

[0098] FIG. 1 shows a cross-sectional view of two elementary cells 1021 and 1022, connected to one another by an intermediate element 104.

[0099] In the example in FIG. 1, the two elementary cells 102 are identical, and the intermediate element 104 has a cross section the area of which is less than the cross-sectional area of each of the cells 102 that it connects.

[0100] In the example in FIG. 1, the two elementary cells 102 have a cross section the shape of which is identical, in this case circular. Alternatively, it is of course possible to have two cells with different shapes and/or a shape other than the circular shape.

[0101] In the example in FIG. 1, the two elementary cells 102 have a cross section the area of which is identical. Alternatively, it is possible to have two elementary cells, the respective cross sections of which have a different area. According to the invention, the intermediate element 104 still has a cross section the area of which is less than the cross-sectional area of each of the cells 102 that it connects, and in particular is equal at maximum to 50% of the area of the smallest elementary cell 102, preferentially equal at maximum to 30%.

[0102] FIG. 2 is a diagrammatic representation of an example hybrid cell capable of being utilized in a waveguide according to the invention.

[0103] FIG. 2 shows a cross-sectional view of a hybrid elementary cell 200. This hybrid elementary cell is constituted by: [0104] a first elementary cell 202.sub.1; [0105] a second elementary cell 202.sub.2, inserted in the first elementary cell 202.sub.1; and [0106] an intermediate element 204 connecting the first elementary cell 202.sub.1 to the second elementary cell 202.sub.2.

[0107] Similarly to the intermediate element 104 in FIG. 1, the intermediate element 204 of the hybrid elementary cell 200 has a cross section the area of which is less than the cross-sectional area of each of the cells 202 that it connects.

[0108] The cross section of the intermediate element 204 is for example less than or equal to 50%, preferably less than or equal to 30%, of the smallest cross section of the elementary cells 202.sub.1 and 202.sub.2, i.e. the cross section of the hybrid elementary cell 202.sub.2.

[0109] FIG. 3 is a diagrammatic representation of an example of three elementary cells connected by an intermediate element, and capable of being utilized in a waveguide according to the invention.

[0110] FIG. 3 shows a cross-sectional view of three elementary cells 302.sub.1, 302.sub.2 and 302.sub.3, connected to one another by an intermediate element 304. The intermediate element 304 has a cross section the area of which is less than the cross-sectional area of each of the cells 302 that it connects.

[0111] The cross section of the intermediate element 304 is for example less than or equal to 50%, preferably less than or equal to 30%, of the cross section of each elementary cell 302.

[0112] In the example shown in FIG. 3, the elementary cell 302.sub.1 is connected to the cells 302.sub.2 and 302.sub.3 only, by the intermediate element 304. On the other hand, the cells 302.sub.2 and 302.sub.3 are directly connected to one another as well as being connected by the intermediate element 304.

[0113] Alternatively, it is also possible to have three elementary cells only connected to one another via one and the same intermediate element.

[0114] FIG. 4 is a diagrammatic representation of an example of three elementary cells connected by two intermediate elements, and capable of being utilized in a waveguide according to the invention.

[0115] FIG. 4 shows a cross-sectional view of an elementary cell 402.sub.1, connected to two other elementary cells 402.sub.2 and 402.sub.3 respectively by intermediate elements 404.sub.1 and 404.sub.2. The intermediate elements 404.sub.1 and 404.sub.2 each have a cross section the area of which is less than the cross-sectional area of each of the cells that it connects.

[0116] The cross section of each intermediate element 404.sub.1 and 404.sub.2 is for example less than or equal to 50%, preferably less than or equal to 30%, of the cross section of each of the elementary cells 402.sub.1-402.sub.3 that it connects.

[0117] In the example shown in FIG. 4, the elementary cell 402.sub.1 is only connected to the cells 402.sub.2 and 402.sub.3 by the intermediate elements 404.sub.1 and 404.sub.2. On the other hand, the cells 402.sub.2 and 402.sub.3 are directly connected to one another as well as being connected to the cell 402.sub.1 by the intermediate element, respectively 404.sub.1 and 404.sub.2.

[0118] FIG. 5 is a diagrammatic representation of an example of three elementary cells connected by three intermediate elements, and capable of being utilized in a waveguide according to the invention.

[0119] The example shown in FIG. 5 comprises all the elements of the example in FIG. 4.

[0120] In addition, in the example in FIG. 5, the elementary cells 402.sub.2 and 402.sub.3 do not touch one another and are connected together by an intermediate element 504.

[0121] In each of the examples that have just been described with reference to FIGS. 1-5, each intermediate element 104, 204, 304, 404.sub.1, 404.sub.2 and 504 has a cross section the shape of which is circular.

[0122] Alternatively, it is possible to have an intermediate element having a cross section the shape of which is different.

[0123] In each of the examples that have just been described with reference to FIGS. 1-5, the elementary cells 102, 202, 302, 402 and 502 as well as the intermediate elements 104, 204, 304, 404 and 504 each have a tubular structure comprising a wall surrounding a central zone. The thickness of the wall of each intermediate element 104, 204, 304, 404 and 504 is preferably less than the thickness of the wall of each of the cells 102, 202, 302, 402 or 502 that it connects, and in particular less than or equal to 50% of the thinnest wall of the cells 102, 202, 302, 402 or 502 that it connects.

[0124] FIG. 6 is a diagrammatic representation of example shapes of elementary cells capable of being utilized in a waveguide according to the invention.

[0125] As mentioned above, the elementary cells comprised in the waveguide according to the invention can have a cross section having various shapes. The cross section of an elementary cell can thus for example have the shape of a circle 6a, a hexagon 6b, a parallelogram 6c or the shape referred to as that of a water droplet, 6d.

[0126] In addition, an elementary cell, called hybrid, can have as cross section at least one first shape inscribed within a second shape, these shapes being capable of being identical or not, and being capable of having one of the aforementioned shapes.

[0127] Views 6e and 6f show hybrid cells with a cross section having the shape of a circle inscribed within another circle. The inscribed circle in views 6e and 6f is respectively in contact or not with the other circle.

[0128] Views 6g and 6h show hybrid elementary cells with a cross section having the shape of a plurality of circles inscribed within one and the same other circle. These views 6g and 6h respectively show two and three circles inscribed within one and the same other circle.

[0129] It is also possible for an elementary cell to have a cross section the shape of which is a combination of the aforementioned shapes.

[0130] FIG. 7 is a diagrammatic representation of example shapes of intermediate elements.

[0131] As mentioned above, the intermediate elements comprised in the waveguide according to the invention can have a cross section having various shapes.

[0132] The cross section of an intermediate element can thus for example have the shape of a circle 7a, a parallelogram 7b, a triangle 7c or a shape 7d the contour of which is composed of two arcs of circle and two rectilinear sides. Examples 7a-7d show intermediate elements having a tubular structure comprising a wall surrounding a central zone.

[0133] Alternatively, these intermediate elements can have a solid structure. This solid structure is either made from a single material, or comprising a wall made from a first material, surrounding a central zone filled with a second material.

[0134] Example 7e shows an intermediate element the cross section of which has the shape of a disc. This example 7e is the solid structure example, comprising a single material, similar to the example 7a having a tubular structure.

[0135] FIG. 8 is a diagrammatic representation in cross-sectional view of a non-limitative embodiment example of an electromagnetic waveguide according to the invention.

[0136] The waveguide 800 shown in FIG. 8 comprises a jacket 802, having a rectangular outer shape and a hexagonal inner shape.

[0137] The waveguide 800 also comprises a hollow core 804 surrounded by a microstructured sheath 806. The sheath 806 is formed by an assembly of elementary cells.

[0138] In the example in FIG. 8, the elementary cells have different cross sections. For example, the elementary cell 808.sub.1 has a cross section of circular shape, the elementary cell 808.sub.2 has a cross section in the shape of a truncated water droplet, and the elementary cell 808.sub.3 has a cross section of hexagonal shape.

[0139] The sheath 806 also comprises intermediate elements 810 connecting elementary cells 808.

[0140] The intermediate elements 810 have a cross section the area of which is less than or equal to 30% of the cross-sectional area of the smallest of the elementary cells that it connects. In the example in FIG. 8, the intermediate elements 810 connect three adjacent elementary cells.

[0141] The sheath 806 comprises a first peripheral ring 812, comprising a first series of elementary cells and a second concentric ring 814, inscribed within the first ring 812, comprising a second series of elementary cells.

[0142] The second ring 814 comprises only a single row of elementary cells distributed along a circular path.

[0143] Each elementary cell of the second ring 814 is connected to two elementary cells of the first ring 812, by an intermediate element 810.

[0144] FIG. 9 is a diagrammatic representation in cross-sectional view of a non-limitative embodiment example of an electromagnetic waveguide according to the invention.

[0145] The waveguide 900 shown in FIG. 9 comprises a jacket 902, having a circular shape enclosing a microstructured sheath 904.

[0146] The elementary cells 906 of the microstructured sheath 904 of the waveguide 900 have a cross section the shape of which is exclusively circular.

[0147] Just like the waveguide 800 in FIG. 8, the sheath 904 of the waveguide 900 in FIG. 9 comprises a first peripheral ring 908, comprising a first series of elementary cells 906 and a second concentric ring 910, inscribed within the first ring, comprising a second series of elementary cells 906.

[0148] Unlike the example in FIG. 8, each elementary cell 906 of the second ring 910 is here connected to two elementary cells 906 of the first ring 908, by two intermediate elements 912.

[0149] The waveguide 900 in FIG. 9 also differs from the waveguide 800 in FIG. 8 in that it comprises other intermediate elements 914 connecting other elementary cells 904 within the first ring 908 together, or with the jacket 902.

[0150] FIG. 10 is a diagrammatic representation in cross-sectional view of another non-limitative embodiment example of an electromagnetic waveguide according to the invention.

[0151] The waveguide 1000 shown in FIG. 10 comprises a jacket 1002, having a circular shape enclosing a microstructured sheath 1004.

[0152] The elementary cells 1006 of the microstructured sheath 1004 of the waveguide 1000 have a cross section the shape of which is exclusively circular.

[0153] Just like the waveguide 900 in FIG. 9, the sheath 1004 of the waveguide 1000 in FIG. 10 comprises a first peripheral ring 1008, comprising a first series of elementary cells 1006 and a second concentric ring 1010, inscribed within the first ring 1008, comprising a second series of elementary cells 1006.

[0154] Unlike the example in FIG. 9, one and the same intermediate element 1012 is used to connect two adjacent elementary cells 1006 of the second ring to one and the same cell 1006 of the first ring 1008.

[0155] FIG. 11 is a diagrammatic representation in cross-sectional view of a non-limitative embodiment example of an electromagnetic waveguide according to the invention.

[0156] The waveguide 1100 shown in FIG. 11 comprises a jacket 1102, having a circular shape enclosing a microstructured sheath 1104.

[0157] The elementary cells 1106 of the microstructured sheath 1104 of the waveguide 1100 have a cross section the shape of which is exclusively circular.

[0158] The sheath 1104 of the waveguide 1100 in FIG. 11 comprises a first peripheral ring 1108, comprising a first series of elementary cells 1106 and a second concentric ring 1110, inscribed within the first ring 1108, comprising a second series of elementary cells 1106.

[0159] Each of the first 1108 and second 1110 rings comprises a single row of elementary cells 1106 distributed along a circular path.

[0160] The elementary cells 1106 of the first ring 1108 have a greater cross section than that of the elementary cells 1106 of the second ring 1110.

[0161] Each elementary cell 1106 of the second ring 1110 is connected to a single elementary cell 1106 of the first ring 1108 by an intermediate element 1112.

[0162] FIG. 12 is a very diagrammatic representation of a non-limitative embodiment example of a device for guiding an electromagnetic wave utilizing an electromagnetic waveguide according to the invention.

[0163] The device 1200 for guiding an electromagnetic wave comprises an electromagnetic waveguide 1202.

[0164] The electromagnetic waveguide 1202 can be that in any one of FIGS. 8-11.

[0165] The device 1200 can be for example a micro-machining device using a laser wave provided to be conveyed by the waveguide 1202.

[0166] Alternatively, the device 1200 can be a telecommunications device emitting and/or receiving at least one electromagnetic wave provided to be conveyed by the waveguide 1202.

[0167] Of course, the invention is not limited to the examples detailed above.