QUARTZ FIBRE WITH HYDROGEN BARRIER LAYER AND METHOD FOR THE PRODUCTION THEREOF

Abstract

A method of manufacturing a quartz glass fibre includes producing a quartz glass primary preform by modified chemical vapor deposition (MCVD) in a quartz glass substrate tube and inserting the quartz glass primary preform into a glass jacketing tube. Defect-generating UV radiation is irridiated into the cross-sectional area of the glass jacketing tube while combining the quartz glass primary preform with the glass jacketing tube in the jacketing process to form a cladding layer to a secondary preform. A quartz glass fibre is pulled from the secondary preform.

Claims

1. A method of manufacturing a quartz glass fibre, said method comprising the steps of: a) producing a quartz glass primary preform by modified chemical vapor deposition (MCVD) in a quartz glass substrate tube; b) inserting the quartz glass primary preform into a glass jacketing tube, c) irradiating defect-generating UV radiation into the cross-sectional area of the glass jacketing tube while combining the quartz glass primary preform with the glass jacketing tube in the jacketing process to form a cladding layer on the fibre core to a secondary preform; and d) pulling a quartz glass fibre from the secondary preform.

2. The method of claim 1, wherein the defect-generating UV radiation generates E′ and NBOHC defects in the cladding layer of the quartz fibre.

3. The method of claim 1, wherein the defect-generating UV radiation is irradiated into the glass jacketing tube.

4. The method of claim 1, wherein the glass jacketing tube consists of quartz glass having an OH concentration of ≤0.2 ppm, a chlorine content of 800-2000 ppm, and/or a refractive index of +0.35 to +0.5×10.sup.−3.

5. The method of claim 1, wherein the quartz glass primary preform has a fluorine-doped radial layer on the fibre core.

6. Quartz glass fibre produced or producible by the method of claim 1.

7. Quartz glass fibre, comprising: a) a fibre core of quartz glass, b) a fluorine-doped radial layer on the fibre core, c) a cladding layer of quartz glass, wherein d1) the cladding layer has E′ and NBOHC defects, or, d2) the cladding layer has Si—OH and Si—H compounds.

8. The quartz glass fibre of claim 7, wherein the cladding layer is quartz glass having an OH concentration of ≤3.2 ppm, a chlorine content 800-2000 ppm, and/or a refractive index of +0.35 to +0.5×10.sup.−3 on the fibre core, and wherein the cladding layer preferably has a higher density of E′ and NBOHC defects than the fibre core.

9. The quartz glass fibre of claim 7, wherein the quartz glass fibre has no further doped layers.

10. The quartz glass fibre of claim 7, wherein the quartz glass fibre has no hermetic coating.

Description

[0042] Further objectives, features, advantages and application possibilities result from the following description of exemplary embodiments, which are not to be understood as restrictive, with reference to the associated drawings. Here all features described and/or depicted show by themselves or in any combination the subject matter disclosed here, even independently of their grouping in the claims or their references. The dimensions and proportions of the components shown in the figures are not necessarily to scale in this case; they may diverge in embodiments to be implemented from what is shown here.

[0043] FIG. 1 shows a schematic representation of a cable with two waveguides;

[0044] FIG. 2 shows a schematic representation of a cable with four waveguides in a first arrangement;

[0045] FIG. 3 shows a schematic representation of a cable with four waveguides in a second arrangement;

[0046] FIG. 4 shows a schematic representation of a method for manufacturing a cable;

[0047] FIG. 5a shows an S-parameter result for a cable with two waveguides according to FIG. 1;

[0048] FIG. 5b shows an S-parameter result for a cable with four waveguides according to FIG. 2;

[0049] FIG. 5c shows an S-parameter result for a cable with four waveguides according to FIG. 2;

[0050] FIG. 5d shows an S-parameter result for a cable with four waveguides according to FIG. 2; and

[0051] FIG. 6 shows a schematic representation of a cable with four waveguide elements each enclosed by a separate part of the dielectric medium.

[0052] The cable and the method are now described on the basis of exemplary embodiments.

[0053] Specific details are set out below, without being restricted thereto, to supply a complete understanding of the present disclosure. It is dear to an expert, however, that the present disclosure can be used in other exemplary embodiments that may deviate from the details set out below.

[0054] FIG. 1 shows a schematic representation of a cable 100 with two waveguides, which are formed by dielectric waveguide elements 110 and 120 together with a dielectric medium 150. The dielectric medium 150 forms a chamber. The chamber can also be filled by the dielectric medium 150. The cable 100 further has a first dielectric waveguide element 110. The cable 100 further has a second dielectric waveguide element 120. The first dielectric waveguide element 110 is spaced at a distance from the second dielectric waveguide element 120. The first dielectric waveguide element 110 runs along a longitudinal direction of the cable through the chamber formed by the dielectric medium. The longitudinal direction runs into the drawing plane in FIG. 1. The chamber formed can be just a part of the cable 100 here, for example, or extend over the entire length of the cable 100. The second dielectric waveguide element 120 also runs along the longitudinal direction of the cable 120 through the chamber formed by the dielectric medium 150. A preferred polarisation direction of the first dielectric waveguide element 110 differs from a preferred polarisation direction of the second dielectric waveguide element 120. In FIG. 1, the preferred polarisation directions are in the y-direction in the case of the first dielectric waveguide element 110 and in the x-direction in the case of the second dielectric waveguide element 120.

[0055] Due to the different preferred polarisation directions, fewer electromagnetic fields can be coupled from the first waveguide element 110 into the second waveguide element 120 and at the same time a space-saving cable 100 can be provided.

[0056] In the example from FIG. 1, each waveguide element 110, 120 forms a waveguide together with the dielectric medium 150. In this case the waveguide element 110, 120 can serve as the transmission medium.

[0057] The first and the second dielectric waveguide element 110, 120 can run/be arranged in parallel along the chamber or the cable 100. According to the example from FIG. 1, the first and second dielectric waveguide elements 110, 120, run in parallel into the drawing plane. They are surrounded here by the dielectric medium 150. Two waveguides are formed hereby along the cable 100.

[0058] The first and the second dielectric waveguide element 110, 120 can each be formed to transmit a high-frequency signal. For example, the first dielectric waveguide element 110 can be used as a transmitting path and the second dielectric waveguide element 120 can be used as a receiving path or vice versa. The first and the second dielectric waveguide element 110, 120 can be used in exactly the same way as transmitting path or receiving path.

[0059] In the example from FIG. 1, the dielectric medium 150 surrounds the first and second dielectric waveguide elements 110, 120 running in the chamber. The dielectric medium 150 can surround the first and the second dielectric waveguide element 110, 120 respectively here so that the first and the second dielectric waveguide element 110, 120 is connectable at end pieces of the cable 100 to a complementary end piece of a cable 100 or plug. Inside the chamber the dielectric medium 150 can fill a section between the first and second waveguide elements.

[0060] The preferred polarisation direction of the first dielectric waveguide element 110 can be predetermined by a cross section of the first dielectric waveguide element 1100 The preferred polarisation direction of the second dielectric waveguide element 120 can be predetermined by a cross section of the second dielectric waveguide element 120. The preferred polarisation direction of the first dielectric waveguide element 110 can differ from the preferred polarisation direction of the second dielectric waveguide element 120 by an angle of at least 45° (or 60° or 75° or 90°), in particular by 90°. In the example from FIG. 1, the preferred polarisation directions of the first dielectric waveguide element 110 and the second dielectric waveguide element 120 differ by 90°. To this end the cross sections of the first and second dielectric waveguide elements 110, 120 can be twisted relative to one another. In the example from FIG. 1, the cross sections of the first and second dielectric waveguide element 110, 120 are twisted by 90° relative to one another. Due to the twisting relative to one another it can be avoided that waves penetrate unintentionally into the respectively other waveguide element 110, 120 and are capable of propagation there. This means that the first and second dielectric waveguide element 110, 120 can be e.g. not point-symmetric and/or axis-symmetric. For example, the dielectric waveguide elements 110, 120 and the waveguides formed thus are not optical fibres or hollow waveguides.

[0061] The cross sections of the first and second dielectric waveguide element 110, 120 are identical in FIG. 1 purely as an example.

[0062] The cross section of the first and/or second dielectric waveguide element 110, 120 can be elliptical or, as shown by way of example in FIG. 1, rectangular. The elliptical cross section can have a main axis a and a secondary axis b. The rectangular cross section can have two side lengths a and b. The main axis a or the side length a can be greater than the secondary axis b or the side length b. In particular, the main axis a or the side length a can be 1.25 times (or 1.5 times or 2 times or 3 times or 4 times) greater than the secondary axis b or the side length b.

[0063] The ratio of a to b can determine the preferred polarisation direction of the first and second dielectric waveguide element 110, 120. If the first and second dielectric waveguide elements 110, 120 are arranged twisted relative to one another in the cable, as is shown in FIG. 1, the interference in the respectively other dielectric waveguide element 110, 120 can be reduced hereby, as the preferred polarisation directions of the first and second dielectric waveguide element 110, 120 are different and have a preferred polarisation predetermined by the geometry that prevents electromagnetic waves of another polarisation direction from being able to link in.

[0064] A distance between the first and second dielectric waveguides 110, 120 can be smaller than 4 times (or 3 times or 2 times) a side length a or main axis a of the first and/or second dielectric waveguide element 110, 120. Furthermore, a distance between the first and second dielectric waveguides 110, 120 can equal at least a side length a or main axis a of the first and/or second dielectric waveguide element 110, 120.

[0065] The dielectric constants of the first and second dielectric waveguide element 110, 120 can be substantially identical. The dielectric medium 150 can have a different dielectric constant than the first and second dielectric waveguide element 110, 120. The dielectric constant of the dielectric medium 150 can be lower than at least one of the dielectric constants of the first and second dielectric waveguide element 110, 120. The dielectric constants of the first and/or second dielectric waveguide element 110, 120 can deviate at most between 0.5% and 5% from one another, for example.

[0066] In the example from FIG. 1, the cable 100 further has a jacket 160. The jacket 160 can surround the chamber. The cable 100 can be made more weather-resistant hereby. The jacket 160 can likewise end at the end pieces of the cable 100.

[0067] The jacket 160 can likewise be conductive. Electromagnetic couplings can be avoided hereby.

[0068] The jacket 160 can also end flush with the dielectric medium 150. Water and oxygen inclusions can be avoided hereby, whereby the cable 100 is rendered more durable.

[0069] The waveguide elements 110, 120 named herein can each consist of a material with a high ε.sub.r. This can be polyethylene (PE), polypropylene (PP), ethylene-tetrafluoroethylene copolymer (ETFE), fluorinated ethylene propylene (FEP), polytetrafluoroethylene (PTFE), polyester (PES), polyethylene terephthalate (PET) or also quartz glass.

[0070] The waveguide elements 110, 120 in FIG. 1 each have a rectangular shape by way of example, but can also have an oval shape. The axis ratio (thus height to width) here is e.g. at least 1 to 1.4 to 4 (thus maximally 4 times wider than high). This axis ratio can determine the preferred polarisation.

[0071] The respective waveguide elements 110, 120 can be surrounded by the dielectric medium 150 with a lower ε.sub.r. This dielectric medium 150 has a lower ε.sub.r than that of the respective waveguide element 110, 120, in order to form the waveguide. Foamed materials (thus mixtures of a gas and a plastic) are preferably used for this, PE, PP, ETFE, FEP, PTFE or also PES can be used here as a polymer. The plastics can be foamed in processing. The foaming can take place here due to a chemical or physical process. The gas bubbles can be smaller than Lambda/4 of a wavelength of a useful frequency of the cable 100 in this case. Another option for the dielectric medium 150 is a banding of expanded PTFE. With this a significantly lower ε.sub.r than that of the respective waveguide elements 110, 120 can likewise be achieved.

[0072] The two waveguide elements 110, 120 (also termed wave-carrying elements or also transmission elements), which are rectangular in FIG. 1, are oriented differently in FIG. 1. For example, the two wave-carrying elements 110, 120 are twisted relative to one another by an angle of 90°, as shown by way of example in FIG. 1. This means in detail that the wide side of one element points to the narrow side of the other element and vice versa. This orientation can avoid mutual interference of the two waveguide elements 110, 120 in the cable. Polarised wave types can be injected into the rectangular (or oval) waveguide elements 110, 120. These are characterised in that they are only capable of propagation in one position, e.g. in the width of one of the waveguide elements 110, 120. Although the waves projecting into the dielectric medium 150 also intersect the other waveguide element 110, 120 twisted by 90° after a distance, they cannot propagate in the length therein, as the height of the waveguide element 110, 120, does not match the frequency of the disruptive coupling

[0073] Further details and aspects are mentioned in connection with the exemplary embodiments described below. The exemplary embodiment shown in FIG. 1 can have one or more optional additional features, which correspond to one or more aspects which are mentioned in connection with the proposed concept or one or more exemplary embodiments described below (e.g. FIGS. 2-6).

[0074] FIG. 2 shows a schematic representation of a cable 200 with four waveguides, which are formed by a dielectric medium 150 and four waveguide elements 110, 120, 130, 140. In addition to the elements and components of the cable 100 from FIG. 1, the cable 200 further has a third dielectric waveguide element 130. According to the example from FIG. 1, the third dielectric waveguide element 130 is spaced at a distance from the first and second dielectric waveguide elements 110, 120. The preferred polarisation direction of the first dielectric waveguide element 110 corresponds in the example from FIG. 2 to a preferred polarisation direction of the third dielectric waveguide element 130. In the case of only three waveguide elements 110, 120, 130, the preferred polarisation directions of the first, second and third dielectric waveguide element 110, 120, 130 can each differ from one another by an angle of 60°.

[0075] The cable 200 further has a fourth dielectric waveguide element 140. The fourth dielectric waveguide element 140 is spaced at a distance from the first, second and third dielectric waveguide elements 110, 120, 130 according to the example from FIG. 2. The preferred polarisation direction of the second dielectric waveguide element 120 corresponds in the example from FIG. 2 to a preferred polarisation direction of the fourth dielectric waveguide element 140.

[0076] Using several waveguides formed by the waveguide elements 110, 120, 130 and 140 and the dielectric medium 150 can provide a greater transmission rate and more throughput. At frequencies of over 100 GHz (without light), a higher bandwidth can likewise be provided.

[0077] A distance between the first and second waveguide element 110, 120, and the second and third waveguide element 120, 130, and the third and fourth waveguide element 130, 140 and also the fourth and first waveguide element 140, 110, is identical hi the example from FIG. 2. This distance is termed value A.

[0078] A distance between the first and third waveguide element 110, 130 corresponds in the example from FIG. 2 to a distance between the second and fourth waveguide element 120, 140. This distance can be termed value B.

[0079] B can be √2*A. Even if the first and third waveguide element 110, 130 and the second and fourth waveguide element 120, 140 have the same preferred polarisation direction, a coupling to the respectively other waveguide element can be reduced by the greater distance (√2 times greater).

[0080] The respective distance between the waveguide elements can be determined starting out from a centre of a respective cross section of the waveguide elements in the same cross-sectional plane of the cable 200.

[0081] In the case of a cable 200 with four waveguides 110, 120, 130, 140 inside the cable 200 (formed by four waveguide elements and a dielectric medium 150 around the same), the conditions are comparable with the case of a cable 200 with two waveguides (formed by two waveguide elements and a dielectric medium 150 around the same, see FIG. 1). The directly adjacent waveguide elements can be rotated by 90° as shown in FIG. 2, diagonally opposed waveguide elements having an identical orientation. Since diagonally opposed waveguide elements have a spacing that is greater by √2, however, the crosstalk is attenuated even here thereby.

[0082] Further details and aspects are mentioned in connection with the exemplary embodiments described above or below. The exemplary embodiment shown in FIG. 2 can have one or more optional additional features, which correspond to one or more aspects, which are mentioned in connection with the proposed concept or one or more exemplary embodiments described above (e,g. FIG. 1) or below (e.g. FIGS. 3-6).

[0083] FIG. 3 shows a schematic representation of a cable 300 with four waveguides in a second arrangement similar to FIG. 2, but with another orientation of the four waveguide elements 110, 120, 130, 140. The dielectric medium 150 can have a sufficiently large diameter here to guarantee that the field components of the propagating mode in the lossy jacket material are negligible (if a jacket is used). The jacket structure to be recognised in the illustration is used here to protect against environmental influences (dirt, water and other environmental influences).

[0084] Further details and aspects are mentioned in connection with the exemplary embodiments described above or below. The exemplary embodiment shown in FIG. 3 can have one or more optional additional features, which correspond to one or more aspects, which are mentioned in connection with the proposed concept or one or more exemplary embodiments described above (e.g. FIGS. 1-2) or below (e.g. FIGS. 4-6).

[0085] FIG. 4 shows a schematic representation of a method for manufacturing a cable. The method comprises provision S410 of a first and second dielectric waveguide element. The first and second dielectric waveguide element are spaced at a distance from one another. The first dielectric waveguide element is twisted by comparison with the second dielectric waveguide element, so that a preferred polarisation direction of the first dielectric waveguide element differs from a preferred polarisation direction of the second dielectric waveguide element in the cable. The method can further comprise embedding S420 of the first and second dielectric waveguide element in a chamber made of a dielectric medium.

[0086] In addition, the method can comprise the separate embedding of the first and second (as well as third and fourth) dielectric waveguide elements in segments of the dielectric medium. Furthermore, the method can comprise stranding of the first and second (as well as third and fourth) dielectric waveguide elements embedded in this way to form a waveguide with two (four) waveguides. Sheathing can take place as a separate step to join the stranded elements together to form the cable.

[0087] Further details and aspects are mentioned in connection with the exemplary embodiments described above or below. The exemplary embodiment shown in FIG. 4 can have one or more optional additional features, which correspond to one or more aspects, which are mentioned in connection with the proposed concept or one or more exemplary embodiments described above (e.g. FIGS. 1-3) or below (e.g. FIGS. 5-6).

[0088] FIG. 5a shows an S-parameter result for a cable with two waveguides. Curve 5a1 describes the insertion loss (IL). Curve 5a2 describes the near end crosstalk (NEXT), Curve 5a3 describes the far end crosstalk (FEXT).

[0089] FIG. 5b shows an S-parameter result for a cable with four waveguides according to the first arrangement. Here the three FEXT curves 5b1, 5b2 and 5b3 are shown in FIG. 5b, which result by measurement during supplying of one of the waveguide elements.

[0090] FIG. 5c shows an S-parameter result for a cable with four waveguides according to the first arrangement Here the three NEXT curves 5c1, 5c2 and 5c3 are shown in FIG. 5c, which result by measurement during supplying of one of the waveguide elements.

[0091] FIG. 5d shows an S-parameter result for a cable with four waveguides according to FIG. 2. The insertion loss is provided in FIG. 5d by 5d1. The FEXT curve 5b1 further corresponds to the FEXT curve 5d3. The NEXT curve 5c1 also corresponds to the NEXT curve 5d2.

[0092] FIG. 6 shows a schematic representation of a cable 600 with four waveguides 110, 120, 130, 140 each surrounded by a separate part of a dielectric medium 150. The chamber in the example from FIG. 6 comprises several segments of the dielectric medium 150, as described above. In this case the dielectric medium 150 is divided into several segments. Each segment of the dielectric medium 150 encloses/surrounds one of the (first/second/third/fourth) waveguide elements 110, 120, 130, 140 separately (in the chamber) in the example from FIG. 6. The segments can be in mutual contact. The segments can each likewise contact the jacket 160.

[0093] If great mechanical loads act on the cable 600, it can be advantageous to strand the waveguides (formed by a respective segment of the dielectric medium and a corresponding waveguide element 110, 120, 130, 140). Here each waveguide element 110, 120, 130, 140 can be fabricated together with the dielectric medium 150 as a separate (individual) waveguide of the cable 600. Several individual waveguides of the cable 500 can then be stranded with one another. Stranding with reverse twist can be used in this case. It is thereby guaranteed that the orientations of the waveguides and also of the corresponding waveguide elements 110, 120, 130, 140 are not displaced to one another.

[0094] Moreover, a torsion of the transmission elements 110, 120, 130, 140 negatively affecting the transmission properties can be avoided. It is not absolutely necessary here, however, that the dielectric medium 150 has a round outer contour. A roughly rectangular contour has advantages in the assignment to one another here. This is because round surfaces easily twist in relation to one another, while faces brace one another. A continuation consists in a segmented outer form of the individual components.

[0095] Further details and aspects are mentioned in connection with the exemplary embodiments described above. The exemplary embodiment shown in FIG. 6 can have one or more option& additional features, which correspond to one or more aspects, which are mentioned in connection with the proposed concept or one or more exemplary embodiments described above (e.g. FIGS. 1-5).

[0096] According to one or more of the aforesaid aspects, a cable optimised for crosstalk can be provided with two or four waveguides in a common jacket. The waveguide elements contained in the cable can each have a rectangular or oval cross section (height to width ratio between 1:1.4 to 4). The dielectric medium 150 used in the cable can be one part (common element for all waveguide elements) or a plurality of parts. Each part can then surround a respective waveguide element separately. The parts surrounding the corresponding waveguide elements can then be stranded with one another, e.g, with reverse twist during production, to retain the orientation. These individual parts can have a rectangular or segmented cross section.

[0097] The cable described above can have the following advantages. A dielectric waveguide can be very light and flexible. It does not break, for example, even in the event of maximum reverse bending demands. In addition, a transmission frequency can be extremely high, e.g. in the range of 100 GHz to 150 GHz, or also over 50 GHz, over 70 GHz, over 90 GHz, over 100 GHz, over 120 GHz, over 130 GHz or over 140 GHz. An extremely large data bandwidth can be provided thereby. Moreover, it can be made possible with the structure described to double or quadruple the transmissible bandwidth with respect to a structure with only one. transmission element without channels significantly influencing one another.

[0098] Furthermore, cables of this kind have the advantage of being able to carry no current. Since no conductor is present, therefore, there cannot be any sparks either. A damage risk can be reduced and electromagnetic compatibility improved by this.

[0099] The aspects and features that were mentioned and described together with one or more of the examples and figures described in detail above can further be combined with one or more of the other examples to replace a similar feature of the other example or to introduce the feature additionally into the other example.

[0100] The present disclosure is not limited in any way to the embodiments described previously. On the contrary, many opportunities for modifications thereto are evident to an average expert without departing from the fundamental idea of the present disclosure as defined in the enclosed claims.