Apparatus and method for manufacturing fiber bundles

Abstract

The present invention relates to an apparatus and method for manufacturing fiber bundles (2), wherein the apparatus comprises: a clamping device (3) for receiving and fixing a plurality of fibers (20); a pressing device (4) for applying force to the clamping device (3); a pressing receptacle (40) arranged on a pressing mechanism (4) for receiving the clamping device (3) and compressing a plurality of fibers (20) arranged in the clamping device (3); and at least one radiation source (5), wherein a beam path (50) of the at least one radiation source (5) is directed to an area within or near the clamping device (3) to connect, in particular to fuse, the plurality of fibers (20) received in the clamping device (3) to each other.

Description

Technology Field

[0001] The present invention relates to a device and a method for manufacturing fiber bundles. Background Technology

[0002] Fiber bundles are used in many places to transmit information and services. For example, fiber bundles are used in the field of optical or laser radiation in optical projectors and laser systems, as well as in spectroscopy and surface analysis. The transmission direction can be freely selected and can be routed from a single input connector to multiple output connectors, from multiple input connectors to a single output connector, or from multiple connectors on one side to multiple connectors on the other, and the number of fibers per connector can vary.

[0003] Additionally, fiber bundles are used for radiative conversion. In this process, light is converted from any one geometric structure to another arbitrary geometric structure (e.g., different aspect ratios, circular / elliptical, polygonal, etc.). Other common applications for fiber bundles include systems such as multimode beam couplers. These systems comprise at least one optical fiber having a step-index or gradient-index structure, or a combination of both, wherein a difference in refractive index is formed at the interface between the core and the cladding, resulting in a numerical aperture that enables stable and uniform radiative output. One or more of these fibers are formed into a bundle. The fibers within the bundle can eventually be separated by appropriate coatings so as to be optically coupled or decoupled from one another. Illumination systems may include multiple such fibers coupled to each of a plurality of laser diodes or other light sources. For example, tapered couplers may comprise multiple optical fibers (or other waveguides) arranged in a rectangular, circular, angular, or hexagonal configuration. Generally, each fiber has the same cross-sectional dimensions. Alternatively, fibers with different geometric structures—particularly fibers with different cross-sectional dimensions—may also be combined. In common types, the fibers have square, round, or trapezoidal cross-sections. Additionally, combinations of different fiber types, such as double-clad fibers, gradient refractive index fibers, or step refractive index fibers, are known.

[0004] While optical fibers are used in many practical applications, other waveguide structures, such as planar waveguides, can also be configured to define coupling interfaces. Examples include rectangular double-clad fibers, rectangular stepped-index fibers, or other fibers that are tapered and / or spliced ​​or fused. Conventional optical fibers are formed by thermally fusing the ends of bundles of optical fiber strands. During thermal fusion, by arranging the glass fiber strands into a dense polygonal structure, such as a hexagon, it is possible to reduce the diameter of the fiber strands or increase the fill factor. In the case of fused spliced ​​structures, the affected section exhibits enhanced heat resistance.

[0005] Methods for processing optical fibers and corresponding devices are also known. In this process, the core of the optical fiber is heated to a core temperature within the glass transition temperature range of the fiber core using minimal light from a directional light source. Additionally, losses cause heating, which can lead to damage in certain regions or at least undesirable heating.

[0006] Conventional methods utilize flame or electric plasma for fusion. Both methods, particularly for larger bundles, have the disadvantage that heat is introduced from the outside into the bundle and transferred internally by heat conduction. If external heat is reduced to protect the fibers on the outer part of the bundle, this can result in insufficient heat reaching the interior, preventing the internal fibers from fusing properly. Conversely, a high external heat input can fuse the internal fibers while simultaneously applying excessive thermal stress to the outer fibers.

[0007] In the following, the term "multiple fibers" refers to multiple individual fibers in a loose state. On the other hand, the term "fiber bundle" refers to a group of fibers bound together.

[0008] Based on known prior art, the object of the present invention is to provide an improved device for manufacturing fiber bundles as well as a corresponding method.

[0009] This problem is solved by an apparatus for manufacturing fiber bundles having the features of claim 1. Advantageous further developments are evident from the dependent claims, description, and drawings.

[0010] Accordingly, a device for manufacturing fiber bundles is proposed. According to the present invention, the device comprises a clamping device for holding and fixing a plurality of fibers, a pressing mechanism for applying force to the clamping device, a press housing arranged on the pressing mechanism for holding the clamping device and compressing a plurality of fibers arranged in the clamping device, and at least one radiation source, wherein a radiation beam of the at least one radiation source is directed toward an area within the clamping device or an area near the clamping device to join the plurality of fibers held within the clamping device together, particularly to fuse the plurality of fibers.

[0011] The clamping device enables loose fibers, which serve as the raw material for the device, to be positioned relative to one another and held in place. The clamping force generated by the clamping device helps to press the fiber cladding surfaces together. However, due to the clamping force of the clamping device, the surfaces of the fiber cladding may be slightly deformed during heating, thereby increasing the contact area between the fibers. This effect can be amplified by the forces applied to the clamping device by the pressing mechanism, which further increases the contact surface area between the fibers. Pre-positioning the fibers relative to one another using the clamping device also has the advantage that the forces applied to the fibers by the pressing mechanism can be utilized optimally. In particular, the clamping device ensures that individual fibers are arranged substantially parallel to one another, so that the maximum possible contact surface area between the fibers can be achieved when the fibers are compressed by the pressing mechanism during heating. For example, in the case of multiple fibers that are initially round, these fibers substantially take on a polygonal, particularly hexagonal, cross-sectional shape during heating and compression by a pressing mechanism. Consequently, a higher packing factor can be achieved for the multiple fibers. The effect described above can be further enhanced by using polygonal fibers.

[0012] In another preferred embodiment of the device, the clamping device is configured to apply a force to the fibers perpendicular to the circumferential surface of the fibers or to the longitudinal axis of the fibers. The advantage of applying such a force to the fibers is that the fibers maintain their positions. This also applies to fibers that do not have an external glass cladding. The fibers are fixed in position relative to each other and relative to the radiation source. The clamping device applies a uniform external force to the fibers over the entire circumference. One advantage of applying force in this manner is that the fibers are not displaced by the force but are rather compressed. Consequently, the gaps between the fibers can be reduced or even completely eliminated when heated by the radiation source. This results in the diameter of the resulting fiber bundle becoming smaller than the diameter of the fibers due to the reduction of the gaps not filled with fibers; this increases the contact surface area between individual fibers and allows for a higher irradiation density per unit area.

[0013] In a preferred embodiment, the spinning source is configured to irradiate at least one defined point within and / or near the clamping device to combine individual fibers of a plurality of fibers in a defined manner, and the spinning source and / or press housing are movable relative to each other, particularly in the radial and / or axial directions, to combine individual fibers of a plurality of fibers in a defined manner. With the clamping force applied by the clamping device and the pressing mechanism, maximum contact between the cladding surfaces of the individual fibers can be achieved during heating, thereby allowing the individual fibers to fuse together. Furthermore, targeted irradiation of the plurality of fibers enables, for example, the fibers to be heated from the inside out. In particular, the inner fibers can be sufficiently heated without applying excessive thermal stress to the outer fibers.

[0014] When there are only a few fibers (e.g., fewer than 10 fibers) or when the fibers have a relatively large diameter (e.g., a diameter exceeding 100 µm), it may be sufficient for the spinning source to irradiate only the contact surfaces between the fibers to fuse the fibers together. Therefore, it is not necessary to heat the entire cross-section of each individual fiber. This can reduce or prevent damage to individual fibers that may occur as a result of heating the fibers, such as unintended changes to the internal fiber structure.

[0015] Consequently, this device can irradiate only a small number of fibers to the extent necessary to form a fiber bundle by bonding nearby fiber cladding surfaces together. Parts that are not involved in forming a connection between a fiber within a plurality of fibers and a nearby fiber, such as the fiber core or the fiber cladding surface forming the cladding surface of the plurality of fibers, can be spared from irradiation and resulting heating.

[0016] In another embodiment, the radiation source is a laser, preferably a diode laser, a CO laser, or a CO2 laser, in particular the diode laser has a wavelength in the range of 2 µm to 3.5 µm, the CO laser has a wavelength in the range of 4.8 µm to 8.3 µm, preferably 5.5 µm, and the CO2 laser has a wavelength in the range of 9.6 µm to 10.6 µm. The CO lasers, CO2 lasers, or diode lasers used as radiation sources are characterized by high energy density and low scattering effects of the lasers within a defined beam diameter. By using a CO laser or a CO2 laser as a radiation source, it is possible to precisely direct the radiation energy into a plurality of fibers held in a clamping device. In particular, the preload provided by the clamping device and the pressing mechanism can be used to deform the plurality of fibers accordingly after the plurality of fibers are heated. This ensures maximum contact between the cladding surfaces of the individual fibers, thereby allowing the fibers to fuse together optimally. The precise irradiation of multiple fibers made possible by the aforementioned lasers allows, for example, the fibers to be heated from the inside out. In particular, the inner fibers can be sufficiently heated without applying excessive thermal stress to the outer fibers.

[0017] When dealing with a small number of fibers (e.g., fewer than 10 fibers), it may be sufficient to simply irradiate the contact surfaces between the fibers with a diode laser, CO laser, or CO2 laser to fuse the fibers together. It is not necessary to completely heat or melt multiple fibers. Negative effects that may occur due to the complete heating or melting of multiple fibers, such as the formation of pores within individual fibers, can be reduced or prevented accordingly.

[0018] In another preferred embodiment of the device described, the pressing mechanism comprises a vacuum chamber, and the vacuum chamber is configured to apply force to a cavity defined by the press housing, particularly to a clamping device located within the press housing, when a vacuum is present within the vacuum chamber. This embodiment has the advantage that the force transmitted from the pressing mechanism to the clamping device—and thereby acting perpendicularly to the circumferential surface or perpendicular to the fibers with respect to the longitudinal axis of the plurality of fibers—can be significantly increased. Due to the negative pressure inside the vacuum chamber, the clamping device surrounding the fibers can be pulled at least partially into the vacuum chamber and thus further compressed. This compression affects the plurality of fibers and helps to hold the fibers together. This ultimately helps to hold the fibers in place and further helps to reduce the gaps between individual fibers, thereby increasing the filling rate. Furthermore, this helps to reduce the diameter of the plurality of fibers, increase the contact surface area between individual fibers, and increase the roughness per unit area. When irradiating fibers using a spinning source, heating or fusing the fibers under vacuum can cause relatively little bubble formation.

[0019] In another preferred embodiment of the described device, the clamping device is arranged substantially concentrically with respect to the press housing in the radial direction and overlaps at least partially with the press housing in the axial direction. One advantage of this embodiment is that the clamping device is maintained in an intended position with respect to the press housing and, consequently, with respect to the pressing mechanism and the radiation source. Additionally, various clamping device designs may be used. The modular design enables the use of various clamping devices and pressing mechanisms, such as those having different inner diameters to accommodate a variable number of fibers, as well as those having different axial lengths.

[0020] In another exemplary embodiment of the described device, the clamping device comprises an elastomer that is transparent and / or partially transparent and heat-resistant, preferably up to the melting point of glass, more preferably up to 1,400°C. The configuration of the clamping device made of the elastomer enables the application of radial pressure—or pressure acting perpendicular to the longitudinal axis of the fibers—to a plurality of fibers. Once the fibers are combined into a fiber bundle, the clamping device can be removed. The elastomer-based clamping device can adapt relatively easily to the geometry of the fiber bundle, whether the fibers are coated or not. First, a relief mold of the finished fiber bundle is created. Then, the elastomer is poured around the relief mold. The cured elastomer forms a finished flexible clamping device. In the next step, the fibers are inserted into the clamping device—for example, by clamping in place—which stretches the clamping device, i.e., the elastomer.

[0021] If implemented instead as a unit combining a clamping device and a press housing, multiple fibers are laterally arranged in the recess of the clamping device. A body positioned in the recess and capable of moving perpendicular to the longitudinal axis of the fibers can apply a force acting perpendicular to the circumferential surface or against the longitudinal axis of the multiple fibers by moving. This ensures that pressure is uniformly distributed along the defined length of the clamping device in the axial direction of the fibers. Additionally, a transparent or partially transparent elastomer allows energy emitted by a spinning source to pass through the multiple fibers. When the multiple fibers are heated by the spinning source, the pressure or preload applied by the clamping device causes the heated fibers to be compressed. Furthermore, the elastomers also exhibit a certain level of heat resistance required during the bonding process, particularly when the fibers are fused together. The clamping devices for this device can be designed as part of a modular system in a sleeve-type configuration, particularly with various dimensions and geometries (e.g., tubular, rectangular, etc.). All that is required is an embossed mold of the desired fiber bundle geometry.

[0022] In another embodiment, the clamping device is tubular and has a stepped shape to provide two zones, in particular, having different cross-sections. Thus, the clamping device can be easily and inexpensively adapted to the geometry of the transition zone, so that even in this zone, sufficiently radial, or perpendicular to the longitudinal axis of the fibers and essentially uniform pressure can be ensured during the heating of the fibers.

[0023] In another preferred embodiment, the direction of the radiation beam from the radiation source differs from the fiber orientation of the plurality of fibers, and preferably is perpendicular to the fiber orientation of the plurality of fibers. This has the advantage that the fibers can be precisely connected at designated points, thereby achieving high irradiation efficiency. Additionally, the position of the fusion zone along the axial direction of the fibers can be controlled by shifting the fibers and / or the radiation source axially. The precise irradiation of the plurality of fibers made possible by the radiation source allows the fibers to be heated, for example, from the inside out. In particular, the inner fibers can be sufficiently heated without applying excessive thermal stress to the outer fibers.

[0024] Additionally, the position of the fusion zone—for example, in the circumferential direction of the fibers—can be controlled by moving the spinning source in the circumferential direction of the fibers, that is, along an orbit around multiple fibers or a single fiber, or by rotating multiple fibers in the circumferential direction. In the case of a small number of fibers (e.g., fewer than 10 fibers), the fibers no longer need to be fully heated, which helps to reduce fiber deformation. To achieve connection, heating of the fibers can be limited to the outer edges of the fibers. Additionally, different regions within the cross-section of the fibers can be processed by adjusting the angle of the spinning source relative to the fibers or the angle of the fibers relative to the spinning source, as well as by selecting an appropriate output level for the spinning source.

[0025] In another preferred embodiment, the radiating beam of the radiating source is aligned in substantially the same orientation as the fibers among the plurality of fibers. In other words, the laser is directed toward the ends of the plurality of fibers, thereby heating parts of the ends of the plurality of fibers and allowing the ends of the plurality of fibers to fuse together. By positioning the radiating source, the radiating energy can be precisely directed along the fiber direction within the cross-section and adapted to the fiber geometry. Homogeneous and complete bonding between the fibers can also be achieved in regions that are not arranged in the circumferential direction. Additionally, by adjusting the beam cross-section, specific regions within the fiber cross-section can be left untreated or smoothed out.

[0026] In another preferred embodiment, the device includes a scanning mechanism for precisely deflecting a laser beam. The scanning mechanism enables the focus of the laser beam to be precisely controlled or adjusted. As a result, a plurality of fibers can be heated or melted in a controlled manner. In particular, the scanning device includes at least two mirrors for precisely controlling the focus of the laser beam.

[0027] In another preferred embodiment, the device includes a detection unit for detecting at least one fiber parameter of a plurality of fibers or connected fiber bundles, in particular, the detection unit is connected to a control / regulation unit.

[0028] Using a detection device, the position and orientation of the near surfaces of multiple fibers can be detected. This information can then be transmitted to a control / regulation unit. The control / regulation unit can then specify the exact position or locations within the multiple fibers where the radiation source will heat or fuse the individual fibers together, based on the fiber parameters determined by the detection device. Consequently, this detection device enables optimized process monitoring and control / regulation for the bonding of multiple fibers. Additionally, process parameters and critical control points can be monitored before, during, and after the bonding process and compared with individual target parameters. Furthermore, the detection system enables the performance of necessary adjustments when values ​​fall below or exceed the target parameters. Additionally, the ability to adjust parameters during the bonding process is advantageous. For example, unwanted overheating of the fibers can be prevented by the control unit regulating the radiation source. Furthermore, if the bonds are unsatisfactory, the parts can be re-irradiated in a later stage or irradiated at a higher energy level. The detection device may include, for example, a thermal imaging camera.

[0029] In another preferred embodiment of the device, at least one or more fiber parameters include the temperature, temperature range, bonding level, shape, and / or dimensions of a plurality of fibers or fiber bundles. Knowledge of fiber bundle parameters, such as the specific shape and size of the fibers, enables not only the energy-efficient transfer of the spinning output but also a smooth bonding customized to the individual fibers. Thus, the temperature range required to bond the fibers—and in particular, to fuse them—can be optimally achieved, thereby preventing unnecessary overheating that could damage the fiber structure. Additionally, temperatures below the level required to fuse the fibers—which could result in unsatisfactory fusion or a complete lack of fusion—can be prevented by readjusting the parameters.

[0030] This problem is further solved by a method for manufacturing fiber bundles having the features of claim 14. Further improvements to the method are described in the dependent claims as well as in this description and drawings.

[0031] Accordingly, a method for manufacturing fiber bundles is proposed. The method comprises the steps of: holding and fixing a plurality of fibers in a clamping device; positioning the clamping device and the plurality of fibers held in the clamping device in a press housing located in a pressing mechanism; compressing the clamping device and the plurality of fibers arranged in the clamping device by the pressing mechanism; and fusing the plurality of fibers held in the clamping device together by at least one radiation source, wherein the radiation beam of the at least one radiation source is directed toward a region of the plurality of fibers within or near the clamping device.

[0032] The clamping device enables loose fibers, which serve as the starting material for this method, to be positioned relative to one another and held in place. The clamping force generated by the clamping device helps to press the fiber cladding surfaces together. However, due to the clamping force of the clamping device, the surfaces of the fiber cladding may be slightly deformed during heating, thereby increasing the contact area between the fibers. This effect can be amplified by the forces applied to the clamping device by the pressing mechanism, which further increases the contact surface area between the fibers. Positioning the fibers relative to one another using the clamping device also has the advantage that the forces applied to the fibers by the pressing mechanism can be utilized optimally. In other words, the clamping device ensures that individual fibers are arranged essentially parallel to one another, so that when the fibers are pressed by the pressing mechanism and heated by the spinning source simultaneously, the maximum possible contact surface between the fibers can be created. In the case of multiple fibers that are originally round, these fibers take on a substantially polygonal—e.g., hexagonal—circular shape during heating and compression by a pressing mechanism. As a result, a higher packing density can be achieved for the multiple fibers.

[0033] In another preferred embodiment of the described method, the pressing mechanism comprises a vacuum chamber, and the step of positioning a clamping device and a plurality of fibers disposed within the clamping device within a press housing located in the pressing mechanism comprises the step of supplying the plurality of fibers into the vacuum chamber through the press housing. The step of compressing the clamping device and the plurality of fibers arranged within the clamping device by the pressing mechanism comprises the step of creating a vacuum within the vacuum chamber to compress the plurality of fibers, particularly in the region of the clamping device, while heating by a spinning source, specifically compressing the plurality of fibers radially or perpendicularly with respect to the longitudinal axis of the plurality of fibers.

[0034] The force transmitted to the clamping device by the pressing mechanism, and thereby acting perpendicularly to the circumferential surface or against the longitudinal axis of the multiple fibers, can be significantly increased by applying negative pressure through the vacuum chamber. Due to the negative pressure inside the vacuum chamber, the clamping device surrounding the fibers is, for example, pulled in at least partially into the vacuum chamber and thus subjected to additional radial compression. This causes a reduction in the gaps between the fibers. Additionally, applying a uniform external force to the multiple fibers has the advantage of keeping the fibers in place. The advantage of applying force in this manner is that the fibers do not shift but instead remain in place.

[0035] In a further preferred embodiment of the described method, the step of fusing a plurality of fibers held in a clamping device comprises the step of heating the fibers by targeting them together by at least one radiation source—wherein the radiation beam of the at least one radiation source is directed toward a region of the plurality of fibers within or near the clamping device—particularly the step of selectively melting defined regions within the plurality of fibers to create predefined connection patterns, and the plurality of fibers and / or the radiation source arranged in a press housing are moved relative to each other, particularly radially and / or axially, to create predefined connection patterns. For example, the heating of the plurality of fibers allows the fibers to be heated from the inside out. In particular, the inner fibers can be sufficiently heated without applying excessive thermal stress to the outer fibers.

[0036] Additionally, the preload generated by the clamping device and the pressing mechanism can be used to ensure maximum contact between the cladding surfaces of individual fibers when multiple fibers are heated.

[0037] If there are only a few fibers (e.g., fewer than 10), it may be sufficient for the spinning source to irradiate only the contact surfaces between the fibers to fuse them together. Therefore, it is not necessary to heat the entire cross-section of each individual fiber. This can reduce or prevent damage to individual fibers that may occur as a result of heating the fibers, such as unintended changes to the internal fiber structure.

[0038] Consequently, the current device can irradiate multiple fibers only to the extent necessary to form a fiber bundle by bonding nearby fiber cladding surfaces together. Parts within the multiple fibers that are not involved in bonding with fibers near each other, such as fiber cores or fiber cladding surfaces forming the cladding surfaces of the multiple fibers, can be excluded from irradiation and resulting heating.

[0039] In another preferred embodiment of the described method, the radiation source may include a diode laser, a CO laser, or a CO2 laser to provide targeted fusion of predefined regions within a plurality of fibers.

[0040] CO2 lasers, CO2 lasers, and diode lasers are characterized by high energy density and low scattering effects within a defined beam diameter. By using a CO2 laser or CO2 laser as a radiation source, it is possible to precisely direct radiated energy into multiple fibers held in a clamping device. In particular, the preload provided by the clamping device and the pressing mechanism can be used to ensure maximum contact between the cladding surfaces of individual fibers, thereby enabling the individual fibers to fuse together optimally. The precise irradiation of multiple fibers made possible by the aforementioned lasers allows the fibers to be heated, for example, from the inside out. In particular, the inner fibers can be sufficiently heated without applying excessive thermal stress to the outer fibers.

[0041] When dealing with a small number of fibers (e.g., fewer than 10 fibers), it may be sufficient to simply irradiate the contact surfaces between the fibers with a diode laser, CO laser, or CO2 laser to fuse the fibers together. It is not necessary to completely heat or melt multiple fibers. Negative effects that may occur due to the complete heating or melting of multiple fibers, such as the formation of pores within individual fibers, can be reduced or prevented accordingly.

[0042] In another preferred embodiment, the fusion of multiple fibers is limited to a predefined fusion zone, in particular, the length of the fusion zone may be greater than the width of the cross-section of the multiple fibers, and / or the fusion zone is located at at least one end of the multiple fibers. The geometric dimensions of the individual fibers and the shape of the fiber bundle are key factors affecting the transmission of the fiber bundle. Additionally, by having a fusion zone that is longer than the cross-sectional length of the fiber bundle and located at at least one end of the fiber bundle, excellent heat resistance, flexibility, and spinning efficiency are achieved.

[0043] In another preferred embodiment, individual fibers of a plurality of fibers may have cladding, and the cladding on the fibers of the plurality of fibers is at least partially removed in the fusion zone. Generally, light transmitted by the fibers is further coupled into the cladding at the end plane. Further fusion of the fiber cladding allows the transmitted light to pass through the cladding and be transmitted to the nearest fiber. Therefore, it is reasonable to fuse the fibers in this transition zone as well. This allows fiber ends stripped to the core to be fused; alternatively, the fibers may also be fused at the rear end (where the cladding still exists).

[0044] Additionally, a computer program product for executing the previously described method is proposed.

[0045] Additionally, fiber bundles manufactured using the method described above are proposed. Brief explanation of the drawing

[0046] Preferred embodiments of the present invention are described in more detail in the following description of the drawings. The following drawings each illustrate the following: FIG. 1a is a schematic diagram of a device for manufacturing fiber bundles. FIG. 1b is a schematic diagram of a device for manufacturing fiber bundles. Figure 2 is a schematic diagram of a device for manufacturing fiber bundles. Figure 3 is a schematic diagram of a device for manufacturing fiber bundles. FIGS. 4a to 4e are schematic cross-sectional views of a plurality of fibers. FIGS. 5a to 5e are schematic examples of radiation beams passing through the cross-sections of a plurality of fibers within a clamping device. FIG. 6 is a schematic perspective view of a radiation beam passing through a plurality of fibers within a clamping device. FIG. 7 is a schematic perspective view of a plurality of fibers within a clamping device. Figure 8 is a transition zone where three fibers change from a section with cladding to a section without cladding. FIGS. 9a to 9c are various schematic combinations of fiber bundles. Specific details for implementing the invention

[0047] Preferred exemplary embodiments are described below with reference to the drawings. In this context, identical, similar, or functionally equivalent elements within the various drawings are given the same reference numerals, and in some cases, the repetitive description of these elements is omitted to avoid duplication.

[0048] FIG. 1a illustrates a schematic diagram of a device (1) for manufacturing fiber bundles (20). A plurality of fibers (2) to be fused into fiber bundles (20) are secured by a clamping device (3). This clamping device (3) is inserted into a vacuum chamber (42) equipped with a pressing mechanism (4) through a press housing (40).

[0049] The vacuum chamber (42) can be designed as a modular unit or as a single piece. In the embodiment illustrated in FIG. 1, the vacuum chamber is formed by a cover and a base that can be hermetically sealed through two connecting flanges (46); in an alternative embodiment, this is achieved through a single connecting flange. The vacuum chamber (42) also has a suction port (44) that allows any desired vacuum to be created in the vacuum chamber (42). In this exemplary embodiment, the pressing mechanism (4) is formed as a cylindrical structure on the cover of the vacuum chamber (42). The pressing mechanism (4) is mounted to slide relative to the vacuum chamber (42), enabling relative movement with respect to the radiation source (5). Additionally, it is possible to adjust the position of the radiation source (5) both linearly and rotationally with respect to the pressing mechanism (4) and the clamping device (3), respectively. The pressing mechanism (4) can be designed in any shape suitable for the intended purpose. Preferably, the pressing mechanism (4) is designed in a modular manner. The pressing mechanism (4) can be designed as a chuck having radially arranged clamping jaws to apply a uniform force to the clamping device (3) in the circumferential direction of the clamping device (3).

[0050] The press housing (40) forms an opening associated with the pressing mechanism (4) so ​​that the clamping device (3) can be positioned at a desired location within the pressing mechanism (4). Thus, the clamping device (3) and a plurality of fibers (2) arranged within the clamping device (3) can be positioned or fixed with respect to the radiation source (5) and the radiation beam (50) of the radiation source (5). In this exemplary embodiment, the radiation source (5) is positioned perpendicular to the fiber direction (F) so that the radiation beam (50) of the radiation source (5) strikes the fibers (2) from the side. Additionally, the radiation source (5) can be positioned at different angles with respect to the fiber direction (F), and the radiation beam (50) can be deflected by optical equipment so that the radiation beam strikes the fibers (20) perpendicular to the fiber direction (F). The radiation source (5) is also monitored and controlled by a control / regulation unit (60). The control / regulation unit (60) is combined with the detection device (6) to enable control of the position of the radiation source (5) and the intensity of the radiation beam (50). The detection device (6) can detect, for example, the dimensions of individual fibers within a plurality of fibers, the paths of individual fibers, particularly the surface profiles of the fibers, and / or the fusion level of the fibers (2), and transmit this information to the control / regulation unit (60). The detection device (6) may be designed to measure various process parameters. The detection device (6) may be configured, for example, as a color or infrared camera for detecting temperature gradients near a plurality of fibers, or in any other suitable form for measuring process parameters. The control / regulation unit (60) may be connected to other components of the device (1) and / or additional equipment to control and regulate other process parameters, such as the negative pressure in the vacuum chamber (42) or the control parameters of the pressing mechanism (4).Additionally, the focus area and focal point of the radiation beam (50) can be variably selected and adjusted using a scanning device (52), so that the radiation beam (50) can be readjusted if the position of the pressing mechanism (4), clamping device (3) and / or radiation source (5) changes.

[0051] FIG. 1b illustrates an alternative configuration of a clamping device (3) and a pressing mechanism (4), wherein the clamping device (3) and the pressing mechanism (4) form a combined unit. The combined clamping device (3) and the pressing mechanism (4) include a press housing (40) into which a plurality of fibers (2) to be fused into a fiber bundle are supplied. A movable body, such as a punch (41), positioned perpendicular to the longitudinal axis of the fibers within the press housing (40) is configured such that the movement of the body applies a force acting perpendicular to the circumferential surface or perpendicular to the longitudinal axis of each of the plurality of fibers. The combined clamping device (3) and the pressing mechanism (4) may be combined with other features of the device for manufacturing fiber bundles illustrated in FIG. 1a.

[0052] FIG. 2 schematically illustrates another exemplary embodiment of a device (1) for manufacturing fiber bundles (20). The exemplary embodiment illustrates the device (1) described in FIG. 1, having an additional exemplary arrangement of a radiation source (5) and a radiation beam (50) of the radiation source (5) with respect to the fiber direction (F). The radiation source (5) is positioned at an acute angle with respect to the fiber direction (F). Accordingly, the radiation beam (50) strikes a plurality of fibers (20) to be fused at an angle after passing through a scanning device (52). As long as the individual fibers within the plurality of fibers are not yet melted, the obliquely incident radiation is reflected at least partially within the plurality of fibers. Consequently, the light reflected within the fibers causes the fibers to heat up more quickly as a result of the coupling of light into the individual fibers.

[0053] FIG. 3 schematically illustrates another exemplary embodiment of a device (1) for manufacturing fiber bundles (20). The exemplary embodiment illustrates a device (1) as described in FIG. 1, having additional examples of the arrangement of a radiation source (5) and a radiation beam (50) of the radiation source (5) with respect to the fiber direction (F). In the exemplary embodiment, the radiation source (5) is arranged so that the radiation beam (50) of the radiation source (5) is aligned along the fiber direction (F). The radiation beam (50) intersects the cross-section of a plurality of fibers (20). The radiation source (5) may be positioned at any distance from the ends of the fibers (20) that is suitable for the intended purpose. Additionally, the focal area and focal point of the radiation beam (50) may be variably selected and adjusted using a scanning device (52) so that the radiation beam (50) may be readjusted if the position of the pressing mechanism (4), the clamping device (3), and / or the radiation source (5) changes.

[0054] FIGS. 4a through 4d illustrate exemplary embodiments of arrangements of multiple fibers (20) having different geometric structures within a fiber bundle (2) surrounded by cladding (24). In alternative embodiments, the fibers (20) may be arranged without cladding (24) in the same manner as shown in FIGS. 4a through 4d. This applies particularly to multiple fibers of rectangular configurations, as it is often difficult to apply cladding (24) in such cases. The cladding (24) may be partially removed only within the melting zone.

[0055] FIG. 4a illustrates a cross-section of a plurality of fibers (20) comprising seven round fibers. Gaps (28) between the fibers (20) and between the fibers and the cladding (24) are also illustrated. Furthermore, the plurality of fibers (20) shown in FIG. 4a may also be implemented without the cladding (24) or with the cladding (24) partially removed in the melting region. The gaps (28) must be reduced by heating, i.e., melting, combined with forced deformation of the plurality of fibers using a clamping device and a pressing mechanism.

[0056] FIG. 4b illustrates an exemplary arrangement of four circular fibers (20) surrounded by a square cladding (24). Furthermore, the plurality of fibers (20) shown in FIG. 4a may also be implemented without the cladding (24) or with the cladding (24) partially removed in the melting area. FIG. 4b illustrates a plurality of fibers (20) in an unfused state.

[0057] FIG. 4c illustrates an exemplary arrangement of seven hexagonal fibers (20) arranged within a circular cladding (24). Furthermore, the plurality of fibers (20) shown in FIG. 4a may also be implemented without the cladding (24) or with the cladding (24) partially removed in the melting zone. It can be confirmed that the gaps (28) are smaller in the unfused state of the plurality of fibers (20) than in the case of round fibers such as those shown in FIG. 4a.

[0058] FIG. 4d illustrates four square fibers (20) surrounded by a square cladding (24). Furthermore, the plurality of fibers (20) shown in FIG. 4a may also be implemented without the cladding (24) or with the cladding (24) partially removed in the melting area. It can be confirmed that the gaps (28) are smaller in the unfused state of the plurality of fibers (20) than in the case of round fibers such as those shown in FIG. 4a.

[0059] FIGS. 5a through 5e schematically illustrate cross-sections of a plurality of fibers (20), each surrounded by a cladding (24) and eventually secured by a circumferential clamping device (3). An exemplary movement and path of the radiation source (5), the radiation beam (50) of the radiation source (5), as well as the radiation beam (50) within the cross-section of the fiber bundle (2), are illustrated. The arrow directions and paths are intended as examples. Any direction or path is possible.

[0060] For example, FIG. 5a schematically illustrates a spiral path of a radiation source (5), which is used to precisely connect fibers (20) to each other along this path. The movement of the radiation source (5) is illustrated for illustrative purposes only. Alternatively, to achieve the path of the radiation source illustrated in FIG. 5a, a plurality of fibers (20) held in a clamping device (3) can be precisely repositioned and rotated.

[0061] FIG. 5b schematically illustrates the linear path of positions investigated within the cross-section of a plurality of fibers (20) held in the clamping device (3). For example, the fibers (20) may be connected in rows.

[0062] FIG. 5c schematically illustrates the meandering path of a radiation source (5) projected onto a cross-section of a plurality of fibers (20) held in a clamping device (3).

[0063] FIG. 5d illustrates a random path of a radiation source (5) projected onto a cross-section of a plurality of fibers (20) held in a clamping device (3).

[0064] FIG. 5e schematically illustrates the path of positions investigated within the cross-section of a plurality of fibers (20) held in a clamping device (3). In the exemplary embodiment illustrated in FIG. 5e using fibers (20) having a larger diameter, the edge regions of the fibers (20) to be fused are particularly investigated.

[0065] A schematic example of an exemplary embodiment illustrated in FIG. 6 depicts a plurality of fibers (20) surrounded by cladding (24) positioned within a clamping device (3). Additionally, the plurality of fibers (20) may also be implemented without cladding (24) or with cladding (24) partially removed in a melting area. The plurality of fibers (20) includes a section (at the top of FIG. 6) without cladding (24). A radiation source (5) is positioned at an angle to the direction of the fibers (20). The exemplary embodiment illustrates a defined irradiation path. The irradiated positions and corresponding connected zones of the fibers are arranged in both the axial and radial directions of the plurality of fibers (20).

[0066] FIG. 7 schematically illustrates an exemplary embodiment for extending a radiation beam (50) of a radiation source (5) directed toward a plurality of fibers (20) partially enclosed by cladding (24) and a clamping device (3) (in the lower section of FIG. 7). The plurality of fibers (20) may also be implemented without cladding (24). The extension of the radiation beam (50) may be adjusted to fit the cross-sectional area of ​​the plurality of fibers (20). Consequently, only specific points on the fibers (20) may be connected, whether the entire cross-sectional area of ​​the plurality of fibers (20) is considered, or, in the case of a bundled radiation beam (50) from the radiation source (5), only specific points on the fibers (20) are considered.

[0067] FIG. 8 shows a cross-section of a fiber bundle (2) comprising three fibers (20), some of which have cladding (24) around the circumference of each of the multiple fibers (20), as well as a transition zone (26) between the fibers with cladding (24) and the fibers without cladding (24). The cladding (24) has been partially removed to reduce losses caused by the core-to-cladding ratio. In the transition zone between the cladding section and the cladding section, radiation leakage can lead to scattering losses. In particular, radiation may escape from the fibers uninhibitedly, causing this area to heat up. To prevent uncontrolled radiation leakage, these areas are typically filled with adhesive. Additionally, the coating ensures a defined aperture of the fiber core, which helps prevent uncontrolled radiation leakage in the transition zones. Applying adhesive to the transition zones also results in increased mechanical stability. For reasons of stability, it is also desirable to fuse the multiple fibers (20) together in this transition zone. One challenge here is the length of the fusion zone where the fiber ends trimmed to the core fuse together. Fusion of longer sections due to smaller bending angles of the individual fibers also leads to increased stability of the fiber bundle (2) against mechanical stress.

[0068] FIGS. 9a through 9c illustrate schematic exemplary embodiments of possible combinations of multiple fibers (20) into one or more fiber bundles (2). The 20 fibers can be connected in any possible combination using the described method.

[0069] FIG. 9a illustrates a fiber bundle (2) composed of three individual fibers (20) that are joined or fused at both ends using the method described above.

[0070] FIG. 9b illustrates a fiber bundle (2). The fiber bundle (2) has a connection of four fibers (20) at one end and branches into two connections at the other end.

[0071] FIG. 9c illustrates a fiber bundle (2) having two connections each composed of four fibers (20) at one end and three connections joined at the other end.

[0072] Where applicable, all individual features described in the exemplary embodiments may be combined and / or exchanged with one another without departing from the scope of the invention. Explanation of the symbols

[0073] 1 device 2 fiber bundle 20 Multiple fibers 22 Fusion Zone 24 cladding 26 Transition Zone 28 gap 3 Clamping device 4 Pressing mechanism 40 Press housing 41 Punch 42 vacuum chamber 44 suction port 46 connection flange 5 Radiation source 50 Radiation beam 52 Scanning device 6 Detection device 60 Control / Regulation Unit F Fiber orientation

Claims

Claim 1 A device (1) for manufacturing fiber bundles (2), comprising: a clamping device (3) for holding and securing a plurality of fibers (20); a pressing mechanism (4) for applying force to the clamping device (3); a press housing (40) mounted on the pressing mechanism (4) for holding the clamping device (3) and compressing the plurality of fibers (20) located within the clamping device (3); and at least one radiation source (5), wherein a radiation beam (50) of the at least one radiation source (5) is directed toward an area within or near the clamping device (3) to connect, in particular to fuse, the plurality of fibers (20) held in the clamping device (3). Claim 2 In claim 1, the clamping device (3) is configured to apply a force acting perpendicular to the longitudinal axis of the plurality of fibers (20) to the plurality of fibers (20), the device (1). Claim 3 In claim 1 or 2, the radiation source (5) is configured to irradiate at least one predetermined point within and / or near the clamping device (3) to combine the individual fibers of the plurality of fibers (20) in a defined manner, and the radiation source (5) and / or the press housing (40) are movable relative to each other, particularly in the radial direction and / or axial direction, in order to combine the individual fibers of the plurality of fibers (20) in a defined manner, the device (1). Claim 4 In any one of claims 1 to 3, the radiation source (5) is a laser, preferably a diode laser, a CO laser, or a CO2 laser, wherein in particular the diode laser has a wavelength in the range of 2 μm to 3.5 μm, the CO laser has a wavelength in the range of 4.8 μm to 8.3 μm, and the CO2 laser has a wavelength in the range of 9.6 μm to 10.6 μm, the device (1). Claim 5 In any one of claims 1 to 4, the pressing mechanism (4) comprises a vacuum chamber (42), and the vacuum chamber (42) is configured to apply force to a cavity defined by the press housing (40), particularly to a clamping device (3) arranged in the press housing (40), when a vacuum exists within the vacuum chamber (42). Claim 6 In any one of claims 1 to 5, the clamping device (3) is substantially concentric with respect to the press housing (40) in the radial direction and at least partially overlaps with the press housing (40) in the axial direction, the device (1). Claim 7 In any one of claims 1 to 6, the clamping device (3) comprises an elastomer that is transparent and / or partially transparent and preferably heat resistant up to a glass transition temperature of 1,400°C, the device (1). Claim 8 In any one of claims 1 to 7, the clamping device (3) is tubular and has a stepped shape to provide two zones having different cross-sections, in particular, the device (1). Claim 9 A device (1) according to any one of claims 1 to 8, wherein the direction of the radiation beam (50) of the radiation source (5) is different from the fiber orientation (F) of the plurality of fibers (20), and preferably perpendicular to the fiber orientation (F) of the plurality of fibers (20). Claim 10 In any one of claims 1 to 8, the radiation beam (50) of the radiation source (5) is substantially arranged in the fiber orientation (F) of the plurality of fibers (20), the device (1). Claim 11 In any one of claims 1 to 10, the device (1) includes a scanning device (52) for precisely deflecting the radiation beam of a laser source, and in particular, the focus of the radiation beam can be precisely controlled or adjusted by the scanning device (52). Claim 12 In any one of claims 1 to 11, the device (1) comprises a detection unit (6) for detecting at least one fiber parameter of the plurality of fibers (20) or connected fiber bundles (2), wherein the detection unit (6) is connected to a control / regulation unit (60). Claim 13 In claim 12, the at least one or a plurality of fiber parameters are related to the temperature, temperature range, bonding level, shape and / or dimensions of the plurality of fibers (20) or the fiber bundle (2), device (1). Claim 14 A method for manufacturing fiber bundles (2), a) Step b) holding and fixing a plurality of fibers (20) to a clamping device (3); c) positioning the clamping device (3) and a plurality of fibers (20) arranged within the clamping device (3) in a press housing (40) located within a pressing mechanism (4); A step of compressing the clamping device (3) and a plurality of fibers (20) arranged within the clamping device (3) by the pressing mechanism (4); and d) A method comprising the step of fusing a plurality of fibers (20) held in the clamping device (3) together by at least one radiation source (5), wherein the radiation beam (50) of the at least one radiation source (5) is directed toward a region of the plurality of fibers (20) within or near the clamping device (3). Claim 15 In claim 14, the pressing mechanism (4) comprises a vacuum chamber (42), step b) comprises supplying the plurality of fibers (20) into the vacuum chamber (42) through the press housing (40), and step c) comprises generating a negative pressure within the vacuum chamber (42) to compress the plurality of fibers (20), particularly in the area of ​​the clamping device (3), specifically perpendicular to the longitudinal axis of the plurality of fibers. Claim 16 A method according to claim 14 or 15, wherein step d) comprises selectively heating, in particular selectively melting, defined regions within the plurality of fibers (20) to create predefined connection patterns, wherein the plurality of fibers (20) arranged in the press housing (40) and / or the spinning source (5) are moved relative to each other, in particular radially and / or axially, to create predefined connection patterns. Claim 17 A method according to any one of claims 14 to 16, wherein the radiation source (5) comprises a CO2 laser or a CO2 laser to provide targeted fusion of predefined regions within the plurality of fibers (20). Claim 18 A computer program product for executing a method according to any one of paragraphs 14 through 17. Claim 19 A fiber bundle manufactured by a method according to any one of claims 14 to 17.

Images