Fiber assembly, hel effector, and laser weapon

Abstract

The invention relates to a fiber assembly (1) for transmitting laser beams (L) for a fiber laser of a laser weapon, the fiber assembly comprising at least one first fiber section (3), in particular a first fiber, and at least one second fiber section (5), in particular a second fiber, wherein: the fiber sections (3, 5) are each designed as optical waveguides; the first fiber section (3) is optically connected, in particular spliced, to the second fiber section (5) in order to transmit laser beams (L); the first fiber section (3) has an in particular first doped fiber core (11), has a first fiber sheath (12) encompassing the fiber core and comprising a first cladding (13), and is designed and configured to generate laser radiation (L) in the first fiber core (11) by means of coupled-in pump radiation (P) from a pump radiation source (25) and to transfer said laser radiation into the second fiber section (5); the second fiber section (5) is designed and configured to guide laser radiation (L) along a longitudinal extent of the second fiber section (5); and the second fiber section (5), at least at its end (9) facing away from the first fiber section (3), has a smaller diameter than the first fiber section (5).

Description

[0001] Title: Fiber array, HEL effector and laser weapon

[0002] Description

[0003] The invention relates to a fiber arrangement for a fiber laser device for transmitting beams, in particular laser beams, a HEL effector (high-energy laser effector) with such a fiber arrangement and a laser weapon.

[0004] Laser devices in the high-energy range are known in the art. For example, several fiber lasers are used and combined to generate total output powers of, for example, 30 kW. Known laser devices and their fiber arrangements for fiber lasers and corresponding HEL effects comprise an optical waveguide into which pump radiation is coupled, with a doped fiber core of the fiber arrangement acting as the active medium to generate laser radiation with the aid of the pump radiation.

[0005] It is known that the divergence of laser beams, particularly at the fiber exit, increases with the broadband operation of the respective laser device. This leads to a reduced beam quality of the combined laser beam when combined at the optical grating.

[0006] At the same time, known laser devices with fiber lasers, in particular their fiber arrays, as well as corresponding HEL effectors and laser weapons in the high-energy range, cannot arbitrarily reduce the bandwidth while simultaneously increasing the energy of the individual lasers, i.e., the individual fiber arrays, because nonlinear effects, particularly stimulated Brillouin scattering (SBS), cause the respective fibers to encounter a power threshold. Above this power threshold, the generated laser power becomes unstable and can, in particular, lead to fiber destruction. The power threshold is lower the more narrow-band the laser is operated.

[0007] This gives rise to the problem in the high-energy range that one generally wants to use individual fiber lasers operated at a narrow band in order to avoid divergences and thus maintain the originally high beam quality of the respective individual fiber lasers even after combining several beams. However, since one also wants to generate high powers, known fiber lasers are limited in their laser power, for example by the SBS, so that an increase in power is only possible by combining an increasingly larger number of individual fiber lasers. However, the beam quality of the outgoing, combined beam is not optimal, so that in known laser devices the attempt is made to work with as narrow a band as possible and at the same time avoid the SBS.

[0008] Furthermore, it is known that in order to focus the laser beams thus generated, in particular a plurality of them, onto a target point, the fiber arrangement is connected to a focusing optics, so that the laser beams pass through the focusing optics after leaving the fiber arrangement and are directed onto the target point.

[0009] Especially in the high-power range, as mentioned above, multiple laser sources are used to combine their radiation outputs. The aim is to achieve the highest possible beam quality, especially to avoid divergences, in order to generate a high power density at the target point.

[0010] The use of fiber lasers is generally known and widespread in the state of the art, as they can generate a high, original beam quality, which is further reduced when beams are combined on an optical grating with increasing divergence of the individual beams in the outgoing, combined beam. Broadband lasers lead to higher beam divergence during spectral combination with gratings in the beam combination and focusing optics, particularly during diffraction at optical diffraction elements, such as an optical grating.

[0011] These processes can lead to reduced beam quality.

[0012] This makes it difficult, particularly over long distances, i.e. long beam paths to a target point, especially in the kilometer range, to generate high power density or a small beam cross-section at the target location.

[0013] The object of the invention is to avoid the aforementioned disadvantages, i.e., at least to mitigate them or to overcome them entirely. In particular, the object of the invention is to improve the beam quality of a fiber laser device and / or in the beam combination of individual fiber lasers and to generate very high power densities at a target location with long laser beam path lengths.

[0014] The object is achieved by an article according to claim 1, with advantageous further developments resulting from the subclaims.

[0015] According to the invention, a fiber arrangement for transmitting laser beams for a fiber laser device of a laser weapon is proposed, wherein the fiber arrangement has at least a first fiber section and at least a second fiber section, wherein the fiber sections are each designed as optical waveguides, wherein the first fiber section is optically connected, in particular spliced, to the second fiber section for transmitting laser beams, wherein the first fiber section has a first, doped fiber core and a first fiber cladding encompassing the fiber core and is designed and configured, by coupled

[0016] Pump radiation of a pump radiation source in the first fiber core in particular to generate laser radiation and in the second

[0017] fiber section, wherein the second fiber section is designed and configured to guide laser radiation along a longitudinal extent of the second fiber section. In this case, it is provided that the second fiber section has a smaller diameter than the first fiber section, at least at its end facing away from the first fiber section. This enables a closer arrangement of several such fiber arrangements. Furthermore, this improves the beam quality of a laser device having such a fiber arrangement in a beam combination of several individual fiber lasers. In addition, this makes it possible to achieve very high power densities at a target point of the laser beam which has passed through the fiber arrangement.

[0018] The first fiber section is preferably a fiber section of a first fiber, and the second fiber section is preferably a fiber section of a second fiber. Preferably, the entire first fiber section corresponds to a complete first fiber, and the entire second fiber section corresponds to a complete second fiber.

[0019] A laser beam is understood here to mean, in particular, an electromagnetic wave, particularly in the wavelength range between 100 nm and 1 mm, especially in the ultraviolet spectrum, the visible spectrum, and / or the infrared spectrum. In the context of this description, this refers in particular to laser wavelengths between 1000 nm and 1300 nm, in particular between 1020 nm and 1140 nm, and / or between 1.5 pm and 3 pm.

[0020] The fiber arrangement is preferably a component of a laser device, which is preferably designed as a solid-state laser and / or as a continuous-wave laser, and preferably has an ytterbium dopant as the active medium in the doped fiber core. The object of the invention is thus also achieved in particular by such a laser device.

[0021] Alternatively, the active medium, in this case the fiber core, is preferably doped with erbium or thulium, and the laser beams generated have wavelengths in the range between 1 pm and 3 pm. Particularly preferably, the laser device as a whole is designed and configured to be operated in a power range between 1 kW and 10 kW, preferably between 1 kW and 3 kW, in particular 2 kW. Preferably, therefore, the first fiber section, in particular each of the first fiber sections, is designed and configured to generate a laser beam in this power range.

[0022] Furthermore, the fiber arrangement is preferably designed and configured to generate a laser beam with a spectral bandwidth of between 0.1 and 0.2 nm during operation. The fiber arrangement is particularly preferably designed and configured to generate a laser beam with the physically best possible beam quality.

[0023] The terms "laser light", "laser beam", "laser radiation", "light" and / or "optical waveguide" in the context of this description preferably refer to the wavelength ranges mentioned above. Unless explicitly stated otherwise, the term

[0024] "Light", in particular "laser light" and "optical fiber", refers not only to radiation in the visible spectrum, but also in particular to radiation outside the visible spectrum, especially in the UV and IR spectrum.

[0025] Accordingly, the term "optics" is also considered to encompass a meaning outside the visible spectrum, particularly in the UV and IR spectral ranges. An "optical connection" is therefore understood to be a connection designed and configured to transmit electromagnetic waves, particularly in the spectral range of the laser beam.

[0026] The optical connection between the first fiber section and the second fiber section can in particular also be designed such that the first fiber section and the second fiber section are part of a common fiber, wherein the first fiber section and the second fiber section are preferably formed from the same material.

[0027] The fiber sections are designed to be at least partially transparent, in particular for the laser beams, so that the latter can propagate through the fiber sections at least along a central axis in the longitudinal direction of the fibers.

[0028] Furthermore, it is possible for the fiber sections, in particular the fiber cladding, to comprise further cladding elements, in particular a jacket, in addition to the cladding, which is designed in particular as an optical waveguide for the pump radiation, in particular to feed the pump radiation to the fiber core. The cladding can in particular also be referred to as a pump core, since in interaction with the above-mentioned fiber core - in particular in the presence of further cladding elements - it forms a common, in particular active core which runs through the first or second fiber section. The further cladding elements can be protective layers and / or further optically relevant and / or light-permeable layers, in particular those which improve the optical waveguide properties and / or enable or optimize the coupling and decoupling of radiation.Preferably, at least one further cladding element is provided which has a lower refractive index than the cladding.

[0029] The fibers and / or fiber sections preferably have an elongated shape with a central axis, wherein the fibers or the fiber sections are preferably designed to be rotationally symmetrical to the central axis at least in sections. In particular, the first and second fiber sections each have, at their two respective ends, two end faces facing away from one another and an outer circumferential surface which encompasses the central axis and extends between the end faces. The fiber sections, in particular fibers, are particularly preferably designed to be flexible in a direction transverse to, in particular perpendicular to, the central axis, so that they can be bent without being destroyed. In the direction of the central axis, the fibers are preferably not designed to be flexible. Furthermore, the fiber sections and / or fibers are preferably designed as glass fibers.

[0030] The end facing away from the first fiber section thus corresponds in particular to an end of the second fiber and / or an end face of the fiber section and / or the fiber. The end facing the first fiber section corresponds in particular to another end of the second fiber and / or another end face of the fiber section and / or the fiber.

[0031] Preferably, the second fiber section is designed and configured to emit the laser radiation in a region spaced apart from the first fiber section, in particular at an end of the second fiber section facing away from the first fiber section.

[0032] Preferably, the diameter of the first fiber section is constant along the entire first fiber section. This provides uniform optical conditions, particularly for the pump radiation, along the entire first fiber section. Furthermore, such fiber sections with a constant diameter can be manufactured comparatively inexpensively.

[0033] The fiber arrangement preferably has a pump radiation source, wherein the pump radiation source is optically connectable, in particular connected, to the first fiber section for coupling in the pump radiation, in particular at a distance from the second fiber section, very particularly at an end of the first fiber section facing away from the second fiber section. Light in the wavelength range between 900 nm and 1100 nm is preferably used as pump radiation. Particularly preferably, with an ytterbium-doped fiber core, pump radiation between 930 nm and 1000 nm, in particular at 940 nm or 970 nm, is used, and with an erbium-doped fiber core, pump radiation between 970 nm and 990 nm, in particular at 980 nm, is used. The pump radiation source is preferably designed as a radiation emitter and is set up to emit such pump radiation and radiate it into the first fiber section.

[0034] Since the first fiber section is designed and configured to generate laser radiation, this first fiber section is also referred to as the active fiber. The second fiber section is also referred to in particular as the transport fiber section or transport fiber. The first fiber section is preferably designed and configured to totally reflect the coupled-in pump radiation on an inner side of an outer wall of the fiber cladding, in particular the cladding (total internal reflection). The first fiber section is further designed and configured to at least partially receive the coupled-in pump radiation in the fiber core, which is also referred to as the active fiber core, in particular to absorb it therein. Laser radiation is generated in the fiber core by the pump radiation and is preferably held in the fiber core, in particular by the laser radiation being totally reflected at the interface to the fiber cladding, in particular the cladding.

[0035] The first fiber section preferably has a length of between 1 m and 20 m, preferably between 5 m and 15 m, preferably between 8 m and 12 m, preferably 10 m. The first fiber section can in particular be wound like a coil. The second fiber section preferably has a longitudinal extent of several meters. The second fiber section can in particular have a length of between 10 cm and 10 m, in particular between 1 m and 5 m. Furthermore preferably, the fiber core of the first fiber section and / or of another fiber section, in particular of the second, third or fourth fiber section, has a diameter of between 1 gm and 100 gm, in particular between 5 gm and 40 gm, in particular between 15 gm and 25 gm, in particular 20 gm.The diameter of the cladding of the first fiber section and / or of another fiber section, in particular of the second, third or fourth fiber section, is preferably between 100 gm and 1000 gm, in particular between 200 gm and 600 gm, in particular between 350 gm and 450 gm, very particularly 400 gm.

[0036] According to one embodiment, the fiber arrangement comprises a third fiber section, which is connected to the second fiber section at its end facing away from the first fiber section for transmitting the laser beams. The third fiber section is designed, in particular, as a fiber section of a third fiber, especially as a third fiber. This allows the fiber arrangement to be adjusted even more flexibly. Furthermore, this makes it easier to achieve a diameter reduction.

[0037] Alternatively or additionally, a fourth fiber section, in particular a fourth fiber, is arranged between the first fiber section and the second fiber section, so that the first fiber section is optically connected to the second fiber section via the fourth fiber section. The fourth fiber section can have a constant outer diameter which corresponds in particular to the outer diameter of the first fiber section. This fourth fiber section can therefore form a transport fiber which provides a connection to the second fiber section, which also serves as a transport fiber. The trans fiber strand can therefore initially have the fourth distance with an unchanged diameter and then a reduced diameter in the second fiber section.

[0038] Alternatively, the diameter can decrease starting from the first fiber section via the fourth fiber section to the second fiber section and further to the third fiber section. In particular, the third fiber section has a diameter that is smaller than the smallest diameter of the second fiber section at least in one region, wherein the second fiber section preferably has a diameter that is smaller than the smallest diameter of the fourth fiber section at least in one region, wherein the fourth fiber section has a diameter that is smaller than the smallest diameter of the first distance at least in one region.

[0039] The second, third, and / or fourth fiber sections—unlike the first fiber section—preferably do not serve to generate laser radiation, but rather to transport the laser radiation to a downstream beam combining device and / or focusing optics. The second, third, and / or fourth fiber sections are therefore also referred to as transport fiber sections or transport fibers, or—in contrast to the first fiber section, which is referred to as the active fiber—as passive fibers.

[0040] In particular, it is not intended that pump radiation is coupled from outside the fiber sections, in particular from outside the fiber arrangement, into the second, third or fourth fiber section. It is certainly possible for a portion of the pump radiation coupled into the first fiber section to pass into the second, third and / or fourth fiber sections arranged behind it. However, this is preferably not required for the correct functionality of the fiber arrangement. In particular, the first, second and / or third fiber section is not designed to guide and hold pump radiation inside the respective fiber section, in particular in its respective fiber cladding. Very particularly, the second, third and / or fourth fiber section is not designed to cause total reflection of the coupled-in pump radiation at its outer circumference, in particular the outer end of a respective fiber cladding.

[0041] Preferably, the first fiber section is designed and configured such that—during operation of the fiber arrangement, in particular in a HEL effector or a laser weapon—a large portion of the pump radiation, preferably all of the coupled-in pump radiation, is absorbed in the first fiber core. Alternatively or additionally, the fiber arrangement or the HEL effector or the laser weapon is designed and configured to remove pump radiation residues from the fiber arrangement, in particular the second, third, and / or fourth fiber section.

[0042] According to one embodiment, the second fiber section has a second, doped fiber core, in particular, and a second fiber cladding, in particular, surrounding the second fiber core, with a cladding. The cladding of the second fiber cladding is also referred to as second cladding. The cladding of the first fiber cladding is correspondingly referred to as first cladding. The second fiber cladding also preferably has at least one further cladding element, for example with a protective function and / or an optical function.

[0043] The third or fourth fiber section also preferably has a third or fourth doped fiber core and a third or fourth fiber cladding encompassing the third or fourth fiber core, respectively, with a third or fourth cladding. The first, second, third and / or fourth fiber section is preferably constructed in the same way. In particular, it is provided that all fiber sections have a fiber core and a fiber cladding with a cladding, wherein the respective fiber cladding preferably has at least one further cladding element with a protective function and / or optical function.

[0044] Preferably, the second fiber core, third fiber core, and / or fourth fiber core have a core diameter that, along the entire longitudinal extent of the second fiber section, corresponds to a core diameter of the first fiber core of the first fiber section. Particularly preferably, all fiber cores in all fiber sections have the same core diameter.

[0045] Alternatively or additionally, one of the fiber sections acting as a transport fiber, in particular the second, third and / or fourth fiber section, preferably has, at least in sections, a core diameter of the fiber core which is in particular slightly larger than the core diameter of the first fiber core.

[0046] Furthermore, the doping in the second, third and / or fourth fiber core preferably corresponds to the doping in the first fiber core.

[0047] Preferably, the refractive index of the respective fiber cladding is lower than the refractive index of the respective fiber core. This improves the properties as an optical waveguide. In particular, this enables total internal reflection of coupled pump radiation.

[0048] Preferably, the refractive indices of the first, second, third, and / or fourth fiber cladding are identical. Alternatively or additionally, the refractive indices of the first, second, third, and / or fourth fiber core are identical. This avoids radiation and power losses at the transition from one fiber section to another, and results in a high overall radiation output.

[0049] Furthermore, it is preferably provided that the fiber claddings of the first, second, third and / or fourth fiber section each consist of the same cladding material and the fiber cores of the first, second, third and / or fourth fiber section each consist of the same core material, in particular with the same doping.

[0050] According to one embodiment, it is provided that the second fiber section or the fourth fiber section has a larger diameter at a connection interface to the first fiber section and / or at its end facing the first fiber section than at the opposite end facing away from the first fiber section, in particular in that the cladding of the second fiber section is thinner at the opposite end facing away from the first fiber section than at the connection interface.

[0051] The cladding of the second fiber section is thinner in a rear region, in particular a rear end of the second fiber section facing away from the first fiber section, than at a front end facing the first fiber section. The reduction in diameter, or the reduced diameter of the second fiber section compared to the first fiber section, is thus preferably achieved by reducing the thickness of the second cladding compared to the thickness of the first cladding.

[0052] The rear region is spaced further from the first fiber section than the front region. "Rear" and "front" thus refer in particular to the direction of a beam path of a laser beam that, starting from the fiber core of the first fiber section, passes through the fiber arrangement and, if appropriate, a beam combining device and / or focusing optics arranged behind it.

[0053] In this context, "thicker" and "thinner" refer, in particular, to a radial extent in the direction starting from the central axis. A thick cladding therefore has a greater radial extent than a thin cladding. Preferably, an inner radius, i.e. the inner distance from the cladding to the central axis, is constant over the course of the first, second, third and / or fourth fiber section and, in particular, identical across all fiber sections. In particular, the inner radius of the cladding corresponds to half the diameter of the respective fiber cores, since the cladding is preferably arranged directly on the fiber core.

[0054] According to one embodiment, it is provided that the diameters of the first fiber section, in particular of the first fiber cladding and / or fiber core, and of the second fiber section, in particular of the second fiber cladding and / or fiber core, are of equal size at the connection interface, and wherein the diameter of the second fiber section tapers, in particular continuously and / or steadily, starting from the connection interface in the direction of the end facing away from the first fiber section. This results in a stable structure of the fiber arrangement. In particular, the connection interface is therefore very stable.

[0055] Alternatively or additionally, at least one further connection interface, preferably all further connection interfaces, between adjacent fiber sections, in particular their fiber claddings and / or fiber cores, is such that the diameters of the adjacent fiber sections at the connection interfaces are identical. Thus, continuous transitions between the fiber sections are realized, whereby the stability is high and the optical properties, in particular the beam quality, are very good.

[0056] Preferably, the circumferential surfaces of the first fiber section and the second fiber section are aligned with one another at the connection interface. Alternatively or additionally, the circumferential surfaces of the third and fourth fiber sections are also aligned with the circumferential surfaces of the first and second fiber sections at the respective connection interfaces to the first and second fiber sections, respectively.

[0057] Preferably, the fiber cores of the first, second, third, and / or fourth fiber sections have the same diameter at least at the connection interface, preferably everywhere, so that the fiber core circumferential surfaces are aligned with one another at the connection interfaces. This results in high laser power and avoids laser radiation losses.

[0058] As already mentioned above, an in particular slightly enlarged core diameter is alternatively preferably provided in the region of the second, third and / or fourth fiber section, wherein the core diameter can be increased in particular by 50% to 10%, in particular by 25%, compared to the core diameter in the first fiber section. In particular, the core diameter can be increased by up to 10 pm, preferably up to 5 pm.

[0059] According to one embodiment, the fiber arrangement has a tapered section, in particular a cone-shaped section, in which an outer diameter tapers from a first value to a second value, the first value preferably corresponding to an outer diameter of the first fiber section and the second value to an outer diameter of the second fiber section. The tapered section is preferably designed as a taper for optically connecting two optical fibers, in particular for optically connecting the first fiber section to the second or fourth fiber section. The outer diameters of the first and second fiber sections are preferably constant - outside the tapered section. This makes the fiber arrangement simple and cost-effective to produce.

[0060] Preferably, the tapered section is formed as a separate element, i.e., at least separately from the first and second fiber sections. However, the tapered section can also be formed as part of the first and / or second fiber section, particularly in the region of the connection interface.

[0061] Preferably, the entire taper of the diameter of the second fiber section, which is smaller than the first fiber section, at its end facing away from the first fiber section is formed exclusively in the tapered section. The diameter remains constant in at least one section of the second fiber section, preferably throughout the entire further course of the second fiber section, particularly outside the tapered section.

[0062] Preferably, the tapered section in the direction of the longitudinal extent of the fiber sections, i.e. in the direction of the central axis, is shorter than half the longitudinal extent of the second fiber section, preferably less than 5 cm, preferably less than 3 cm, preferably less than 1 cm.

[0063] According to one embodiment, it is provided that the

[0064] Fiber arrangement comprising a plurality of first fiber sections and a plurality of second or a plurality of third fiber sections, wherein the second or third fiber sections are arranged, in particular fixed, at a center-to-center distance from a respective adjacent second fiber section, which is smaller than a diameter of the fiber cladding of the first fiber section. As a result, a plurality of fibers and the laser radiation emitted therefrom can be combined particularly efficiently with one another in order to achieve an overall high laser power with a high beam quality.

[0065] Unless explicitly stated otherwise, diameter is understood to mean an outside diameter.

[0066] Preferably, at least two first fiber sections and at least two second fiber sections are provided, wherein a center-to-center distance between a first of the first fiber sections (i.e., a "first first fiber section") and a second of the first fiber sections (i.e., a "second first fiber section") is greater than a center-to-center distance between a first of the second fiber sections (i.e., a "first second fiber section") and a second of the second fiber sections (i.e., a "second second fiber section"). In this case, the first first fiber section is adjacent to the second first fiber section, and the first second fiber section is adjacent to the second second fiber section.In particular, the second first fiber section is arranged to the first first fiber section and / or the second second fiber section is arranged to the first second fiber section as such a nearest neighbor that no other first fiber section is arranged closer to the first first fiber section or no other second fiber section is arranged closer to the first second fiber section.

[0067] Preferably, a plurality of third fiber sections and / or a plurality of fourth fiber sections are also provided, which are connected in pairs to the first and / or second fiber sections.

[0068] Preferably, the plurality of first and second fiber sections are connected to one another in pairs such that each of the plurality of first fiber sections is connected to exactly one of the plurality of second fiber sections. The same applies to the third and / or fourth fiber sections. The "plural" first, second, third, and / or fourth fiber sections thus combine to form, in particular, an equal number of "plural" fiber strands.

[0069] Preferably at least 30, preferably at least 40, preferably at least 50, preferably exactly 50 fiber strands are formed.

[0070] The plurality of fiber strands, in particular the plurality of first fiber sections and / or the plurality of second fiber sections are arranged as a fiber array, in particular in a linear arrangement relative to one another. The plurality of fiber strands are preferably arranged at essentially constant distances from one another along one or more axes, the fiber arrangement being designed such that the deviations from the constant distances (tolerances) amount to a maximum of 100 pm, preferably a maximum of 50 pm, preferably a maximum of 10 pm, preferably a maximum of 1 pm. This enables a very precise beam combination and therefore a very high beam quality of the combined beam.

[0071] According to one embodiment, the second and / or third fiber section has a curved profile - in particular along the center axis of the respective fiber - in particular such that the fiber cores of two of the plurality of second and / or third fiber sections are closer together than the fiber cores of two of the first fiber sections. As a result, the distances between the second and / or third fiber sections can be arranged flexibly and closer to one another, in particular at their ends facing away from the first fiber sections. As a result, the beam quality is improved during spectral combination with an optical grating and thus the power density at the target location is increased.

[0072] Preferably, the second, third and / or fourth fiber sections have a curved course, in particular such that their ends facing away from the first fiber sections are arranged closer to one another such that a total diameter of the fiber arrays formed by the second, third and / or fourth fiber sections is smaller than the total diameter of the plurality of first fiber sections.

[0073] According to one embodiment, the first fiber sections are arranged, in particular fixed, at a center-to-center distance from a respective adjacent first fiber section that is greater than the center-to-center distance of the second and / or third fiber sections. This allows the dimensioning of the first fiber sections to be adjusted independently of the radiation dimensioning. Preferably, an outer distance between the first fiber sections is smaller than a diameter of the first fiber sections.

[0074] Alternatively or additionally, it is provided that the plurality of first and / or fourth fiber sections touch each other at their outer surfaces, at least in sections, preferably along their entire longitudinal extent. Furthermore, it is preferably provided that the plurality of second and / or third fiber sections touch each other at their outer surfaces, at least in sections, in particular at their ends facing away from the first fiber sections. This results in a compact arrangement and - in particular with regard to the second and third fiber sections - an improved beam quality in the beam combination.

[0075] According to one embodiment, it is provided that the diameter of the second and / or third fiber section, in particular of the second and / or third cladding, at its end facing away from the first fiber section is less than 0.3 mm, preferably less than 0.2 mm, preferably less than 0.1 mm, preferably less than 0.05 mm, preferably less than 0.03 mm, and wherein the diameter of the first fiber section, in particular of the first cladding, is at least in sections at least 0.3 mm, preferably at least 0.4 mm, in particular 0.4 mm. Preferably, the diameter of the first fiber section, in particular of the first cladding, is at most 1 mm, preferably at most 0.6 mm, preferably at most 0.5 mm. This enables good beam quality when combining the beams with a high laser power.The thickness of the second and / or third cladding is preferably smaller than the radial extent of the first fiber core. Preferably, the thickness of the second and third cladding is so small that the optical waveguide property for the pump radiation is reduced or lost, in particular such that no total reflection of the pump radiation occurs in the cladding, in particular at an interface between the cladding and a radially outwardly adjoining region, for example a further layer of the fiber cladding and / or an environment. This enables a particularly close arrangement of the second and / or third fiber sections to one another.

[0076] Preferably, the pump radiation is completely absorbed in the active fiber during operation of the fiber arrangement as a component of a laser device, in particular a HEL effector and / or a laser weapon. To remove any unabsorbed residues of the pump radiation, at least one pump radiation removal device is preferably provided, which removes the pump radiation from the second, third, and / or fourth fiber section.

[0077] According to one embodiment, the second or third fiber section is preferably attached to an optically transparent fixing element, in particular a glass body, at its end facing away from the first fiber section. This establishes a defined beam geometry, and the laser beams can be precisely aligned to a downstream beam combining device and / or focusing optics, so that a high beam quality can be achieved overall. The attachment to the fixing element is preferably realized by a splice connection and / or a welded connection.

[0078] Furthermore, the fixing element is preferably designed as an optical body such that an incoming laser beam is split into diverging beam paths.

[0079] According to one embodiment, the plurality of first fiber sections are designed and configured to generate laser radiation with different wavelengths. This enables a spectral combination that can be used to achieve particularly high laser output powers.

[0080] Preferably, the plurality of first fiber sections are designed and configured to generate a single laser beam by spectral beam combination - at least after passing through a beam combining device with the focusing optics.

[0081] Preferably, the plurality of first fiber sections are designed and configured to generate laser radiation at wavelength intervals from one another, wherein particularly preferably the wavelengths of the laser beams generated in different ones of the first fiber sections differ between 1 nm and 5 nm, preferably by 2 nm.

[0082] The above-mentioned object is also achieved according to the invention by a HEL effector, in particular for a laser weapon, wherein the HEL effector comprises a fiber arrangement according to one of the preceding embodiments, which is designed in particular as part of a fiber laser of the HEL effector, a beam combining device which comprises a transformation optics device, in particular a transformation lens and / or a transformation mirror, and / or an optical grating, and the pump radiation source, which is connected to the at least one first fiber section, in particular the plurality of first fiber sections, for coupling in the pump radiation, wherein the transformation optics device is arranged behind the optically transparent fixing element in a beam path of the laser beams, wherein the transformation optics device is designed and configured,The incoming laser beams are directed, particularly in a collimated manner, onto the optical grating. This allows the generation of a combined, focused laser beam with high energy density and high beam quality.

[0083] The beam combining device is designed and configured to combine at least two, preferably all, laser beams generated in and emerging from the fiber arrangement into a single bundled laser beam. A laser beam bundled in this way exhibits increased beam quality, allowing small beam diameters and high power densities to be achieved even at long distances.

[0084] The above-mentioned object is also achieved according to the invention by a laser weapon and / or a laser weapon system with a fiber arrangement according to one of the preceding embodiments, wherein the fiber arrangement is preferably a component of a fiber laser of the laser weapon, and / or a HEL effector according to one of the preceding embodiments, wherein the laser weapon has a target detection device for detecting a target object and preferably a control device for controlling the target detection device and / or for actuating, in particular activating and deactivating, a laser beam.

[0085] The laser weapon is designed in particular as a laser defense weapon and is configured to detect a weapon, in particular a fired weapon, and / or a missile, such as a drone, as a target object.

[0086] The target detection device is preferably designed and configured to detect and track a moving, in particular flying, target object as the target object and / or to predict a movement of the target object.

[0087] According to a further development of the laser weapon, the HEL effector is designed and configured to combine a plurality of laser beams of the fiber arrangement such that the bundled laser beam has a total power of at least 5 kW, preferably at least 10 kW, preferably at least 20 kW, preferably at least 50 kW, preferably at least 80 kW, preferably at least 100 kW. This total power is high enough to effectively damage or destroy a particularly dangerous target object, such as a particularly armed drone, with the laser weapon from a great distance.

[0088] Further embodiments also relate in particular to a

[0089] Demonstrator with a fiber arrangement according to one of the preceding embodiments and / or a HEL effector according to one of the preceding embodiments, as well as a laser device according to one of the preceding embodiments.

[0090] Further advantages will become apparent from the description and the accompanying drawings. Exemplary embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. Identical reference numerals in different figures designate identical or at least functionally comparable elements. When describing individual figures, reference may also be made to elements from other figures. These show, in schematic form:

[0091] Fig. 1 shows a fiber arrangement according to a first embodiment,

[0092] Fig. 2 first fiber sections of a fiber arrangement without second fiber sections,

[0093] Fig. 3 shows a fiber arrangement according to a second embodiment,

[0094] Fig. 4 shows a fiber arrangement according to a third embodiment,

[0095] Fig. 5 shows a HEL effector with a fiber arrangement according to one of Figs. 1 to 4, and

[0096] Fig. 6 shows a beam combining device according to the HEL effector shown in Fig. 5. Fig. 1 shows a fiber arrangement 1 having a first fiber section 3 and a second fiber section 5 for transmitting laser beams. The first fiber section 3 and the second fiber section 5 have an elongated shape and preferably extend over a greater longitudinal extent than shown in Fig. 1.

[0097] The fiber sections 3, 5 are preferably designed as fibers that are spliced ​​together. The fibers, in particular, each have a constant diameter and are connected to one another via a conical tapered section 7.

[0098] In the embodiment shown here, the first fiber section 3, the tapered section 7 and the second fiber section 5 extend in particular concentrically around a common central axis M.

[0099] The conical tapered section 7 can be provided by a separate taper element or formed integrally with the second fiber section 5. If a separate taper element is provided, the two fiber sections are optically connected to it, in particular spliced. The first fiber section 3 is preferably spliced ​​to one end of the taper element with the larger diameter, while the second fiber section 5 is spliced ​​to another end of the taper element with the smaller diameter.

[0100] In this case, a first diameter D1 of the first fiber section 3 is larger than a second diameter D2 of the second fiber section 5. In particular, the diameter of the second fiber section 5 at its end 9 facing away from the first fiber section 3 is smaller than the first diameter D1 of the first fiber section 3. This allows a high beam quality to be achieved and overall high energy densities to be achieved at a target location of the laser.

[0101] The first fiber section 3 has a first fiber core 11 and a first fiber cladding 12 with a first cladding 13. The second fiber section 5 has a second fiber core 15 and a second fiber cladding 16 with a second cladding 17.

[0102] The fiber cores 13, 17 are aligned with one another and thus form a common fiber core which extends through the first fiber section 3, the tapered section 7 and the second fiber section 5.

[0103] The first cladding 13 of the first fiber section 3 and the second cladding 17 of the second fiber section 5 preferably comprise the same cladding material and, in particular, consist of this cladding material. The cladding in the tapered section 7 also preferably comprises the same cladding material, so that the same optical conditions are created over the entire length of the fiber sections at the interface between the fiber cores and the cladding.

[0104] Since the two fiber sections 3, 5 in Fig. 1 are formed concentrically to the central axis M, the fiber cores 11, 15 are also concentrically aligned with one another, starting from the first fiber section 3 via the tapered section 7 to the second fiber section 5. As a result, a laser beam is guided through the fiber sections without loss or at least with low loss.

[0105] The first cladding 13 is in particular designed such that a pump radiation introduced into the first fiber section 3 is totally reflected at the outer wall 19 of the first cladding 13 in order to thereby achieve a high pump power.

[0106] The laser radiation generated by the pump radiation in the first fiber core 11 is held in the first fiber core 11 and is totally reflected there at the interface with the first cladding 13. The laser radiation is also held in the respective fiber core by total reflection in the region of the second fiber section 5 and in the tapered section 7.

[0107] Fig. 2 shows a fiber arrangement with several similarly designed fiber sections, in particular first fiber sections 3, which have the same diameter at both ends. The direction of a laser beam is indicated by an arrow L.

[0108] It can be seen that the first fiber sections 3 taken individually and their first fiber cores 11 are arranged at a greater distance than the first diameter Dl and in particular cannot be arranged at a smaller distance than the first diameter Dl.

[0109] Fig. 3 shows a plurality of first fiber sections 3 and a plurality of second fiber sections 5, the second fiber sections 5 at least partially, namely the upper and lower of the three second fiber sections 5 in Fig. 3, having a curved course. Their ends 9 facing away from the first fiber section 3 are arranged closer to one another than the ends facing the first fiber section 3, via which ends the second fiber section 5 is optically connected to the first fiber section 3. The second fiber cores 15 of each two adjacent second fiber sections 5 are arranged at a center-to-center distance A from one another which is smaller than the first diameter D1 of the first fiber sections 3, in particular of the first cladding 13.

[0110] The second fiber sections 5 are here in particular fixed by being attached to an optically transparent fixing element 21, in particular a quartz body.

[0111] The beams emerge from the fibers in a divergent manner, forming a beam cone. In addition to a central beam L2, an upper edge beam LI and a lower edge beam L3 of the beam cone are shown for each fiber in Figs. 3 to 6.

[0112] This formation of the beam cone is shown again in Fig. 4 in schematic form using eight second fiber sections 5. For the sake of clarity, the second fiber sections 5 are shown without their second fiber cores.

[0113] From these second fiber cores, the laser beams L emerge at the end 9 facing away from the first fiber section 3, forming a divergent beam in the fixing element 21, wherein in Fig. 4, three diverging individual beams are shown to illustrate the beam cone, namely an upper, first edge beam L1, a central beam L2 and a lower, second edge beam L3. The individual beams L1, L2, L3 are then fed to a beam combining device 23, which is indicated schematically in Fig. 5 and shown in more detail in Fig. 6. This produces a bundled laser beam L B with very high beam quality and energy density.

[0114] Fig. 5 also shows a HEL effector 24, the HEL effector 24 having a pump beam source 25 which is designed and configured to couple pump radiation P into the first fiber sections 3. The first fiber sections 3 are shown schematically in Fig. 5 as a single box. The first fiber sections 3, in particular their first fiber cores 11, are optically connected to the second fiber sections 5, in particular their second fiber cores 15, so that the laser beams L generated by the pump radiation P in the first fiber sections 3 pass through the second fiber cores 15 and exit at the end 9 facing away from the first fiber section 3 in order to pass into the optically transparent fixing element 21, i.e. the quartz body.

[0115] Fig. 6 shows the diverging laser beams L D. The beam combining device 23 has at least one transformation optics device 27, in particular a transformation lens and / or a transformation mirror. The transformation optics device 27 is in a beam path of the laser beams L D arranged such that the diverging laser beams L D onto an optical grating 29 of the beam combining device 23. As a result, the bundled laser beam L B which has a high beam quality. In particular, with the described fiber arrangement 1 and the described HEL effector 24, it is possible to combine many fiber sections and the laser beams generated therein to produce a bundled laser beam L B with very high overall performance and high beam quality.

Claims

Patent claims 1. Fiber arrangement (1) for transmitting laser beams (L) for a fiber laser of a laser weapon, comprising at least one first fiber section (3), in particular a first fiber, and at least one second fiber section (5), in particular a second fiber, wherein the fiber sections (3, 5) are each designed as optical waveguides, wherein the first fiber section (3) is optically connected, in particular spliced, to the second fiber section (5) for transmitting laser beams (L), wherein the first fiber section (3) has, in particular, a first, doped fiber core (11) and a first fiber cladding (12) surrounding the fiber core (11) and having a first cladding (13), and is designed and configured to generate laser radiation (L) in the first fiber core (11) by coupled-in pump radiation (P) from a pump radiation source (25) and to transfer it into the second fiber section (5), wherein the second fiber section (5) is designed and configuredto guide laser radiation (L) along a longitudinal extent of the second fiber section (5), characterized in that the second fiber section (5) has a smaller diameter than the first fiber section (5), at least at its end (9) facing away from the first fiber section (3).

2. Fiber arrangement (1) according to claim 1, wherein the fiber arrangement (1) has a third fiber section, in particular a third fiber, which is provided with the second fiber section (5) is connected at its end (9) facing away from the first fiber section (3) for transmitting the laser beams (L).

3. Fiber arrangement (1) according to at least one of the preceding claims, wherein the second fiber section (5) has a particularly second, doped fiber core (15) and a particularly second fiber cladding (16) encompassing the second fiber core (15) and having a second cladding (16).

4. Fiber arrangement (1) according to at least one of the preceding claims, wherein the second fiber section (5) has a larger diameter at a connection interface to the first fiber section (3) than at the opposite end (9) facing away from the first fiber section (3), in particular in that the second cladding (16) of the second fiber section (5) is thinner at the opposite end (9) facing away from the first fiber section than at the connection interface.

5. Fiber arrangement (1) according to at least one of the preceding claims, wherein the diameters of the first fiber section (3) and of the second fiber section (5) are of equal size at the connection interface, and wherein the diameter of the second fiber section (5) tapers, in particular continuously and / or steadily, starting from the connection interface in the direction of the end (9) facing away from the first fiber section (3).

6. Fiber arrangement (1) according to at least one of the preceding claims, wherein the fiber arrangement (1) a particularly conical tapered section (7) in which a diameter tapers from a first value to a second value, wherein the first value preferably corresponds to a diameter of the first fiber section (3) and the second value corresponds to a diameter of the second fiber section (5).

7. Fiber arrangement (1) according to at least one of the preceding claims, wherein the fiber arrangement (1) has a plurality of first fiber sections (3) and a plurality of second fiber sections (5), wherein the second fiber sections (5) are arranged, in particular fixed, at a center-to-center distance (A) from a respective adjacent second fiber section (5) which is smaller than a diameter of the fiber cladding (12) of the first fiber section (3), and wherein the plurality of first fiber sections (3) and / or the plurality of second fiber sections (5) are preferably arranged as a fiber array.

8. Fiber arrangement (1) according to at least one of the preceding claims, wherein the second and / or third fiber section - along a central axis (M) of the respective fiber - has a curved course, in particular such that the fiber cores (15) of two of the plurality of second and / or third fiber sections are closer to one another than the fiber cores (11) of two of the first fiber sections.

9. Fiber arrangement (1) according to at least one of the preceding claims, wherein the first fiber sections (3) are arranged at a center distance (A) from a respective adjacent first fiber section (3) arranged, in particular fixed, which is greater than the center distance (A) of the second and / or third fiber sections.

10. Fiber arrangement (1) according to at least one of the preceding claims, wherein the diameter (D2) of the second and / or third fiber section at its end (9) facing away from the first fiber section (3) is less than 0.3 mm, preferably less than 0.2 mm, preferably less than 0.1 mm, preferably less than 0.05 mm and wherein the diameter (D1) of the first fiber section (3) is at least 0.3 mm, preferably at least 0.4 mm, at least in sections.

11. Fiber arrangement (1) according to at least one of the preceding claims, wherein the second fiber section (5) or the third fiber section is preferably fastened at its end facing away from the first fiber section (3) to an optically transparent fixing element (21), in particular a glass body.

12. Fiber arrangement (1) according to at least one of the preceding claims, wherein the plurality of first fiber sections (3) are designed and arranged to generate laser radiation (L) with different wavelengths.

13. HEL effector (24) for a laser weapon with a fiber arrangement (1) according to one of the preceding claims, a beam combining device (23) which comprises a transformation optics device (27) and an optical grating (29), and with the pump radiation source (25) which is used for coupling the Pump radiation (P) with at least one first Fiber section (3), in particular the plurality of first Fiber sections (3), wherein the transformation optics device (27) is arranged in a beam path of the laser beams (L) behind the optically transparent fixing element (21), wherein the transformation optics device (27) is designed and configured to direct the incoming laser beams (L), in particular in a collimated manner, onto the optical grating (29).

14. Laser weapon with a fiber arrangement (1) according to one of the preceding claims and / or a HEL effector (24) according to one of the preceding claims, wherein the laser weapon has a target detection device for detecting a target object and preferably a control device for controlling the target detection device and / or for actuating a bundled laser beam.

15. Laser weapon according to claim 14, wherein the HEL effector (24) is designed and configured to combine a plurality of laser beams of the fiber arrangement (1) into a bundled laser beam with a total power of at least 5 kW, preferably at least 10 kW, preferably at least 20 kW, preferably at least 50 kW, preferably at least 80 kW, preferably at least 100 kW.

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