Laser medium device and laser system

Abstract

The invention relates to a laser medium arrangement for generating or amplifying laser light by stimulated emission of photons, the laser medium arrangement defining a longitudinal direction and a cross-section extending transversely to the longitudinal direction, and wherein the laser medium arrangement comprises a plurality of structural elements, the invention relates to a laser device comprising at least two different types of structural elements, i.e. A first type having a first refractive index and a second type having a second refractive index, each of the structural elements extending in a longitudinal direction and partially extending in a cross-section, at least one of the structural elements comprising a laser active material. The invention further relates to a laser system comprising such a laser medium arrangement.

Description

Technical Field

[0001] The present invention relates to a laser medium device for generating or amplifying a laser by stimulated emission of photons, and a laser system having such a laser medium device. Background Art

[0002] In a laser system, a laser medium is used to provide population inversion so that photons are stimulated to emit, thereby achieving optical amplification. Energy is supplied to the laser medium by a pump source to cause population inversion. In order to increase the optical path of photons in the laser medium, an optical resonator can be used, in which light is reflected multiple times, and thus the direction of the generated laser can also be defined.

[0003] Therefore, a classical resonator laser of this structural type can emit light with a high power density in a directional manner. However, the usually also high interference ability of the emitted light can cause so-called speckle artifacts. Speckles are phenomena that may occur when irradiating the surface of a rough object or passing through a scattering medium. Irregularities, roughnesses or structures on the order of the wavelength impose a random phase modulation on the wavefront of light, which appears as a granular structure of random intensity maxima and minima in the far field. Although this effect is utilized in some measurement principles for surface analysis, speckles are disturbing factors that destroy uniform illumination in illumination applications.

[0004] In contrast, uniform, speckle-free illumination can be achieved using so-called random lasers. In a random laser, a disordered laser medium is usually used, and the light return for increasing the optical path in the laser medium is not carried out through a resonator, but especially through scattering structures in the laser medium. Thereby, the residence time of photons in the laser medium is increased, and thus laser activity can occur. However, random lasers usually do not have a preferred direction for emitting light, and thus usually do not provide a directional laser.

[0005] In addition, random fiber lasers are also known. For example, in a random fiber laser, scattering structures are provided in the fiber and used to return light. Although the introduction of light in the fiber results in output of directional light, in this case, speckle artifacts are also caused, resulting in non-uniform illumination. Summary of the Invention

[0006] The object of the present invention is to provide a laser medium that can, on the one hand, achieve directional light output and, on the other hand, achieve uniform illumination, especially aiming to reduce or avoid speckle artifacts. One aspect of the object of the present invention is to inherently achieve these characteristics through the laser medium itself, that is, especially without the need for supplementary mode mixers, etc. The object of the present invention also lies in providing a laser system having the above characteristics of directional and uniform low-speckle light output, and preferably also providing a laser system in which at least the uniformity of illumination and the speckle resilience can be adjusted and reduced.

[0007] The present invention relates to a laser medium device for generating or amplifying a laser by stimulated emission of photons.

[0008] The laser medium device defines a longitudinal direction and a cross-section extending transversely to the longitudinal direction, wherein the laser medium device thus particularly defines a preferred direction of light propagation, which preferably extends along the longitudinal direction.

[0009] The laser medium device includes a plurality of structural elements, which respectively extend along the longitudinal direction and partially extend in the cross-section, including at least two different types of structural elements, namely a first type having a first refractive index and a second type having a second refractive index.

[0010] Therefore, the plurality of structural elements included may include at least one structural element of the first type and one or more structural elements of the second type, or conversely, may include one or more structural elements of the first type and one structural element of the second type, or may also include a plurality of structural elements of the first type and a plurality of structural elements of the second type. Of course, more than two different types may also be included, such as three different types of structural elements.

[0011] At least one of the structural elements includes a laser active material herein. However, it can also be provided that a plurality or all of the structural elements of one type or a plurality or all of the structural elements of multiple types include a laser active material, as will be explained in more detail below.

[0012] In some embodiments, the laser medium device has a feedback device configured to partially feedback the generated laser back into the laser active material. The feedback device is particularly for providing optical feedback such that photons pass through the laser active material for a sufficient length of time to achieve macroscopic amplification.

[0013] For example, it can be provided that the laser medium device has two ends that limit the extension of the laser medium device along the longitudinal direction, wherein the ends are preferably configured to partially feedback the generated laser back into the laser active material, and in particular, the ends form end faces extending perpendicular to the longitudinal direction and / or end faces with a mirror configuration.

[0014] However, for example, it can also be provided that the laser medium device, particularly the structural element, particularly the laser active material, includes an embedded light scattering structure configured to partially feedback the generated laser back into the laser active material.

[0015] Furthermore, for example, it can be stipulated that the laser medium device includes an optical resonator surrounding the end, which is configured to partially feedback the generated laser back into the laser-active material. Such an optical resonator can in particular include two mirrors, at least one of which is partially transparent in order to extract the laser from the resonator, and which is referred to as an external resonator in the context of the present disclosure.

[0016] The above examples can be used alternately or in combination, but are not exhaustive. Other variants or improvements of the feedback device are possible, for example including at least one of the following features: fiber Bragg gratings, dielectric coatings at the ends, high-reflection coatings (HR), partial-reflection coatings (PR) and / or anti-reflection coatings (AR).

[0017] In other embodiments, the ends can be beveled, especially in the case of externally constructed resonators. This design helps to prevent the internal resonator from competing with the external resonator. This embodiment is also meaningful for random lasers.

[0018] Generally speaking, the ends can have an angle other than 90° with respect to the longitudinal axis, for example they can be arranged at the Brewster angle with respect to the light propagating in the resonator.

[0019] Regarding the wavelength of the laser that can be generated, several factors determine the emitted spectrum. The amplification bandwidth ∆λ is a measure of the wavelength range within which incident light in the medium can in principle be amplified by stimulated emission. It is a property of the laser medium and is dominated by the laser-active ions and the host material. Furthermore, the resonator defines longitudinal modes through its geometric boundary conditions, which limit the number of possible emission wavelengths, since multiples of a 2π phase delay are preferred and in some cases even necessary for constructive interference after one round-trip in the resonator. For example, for a linear standing-wave resonator, the resonator length is a multiple of half the wavelength. The quality of the resonator defines here how narrowband a single resonance peak is. Usually, there are multiple longitudinal modes in the amplification profile, which can also lase simultaneously in the case of non-uniform broadening of the laser medium, such as laser glass. These broadband light sources form the basis for various technologies, such as generating short laser pulses, or serving as light sources for special measurement methods, such as optical coherence tomography. Other applications require monochromatic light, i.e., a light source that ideally emits only in one longitudinal mode. To achieve this, additional frequency-selective elements are introduced into the resonator, such as Lyot filters, diffraction gratings, etalons or electro-optic modulators, to increase the losses of the unwanted modes so that they dominate the amplification and force the resonator into longitudinal single-mode operation.

[0020] Preferably, a plurality of transverse modes can be excited in the laser medium device, and the laser medium device, in particular the structural elements, in particular their geometry and / or their arrangement in the cross-section of the laser medium device, is designed such that such a plurality of transverse modes can be excited.

[0021] In particular, it can be provided that a mode density of at least 1000, in particular at least 5000, in particular at least 10000, in particular at least 20000, in particular at least 50000 modes per square millimeter can be excited in the laser medium device.

[0022] In particular, it can also be provided that at least 10 transverse modes can be excited in the laser medium device, particularly preferably at least 100 transverse modes can be excited, even more preferably at least 500 transverse modes can be excited, and even more preferably at least 1000 transverse modes can be excited.

[0023] In a preferred embodiment, the laser medium device is configured to guide light along the longitudinal direction of the laser medium device and to optically confine the light transversely to the longitudinal direction.

[0024] The laser medium device can in particular be configured to transmit light locally transversely to the longitudinal direction, in particular with spatial resolution in the cross-section of the laser medium device, such that the laser medium device forms an image conductor.

[0025] The spatial resolution can preferably be higher than 5 line pairs per millimeter (lp / mm), more preferably higher than 10 lp / mm, or higher than 25 lp / mm, or higher than 50 lp / mm, or higher than 100 lp / mm, or higher than 150 lp / mm, or higher than 200 lp / mm.

[0026] The structural elements of the laser medium device preferably extend in the cross-section of the laser medium device in such a way that a plurality of cross-sectional regions are defined in the cross-section of the laser medium device, the cross-sectional regions corresponding respectively to the cross-sections of the individual structural elements.

[0027] Thus, the structural elements extend in particular adjacent to one another, in particular parallel to one another, along the longitudinal direction of the laser medium device, and their cross-sections each occupy a planar part of the cross-section of the laser medium device, and thus each define a cross-sectional region of the cross-section of the laser medium device. Thus, the cross-sectional regions correspond in particular to the surface regions formed by the structural elements when observing the cross-sectional regions of the laser medium device, such as end faces.

[0028] It can be stipulated that the structural elements, in particular their cross-sectional regions, are arranged unevenly in order to achieve transverse Anderson localization transverse to the longitudinal direction. The uneven arrangement can be, for example, a random arrangement, but a non-random uneven arrangement is also possible, as will be explained in more detail below.

[0029] As described above, the laser medium device includes a plurality of structural elements, among which there are at least two different types of structural elements.

[0030] In certain embodiments of the laser medium device, it can now be stipulated that there is a first type of structural element and a plurality of second type of structural elements. Thus, the plurality of structural elements particularly includes exactly one first type of structural element. The first type of structural element is particularly designed to be, for example, an integral matrix having a first medium or made of a first medium, where the first medium has a first refractive index. The second type of structural element can be formed as a cavity in the matrix, where the cavity preferably forms a second refractive index, for example, by the refractive index of air or gas that can be present as a medium in the cavity, or is filled with a second medium, particularly a solid, where the second medium has a second refractive index.

[0031] In certain embodiments of the laser medium device, it can also be stipulated that there are a plurality of first type of structural elements and a plurality of second type of structural elements. In this case, the first type of structural element can be designed to be a rod-shaped body or a tubular body having a first medium or made of a first medium, where the first medium has a first refractive index. In this case, the second type of structural element can be designed to be a rod-shaped body or a tubular body having a second medium or made of a second medium, where the second medium has a second refractive index and / or is designed as a cavity in the first type of structural element, where the cavity preferably forms a second refractive index or is filled with a second medium, particularly a solid, where the second medium has a second refractive index.

[0032] Especially in the case where the second type of structural element exists as a filled cavity in the first type of structural element, the structural element can be designed as a core-cladding system such that the core corresponds to the filled cavity.

[0033] Here, the rod-shaped body or the tubular body does not only refer to a geometry with a circular cross-section.

[0034] As described above, at least one of the structural elements in the laser medium device includes a laser active material.

[0035] More specifically, for example, at least one first type of structural element, preferably the first type of structural element, and particularly preferably the first medium can include a laser active material.

[0036] In this case, in an improvement of the present invention in which the laser medium device includes two different laser-active materials, it may be provided that at least one structural element of a second type, preferably a structural element of a second type, particularly preferably a second medium, includes another different laser-active material.

[0037] Conversely, however, for example, at least one structural element of a second type, preferably a structural element of a second type, particularly preferably a second medium, may also include a laser-active material.

[0038] In this case, in an improvement of the present invention in which the laser medium device includes two different laser-active materials, it may be provided that at least one structural element of a first type, preferably a structural element of a first type, particularly preferably a first medium, includes another different laser-active material.

[0039] The laser-active material may include a crystalline or amorphous solid, in particular glass, as a matrix material doped with foreign ions.

[0040] In particular, the laser-active material includes multicomponent glass, phosphate glass, fluorophosphate glass, silicate glass or quartz glass as the matrix material, and the matrix material includes doping with ions of at least one transition metal and / or rare earth element, particularly 4f n ground state doping.

[0041] Optionally, in an embodiment in which the laser medium device includes at least two different laser-active materials, another laser-active material may include a crystalline or amorphous solid, in particular glass, as a matrix material doped with foreign ions.

[0042] In particular, other laser-active materials include multicomponent glass, phosphate glass, fluorophosphate glass, silicate glass or quartz glass as the matrix material, and the matrix material includes doping with ions of at least one transition metal and / or rare earth, particularly 4f n ground state ion doping.

[0043] One possible implementation provides that one or more structural elements of the first type include glass, such as multicomponent glass, phosphate glass, fluorophosphate glass, silicate glass, or quartz glass. Additionally, one or more structural elements of the second type contain another glass, such as multicomponent glass, phosphate glass, fluorophosphate glass, silicate glass, or quartz glass. For example, the first type may include phosphate glass and the second type may include silicate glass, and vice versa. It is also possible that the refractive index difference is at least 0.05 or preferably at least 0.075. In particular, the following refractive index differences may also be provided, which are in particular at least 0.1, in particular at least 0.2, in particular at least 0.3, in particular at least 0.4. Additionally, in this case it may be provided that the laser medium device is designed to laterally locally transmit light transversely to the longitudinal direction, in particular to transmit light with spatial resolution in the cross-section of the laser medium device, such that the laser medium device forms an image conductor or the structural elements are unevenly arranged in order to achieve lateral Anderson localization transversely to the longitudinal direction. This enables the image conductor to act as a laser medium device in a surprising manner.

[0044] Some examples will be given again below on how to design the laser medium device and its structural elements and laser-active material.

[0045] According to one example, the laser medium device may include a structural element of the first type, which is designed as a first medium (in particular glass) having a first refractive index or as a monolithic matrix made of the first medium. Additionally, it may also include a plurality of structural elements of the second type, which are designed as cavities in the matrix, the cavities being filled with a second medium (in particular glass) designed as a solid, which has a second refractive index and contains a laser-active material.

[0046] According to another example, the laser medium device may include a structural element of the first type, which is designed as a first medium (in particular glass) or as a particularly monolithic matrix made of the first medium, which has a first refractive index and includes a laser-active material. Additionally, it may include a plurality of structural elements of the second type, which are designed as cavities in the matrix, the cavities forming a second refractive index or being filled with a second medium, in particular a solid or liquid having a second refractive index, and optionally including another different laser-active material.

[0047] According to another example, the laser medium device may include a plurality of structural elements of a first type, which are designed as, in particular, rod-shaped or tubular bodies, which have a first medium (in particular glass) or are made of a first medium, which first medium has a first refractive index and includes a laser-active material. Furthermore, a plurality of structural elements of a second type may be included, which are designed as, in particular, rod-shaped or tubular bodies, which have a second medium (in particular glass) or are made of a second medium, which second medium has a second refractive index and optionally includes a different laser-active material.

[0048] According to another example, the laser medium device may include a plurality of structural elements of a first type, which are designed as, in particular, rod-shaped or tubular bodies, which have a first medium (in particular glass) or are made of a first medium, which first medium has a first refractive index and includes a laser-active material. Furthermore, a plurality of structural elements of a second type may be included, which are configured as cavities in the structural elements of the first type and form a second refractive index or which are filled with a second medium, in particular glass having a second refractive index, and optionally include a different laser-active material.

[0049] According to another example, the laser medium device may include a plurality of structural elements of a first type, which are designed as, in particular, rod-shaped or tubular bodies, which have a first medium (in particular glass) or are made of a first medium, the first medium having a first refractive index. Furthermore, a plurality of structural elements of a second type may be included, which are configured as cavities in the structural elements of the first type, which are filled with a second medium, in particular glass, which second medium has a second refractive index and includes a laser-active material.

[0050] Regarding the refractive index, it may be stipulated that the first refractive index of the structural elements of the first type differs from the second refractive index of the structural elements of the second type by at least, in particular, at least 0.1, in particular, at least 0.2, in particular, at least 0.3, in particular, at least 0.4. A refractive index difference of at least 0.05 or preferably at least 0.075 is also possible. In order to achieve the above-mentioned refractive index difference, in particular, multi-component glass may be used as the material of one or more structural elements.

[0051] As described above, the structural elements of the laser medium device may extend in the cross-section of the laser medium device in such a way that a plurality of cross-sectional regions are defined in the cross-section of the laser medium device, the cross-sectional regions corresponding respectively to the cross-sections of the individual structural elements.

[0052] The ratio of the total area of the cross-sectional regions of the structural elements of the first type to the total area of the cross-sectional regions of the structural elements of the second type is, for example, in the range between 1:9 and 9:1, preferably in the range between 3:7 and 7:3, and particularly preferably in the range between 4:6 and 6:4.

[0053] However, it should not be excluded that the ratio of the total cross-sectional area of the structural elements of the first type to the total cross-sectional area of the structural elements of the second type can also be in the range between 1:150 and 150:1, preferably in the range between 1:100 and 100:1, and particularly preferably in the range between 1:50 and 50:1.

[0054] The total cross-sectional area of the structural elements of each type is, for example, at least 1 / (10*T) of the cross-sectional area, preferably at least 1 / (5*T), and particularly preferably at least 1 / (3*T), where T represents the number of types of structural elements.

[0055] Regarding the lateral extent of the structural elements, it can be stipulated that at least one cross-sectional area has a diameter of 100 nm to 50 μm, preferably 400 nm to 20 μm, and particularly preferably 500 nm to 2000 nm.

[0056] Regarding the geometry of the structural elements, it can be stipulated that the cross-sectional area has a non-circular or polygonal geometry, such as a pentagonal or hexagonal geometry.

[0057] As described above, the structural elements, in particular their cross-sectional areas, preferably have a non-uniform arrangement, where this non-uniform arrangement can particularly be random. However, it can also be stipulated that the arrangement is non-uniform but determined by a predefined rule, i.e., not random.

[0058] The non-uniform arrangement of the structural elements, in particular the non-uniform arrangement of their cross-sectional areas, can in particular be designed as follows: As a periodic positioning of the structural elements, in particular their cross-sectional areas, where the periodically positioned structural elements have a random and / or non-uniform but clearly determined variation by a predefined rule among each other, where the variation among the periodically positioned structural elements is preferably designed as a variation in the type of structural element, the refractive index of the structural element, and / or the geometry, such as a variation in the shape, diameter, and / or sub-structure of the structural element, As a non-periodic positioning of the structural elements, in particular their cross-sectional areas, where the non-periodic positions of the structural elements are random and / or non-uniform but clearly determined by a predefined rule, where, optionally, the structural elements also have a variation among each other, which is random and / or non-uniform but clearly determined by a predefined rule, and / or (c) as a positioning of the structural elements, in particular their cross-sectional areas, at periodic positions, where some periodic positions are occupied and some periodic positions are unoccupied, and the occupation is random and / or non-uniform but clearly determined by a predefined rule, Optionally, there are also variations between the structural elements, which are random and / or non-uniform, but are clearly determined by a predetermined rule.

[0059] The invention also relates to a laser system having a laser medium device as described above, at least one pump source for optically exciting the laser-active material, and an output section for coupling out the generated laser.

[0060] In one embodiment, the pump source can be designed to longitudinally couple pump light into the end of the laser medium device. One or more pump sources can also be designed to longitudinally couple pump light into both ends of the laser medium device. The pump source can also be designed to couple pump light into the laser medium device in a radial and / or tangential direction, for example, laterally into the side surface of the laser medium device. The pump geometries mentioned are merely exemplary. There may also be other pump geometries, such as the so-called double-clad geometry or other pump geometries.

[0061] Particularly preferably, the laser system has a feedback device which is designed to partially feedback the generated laser back into the laser-active material. The feedback device is particularly used to provide optical feedback so that photons pass through the laser-active material for a sufficient length of time to achieve macroscopic amplification.

[0062] For examples of the feedback device, please refer to the above description. Optionally, the laser system can include a frequency selection element for manipulating the emission wavelength.

[0063] In an improved embodiment, the laser system, particularly the pump source, is designed such that only a defined portion of the cross-section of the laser medium device can be excited by the pump source to reduce the spatial incoherence of the coupled-out laser or increase the spatial coherence of the coupled-out laser.

[0064] For example, in the case where pump light is longitudinally incident on the end of the laser medium device, the pump spot at the end can only irradiate a defined portion of the cross-section. For example, in the case of radial or tangential irradiation of the pump light, only a specific portion of the cross-section can be excited.

[0065] In particular, the laser system can preferably be designed and / or include a device such that the defined portion of the cross-section can be changed, so that the spatial coherence of the coupled-out laser can be adjusted.

[0066] For example, in the case where pump light is longitudinally incident on the end of the laser medium device, the size and / or shape of the pump spot at the end can be adjusted. For example, in the case of radial or tangential irradiation of the pump light, for example, the proportion of the excited cross-section can also be adjusted.

[0067] The present invention also relates to a method for generating or amplifying a laser by stimulated emission of photons, wherein a laser medium device is provided as described above, wherein the laser medium device comprises a plurality of structural elements, each structural element comprising a laser-active material, and wherein a pump source for optically exciting the laser-active material is provided, and the laser-active material is excited by the pump source, wherein the laser-active material is excited simultaneously within the plurality of structural elements, in particular for generating a laser with spatial incoherence, and / or wherein the laser-active material is not excited in at least one structural element, preferably in a plurality of adjustable structural elements, in particular for reducing the spatial incoherence of the laser, and / or wherein a defined portion of the cross-section of the laser medium device is excited by the pump source, in particular such that the lateral profile of the laser corresponds to the geometry of the excited defined portion of the cross-section. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] The present invention will be described in detail below with reference to the drawings. Shown herein are: Figure 1 A schematic view of a laser system having a laser medium device, the laser medium device having an optical resonator and a pump source for optically exciting a laser-active material, Figure 2 A schematic view of a laser medium device, wherein only a defined portion of the cross-section of the laser medium device is excited, Figure 3 A schematic cross-sectional view of different laser medium structures, wherein (a), (b), (c) are two types of structural elements or (d), (e) are three types of structural elements, and the cross-sectional areas of the structural elements are arranged unevenly, Figure 4 Schematic perspective views of two laser medium structures, wherein (a) is two types of structural elements, the cross-sectional areas of which are distributed unevenly on a grid, and (b) is a plurality of structural elements with non-uniform refractive indices (multiple types) and / or geometries (diameters), Figure 5 Schematic views of various possibilities of a laser medium device having structural elements or their cross-sectional areas arranged unevenly, Figure 6 Schematic views of various aspects of changes in structural elements or their cross-sectional areas and the possible combinations of these aspects, Figure 7 Schematic views of various other possibilities of a laser medium device having structural elements or their cross-sectional areas arranged unevenly, wherein the laser medium device comprises a first type of structural element and a plurality of second type of structural elements respectively, Figure 8Schematic diagrams show various other possibilities of a laser medium device having structural elements or cross-sectional regions thereof with non-uniform arrangements, wherein the laser medium device respectively includes a plurality of structural elements of a first type, a plurality of structural elements of a second type, and possibly other types. Figure 9 Schematic diagrams show embodiments including a master oscillator power amplifier assembly (MOPA), in which a resonator or in particular a system with optical feedback, in particular the laser systems described herein for the master oscillator and the laser medium devices described herein, is used as an optical amplifier system, and population inversion is generated in the laser-active medium used as an amplifier by a pump source. Detailed implementation

[0069] Figure 1 Schematic diagrams show a laser system 100 having a laser medium device 1, the laser medium device including an optical resonator 300, a pump source 200, and an output section 400, in which case the output section is formed by a partially transparent mirror of the optical resonator 300. In the example shown, the pump source 200 is arranged laterally and is designed to couple pump energy into the laser medium device 1 in a radial direction 6, i.e., in particular perpendicular to the longitudinal direction 5 of the laser medium device 1.

[0070] The laser medium device 1 includes a plurality of structural elements 10, the structural elements 10 respectively extending along the longitudinal direction 5 and respectively partially extending in the cross-section of the laser medium device 1. In the example shown, the laser medium device 1 includes exactly one structural element 10a designed as a matrix having a first refractive index and a plurality of structural elements 10b located therein, the structural elements respectively having a second refractive index and including a laser-active material. In this case, both types of structural elements 10a and 10b are formed as solids, for example respectively made of glass, and the second type of structural element 10b including the laser-active material particularly has foreign ion doping. In the cross-section, the structural elements 10 form a non-uniform arrangement, thereby enabling transverse Anderson localization transverse to the longitudinal direction 5 of the laser medium device 1.

[0071] Figure 2The laser medium device 1 is again shown, which extends from one end 2 to the other end 4 along the longitudinal direction 5, and in which the cross-section of the end 2 can be seen. The structural element 10 extends in the cross-section of the laser medium device 1 such that a plurality of cross-sectional regions 20 are defined in the cross-section of the laser medium device 1, and the cross-sectional regions respectively correspond to the cross-sections of the individual structural elements 10. That is to say, each structural element 10 forms and / or occupies a part of the cross-sectional area of the laser medium device 1 and this part is called the cross-sectional region 20 of the structural element 10. In this example, the cross-sectional regions 20 of the structural elements have a non-uniform arrangement such that the cross-sectional regions of the second type of structural element 10b containing the laser-active material are arranged aperiodically.

[0072] As Figure 2 can also be seen, the laser system 100 or its pump source 200 can be designed such that only a defined part 7 of the cross-section of the laser medium device 1 can be excited or is excited. Thereby, for example, laser activity can be generated only in a part of the second type of structural element 10b including the laser-active material, so that the spatial incoherence of the coupled-out laser can be reduced. This can provide radial and / or tangential and / or longitudinal coupling-in of the pump energy. The defined part 7 of the cross-section can also be variable so that the spatial incoherence of the coupled-out laser can be adjusted. In the case of longitudinal coupling-in of the pump energy, i.e., coupling-in along the longitudinal direction 5, the defined part 7 of the cross-section can correspond to the pump spot.

[0073] Figure 3 Various principle examples of the laser medium device 1 are shown. These principle representations are used to illustrate different variants of the non-uniform arrangement of the structural elements or their cross-sectional regions and the presence of the laser-active material in the structural elements.

[0074] Figure 3(a) The laser medium device shown in cross-section has a first type of structural element 10a designed as a matrix, which houses a plurality of second type of structural elements 10b. The second type of structural element 10b can be designed, for example, as cavities or hollow channels extending in the longitudinal direction in the first type of structural element 10a. The first type of structural element 10a is designed as a matrix, which here includes a first material having a first refractive index, and the second type of structural element 10b is designed, for example, as a cavity, which forms a second refractive index, for example, by the air or other gas contained therein. In this case, the cross-sectional area 20 of the first type of structural element 10a corresponds to the cross-sectional area of the laser medium device minus the holes defined by the cavities in this area, while the cross-sectional area 20 of the second type of structural element 10b corresponds to the cross-sectional area of the cavities respectively. However, the cavities in the matrix can also be filled with a second material, so that the second type of structural element 10b corresponds to the filled cavities. As schematically shown, the cross-sectional areas 20 of the second type of structural element 10b are non-uniform because their positions are unevenly distributed in the cross-section, especially they are not located on a periodic grid. In this case, the structural element 10a designed as a matrix can include a laser-active material. If the cavities are filled, the structural element 10b corresponding to the filled cavities can also include a laser-active material. It is also possible that, on the one hand, the structural element 10a includes a laser-active material, and on the other hand, the structural element 10b includes another laser-active material.

[0075] Figure 3 (b) The laser medium device shown in cross-section in (b) also has two types of structural elements 10a, 10b, namely, exactly one structural element 10a with a first refractive index designed as a matrix and a plurality of structural elements 10b with a second refractive index different from it. In the example shown here, the cross-sectional areas 20 of the second type of structural element 10b are not only arranged non-uniformly, but also have non-uniform geometries, in this case having non-uniform diameters, where, in this case, there are a finite number (i.e., two) of different diameters. The structural element 10a can include a laser-active material. The structural element 10b can also contain a laser-active material. In addition, both the structural element 10a and the structural element 10b can include a laser-active material, where preferably different laser-active materials are provided for the two types.

[0076] Figure 3(c) The laser medium device shown in the cross-section also has two types of structural elements 10a, 10b. Among them, the cross-sectional areas of the second type of structural elements 10b are respectively arranged within the first type of structural elements 10a, especially as a core-cladding system. In this case, a plurality of the first type of structural elements 10a and a plurality of the second type of structural elements 10b are provided. The structural elements or their cross-sectional areas are constructed in a non-uniform manner such that the first type of structural elements 10a (which accommodate the second type of structural elements 10b) are arranged non-uniformly, especially non-periodically, on the cross-section of the laser medium device. The structural elements 10a forming the cladding may contain laser-active material. The structural elements 10b forming the core may also contain laser-active material. In addition, both the structural elements 10a and the structural elements 10b may include laser-active material, where preferably different laser-active materials are provided for the two types.

[0077] Figure 3 The laser medium devices shown in the cross-sections of (d) and (e) correspond in some aspects to Figure 3 the laser medium devices shown in (a) and (b), but have three types of structural elements 10a, 10b, 10c with different refractive indices. In particular, the cavities in the structural elements 10a designed as the matrix can be filled with various media. The structural elements 10a may include laser-active material. The structural elements 10b and / or 10c may also contain laser-active material. In addition, both the structural elements 10a and the structural elements 10b and / or 10c may include laser-active material, where preferably different laser-active materials are provided for different types.

[0078] Figure 4 Two further examples of the laser medium device 1 are shown, which can in particular be used as image conductors. The laser medium device 1 also includes a plurality of structural elements 10, which respectively extend from the first end 2 to the second end 4 of the laser medium device 1 along the transport direction 5 and are, for example, constructed in the shape of a rod.

[0079] Figure 4 The laser medium device shown in (a) includes a plurality of the first type of structural elements 10a and a plurality of the second type of structural elements 10b. In this example, the cross-sectional areas of the structural elements are arranged on a periodic grid. However, the structural elements have a non-uniform arrangement such that the first type of structural elements 10a, the second type of structural elements 10b, and the refractive indices are non-uniformly set and / or distributed and / or the occupancy at the periodic positions is non-uniform. The structural elements 10a may contain laser-active material. The structural elements 10b may also contain laser-active material. In addition, both the structural elements 10a and the structural elements 10b may include laser-active material, where preferably different laser-active materials are provided for the two types.

[0080] Figure 4 (b) The laser medium device shown again includes a plurality of structural elements 10 arranged on a periodic grid, where in this example, the cross-sectional area of the structural elements has a non-uniform geometry. The difference in geometry can in particular be that the diameters of the structural elements or their cross-sectional areas are different from each other. In addition, the structural elements 10 can have non-uniformities such that the refractive indices of the structural elements are different from each other. A discrete number of different refractive indices can be provided here, such as two, three, four, etc., but in principle a continuously varying refractive index can also be provided. In this variant, at least some of the structural elements 10 include a laser-active material.

[0081] Figure 5 The different possibilities for achieving a non-uniform arrangement are presented according to a tree diagram. In Figure 5 a, the structural element 10a is shown as the starting point, which can be formed, for example, as a matrix material (the structural element 10a can also be formed as air or not present). Figure 5 b shows another starting point derived therefrom, which has the structural element 10a and a plurality of periodic positions P to be occupied by the structural element, so that the structural element has a periodic positioning. Figure 5 d shows another starting point derived from Figure 5 a, which has the structural element 10a and a plurality of aperiodic positions P to be occupied by the structural element to achieve an aperiodic positioning. Starting from the Figure 5 starting points shown in b and 5d, the laser medium device is obtained by occupying the positions P with the structural elements, as described in more detail below.

[0082] Starting from Figure 5 b, Figure 5 c shows the laser medium device 1 having the structural elements 10b, 10c, whose cross-sectional areas have a periodic positioning and / or are located at periodic positions. Figure 5 The laser medium device shown in c has three types of structural elements 10a, 10b, 10c, and the structural elements can respectively have different refractive indices. For example, the structural element 10a can be formed as a matrix material, while the structural elements 10b and 10c can be cavities in the matrix material filled with materials having different refractive indices.

[0083] However, it is also possible that one of the materials of the structural elements 10b and 10c corresponds to the matrix material of the structural element 10a, or the (filled) cavities corresponding to these structural elements in the matrix material are missing (see below Figure 7 a). It is also possible that the structural element 10a is formed as air or not present, and the structural elements 10b and 10c are adjacent to each other (see below Figure 8 a).

[0084] Figure 5The laser medium device 1 shown in c has structure elements 10b, 10c that are periodically positioned. However, the types of the structure elements 10b, 10c are different, and the occupation of the different types on the regular grid is non-uniform. In particular, the variation between the structure elements 10b, 10c is thus non-uniform. Therefore, Figure 5 c shows a situation of the laser medium device 1 in which the structure elements or their cross-sectional areas have a non-uniform arrangement. In this case, the term "arrangement" should be understood such that the selection or occupation of the different types of structure elements 10b, 10c at the corresponding periodic positions is non-uniform.

[0085] It is also possible that the structure elements 10b, 10c do not differ in terms of their refractive index, i.e., they have the same refractive index or are made of the same material, but differ in other respects (see below Figure 6 ). It is also possible that the structure elements 10b, 10c differ both in terms of their refractive index and in other respects.

[0086] In particular, the structure element 10a can comprise a laser-active material and / or the structure elements 10b and / or 10c can comprise a laser-active material or different laser-active materials.

[0087] Starting from Figure 5 d, Figure 5 e shows a laser medium device 1 having two types of structure elements, namely a structure element 10a that can be designed as a matrix material, for example, and a plurality of structure elements 10b that can be designed as, for example, particularly filled cavities in the matrix material. In this case, the cross-sectional areas of the structure elements 10b are positioned non-periodically. In this case, the positioning of the structure elements 10b can now exhibit irregularities. In particular, the second type of structure element 10b can have non-uniform positions. Therefore, Figure 5 e shows a situation of the laser medium device 1 in which the structure elements or their cross-sectional areas have a non-uniform arrangement. The term "arrangement" should be understood such that the said or certain structure elements or their cross-sectional areas are positioned in a non-periodic manner. In Figure 5 the case of e it is specifically stipulated that the second type of structure element 10b has a uniform refractive index, a uniform geometry and / or is uniformly designed in other respects, in particular identically designed. In this case, one can speak of a uniform occupation of the non-periodic positions.

[0088] The structure element 10a can comprise a laser-active material and / or the structure element 10b can comprise the said laser-active material or different types of laser-active materials.

[0089] Starting from Figure 5 d, Figure 5f shows a laser medium device 1 in which an aperiodic positioning of structural elements is provided and at the same time different types of structural elements 10b, 10c are provided. In this case, the inhomogeneity of the arrangement can lie in the aperiodic positioning or occupancy of the structural elements 10b, 10c, i.e. the variation between the structural elements 10b, 10c with respect to each other, or both in terms of positioning and occupancy.

[0090] The structural element 10a can comprise a laser-active material and / or the structural elements 10b and / or 10c can comprise the laser-active material or different laser-active materials.

[0091] Figure 6 Shows the various possibilities (middle row) of the variations that can exist between the structural elements with respect to each other and exemplary, non-exhaustive possible combinations of the variations (bottom row). The variations shown can in particular be used to occupy the positions of structural elements with an inhomogeneous structure. Structural elements whose cross-sectional areas are located at periodic or aperiodic positions (e.g. within a matrix material) can vary, for example, in terms of their shape, in terms of their type or refractive index, in terms of their sub-structure and / or in terms of their rotation (and / or local position).

[0092] For example, the variation of the geometry of the structural elements, in particular the variation of their cross-sectional areas, can be designed as a shape variation (number of corners, diameter). The variation of the geometry can also be configured as a variation of the sub-structure. The sub-structure can in particular consist in that the structural element, in particular its cross-sectional area, has at least two different regions with different refractive indices, in particular a core and a surrounding cladding (core-cladding system).

[0093] Combined, for example, a first type of structural element can have a polygonal cladding and / or a polygonal core, and a second type of structural element can have a circular cladding and a polygonal core (bottom row, first column). Then these two types of structural elements can be used to occupy periodic or aperiodic positions.

[0094] In addition, for example, a structural element of the first type may have a first refractive index and a first diameter, and a structural element of the second type may have a second refractive index and a second diameter (bottom row, second column); or the structural element of the first type is a core-cladding system where the core has a first diameter, and the structural element of the second type is a core-cladding system where the core has a second diameter (bottom row, third column); or the structural element of the first type is a core-cladding system where the core has a first refractive index, and the structural element of the second type is a core-cladding system where the core has a second refractive index (bottom row, fourth column); or the structural element of the first type has a first diameter and rotates about a pivot point outside the structural element and the structural element of the second type has a second diameter and rotates about a pivot point outside the structural element (bottom row, fifth column), or the structural element of the first type is a core-cladding system with a central core and the structural element of the second type is a core-cladding system that rotates about a pivot point outside the core (bottom row, sixth column), and so on.

[0095] Figure 7 a shows a laser medium device 1, which is in some respects similar to Figure 5 the laser medium device of c. The laser medium device has a first structural element 10a, which can be configured, for example, as a matrix material. In addition, the laser medium device has a plurality of structural elements 10b, which can be configured, for example, as cavities in the matrix material. The structural elements 10b are located at periodic positions, but not all of the periodic positions are occupied by structural elements. Thus, Figure 7 a shows a situation of the laser medium device 1, in which the structural elements or their cross-sectional areas have a non-uniform arrangement, which is clearly determined by a predetermined rule. The term "arrangement" should be understood herein as meaning that the structural elements or some of the structural elements or their cross-sectional areas are located at periodic positions, where some of the periodic positions are occupied and some are not. It is possible that the structural element 10a includes a laser-active material. It is also possible that the structural elements 10b contain a laser-active material, especially if these structural elements are designed as filled cavities. In addition, both the structural element 10a and the structural element 10b can include a laser-active material, where preferably different laser-active materials are provided for the two types.

[0096] Figure 7 b shows a laser medium device 1, which is in some respects similar to Figure 5 the laser medium device of f. The laser medium device has a first structural element 10a, which can be configured, for example, as a matrix material. In addition, the laser medium device has a plurality of structural elements 10b having a first diameter and a plurality of structural elements 10c having a second diameter. In this example, the structural elements are positioned non-periodically. Thus, Figure 7b shows a situation of the laser medium device 1, in which the structural elements or their cross-sectional areas have a non-uniform arrangement. The term "arrangement" should be understood here as that the structural elements or some of the structural elements or their cross-sectional areas are positioned non-periodically and / or there are non-uniformly formed variations between the structural elements, where the variations are formed into two types of structural elements, for example, having different diameters. The structural element 10a may include a laser-active material. The structural elements 10b and / or 10c may also include a laser-active material, especially if these structural elements are designed as filled cavities. In addition, both the structural element 10a and the structural elements 10b and / or 10c may include a laser-active material, where preferably different laser-active materials are provided for different types.

[0097] Figure 8 show some laser medium devices 1, each having a plurality of structural elements of a first type and a plurality of structural elements of a second type (sometimes other types in Figure 8 d). In particular, the laser medium devices 1 shown here do not have any matrix material, but the structural elements are adjacent to each other. Figure 8 The common point of the shown laser medium devices 1 is that the different types of structural elements, especially their cross-sectional areas, are positioned periodically, but the occupation of the periodic positions by these types of structural elements is non-uniform. Therefore, Figure 8 the laser medium device 1 shown in

[0098] Figure 8 a shows, for example, a laser medium device 1 having a plurality of structural elements 10a and a plurality of structural elements 10b, the plurality of structural elements having different refractive indices. The structural element 10a may contain a laser-active material. The structural element 10b may also contain a laser-active material. In addition, both the structural element 10a and the structural element 10b may include a laser-active material, where preferably different laser-active materials are provided for the two types.

[0099] Figure 8b shows a laser medium device 1 having a plurality of structural elements 10d and a plurality of structural elements 10e, which have different refractive indices and different sub-structures, where the sub-structures are defined by sub-structure elements 10a and 10b (having refractive indices a and b) or 10a and 10c (having refractive indices a and c). The sub-structure is such that the structural elements 10d and 10e are designed as core-cladding systems, where the cores are different. Preferably, at least one of the types 10a, 10b, 10c, 10d, 10e includes a laser-active material. It is also possible that several types contain a laser-active material or certain types contain different laser-active materials.

[0100] Figure 8 c similarly shows a laser medium device 1 having a plurality of structural elements 10d and a plurality of structural elements 10e, the plurality of structural elements having different refractive indices and different sub-structures, where the sub-structures are defined by sub-structure elements 10a and 10b (having refractive indices a and b) or 10c and 10b (having refractive indices c and b). The sub-structure is such that the structural elements 10d and 10e are designed as core-cladding systems, where the claddings are different. Preferably, at least one of the types 10a, 10b, 10c, 10d, 10e includes a laser-active material. It is also possible that several types contain a laser-active material or certain types contain different laser-active materials.

[0101] Figure 8 d similarly shows a laser medium device 1 having a plurality of structural elements 10e, a plurality of structural elements 10f, a plurality of structural elements 10g and a plurality of structural elements 10h, which have different refractive indices and different sub-structures, where the sub-structures are defined by sub-structure elements 10a and 10b (having refractive indices a and b) or 10a and 10c (having refractive indices a and c) or 10b and 10d (having refractive indices b and d) or 10c and 10d (having refractive indices c and d). The sub-structure is such that the structural elements 10e, 10f, 10g and 10h are designed as core-cladding systems, where both the cores and the claddings are different. Preferably, at least one of the types 10a, 10b, 10c, 10d includes a laser-active material. It is also possible that several types contain a laser-active material or certain types contain different laser-active materials.

[0102] Figure 8e shows a laser medium device 1 having a plurality of structural elements 10c and a plurality of structural elements 10d, the plurality of structural elements having different geometries and different sub-structures, wherein the sub-structure of the structural element 10c is defined by sub-structure elements 10a and 10b (having refractive indices a and b and a first core diameter), and the sub-structure of the structural element 10d is defined by sub-structure elements 10a and 10b (having refractive indices a and b and a second core diameter). Preferably, one of the types 10a, 10b includes a laser-active material. It is also possible that both types contain a laser-active material, or one type contains a laser-active material while the other type contains a different laser-active material.

[0103] Figure 8 f shows a laser medium device 1 having a plurality of structural elements 10c and a plurality of structural elements 10d, the plurality of structural elements having different geometries and different sub-structures, wherein the sub-structure of the structural element 10c is defined by sub-structure elements 10a and 10b (having refractive indices a and b and a core located at the center), and the sub-structure of the structural element 10d is defined by sub-structure elements 10a and 10b (having refractive indices a and b and an eccentrically located core). Preferably, one of the types 10a, 10b includes a laser-active material. It is also possible that both types contain a laser-active material, or one type contains a laser-active material while the other type contains a different laser-active material.

[0104] In addition to being used in a resonator or a general system with optical feedback, the laser-active medium can also be used in particular as an optical amplifier system. In this case, a pump source creates a population inversion in the laser-active medium used as an amplifier.

[0105] This embodiment is shown in Figure 9 In

[0106] The light to be amplified is emitted here by an external laser system 100 and is preferably amplified unidirectionally in the laser medium device 1 shown on the right in Figure 9 The equally possible amplification of spontaneously emitted photons (ASE - amplified spontaneous emission) is only a parasitic effect.

[0107] In this case, a laser system device 500 is provided, which includes the first laser system 100 disclosed here, in particular as a master oscillator 501, and the laser medium device 1 disclosed here, in particular as a power amplifier 502, in which the laser generated by the laser system 100 through stimulated emission of photons is guided into the laser medium device 1 and amplified through stimulated emission of photons in the laser medium device 1.

[0108] In the embodiments disclosed herein, the laser system device 500 and in particular its laser system 100 can operate in a continuous manner.

[0109] In other designs of the currently disclosed embodiments, the laser system device 500 and in particular its laser system 100 operate in a pulsed manner.

[0110] For example, such a system can be used for power scaling of a laser system, which includes a master oscillator and at least one power amplifier as described above.

[0111] In particular, more than one laser medium device 1 (as disclosed herein) can also be included in the laser system device 500, in particular as power amplifiers 502 respectively.

[0112] In this case, the master laser or seed laser 501 mainly determines the characteristics of the emitted light through its resonator design, and the resonator design determines its respective characteristics, such as wavelength, linewidth or pulse duration.

[0113] The light to be amplified, especially the seed light, emitted by the master laser or seed laser 501 is then highly amplified in a power stage decoupled therefrom, i.e., the power amplifier 502 described above, see Figure 9 , which usually has different requirements from the master oscillator 501, such as requirements in terms of power stability.

[0114] An example of such an arrangement is a ladder amplifier or a fiber amplifier.

[0115] In particular, the present invention also allows for selective amplification in a region transverse to the propagation direction, which follows the intensity distribution of the seed source and thus the intensity distribution of the laser system 501, wherein this remains substantially unchanged during the propagation and amplification through the laser medium of the power amplifier 502 and thus the laser medium device 1.

[0116] Another application area of optical amplifiers is the field of data communication, in which signal losses in long-distance transmission are compensated. If spatial multiplexing (also known as SDM - space division multiplexing) is used to increase the data rate and the data is distributed transversely to the transmission direction through different modes or channels, this can also be achieved by a corresponding amplifier system with laser system components 500 disclosed herein.

[0117] Due to the high mode density and the associated laterally local optical amplification, the laser medium device 1 according to the present invention used here can achieve this in a particularly advantageous manner.

Claims

1. A laser medium device (1) for generating or amplifying laser light by stimulated emission of photons, Among them, The laser medium device (1) defines a longitudinal direction (5) and a cross-section extending transversely to the longitudinal direction (5), and wherein the laser medium device (1) includes a plurality of structural elements (10), which respectively extend along the longitudinal direction (5) and partially extend in the cross-section, including at least two different types of structural elements, namely a first type (10a) having a first refractive index and a second type (10b) having a second refractive index, wherein at least one of the structural elements (10) includes a laser active material.

2. The laser medium device (1) according to the preceding claim, Among them, The laser medium device includes a feedback device configured to partially feedback the generated laser light back into the laser active material, wherein preferably it is provided that the laser medium device has two ends that limit the extension of the laser medium device along the longitudinal direction, and wherein the ends are preferably configured to partially feedback the generated laser light back into the laser active material, in particular the ends form end faces extending perpendicular to the longitudinal direction and / or end faces with a mirror configuration, and / or wherein preferably it is provided that the laser medium device, in particular the structural element, in particular the laser active material, includes a light scattering structure configured to partially feedback the generated laser light back into the laser active material, and / or wherein preferably it is provided that the laser medium device includes an optical resonator surrounding the ends, and the optical resonator is configured to partially feedback the generated laser light back into the laser active material.

3. The laser medium device (1) according to any one of the preceding claims, Among them, The laser medium device includes one or more frequency selection elements, in particular including one or more of the following components: Lyot filter, diffraction grating, etalon or electro-optic modulator, wherein the one or more frequency selection elements are preferably installed in the feedback device, in particular in the optical resonator, in particular as a fiber Bragg grating.

4. The laser medium device (1) according to any one of the preceding claims, Among them, The laser medium device, in particular the structural element, in particular its geometry and / or its arrangement in the cross-section of the laser medium device, is designed such that a plurality of transverse modes can be excited in the laser medium device, wherein preferably in the laser medium device a mode density of at least 1000, in particular at least 5000, in particular at least 10000, in particular at least 20000, in particular at least 50000 modes per square millimeter can be excited, and / or wherein preferably in the laser medium device at least 10 transverse modes can be excited, particularly preferably at least 100 transverse modes can be excited, even more preferably at least 500 transverse modes can be excited, even more preferably at least 1000 transverse modes can be excited.

5. The laser medium device (1) according to any one of the preceding claims, Among them, is configured to guide light along the longitudinal direction of the laser medium device and optically confine the light transversely to the longitudinal direction, and / or wherein the laser medium device is configured to laterally locally transmit light transversely to the longitudinal direction, in particular to transmit light with spatial resolution in a cross-section of the laser medium device, such that the laser medium device forms an image conductor, wherein the spatial resolution is preferably higher than 5 line pairs per millimeter, particularly preferably higher than 10 line pairs per millimeter, or higher than 25 line pairs per millimeter, or higher than 50 line pairs per millimeter, or higher than 100 line pairs per millimeter, or higher than 150 line pairs per millimeter, or higher than 200 line pairs per millimeter, and / or wherein the structural element extends in the cross-section of the laser medium device such that a plurality of cross-sectional regions are defined in the cross-section of the laser medium device, the cross-sectional regions respectively corresponding to the cross-section of a single structural element, and / or wherein the structural element, in particular its cross-sectional region, is unevenly arranged in order to achieve lateral Anderson localization transversely to the longitudinal direction.

6. The laser medium device (1) according to any one of the preceding claims, Among them, comprises a structural element of a first type and a plurality of structural elements of a second type, and wherein the structural element of the first type is designed as a matrix having or made of a first medium, in particular an integral matrix, wherein the first medium has a first refractive index, and wherein the structural element of the second type is designed as a cavity in the matrix, wherein the cavity preferably forms a second refractive index or is filled with a second medium, in particular a solid, wherein the second medium has a second refractive index.

7. The laser medium device (1) according to any one of the preceding claims, Among them, comprises a plurality of structural elements of a first type and a plurality of structural elements of a second type, and wherein the structural element of the first type is designed as a rod-shaped body or a tubular body having or made of a first medium, wherein the first medium has a first refractive index, and wherein the structural element of the second type is designed as a rod-shaped body or a tubular body having or made of a second medium, wherein the second medium has a second refractive index, or wherein the structural element of the second type is designed as a cavity in the structural element of the first type, wherein the cavity preferably forms a second refractive index or is filled with a second medium, in particular a solid, wherein the second medium has a second refractive index.

8. The laser medium device (1) according to any one of the preceding claims, Among them, at least one structural element of the first type, preferably the structural element of the first type, particularly preferably the first medium, comprises a laser-active material, and wherein preferably, in addition, at least one structural element of the second type, preferably the structural element of the second type, particularly preferably the second medium, comprises a different laser-active material, and / or Wherein, at least one structural element of the second type, preferably the structural element of the second type, particularly preferably the second medium, comprises a laser-active material, and wherein preferably, in addition, at least one structural element of the first type, preferably the structural element of the first type, particularly preferably the first medium, comprises a different laser-active material.

9. The laser medium device (1) according to any one of the preceding claims, Among them, The laser-active material comprises a crystalline or amorphous solid, in particular glass, as a matrix material doped with foreign ions, Among them, the laser active material especially includes multicomponent glass, phosphate glass, fluorophosphate glass, silicate glass or quartz glass as the matrix material, and the matrix material includes ion doping of at least one transition metal and / or rare earth element, especially doping in the 4f n ground state, and / or Wherein, optionally, the other laser-active material comprises a crystalline or amorphous solid, in particular glass, as a matrix material doped with foreign ions, Among them, another laser active material particularly includes multicomponent glass, phosphate glass, fluorophosphate glass, silicate glass or quartz glass as a matrix material, and the matrix material includes ion doping of at least one transition metal and / or rare earth element, especially doping in the 4f n ground state.

10. The laser medium device (1) according to any one of the preceding claims, Among them, Comprising a structural element of the first type, which is designed as a first medium, in particular glass, or an integral matrix made of a first medium, in particular glass, having a first refractive index, and Wherein, comprising a plurality of structural elements of the second type, which are designed as cavities in the matrix, the cavities being filled with a second medium, in particular glass, designed as a solid, the structural elements of the second type having a second refractive index and containing a laser-active material.

11. The laser medium device (1) according to any one of the preceding claims, Among them, Comprising a structural element of the first type, which is designed as a first medium, in particular glass, or an integral matrix made of a first medium, in particular glass, the first medium, in particular glass, having a first refractive index and comprising a laser-active material, and Wherein, comprising a plurality of structural elements of the second type, which are designed as cavities in the matrix, the cavities forming a second refractive index, or The cavities are filled with a second medium, in particular a solid having a second refractive index, and optionally comprise a different laser-active material.

12. The laser medium device (1) according to any one of the preceding claims, Among them, Comprising a plurality of structural elements of the first type, the plurality of structural elements of the first type being designed as a first medium, in particular glass, or a rod-shaped or tubular body made of a first medium, in particular glass, the first medium, in particular glass, having a first refractive index and comprising a laser-active material, and Wherein, comprising a plurality of structural elements of the second type, the plurality of structural elements of the second type being designed as a second medium, in particular glass, or a rod-shaped or tubular body made of a second medium, in particular glass, the second medium, in particular glass, having a second refractive index and optionally comprising a different laser-active material.

13. The laser medium device (1) according to any one of the preceding claims, Among them, Comprising a plurality of structural elements of the first type, the plurality of structural elements of the first type being designed as a first medium, in particular glass, or a rod-shaped or tubular body made of a first medium, in particular glass, the first medium, in particular glass, having a first refractive index and comprising a laser-active material, and Among them, it includes a plurality of structural elements of a second type, and the plurality of structural elements of the second type are configured as cavities in the structural elements of the first type and form a second refractive index, or the cavities are filled with a second medium having a second refractive index, especially glass, and optionally include another different laser active material.

14. The laser medium device (1) according to any one of the preceding claims, Among them, includes a plurality of structural elements of a first type, and the plurality of structural elements of the first type are designed to have a first medium, especially glass, or are especially rod-shaped or tubular bodies made of a first medium, especially glass. The first medium, especially glass, has a first refractive index, and among them, it includes a plurality of structural elements of a second type, and the plurality of structural elements of the second type are configured as cavities in the structural elements of the first type. The cavities are filled with a second medium, especially glass, and the second medium has a second refractive index and includes a laser active material.

15. The laser medium device (1) according to any one of the preceding claims, Among them, the first refractive index of the structural elements of the first type differs from the second refractive index of the structural elements of the second type by at least 0.05, at least 0.075, especially at least 0.1, especially at least 0.2, especially at least 0.3, especially at least 0.

4.

16. The laser medium device (1) according to any one of the preceding claims, Among them, the structural elements extend in the cross-section of the laser medium device, so that a plurality of cross-sectional regions are defined in the cross-section of the laser medium device, and the cross-sectional regions respectively correspond to the cross-sections of individual structural elements, and among them, the ratio of the total area of the cross-sectional regions of the structural elements of the first type to the total area of the cross-sectional regions of the structural elements of the second type is in the range of 1:9 to 9:1, preferably in the range of 3:7 to 7:3, particularly preferably in the range of 4:6 to 6:4, and / or among them, the total area of the cross-sectional regions of each type of structural element is at least 1 / (10*T) of the cross-sectional area, preferably at least 1 / (5*T) of it, particularly preferably at least 1 / (3*T) of it, where T represents the number of types of structural elements.

17. The laser medium device (1) according to any one of the preceding claims, Among them, the structural elements extend in the cross-section of the laser medium device, so that a plurality of cross-sectional regions are defined in the cross-section of the laser medium device, and the cross-sectional regions respectively correspond to the cross-sections of individual structural elements, and among them, the structural elements, especially their cross-sectional regions, have a non-uniform arrangement, and the non-uniform arrangement is especially random and / or non-uniform, but is determined by a predetermined rule. Among them, the non-uniform arrangement is preferably configured as: (a) As a periodic positioning of the structural elements, especially their cross-sectional regions, where the periodically positioned structural elements have random and / or non-uniform, but clearly determined changes by a predetermined rule between each other, Among them, the variations between the periodically positioned structural elements are preferably designed as variations in the type of the structural elements, the refractive index of the structural elements, and / or the geometry, such as variations in the shape, diameter, and / or sub-structure of the structural elements, (b) The aperiodic positioning of the structural elements, especially their cross-sectional areas, where the aperiodic positions of the structural elements are random and / or non-uniform but clearly determined by a predetermined rule, wherein, optionally, the structural elements also have variations between each other, and such variations are random and / or non-uniform, but clearly determined by a predetermined rule, and / or (c) The positioning of the structural elements, especially their cross-sectional areas, at periodic positions, where some of the periodic positions are occupied and some are not, and the occupation is random and / or non-uniform, but clearly determined by a predetermined rule, wherein, optionally, the structural elements also have variations between each other, and such variations are random and / or non-uniform, but clearly determined by a predetermined rule.

18. A laser system (100), the laser system comprising: The laser medium device (1) according to any one of the preceding claims, At least one pump source (200) for optically exciting the laser-active material, and An output section (400) for outputting the generated laser.

19. The laser system (100) according to any one of the preceding claims, Among them, The laser system (100) is configured such that, in particular, the pump source is configured such that only a defined portion (6) of the cross-section of the laser medium device (1) can be excited by the pump source to reduce the spatial incoherence of the output laser, wherein the laser system (100) is preferably configured to and / or includes a device for varying the defined portion (6) of the cross-section, so as to be able to adjust the spatial incoherence of the output laser.

20. A laser system device (500), especially a master oscillator power amplifier device, which includes A first laser system (100), especially the first laser system according to claim 18 or 19, especially as a master oscillator (501), And at least one laser medium device (1) according to any one of the preceding claims 1 to 17, especially as a power amplifier (502), Among them, The laser generated by stimulated emission of photons by the laser system (100) is guided into the laser medium device (1) and amplified by stimulated emission of photons in the laser medium device (1).

21. The laser system device (500) according to claim 20, It includes more than one laser medium device (1) according to any one of the preceding claims 1 to 17, especially as a power amplifier (502).

22. The laser system device (500) according to claim 20 or 21, Wherein the laser system operates in a continuous manner.

23. The laser system device (500) according to claim 20 or 21, Wherein the laser system operates in a pulsed manner.

24. A method for generating or amplifying a laser by stimulated emission of photons, Among them, Provided is a laser medium device (1) according to any one of the preceding claims 1 to 17, wherein the laser medium device comprises a plurality of structural elements, each structural element comprising a laser-active material, and wherein a pump source for optically exciting the laser-active material is provided, and the laser-active material is excited by the pump source, wherein the laser-active material is simultaneously excited within the plurality of structural elements, in particular to generate a laser with spatial incoherence, and / or wherein the laser-active material is not excited in at least one structural element, preferably a plurality of adjustable structural elements, in particular to reduce the spatial incoherence of the laser, and / or wherein a defined portion of the cross-section of the laser medium device is excited by the pump source, in particular such that the transverse profile of the laser corresponds to the geometry of the excited defined portion of the cross-section.

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