Optical functional group for a laser beam generating system, laser beam generating system and method for changing a propagation property

Abstract

The invention relates to an optical functional group (10) for a laser beam generating system (12); comprising a first optical system (16) and an optical transformer (28) disposed downstream of the first optical system (18) in a laser beam direction (20); wherein the optical transformer (28) comprises at least three optical lenses (30a-d) arranged one behind another along a common optical axis (32) of the optical transformer (28); wherein the first optical system (16) is designed to emit an input laser beam (14a) having at least one temporally varying propagation property; and wherein the optical transformer (28) is designed to transform the input laser beam (14a) into an output laser beam (14b) having time-independent propagation properties by moving at least one movable optical lens (30a-d) in order to vary lens distances (34a-c) between at least two of the optical lenses (30a-d). The invention additionally relates to a laser beam generating system (12) and a method (64) for conditioning the laser beam (14).

Description

[0001] Optical functional group for a laser beam generating system, laser beam generating system and method for changing a propagation property

[0002] Background of the invention

[0003] The invention relates to an optical functional group for a laser beam generation system, wherein the optical functional group comprises optical lenses for modifying a propagation property of a laser beam. The invention also relates to a laser beam generation system and a method for conditioning a laser beam.

[0004] Such devices and methods are used in the prior art for conditioning or transforming a laser beam with time-varying propagation properties into a laser beam with time-invariant propagation properties. Furthermore, conditioning or transforming the laser beam may be necessary if one or more components of the laser beam generation system have been replaced and / or if manufacturer tolerances result in differing propagation properties.

[0005] Particularly in laser beam generation systems for generating pulsed CO2 laser radiation, one or more predetermined propagation properties, such as a specific beam diameter and / or a specific beam divergence, are typically required, which are adapted to the existing optical systems or apertures. Deviations in the propagation properties from the target values ​​make effective and powerful laser beam generation difficult or even impossible. Common laser beam generation systems include the necessary optical systems and / or components for generating the laser beam, the use of which, however, causes a temporal change in the propagation properties of the laser beam.

[0006] Therefore, in conventional laser beam generation systems, it is structurally required that one or more of the propagation properties of the laser beam can be at least slightly modified by optical means. This can increase the effectiveness of the laser beam generation system in generating the laser beam. To change a propagation property, two lenses are typically used in a telescope-like arrangement. By moving one of the lenses in or against the beam direction of the laser beam, a propagation property of the laser beam leaving the optical means can be changed or brought closer to a desired value. However, such arrangements only have a limited adjustment or modification range within which a propagation property of the laser beam can be changed without influencing another propagation property.If changes outside the change range are necessary, one of the lenses must be replaced, which is a complex process.

[0007] In addition, the optical devices known from the prior art have extensive dimensions due to the necessary adjustment range of the lenses within the possible range of changes in propagation properties. This leads to a larger installation space and increases the space requirements of the entire laser beam generation system.

[0008] Object of the invention

[0009] It is an object of the invention to provide an optical functional group in which a change in a propagation property is possible over a wider range. It is also an object of the invention to provide a laser beam generation system and a method for changing a propagation property.

[0010] Description of the invention

[0011] This object is achieved according to the invention by an optical functional group according to claim 1. The object is also achieved by a laser beam generation system according to claim 12. Furthermore, the object is achieved by a method according to claim 13. The subclaims relate to preferred embodiments of the invention.

[0012] According to the invention, an optical functional group is provided. The optical functional group is suitable or designed for arrangement or use in a laser beam generation system described above and below.

[0013] The optical functional group comprises a first optical system and an optical transformer. The optical transformer is arranged downstream of the first optical system in a laser beam direction.

[0014] The first optical system is configured to output an input laser beam with at least one temporally varying or changing propagation property. In other words, the use of the first optical system in laser beam generation results in the output of an input laser beam for the optical functional group with temporally inconstant propagation properties. For example, a temporal change in a laser beam width and / or a beam waist position may occur when generating the laser beam by a laser diode.

[0015] The optical transformer can be understood as a system for transforming, conditioning, and / or modulating at least one propagation property of the laser beam. In other words, the optical transformer can be flexibly adapted to a temporal change in a propagation property of the input laser beam.

[0016] The optical transformer has at least three optical lenses. In a particular embodiment, the optical transformer has exactly three optical lenses. The optical lenses are arranged one behind the other along a common optical axis of the optical transformer. In other words, the optical lenses are arranged in a row along the optical axis so that a laser beam passes through the optical lenses one after the other in one beam direction. The optical transformer can have further optical elements, e.g. mirrors. The further optical elements can be arranged or positioned before, between and / or after the optical lenses and, for example, bring about a change in the direction of the optical axis. This allows the optical functional group to be adapted to an available installation space.

[0017] The optical lenses are arranged in a telescope-like manner within the optical functional group. In other words, the optical properties, such as focal lengths, of the optical lenses are coordinated.

[0018] At least one of the optical lenses is designed to be movable along the optical axis relative to the other optical lenses. In other words, the position of at least one optical lens relative to the other optical lenses can be changed or adjusted. This allows the optical properties of the optical transformer to be adapted to a changing propagation property.

[0019] By moving the at least one movable optical lens, the lens spacing between at least two of the optical lenses can be changed or adjusted. This results in the transformation, conditioning, and / or modulation of the input laser beam into an output laser beam with time-independent or constant propagation properties. The time-constant propagation property preferably corresponds to a target value of the propagation property that the laser beam generation system and / or an optical system downstream of the optical transformer requires of the output laser beam for effective processing of the laser beam.

[0020] Typically, the at least one time-varying propagation property is conditioned. In other words, the at least one time-varying propagation property is kept constant over time by the optical functional group. In this case, it can be provided that a regular or continuous change in the lens spacing, or a regular or continuous adjustment of the at least one movable optical lens, takes place.

[0021] In summary, the object underlying the invention is achieved in a particularly simple manner by designing an optical functional group with more than two optical lenses. By using at least three optical lenses, a change range for one or more propagation properties can be increased, so that a change in the propagation properties can occur without and / or with an intended effect on another propagation property. In this way, input laser beams with time-varying or fluctuating propagation properties can be adjusted to a required target value for further processing in the laser beam generation system. Furthermore, a desired change in the movable lens can be achieved with a smaller adjustment range when using at least three optical lenses.This allows the optical functional group to be made more compact, thereby reducing the required installation space in the laser beam generation system.

[0022] In a preferred embodiment of the optical functional group, the first optical system is designed as a laser beam source of the laser beam generation system, as a laser amplifier, in particular a CO2 laser amplifier, for amplifying a laser beam to be generated, as an acousto-optical modulator (AOM) of the laser beam to be generated, or as an electro-optical modulator (EOM) of the laser beam to be generated. In laser beam generation systems, such optical systems cause propagation properties in the laser beam that vary over time and / or from functional group to functional group, which complicate processing of the laser beam during laser beam generation. The optical functional group has proven particularly effective in combination with one of the aforementioned optical systems.

[0023] Further preferred is an embodiment of the optical functional group in which the optical functional group comprises a second optical system. The second optical system is typically arranged downstream of the optical transformer in the laser beam direction and is designed to receive an exit laser beam with temporally constant or constant propagation properties and / or propagation properties with a specific value. In other words, the second optical system typically requires specific propagation properties for effective further processing, e.g., a specific beam width and / or a specific beam waist position.

[0024] In a preferred embodiment of the optical functional group, the second optical system is configured as a laser amplifier, in particular as a CO2 laser amplifier, as a spatial filter, as an acousto-optical modulator (AOM), as an electro-optical modulator (EOM), or as a system output. Such optical systems place high demands on temporally constant propagation properties for effective processing of the output laser beam, so that an upstream arrangement of the optical functional group has a particularly favorable effect on the effectiveness of laser beam generation.

[0025] An embodiment of the optical functional group is preferred in which the optical transformer has at least four or more optical lenses arranged one behind the other along the common optical axis of the optical transformer. Using four or more optical lenses, the range of change of one or more propagation properties can be further increased, so that the optical functional group can be adapted even more flexibly to temporal changes in the propagation properties. Furthermore, the adjustment path of the movable optical lenses can be reduced with an increasing number of optical lenses, and thus the required installation space of the optical functional group.

[0026] In a preferred embodiment of the optical functional group, at least two of the optical lenses are designed to be movable relative to one another along the optical axis. The optical transformer is typically designed to change the propagation properties by changing the lens spacing between at least three of the optical lenses. This allows the range of variation of the propagation properties to be further increased.

[0027] In addition, a further development of the optical functional group is preferred in which all optical lenses are designed to be movable relative to one another along the optical axis. Typically, the optical transformer is designed to change all lens distances between the optical lenses and / or to change a system distance of the optical transformer from the first optical system and / or from a second optical system arranged downstream of the optical transformer along a laser beam direction. In other words, in addition to a change in the position of one or more optical lenses, a change in the position or a uniform displacement of all optical lenses relative to the first and / or the second optical system can also take place. This allows the range of change in the propagation properties to be further increased.

[0028] In a preferred embodiment of the optical functional group, it comprises a control system. The control system is typically designed to, in particular automatically, change the position or displacement of the movable optical lens depending on a time-varying propagation property. Alternatively or additionally, the optical functional group can comprise a laser beam measuring section downstream of the first optical system in the laser beam direction. The laser beam measuring section is preferably configured to determine at least one propagation property of the incoming laser beam. Particularly preferably, the optical functional group is designed to automatically transform, condition, and / or modulate the incoming laser beam depending on the determined propagation property. This allows adaptation of the time-varying propagation property even more effectively.

[0029] A preferred development of the optical functional group provides that the laser beam measuring section is designed to determine a propagation property in the form of a beam divergence, a beam waist position, a beam waist width, and / or a beam diameter of the laser beam. Adjusting or maintaining these propagation properties constant over time results in particularly effective laser beam generation.

[0030] In a preferred embodiment of the optical functional group, at least two of the optical lenses are designed as converging lenses. The inventor has recognized that adapting propagation properties to a desired value and / or maintaining propagation properties constant over time within a wide range of variation, as well as compact dimensions of the optical functional group, is favored by using at least two converging lenses.

[0031] A further preferred embodiment of the optical functional group is one in which at least one of the optical lenses is designed as a diverging lens. Preferably, the at least one diverging lens is arranged along the optical axis between the at least two converging lenses. Such a design and arrangement of the optical lenses further enhances the change range and compact dimensions of the optical transformer.

[0032] The underlying problem is also solved by a laser beam generation system. The laser beam generation system is, in particular, a high-power laser system and is designed to generate, preferably pulsed, laser radiation. The laser beam generation system can be designed as a CO2 laser system.

[0033] The laser beam generation system comprises at least one optical functional group as described above and below. Preferably, the laser beam generation system comprises two or more optical functional groups as described above and below. The second optical system of a first optical functional group can be configured as the first optical system of a second optical functional group. This allows the laser beam to be generated particularly effectively.

[0034] The laser beam generation system preferably comprises a laser beam source. The laser beam source may comprise a laser diode and / or a seed laser.

[0035] In addition, the laser beam generation system can comprise one or more of the optical systems described above and below. Typically, the laser beam generation system comprises a housing. The housing is preferably designed as a radiation shield against stray laser radiation.

[0036] The object underlying the invention is further achieved by a method.

[0037] The method is designed for conditioning a laser beam using an optical functional group described above and below.

[0038] The procedure comprises at least the following steps:

[0039] In a first method step, the determination of at least one time-varying propagation property of the incoming laser beam is provided. The determination of the propagation property is carried out in particular by means of a method described above and below.

[0040] Laser beam I measuring section .

[0041] A further method step involves determining a desired arrangement of the optical lenses based on the determined propagation property. In other words, a desired arrangement of the optical lenses of the optical transformer is determined in which a propagation property of the exit laser beam can be kept constant despite temporally changing propagation properties in the entry laser beam. The desired arrangement can be determined from a change characteristic map. The desired arrangement can be determined by a control system of the optical functional group, as described above and below. The change characteristic map can, for example, be stored in the control system.

[0042] A further method step involves changing at least two lens spacings by changing the position of at least one of the optical lenses. This allows the optical transformer to be adapted to the changed propagation properties of the input laser beam in order to keep the propagation properties of an output laser beam constant over time.

[0043] The procedural steps described are not to be understood as exhaustive.

[0044] In particular, it can be provided that the method steps of the method are performed multiple times. Preferably, the method steps are performed at regular intervals and / or continuously in order to adapt the optical transformer to the temporally changing propagation properties.

[0045] Further features and advantages of the invention will become apparent from the description, the claims, and the drawings. According to the invention, the above-mentioned and further-described features can be used individually or in combination in any convenient way. The embodiments shown and described are not to be understood as an exhaustive list, but rather are exemplary.

[0046] Character for the description of the invention.

[0047] Detailed description of the invention and drawing

[0048] Fig. 1 shows a first embodiment of an optical functional group with three optical lenses in a schematic representation.

[0049] Fig. 2 shows the first embodiment of the optical functional group from Fig. 1 with a modified arrangement of the optical lenses in a schematic representation.

[0050] Fig. 3 shows the first embodiment of the optical functional group from Fig. 1 with a further modified arrangement of the optical lenses in a schematic representation.

[0051] Fig. 4 shows an embodiment of a laser beam generation system with the first embodiment of the optical functional group from Figs. 1-3 in a schematic representation.

[0052] Fig. 5 shows a second embodiment of an optical functional group with three optical lenses in a schematic representation.

[0053] Fig. 6 shows a third embodiment of an optical functional group with four optical lenses in a schematic representation.

[0054] Fig. 7 shows a first change characteristic diagram of an optical transformer in a schematic representation.

[0055] Fig. 8 shows a second variation characteristic diagram of an optical transformer with two movable optical lenses.

[0056] Fig. 9 shows a third variation characteristic diagram of an optical transformer with three movable optical lenses.

[0057] Fig. 10 shows a method for conditioning a laser beam using an optical functional group.

[0058] Fig. 1 shows an optical functional group 10 according to the invention for a laser beam generation system 12 (see Fig. 4) for generating a laser beam 14. The optical functional group 10 has a first optical system 16 and a second optical system 18. The second optical system 18 is arranged downstream of the first optical system 16 in a laser beam direction 20 of the laser beam 14. The laser beam direction 20 is understood to mean a direction of a predetermined beam propagation or beam propagation of the laser beam 14.

[0059] The first optical system 16 is typically designed to emit laser radiation with at least one time-varying propagation property. For example, a time-varying

[0060] Beam diameter 22 and / or a time-varying

[0061] Beam waist position 24 of the laser beam 14 as a time-varying

[0062] Propagation property can be understood.

[0063] The first optical system 16 can be configured as a laser beam source 26. The laser beam source 26 can, for example, comprise a seed laser and / or one or more laser diodes.

[0064] For effective reception and / or processing of the laser beam 14, the second optical system 18 typically requires laser radiation with time-independent or constant propagation properties. Typically, a target value for the propagation property is predetermined by the design.

[0065] The second optical system 18 can be designed, for example, as a laser amplifier, in particular as a CO2 laser amplifier, as a spatial filter, as an acousto-optical modulator (AOM), as an electro-optical modulator (EOM) or as a system output.

[0066] The optical functional group 10 has an optical transformer 28. The optical transformer 28 can be understood as a conditioning system for changing propagation properties of the laser beam 14. The optical transformer 28 is typically arranged between the first optical system 16 and the second optical system 18. As shown, the optical transformer 28 can have three optical lenses 30a-c arranged one behind the other along a common optical axis 32 of the optical transformer 28. The optical lenses 30a-c are typically arranged in a telescope-like manner. In other words, the optical lenses 30a-c are arranged so as to be coordinated with one another with regard to their optical properties, in particular with regard to their respective focal positions.

[0067] According to the illustrated embodiment, the optical lens 30a and the optical lens 30c are designed as a converging lens and the optical lens 30b is designed as a diverging lens.

[0068] Preferably, at least one of the optical lenses 30a-c is designed to be movable relative to the other optical lenses 30a-c, in particular along the optical axis 32.

[0069] According to the invention, the optical transformer 28 causes a change or adjustment of lens spacings 34a-c between at least two of the optical lenses 30a-c by moving the at least one movable optical lens 30a-c. This allows the input laser beam 14a with at least one temporally varying propagation property to be transformed or conditioned within the optical transformer 28 into an output laser beam 14b with temporally unchanged or constant propagation properties.

[0070] Fig. 2 shows the optical functional group 10 from Fig. 1.

[0071] As shown, the entrance laser beam 14a according to Fig. 2 is changed compared to the entrance laser beam 14a according to Fig. 1 in several propagation properties, here in the beam diameter 22 and in the beam waist position 24.

[0072] As shown, the optical functional group 10 differs from the optical functional group 10 of Fig. 1 in a modified arrangement of the optical lenses 30a-c. The position of the movable optical lens 30a is changed opposite to the laser beam direction 20 of the laser beam 14 and along the optical axis 32.

[0073] This causes a change in the lens distances 34a and 34b, whereby an exit laser beam 14b with the same propagation properties as in Fig. 1 can be generated.

[0074] As a result, the second optical system 18 can be tuned to a laser beam 14 with temporally constant propagation properties.

[0075] Fig. 3 shows the optical functional group 10 from Figs. 1 and 2.

[0076] As shown, the entrance laser beam 14a according to Fig. 3 is changed in diameter 22 and beam waist position 24 compared to the entrance laser beam 14a according to Figs. 1, 2.

[0077] As shown, the optical functional group 10 differs from the optical functional group 10 of Fig. 1 in a modified arrangement of the optical lenses 30a-c and the number of movable optical lenses 30a and 30b. The position of the movable optical lenses 30a, 30b is changed opposite to the laser beam direction 20 of the laser beam 14 and along the optical axis 32.

[0078] This causes a change in the lens distances 34a, 34b and 34c, whereby an exit laser beam 14b with the same propagation properties as in Figs. 1 and 2 can be generated.

[0079] Fig. 4 shows a laser beam generation system 12. The

[0080] Laser beam generation system 12 is preferably a high-power laser system for generating laser radiation, in particular pulsed CO2 laser radiation. The laser beam generation system 12 comprises an optical functional group 10 with a first optical system 16, a second optical system 18, and an optical transformer 28.

[0081] In addition, the laser beam generation system 12, as shown, may include a housing 36. Typically, the housing 36 surrounds the components of the laser beam generation system 12. Preferably, the housing 36 provides radiation protection against, in particular, scattered laser radiation from the laser beam 14.

[0082] Alternatively or additionally, the laser beam generation system 12 can comprise a third optical system 38, a fourth optical system 40, and / or a fifth optical system 42. In other words, the laser beam generation system 12 can have further optical systems 38, 40, 42 in addition to the first and second optical systems 16, 18. The further optical systems 38, 40, 42 can be arranged downstream or upstream of the first and / or second optical systems 16, 18 along the optical axis 32.

[0083] Typically, the third optical system 38 is designed as a laser beam source 26. According to the illustrated embodiment, the first optical system 16 can be designed, for example, as a laser amplifier, in particular as a CO2 laser amplifier. Furthermore, the second optical system 18 can be designed as an acousto-optical modulator. The fourth optical system 40 can be designed as a further optical transformer 28. The fifth optical system 42 can be designed as a system output.

[0084] Alternatively or additionally, the optical functional group 10 can comprise a laser beam measuring section 44. The laser beam measuring section 44 is preferably designed to determine at least one propagation property of the input laser beam 14a of the laser beam 14. The laser beam measuring section 44 can comprise a mirror 46 for reflecting a measuring beam 48 from the input laser beam 14a onto a propagation property detector 50.

[0085] The propagation property can be determined by a control system 52 of the optical functional group 10. The control system 52 is preferably integrated into a controller 53 of the laser beam generation system 12. The control system 52 is preferably configured to change the arrangement of the optical lenses 30a-c of the optical transformer 28. In particular, the control system 52 is configured to change the lens spacings 34a-c. This allows the input laser beam 14a to be transformed or conditioned, in particular automatically, by the control system 52 or by the laser beam generation system 12.

[0086] To change the arrangement of the optical lenses 30a-c, the control system 52 may perform a change in the arrangement of the optical lenses 30a-c using a predetermined change map 54 (see Figs. 7-9).

[0087] The third optical system 38 can be embodied as a laser beam source 26. The laser beam source 26 can, for example, comprise a seed laser or one or more laser diodes. As shown, the first optical system 16 can be arranged downstream of the third optical system 38 in a laser beam direction 20 of the laser beam 14.

[0088] Fig. 5 shows a further embodiment of an optical functional group 10 with an optical transformer 28 having three optical lenses 30a-c.

[0089] As shown, the optical lenses 30b and 30c are designed as converging lenses, and the optical lens 30a is designed as a diverging lens. This facilitates the transformation or conditioning of incoming laser beams 14a with a particularly small beam diameter 22. Fig. 6 shows another embodiment of an optical functional group 10 with four optical lenses 30a-d.

[0090] As shown, the optical lenses 30a, 30b and 30d are designed as converging lenses and the optical lens 30c is designed as a diverging lens.

[0091] By using more than three - here four - optical lenses 30a-d, a transformation area 56 (see Figs. 7-9) of the entrance laser beam 14a can be enlarged and the dimensions of the optical transformer 28 can be further reduced.

[0092] Fig. 7 shows a first change map 54 in a schematic representation.

[0093] The change characteristic map 54 shows a transformation range 56 of an optical transformer 28 according to the invention (see Figs. 1-4), wherein a beam waist width 58 of the laser beam 14 (see Figs. 1-3) is represented as a function of the beam waist position 24 of the laser beam 14. In other words, the change characteristic map 54 shows how a change in the beam waist width 58 in the exit laser beam 14b (see Figs. 1-3) affects a beam waist position 24 of the exit laser beam 14b. The change characteristic map 54 thus represents all beam waist widths 58 and beam waist positions 24 that can be transformed by the optical transformer 28 into a fixed, predetermined exit laser beam 14b. The larger the change characteristic field 54 is, the larger the transformation range 56 of the optical transformer 28 is.

[0094] For example, according to the illustrated transformation range 56, a change in the beam waist position 24 can occur along a beam width constant 60 without changing the beam waist width 58.

[0095] To explain the invention, the change characteristic map 54 also shows a reference curve 62 of a two-lens arrangement already known from the prior art. The reference curve 62 shows the possible range of change in the propagation properties using two lenses. As shown, this results in only a small or selective adjustment range of the lenses without mutual influence between the beam waist width 58 and the beam waist position 24. In other words, according to the known prior art, adjustment can only occur with mutual influence between the beam waist width 58 and the beam waist position 24.

[0096] Fig. 8 shows a second change map 54 in a schematic representation.

[0097] The change characteristic map 54 shows three transformation regions 56a-c of an optical transformer 28 according to the invention (see Figs. 1-4) with three optical lenses 30a-c (see Figs. 1-5), wherein a beam waist width 58 of the laser beam 14 (see Figs. 1-3) is shown as a function of the beam waist position 24 of the laser beam 14. In other words, the change characteristic map 54 shows which beam waist width 58 and beam waist position 24 can be transformed in a fixed, predetermined exit laser beam 14b (see Figs. 1-3).

[0098] The transformation areas 56a-c are each represented as a cluster of points, with each point representing a specific arrangement of the respective optical lenses 30a-c.

[0099] The transformation range 56a results from changing or shifting the optical lens 30a and the optical lens 30b. The transformation range 56b or 56c can result in an analogous manner by changing or shifting the respective optical lenses 30b and 30c, or 30a and 30c.

[0100] In other words, the transformation regions 56a-c result in an optical transformer 28 with two movable optical lenses 30a-d.

[0101] Fig. 9 shows a third change characteristic map 54 in a schematic representation. The change characteristic map 54 shows the transformation range 56d of an optical transformer 28 according to the invention (see Figs. 1-4) with three optical lenses 30a-c (see Figs. 1-5), wherein a beam waist width 58 of the laser beam 14 (see Figs. 1-3) is shown as a function of the beam waist position 24 of the laser beam 14. In other words, the change characteristic map 54 shows which beam waist width 58 and beam waist position 24 can be transformed in a fixed, predetermined exit laser beam 14b (see Figs. 1-3).

[0102] The transformation region 56d results from changing or shifting all three optical lenses 30a-c of the optical transformer 28. The transformation region 56 can be understood as the resulting transformation region 56 of the three transformation regions 56a-c (see Fig. 8).

[0103] Fig. 10 shows a method 64 for conditioning the laser beam 14 (see Figs. 1-4) in a schematic representation.

[0104] The method 64 is carried out using an optical functional group 10 (see Figs. 1-6) with at least one optical transformer 28 (see Figs. 1-6) having three optical lenses 30a-d (see Figs. 1-6).

[0105] The method 64 comprises at least the following method steps:

[0106] A first method step 66 provides for determining at least one time-varying propagation property of an input laser beam 14a (see Figs. 1-3) of the laser beam 14. The propagation property can be determined, in particular automatically, by means of a laser beam measuring section 44 (see Fig. 4).

[0107] A further method step 68 provides for determining a desired arrangement of the optical lenses 30a-d depending on the determined propagation property. In other words, a desired arrangement of the optical lenses 30a-d is determined in which a propagation property of the exit laser beam 14b can be kept constant despite temporally changing propagation properties in the entry laser beam 14a. The desired arrangement can be determined from a change characteristic map 54 (see Figs. 7-9). The desired arrangement can be determined by a control system 44 (see Fig. 4) of the optical functional group 10. The change characteristic map 54 can, for example, be stored in the control system 44.

[0108] A further method step 70 provides for changing at least two lens spacings 34a-c (see Figs. 1-4) by changing the position of at least one of the optical lenses 30a-d. This allows the optical transformer 28 to be adapted to the changed propagation characteristic of the input laser beam 14a in order to keep a propagation characteristic of an output laser beam (14b) constant over time.

[0109] List of reference symbols

[0110] 10 optical functional group;

[0111] 12 laser beam generation system;

[0112] 14 laser beam;

[0113] 14a entrance laser beam;

[0114] 14b Exit laser beam;

[0115] 16 first optical system;

[0116] 18 second optical system;

[0117] 20 Laser beam direction;

[0118] 22 beam diameters;

[0119] 24 beam waist position;

[0120] 26 laser beam source;

[0121] 28 optical transformer;

[0122] 30a-d optical lens;

[0123] 32 optical axis;

[0124] 34a-c lens distance;

[0125] 36 housings;

[0126] 38 third optical system;

[0127] 40 fourth optical system;

[0128] 42 fifth optical system;

[0129] 44 laser beam I measuring distance;

[0130] 46 mirrors;

[0131] 48 measuring beam;

[0132] 50 Propagation properties detector;

[0133] 52 control system;

[0134] 53 Control;

[0135] 54 Change map;

[0136] 56, 56a-d T ransformation area;

[0137] 58 waist width;

[0138] 60 beamwidth constant;

[0139] 62 Reference curve;

[0140] 64 procedures;

[0141] 66, 68, 70 process step.

Claims

Patent claims 1. Optical functional group (10) for a laser beam generation system (12), in particular for generating laser radiation, with a Laser beam source (26), comprising a first optical system (16) and an optical transformer (28) arranged downstream of the first optical system (18) in a laser beam direction (20); wherein the optical transformer (28) has at least three optical lenses (30a-d) arranged one behind the other along a common optical axis (32) of the optical transformer (28); wherein the first optical system (16) is designed to output an input laser beam (14a) with at least one time-varying propagation property; wherein the optical transformer (28) is configured to transform the input laser beam (14a) into an output laser beam (14b) with time-independent propagation properties by moving at least one movable optical lens (30a-d) to change lens distances (34a-c) between at least two of the optical lenses (30a-d). Propagation properties are developed.

2. Optical functional group (10) according to claim 1, wherein the first optical system (16) is designed as the laser beam source (26) of the laser beam generation system (12), as a laser amplifier, as an acousto-optical modulator or as an electro-optical modulator.

3. Optical functional group (10) according to claim 1 or 2, comprising a second optical system (18), wherein the second optical system (18) is designed to receive the exit laser beam (14b) with time-independent propagation properties.

4. Optical functional group (10) according to claim 3, wherein the second optical system (18) is designed as a laser amplifier, as a spatial filter, as an acousto-optical modulator, as an electro-optical modulator or as a system output.

5. Optical functional group (10) according to one of the preceding claims, wherein the optical transformer (28) has at least four or more optical lenses (30a-d) arranged one behind the other along the common optical axis (32) of the optical transformer (28).

6. The optical functional group (10) according to one of the preceding claims, wherein at least two of the optical lenses (30a-d) are configured to be movable relative to one another along the optical axis (32); wherein the optical transformer (28) is configured to change the lens spacings (34a-c) between at least three of the optical lenses (30a-d).

7. The optical functional group (10) according to claim 6, wherein all optical lenses (30a-d) are designed to be movable relative to one another along the optical axis (32); wherein the optical transformer (28) is designed to change the lens spacings (34a-c) between the optical lenses (30a-d) and / or to change a system spacing of the optical transformer (28) from the first optical system (16) and / or from a second optical system (18) arranged downstream of the optical transformer (28) along a laser beam direction (20).

8. Optical functional group (10) according to one of the preceding claims, comprising a control system (52) and a laser beam measuring section (44) arranged downstream of the first optical system (16) in the laser beam direction (20) for determining at least one propagation property of the input laser beam (14a), wherein the optical functional group (10) is designed to automatically transform the input laser beam (14a) depending on the determined propagation property.

9. Optical functional group (10) according to claim 8, wherein the laser beam measuring section (44) is used to determine a beam divergence, a Beam waist position (24) and / or a beam diameter (22), in particular a beam waist width (58) of the laser beam (14).

10. Optical functional group (10) according to one of the preceding claims, wherein at least two of the optical lenses (30a-d) are designed as converging lenses.

11. The optical functional group (10) according to claim 10, wherein at least one of the optical lenses (30a-d) is designed as a diverging lens; wherein the at least one diverging lens is arranged along the optical axis (32) between the at least two converging lenses.

12. Laser beam generation system (12), in particular High-power laser system for generating laser radiation, comprising an optical functional group (10) according to one of the preceding claims.

13. Method (64) for conditioning a laser beam (14) using an optical functional group (10) with at least one optical transformer (28) having three optical lenses (30a-d) according to one of claims 1 to 11, comprising the method steps: a) determining at least one time-varying Propagation property of an entrance laser beam (14a) of the Laser beam (14), in particular by means of a laser beam measuring section (44); b) determining an arrangement of the optical lenses (30a-d) as a function of the determined propagation property; c) changing at least two lens distances (34a-c) by changing a position of at least one of the optical lenses (30a-d) in order to keep a propagation property of an exit laser beam (14b) constant over time.

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