TW202321777A - Device for shaping a laser radiation - Google Patents

Abstract

An apparatus for shaping a laser radiation (7), comprising a first homogenizer (1) having a first array (2) of lenses (3) and a second homogenizer (4) having a second array (5) of lenses (6) through which the laser radiation (7) successively passes, a lens device (8) superimposing the laser radiation (7) passed through the second array (5) of lenses (6) in a working plane and a first prism (9) and a second prism (10) arranged between the second homogenizer (4) and the lens device (8), wherein the laser radiation (7) passed through the second array (5) of lenses (6) passes successively through the first and second prisms (9, 10) before impinging on the lens device (8).

Description

Devices that generate laser radiation

The present invention relates to a device for forming laser radiation in general terms according to claim 1, in particular for forming a linear intensity distribution of laser radiation, and to a general term according to claim 13 for use in Generating an intensity distribution of laser radiation in a working plane, in particular a laser device for generating a linear intensity distribution of laser radiation in a working plane.

, 其中p為陣列之並列透鏡之中心間距離（間距）， f _H 為第二陣列之透鏡之焦距，且 f _F 為第二均勻器後方的傅里葉透鏡之有效焦距。此等量在製造期間可自由選擇，但此後固定。因此，在製造之後，通常不再有可能影響作業平面中之雷射輻射的線長度或場大小。 In known devices for forming a linear intensity distribution of laser radiation comprising two homogenizers with a lens array and a Fourier lens, the length L of the linear intensity distribution results from the following relationship:

, where p is the center-to-center distance (pitch) of the juxtaposed lenses of the array, f _H is the focal length of the lenses of the second array, and f _F is the effective focal length of the Fourier lens behind the second homogenizer. These quantities are freely selectable during manufacture, but fixed thereafter. Consequently, after production it is generally no longer possible to influence the line length or the field size of the laser radiation in the working plane.

A device of the aforementioned type and a laser device are known from DE 10 2007 026 730 A1. The devices described herein include a first homogenizer stage with a lens array and a second homogenizer stage with two substrates, each of which has a lens array disposed thereon. A lens is further provided for superimposing the partial beams emerging from the second homogenizer stage in the working plane, so that a linear intensity distribution of the laser radiation is produced there. In order to be able to adjust the line length of the linear intensity distribution, the two base plates of the second homogenizer stage can be moved relative to each other so that different distances can be achieved in the direction of light propagation.

Since the two substrates of the second homogenizer stage can move relative to each other, the optical effectiveness of the device and the uniformity of the intensity distribution in the working plane are affected.

From this beginning, the invention is based on the problem of producing a device of the type mentioned at the outset, whereby a greater optical effectiveness of the device and/or a better homogeneity of the intensity distribution in the working plane can be achieved. In addition, a laser device having this device will be described in detail.

According to the invention, this is achieved by a device of the type mentioned at the outset having the characterizing features of claim 1 and by means of a laser device of the type mentioned at the outset having the characterizing features of claim 13 to fulfill. The sub-claims are related to preferred specific examples of the present invention.

According to claim 1, the device comprises a first lens and a second lens arranged between the second homogenizer and the lens arrangement, the device being adapted so that the laser radiation passing through the second array of lenses is irradiated on the lens Pass through the first and second openings in sequence before getting on the device. The insertion of the two discs between the second homogenizer and the lens arrangement has little or no influence on the optical effectiveness of the arrangement and the homogeneity of the resulting intensity distribution in the working plane.

In particular, it may be provided that the aperture is arranged to at least partially reduce or increase the cross-section and/or the divergence of the laser radiation passing through the aperture in a first direction, in particular wherein by means of the divergence The length of the linear intensity distribution is increased by increasing the divergence, and the length of the linear intensity distribution is decreased by reducing the divergence. In particular, the linear intensity distribution thereby extends in the first direction.

Preferably, the aperture may be configured to vary the divergence of the laser radiation passing through the aperture at least partially in a first direction by a factor between 0.5 and 2.0, in particular wherein the linear intensity The length of the distribution is thereby varied by a factor between 0.5 and 2.0. Therefore, it can be used to influence the shape of the intensity distribution, the length of the generated laser line in the working plane, over a relatively large range.

It is possible that the lenses of the first array and the second array are respectively arranged adjacent to each other, in particular the direction in which the lenses of the first array and the second array are arranged adjacent to each other corresponds to the first direction. In this regard, the lenses of the first and second arrays may be cylindrical lenses having their cylindrical axes aligned parallel to each other, wherein the cylindrical axes extend in a second direction perpendicular to the first direction. In this way, the lens can promote homogenization in the direction of the longitudinal lines. It is conceivable to provide further lenticular lenses in the homogenizer for a direction perpendicular to the transverse lines, the lenticular axes of which extend in the first direction.

Possibly, the first lens is arranged in the device in such a way that partial beams of the laser radiation passing through adjacent lenses of the second array do not yet overlap each other at least in the first direction when entering the first lens, In this way, partial beams that have passed through individual lenses can be formed separately from the beam.

It may be provided that at least one of the bells, preferably both of the bells, is movable, preferably pivotable about an axis. Thereby, the movement (pivoting) of at least one of the canals can change the factor by which the cross-section of the laser radiation passing through the canal changes. In particular, the axis about which at least one, preferably both, of the shells is pivotable extends in the second direction. This design makes it extremely easy to influence the field size or line length of the laser radiation in the working plane.

It is possible that two fennels have the same design, same size and/or same shape. With this design, the manufacturing cost of the device can be reduced.

It may be provided that the distance between the lenses of the first array and the lenses of the second array corresponds to the focal length of at least some, preferably all, lenses of the second array. Furthermore, the lens arrangement can be positioned in the device in a Fourier configuration such that the distribution of laser radiation present in the angular space between the second array and the lens arrangement is transformed by the lens arrangement into an intensity distribution in volumetric space.

As with the device of claim 13, it may be provided that the device for forming the laser beam is a device according to the invention.

It is possible that the laser device comprises two laser sources configured to generate laser beams having mutually different properties, for example two divergence or beam profiles which are different from each other, wherein the laser device is configured such that the laser beams Irradiations are made on devices adjacent to each other, and the lens arrangement superimposes two laser beams in the working plane, in particular in a linear intensity distribution. It has proven to be extremely advantageous that a single lens arrangement in a Fourier configuration superimposes two possibly very different laser beams in the working plane, in particular in a linear intensity distribution in the working plane, while the length of the line can be given by Corresponding location designation.

For this purpose it may be provided that the means for forming the laser beams comprises four beams, two of which are provided for each of the mutually different laser beams.

Alternatively, provision may be made for the means for forming the laser beam to comprise two beams which are provided for two mutually different laser beams.

In the figures, identical and functionally identical parts are provided with the same reference symbols. In some drawings, a Cartesian coordinate system is drawn for better orientation.

The specific example of a device for forming a laser beam shown in FIG. 1 comprises, in a manner known per se, a first homogenizer 1 with a first array 2 of lenses 3 and a second homogenizer with a second array 5 of lenses 6. device 4. The device is configured for forming a laser beam 7 to pass sequentially through the first array 2 of lenses 3 and the second array 5 of lenses 6 .

The lenses 3 and 6 are arranged side by side in the first direction x. The lenses 3 , 6 are cylindrical lenses, the cylindrical axis of which extends in a direction y perpendicular to the first direction x, and the second direction y extends out of the plane of FIG. 1 . The lenses 3, 6 thus act in the first direction x. The laser beam 7 moves substantially in a third direction z perpendicular to the first direction x and the second direction y.

It is of course possible to provide spherical lenses or lenses of different shape instead of cylindrical lenses, which act both in the first direction x and in the second direction y.

In the drawing, the first array 2 is arranged on the outlet surface of the first homogenizer 1 and the second array 5 is arranged on the inlet surface of the second homogenizer 4 . It is quite possible to arrange both the arrays 2, 5 on the inlet surface or the outlet surface, or to arrange the first array 2 on the inlet surface of the first homogenizer 1 and the second array 5 on the outlet of the second homogenizer 4 On the surface. Furthermore, it can also be provided that only a single transparent substrate is provided, on the entrance surface of which substrate the first array 2 is arranged and on the exit surface of which substrate the second array 5 is arranged.

For example, other possibilities are that a lens array not shown in the figure is arranged on the entrance surface of the first homogenizer 1 and/or on the exit surface of the second homogenizer 4, and these lenses act on the second direction y. For example, the lenses may be cylindrical lenses whose cylindrical axis extends in the first direction x.

All lenses 6 of the second array 5 have the same focal length. The distance between the two arrays 2 , 5 is equal to the focal length of the lens 6 of the second array 5 .

The device illustrated in FIG. 1 further comprises, in a manner known per se, a lens arrangement 8 formed in the illustrated embodiment as a plano-convex lens 8 in a Fourier configuration. The lens arrangement 8 superimposes, in a manner known per se, the partial beams of the laser radiation 7 emanating from the lenses 6 of the second array 5 in the working plane in the first direction x, not shown in the figure. In this way, the distribution of the laser radiation in angular space is converted into a distribution in solid space in the working plane.

It is of course possible to provide lenses of other shapes, such as bi-convex lenses. Furthermore, lens systems may also be provided instead of a single lens.

The device illustrated in FIG. 1 further comprises two apertures 9 , 10 between the second homogenizer 4 and the lens arrangement 8 through which the laser radiation 7 passes sequentially. In the illustrated specific example embodiment, the bells 9 , 10 have the same size and the same shape, and the cross-section evident in FIG. 1 continues into the plane of extension of FIG. 1 .

The first laser beam 9 on the left side in Fig. 1 is such that when the laser radiation 7 is irradiated on the incident surface 11 of the first laser beam 9, the part of the laser radiation 7 that has passed through the adjacent lens 6 of the second array 5 The light beams are arranged in such a way that they do not yet overlap each other in the first direction x.

By means of a suitable alignment of the beams 9, 10, a change in cross-section and/or divergence of the partial light beams emanating from each of the lenses 6 can be achieved, in particular changed equally for each of the partial light beams . The following applies to change: D _in · F _in = D _out · F _out , where D _in is the range of the part of the radiation that enters 9, 10 in the first direction x in the solid space, and F _in is the range in the angular space In the first direction x, the part of the radiating range that enters the 稜鏡 9, 10, D _out is the range of the part of the radiation that leaves the 稜 9, 10 in the first direction x in the three-dimensional space, and F _out is in the angular space In the first direction x, the range of the part of the radiation emitted from 騜鏡 9, 10.

FIG. 2 a shows in the left figure a cross-section 12 a and a range Din of a part of the radiation entering the beams 9 , 10 in a first direction x, respectively, in three-dimensional space. Fig. 2a shows in the right figure the divergence 13a, the range Din, respectively, of the part of the radiation entering the beams 9, 10 in the first direction x in angular space.

Fig. 2b and Fig. 2c illustrate the influence of two different positions of the fen 9, 10 on the part of the radiation emitted from the fen.

FIG. 2b thus shows alone in the left figure a cross-section 12b of the area D _out of the partial radiation emerging from the beams 9 , 10 in the first direction x in three-dimensional space. FIG. 2b shows in the right figure alone the divergence 13b of the area outside the part of the radiation emerging from the beams 9, 10 in angular space in the first direction x. It can be seen that the divergence 13b is smaller than the divergence 13a. A smaller divergence 13b or a smaller spread in angular space is converted by the lens arrangement 8 into a distribution in solid space in the working plane, resulting in a smaller spread of the field in the working plane in the first direction x, in particular The smaller length of the linear intensity distribution.

FIG. 2 c shows alone in the left figure a cross-section 12 c of the range D _out of the partial radiation emerging from the beams 9 , 10 in the first direction x in three-dimensional space. FIG. 2 c shows in the right figure alone the divergence 13 c of the area outside the part of the radiation emerging from the beams 9 , 10 in angular space in the first direction x. It can be seen that the divergence 13c is greater than the divergence 13a. The greater divergence 13c or greater expansion of angular space is converted by the lens arrangement 8 into a distribution in solid space in the working plane, resulting in a greater expansion of the field in the working plane in the first direction x, in particular The greater length of the linear intensity distribution.

In Figures 3a to 4b this is illustrated by a specific embodiment embodiment of a device for forming a linear intensity distribution 14 of laser radiation in a working plane.

Fig. 3a shows the device with the bells 9, 10 in a first position. In this first position, the length of the linear intensity distribution 14 is slightly greater than 700 mm, as can be seen from Fig. 3b.

Figure 4a shows the same device as in Figure 3a. However, in Fig. 4a, the bells 9, 10 are in a second position different from the first position. In this second position, the length of the linear intensity distribution 14 is about 500 mm, as can be seen in Fig. 4b.

The different positions of the scallops 9, 10 can be achieved by pivoting the individual scallops 9, 10 about an axis extending in the second direction y. For example, in the position shown in Figures 3a and 4, the first knob 9 in Figure 4a is pivoted clockwise relative to the knob 9 in Figure 3a about a corresponding axis extending in the second direction y. Furthermore, in the position shown in Figures 3a and 4, the second drum 10 in Figure 4a is pivoted counterclockwise relative to the drum 9 in Figure 3a about a corresponding axis extending in the second direction y.

Fig. 5 shows a specific example of a device according to the invention which differs from the device in Fig. 1 in that instead of two notches 9, 10 four notches 9a, 9b, 10a, 10b are provided. Here, the two first paddles 9a, 9b are arranged side by side in the first direction x. Furthermore, the two second paddles 10a, 10b are arranged in close proximity to each other in the first direction x.

Two laser beams 7 a , 7 b , which differ from each other, for example by their divergence or beam profile, impinge on the device. The first laser beam 7a is irradiated on the upper area of the first homogenizer 1 in FIG. 5 , and the second laser beam 7b is irradiated on the lower area of the first homogenizer 1 in FIG. 5 .

The arrangement is thereby arranged such that the laser radiation 7a which has passed through the upper first 9a in FIG. 5 then passes through the upper second 10a in FIG. The laser radiation 7b of the first cell 9b then passes through the lower second cell 10b in FIG. 5 . Furthermore, the arrangement is arranged such that the two laser beams 7a, 7b which have passed through the second laser beam 10a, 10b pass together through the lens arrangement 8 and are superimposed by it in the working plane, in particular in a linear intensity distribution.

It has proven to be extremely advantageous that a single lens arrangement 8 in a Fourier arrangement superimposes two possibly very different laser beams 7a, 7b in the working plane, in particular in a linear intensity distribution in the working plane, while the length of the line It can be pre-determined by the corresponding positions of 稜鏡9a, 9b, 10a, 10b.

It can be provided that the homogenizers 1, 4 have different design areas for the different laser beams 7a, 7b which are adjacent or spaced apart from each other in the first direction x.

It is also possible that the means for forming the two different laser beams 7a, 7b do not contain four but only two (not shown) beams, which in this case are passed through Provision is made for both of the different laser beams 7a, 7b.

Other possibilities, in the embodiments illustrated in Figures 1, 3a, 4a and 5, other lenses are provided for focusing the laser radiation or the laser radiation into the working plane and/or for The second direction y forms the laser radiation or the laser radiation. Where applicable, such lenses have not been shown for reasons of clarity.

1: The first homogenizer 2: first array 3: Lens 4: Second homogenizer 5: second array 6: Lens 7: Laser beam 7a: Laser Beam 7b: Laser Beam 8: Lens device 9: 稜鏡 9a: 稜鏡 9b: 稜鏡 10: 稜鏡 10a: 稜鏡 10b: 稜鏡 11: Incident surface 12a: Cross section 12b: Cross section 12c: Cross section 13a: Divergence 13b: Divergence 13c: Divergence 14: Linear intensity distribution

Other features and advantages of the present invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings. Shown in this article: [ FIG. 1 ] is a schematic side view of a first embodiment of the device according to the present invention, wherein a beam of laser radiation to be formed has been introduced; [Fig. 2a] are two diagrams schematically illustrating the distribution of the laser radiation behind the second homogenizer in three-dimensional space and in angular space; [ FIG. 2 b ] are two diagrams schematically illustrating the distribution of the laser radiation behind the second horn in the three-dimensional space and in the angular space in the first position of the two horns; [FIG. 2c] Two diagrams schematically illustrating the distribution of the laser radiation behind the second horn in solid space and in angular space in the second position of the two horns; [Fig. 3a] is a schematic side view according to the specific example of Fig. 1 in the first position of the two 稜鏡; [Fig. 3b] is a graph in which the intensity of the laser radiation in the working plane is plotted in arbitrary units with respect to the spatial coordinates in the line longitudinal direction of the linear intensity distribution in mm, wherein two of them are shown in Fig. 3a in the first position shown; [Fig. 4a] is a schematic side view according to the embodiment of Fig. 1 in the second position of the two 稜鏡; [Fig. 4b] is a graph in which the intensity of the laser radiation in the working plane is plotted in arbitrary units with respect to the spatial coordinates in the line longitudinal direction of the linear intensity distribution in mm, and the two beams are shown in Fig. 4a in the second position; [ FIG. 5 ] is a schematic side view of a second embodiment of the device according to the invention, in which a beam of laser radiation to be formed has been introduced.

1: The first homogenizer

2: first array

3: Lens

4: Second homogenizer

5: second array

6: Lens

7: Laser beam

8: Lens device

9: 稜鏡

10: 稜鏡

11: Incident surface

Claims (16)

A device for forming laser radiation (7, 7a, 7b), in particular a device for forming a linear intensity distribution (14) of laser radiation (7, 7a, 7b), comprising: A first homogenizer (1) comprising a first array (2) of lenses (3), the device configured for passing the laser radiation (7, 7a, 7b) to be shaped through the first The lens (3) of the array (2), A second homogenizer (4) having a second array (5) of lenses (6), said device configured for irradiating laser light which has passed through said first array (2) of lenses (3) (7, 7a, 7b) passing through the lens (6) of said second array (5), A lens arrangement (8) configured for passing said laser radiation (7, 7a, 7b) having passed through a lens (6) of said second array (5) through said lens arrangement ( 8) such that at least part of the beams of laser radiation (7, 7a, 7b) which have passed through some of the lenses (6) of said second array (5) are superimposed in the working plane, wherein said means comprise The first 稜鏡 (9, 9a, 9b) and the second 稜鏡 (10, 10a, 10b) arranged between the second homogenizer (4) and the lens device (8), the device is configured such that said laser radiation (7, 7a, 7b) passing through the lenses (6) of said second array (5) sequentially passes through said first lenses before impinging on said lens means (8) Mirror and the second 騜鏡 (9, 9a, 9b, 10, 10a, 10b). The apparatus of claim 1, wherein said 稜鏡 (9, 9a, 9b, 10, 10a, 10b) is configured to reduce or increase at least partially across said 稜叡 in a first direction (x) The cross-section (12a) and/or divergence (13a) of said laser radiation (7, 7a, 7b), in particular, wherein the length of said linear intensity distribution (14) is increased by said divergence The increase of the divergence (13a) is achieved and the reduction of the length of the linear intensity distribution (14) is achieved by the decrease of the divergence (13a). The apparatus of claim 2, wherein said 稜鏡 (9, 10) is configured to direct said laser radiation (7, 7a, 7b) said divergence (13a) is varied by a factor between 0.5 and 2.0, in particular whereby the length of said linear intensity distribution (14) is varied by a factor between 0.5 and 2.0. The device according to any one of claims 1 to 4, wherein the lenses (3, 6) of the first array (2) and the second array (5) are arranged adjacent to each other, specifically, wherein The direction (x) in which the lenses (3, 6) of the first array (2) and the second array (5) are arranged adjacent to each other corresponds to the first direction (x). The device according to any one of claims 1 to 4, wherein the lenses (3, 6) of the first array (2) and the second array (5) are cylindrical lenses, and the cylindrical lenses of the lenses The axes are aligned parallel to each other, in particular wherein said cylindrical axis extends in a second direction (y) perpendicular to said first direction (x). The device according to any one of claims 2 to 5, wherein the first lens (9, 9a, 9b) is positioned so that the adjacent lens (6) that has passed through the second array (5) Partial beams of said laser radiation (7, 7a, 7b) are arranged in said first beam (9, 9a, 9b) in such a way that they do not yet overlap each other at least in said first direction (x) when they enter said first beam (9, 9a, 9b). in the device described above. The device according to any one of claims 1 to 6, wherein, at least one of the 稜鏡 (9, 9a, 9b, 10, 10a, 10b), preferably two 稜鏡 (9, 9a, 9b, 10, 10a, 10b) are movable, preferably pivotable about an axis. Apparatus according to claim 7, wherein the movement, in particular said pivoting, of said at least one scallop (9, 9a, 9b, 10, 10a, 10b) changes across said scallop (9, 9a, 9b, 10, 10a, 10b), said factor by which said cross-section of said laser radiation (7, 7a, 7b) changes. The device according to any one of claim 7 or 8, wherein, at least one of the 稜鏡 (9, 9a, 9b, 10, 10a, 10b), preferably two 稜鏡 (9, 9a, 9b, 10, 10a, 10b) about which the axis is pivotable extends in the second direction (y). The device according to any one of claims 1 to 9, wherein said two scorpions (9, 9a, 9b, 10, 10a, 10b) have the same design, in particular, the same size and/or the same shape . The device according to any one of claims 1 to 10, wherein the distance from the lens (3) of the first array (2) to the lens (6) of the second array (5) corresponds to The focal length of at least some lenses (6), preferably all lenses (6) of said second array (5). The device of any one of claims 1 to 11, wherein said lens arrangement (8) is positioned in said device in a Fourier configuration such that between said second array (5) and said lens arrangement The distribution of said laser radiation (7, 7a, 7b) in angular space is converted by said lens means (8) into an intensity distribution in solid space. A device for generating an intensity distribution (7, 7a, 7b) of laser radiation (7, 7a, 7b) in a working plane, in particular for generating a linear intensity distribution (14) of laser radiation (7, 7a, 7b) in a working plane Laser device comprising at least one laser light source and means for forming laser radiation (7, 7a, 7b), wherein said means for forming laser radiation (7, 7a, 7b) is as claimed The device of any one of 1 to 12. The laser device according to claim 13, wherein the laser device comprises two lasers configured to generate laser beams (7a, 7b) having different properties from each other, such as having different divergence or beam profiles from each other a light source, wherein said laser devices are configured to impinge said laser beams (7a, 7b) on said devices adjacent to each other, and said lens device (8) superimposes two Two laser beams (7a, 7b), in particular superimposed said laser beams in said linear intensity distribution (14). The laser device according to claim 13, wherein said means for forming a laser beam (7, 7a, 7b) comprises four beams (9a, 9b, 10a, 10b), two of said beams are provided in each case for one of said laser beams (7a, 7b) which differ from each other. Laser device according to claim 13, wherein said means for forming laser beams (7, 7a, 7b) comprises being provided for two of said mutually different laser beams (7a, 7b) The two 稜鏡.

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