Optical devices, methods and uses

Abstract

The present invention relates to an optical device for interference structuring of a sample, its use, and a method. A laser emits a laser beam, which is split into at least two partial beams by a splitter. A first cylindrical lens and a second cylindrical lens are arranged in the beam path to refract the partial beams into an interference region. The partial beams interfere so that structures with linear structural elements can be formed in the structure region of the sample. The cylindrical axis of the first cylindrical lens is oriented parallel to the cylindrical axis of the second cylindrical lens.

Description

[Technical field]

[0001] The present invention relates to an optical device, a method and a use for interferometric structuring of a sample. [Background technology]

[0002] In the context of the invention, samples are components which are, for example, integrated into complex components and which are provided with a relatively large structure during processing. From the standpoint of productivity, it is desirable to produce the structuring over a large area and in the shortest possible time.

[0003] For this purpose, it is known to perform the structuring of the sample by interference structuring, in which a laser beam is split into two partial beams which interfere with each other in the structure area of ​​the sample by means of further optical components, and the structuring of the sample is formed as a result of the spatial interference energy distribution of the interfering partial beams. Known devices of this kind are disclosed, for example, in DE 10 200 43 331 A1, with which structures with linear structuring elements can in particular be formed. Due to the large number of optical components, known devices are expensive and vulnerable to misadjustments. Particularly high efforts must therefore be expended when shaping and deflecting the individual partial beams, and the angles must be precisely maintained during the beam deflection of the partial beams. This is particularly complicated when parameters are to be changed during processing in order to have the desired effect on changes in the individual structures or structural elements. In addition, the difference in the path lengths traveled by the partial beams can be so large, in particular in the case of pulsed laser beams with short or even ultrashort pulse durations, that it exceeds the coherence length of the laser beam, as a result of which the partial beams do not interfere and therefore no structuring of the sample takes place. The known devices are therefore not suitable for ultrashort laser pulses with pulse durations in the femtosecond and / or picosecond range. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] European Patent Application Publication No. 2596899 Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the present invention can therefore be seen as providing an improved device that allows for a more efficient interference structuring of a sample while eliminating the disadvantages of the prior art, which device should provide for simple and cost-effective handling and in particular allow for interference structuring of a sample with short pulse durations. The corresponding applies to the method and the use. [Means for solving the problem]

[0006] This problem of the invention is solved by an optical device for interference structuring of a sample, comprising a laser for emitting a laser beam, a beam splitter for splitting the laser beam into at least two partial beams, at least one first cylindrical lens and at least one second cylindrical lens for refracting the at least two partial beams in the direction of an interference region, wherein the beam splitter, the at least one first cylindrical lens and the at least one second cylindrical lens are arranged in the beam path of the laser beam such that at least two partial beams of the laser beam interfere with each other in the interference region in such a way that structures with linear structural elements can be formed in a structural region of the sample, and wherein a cylindrical axis of the at least one first cylindrical lens is oriented parallel to a cylindrical axis of the at least one second cylindrical lens.

[0007] The object of the invention is further achieved by a method for interference structuring of a sample, comprising the steps of providing a laser for emitting a laser beam, splitting the laser beam into at least two partial beams, arranging at least one first cylindrical lens, arranging at least one second cylindrical lens in such a way that the at least two partial beams are refracted in the direction of an interference region, such that the at least two partial beams of the laser beam interfere with one another in the interference region so that structures with linear structural elements can be formed in a structural region of the sample, and orienting a cylindrical axis of the at least one first cylindrical lens parallel to a cylindrical axis of the at least one second cylindrical lens.

[0008] Furthermore, the object of the present invention is achieved by the use of an apparatus according to the invention for interference structuring of a specimen, in particular a component.

[0009] The invention is based on the basic idea that by orienting the cylindrical axis of at least one first and at least one second cylindrical lens according to the invention, the manipulation of the laser beam, including the partial beams, is possible in a targeted manner in a first plane which contains the optical axis and is arranged perpendicular to the cylindrical axis of the at least one first cylindrical lens, without the beam path of the laser beam being affected in a second plane which is arranged perpendicular to the first plane. This allows the interference structuring of the sample to be influenced particularly simply and efficiently. The handling of the inventive device is thereby significantly simplified compared to known devices. The same also applies to the inventive method and to the use of the invention. A further advantage of the inventive device results from the fact that the path difference of the partial beams is relatively small and therefore does not exceed the coherence length of the laser beam, so that interference of the partial beams can take place, and thus interference structuring of the sample is possible, especially with laser beams with short and / or ultrashort laser pulses. The inventive device is therefore particularly suitable for laser beams with short pulse durations.

[0010] In the present invention, interference structuring is the structuring of a sample by interference of at least two beams. The spatial energy distribution formed by the interference of the partial beams interacts with the sample material in such a way that the structuring of the sample takes place in accordance with the energy distribution of the interference structure. In particular, this allows the structuring of the sample to take place by linear structural elements arranged in a structural period. In this respect, interference structuring comprises material removal of the sample, for example by removal, and targeted modification of the sample material, for example by photopolymerization. Furthermore, targeted refinement and / or targeted modification of the chemical composition and / or modification of the (crystalline) structure of the sample material can be carried out by interference structuring. The structuring of the sample takes place in the present invention, for example, on the sample surface and / or in the sample volume, in particular the sample can be processed lithographically by interference structuring, which is also referred to as interference lithography. The structuring of the sample is used to provide the sample with technical functions, aesthetic impressions and / or labels. Beam upstream in the present invention refers to the direction opposite to the propagation direction of the laser beam, which direction therefore points towards the laser. Correspondingly, the beam downstream represents the direction away from the laser.

[0011] The laser may be configured as a diode-pumped solid-state laser and may in particular emit a pulsed laser beam, the laser pulses having a pulse duration in the femtosecond, picosecond and / or nanosecond range and a wavelength in the UV, VIS and / or IR range. As is known, laser pulses having a pulse duration in the femtosecond and / or picosecond range are called ultrashort pulses. The laser pulses preferably have a pulse duration between 10 fs and 10 ms. The laser preferably emits a collimated laser beam, which is in particular oriented parallel to the optical axis.

[0012] The beam splitter is preferably a diffractive optical element, in particular configured as a grid. Alternatively, the beam splitter can be configured as a prism or, for example, as a semi-transparent mirror. The mirror is preferably configured as a partially reflecting mirror. The at least two partial beams are arranged in particular in a common plane, which plane contains the optical axis and is arranged perpendicular to the cylindrical axis of the at least one first cylindrical lens. Due to the simple configuration of the device, the at least two partial beams each have a respective propagation direction arranged at the same angle to the optical axis. In a further embodiment of the invention, the at least two partial beams are configured to be intensity-wise identical, so that, for example, the intensity of the first partial beam is substantially the same as the intensity of the second partial beam.

[0013] In the present invention, the interference angle is the angle at which the partial beams are refracted towards the interference region with respect to the optical axis behind at least one second cylindrical lens. The interference angle can relate to a first plane, for example the yz-plane, and / or a second plane, for example the xz-plane, since the partial beams can be manipulated according to the present invention independently of one another in the first and second planes. The interference angle can be variable in order to change the structural period of the interference pattern. For this purpose, the beam splitter can preferably be translated parallel to the optical axis.

[0014] The at least one first cylindrical lens may be configured as a focusing lens with at least one convex surface and / or may be located beam upstream or beam downstream of the beam splitter. Alternatively, the at least one first cylindrical lens may be translated parallel to the optical axis.

[0015] The at least one second cylindrical lens is preferably arranged so as to be refracted towards an interference region where the partial beams interfere with each other and is preferably configured as a converging lens with at least one convex surface. The focal length of the at least one second cylindrical lens is preferably smaller than the focal length of the at least one first cylindrical lens, so that a maximum possible interference angle can be adjusted. To improve the adjustment of the inventive device, the at least one second cylindrical lens can be translated, preferably parallel to the optical axis.

[0016] The distance between the at least one first cylindrical lens and the at least one second cylindrical lens is preferably at least or at most, in particular substantially the sum of two focal lengths. This allows the partial beams to be focused at a focal point that is actually in front of the second cylindrical lens or virtually behind it, respectively. The path difference of the partial beams is small so that the interference of the partial beams takes place volumetrically, so that the interference region is three-dimensional, i.e. has an extent in particular in the direction of the optical axis. This allows a volumetric structuring of the sample, in particular when using ultrashort pulse lengths. The focal points of all partial beams are preferably in a common focal plane, which can be oriented perpendicular to the optical axis. In a further embodiment of the invention, the convex surfaces of the first and second cylindrical lenses face each other and / or the flat surfaces of the first and second cylindrical lenses face away from each other.

[0017] At least one third cylindrical lens is preferably provided as a focusing lens, the cylindrical axis of which is oriented perpendicular to the cylindrical axis of the at least one first cylindrical lens, in particular perpendicular to the optical axis, so that the beam path in the second plane can be influenced by the at least one third cylindrical lens independently of the first plane. In a particularly simple development of the invention, the at least one third cylindrical lens is arranged beam-upstream and / or beam-downstream of the beam splitter. Preferably, the distance of the interference region from the at least one third cylindrical lens corresponds to its focal length, so that the laser beam, including its partial beams, is focused in the second plane to the interference region. Alternatively, the distance of the interference region from the at least one third cylindrical lens is greater or smaller than its focal length. The at least one third cylindrical lens is translated parallel to the optical axis to vary the extent of the interference pattern perpendicular to the cylindrical axis of the at least one third cylindrical lens.

[0018] In an advantageous embodiment of the invention, at least one fourth cylindrical lens is provided as a concave lens, the cylindrical axis of which is arranged in particular parallel to the cylindrical axis of the at least one first cylindrical lens. The at least one fourth cylindrical lens can be arranged in the beam downstream of the beam splitter and / or the at least one first cylindrical lens, but preferably in the beam upstream of all focal points of the partial beams. The at least one fourth cylindrical lens can be translated in particular parallel to the optical axis. In addition, the at least one fourth cylindrical lens can be rotated about its cylindrical axis. In an especially advantageous embodiment of the invention, exactly one fourth cylindrical lens is assigned to each partial beam, and the fourth cylindrical lens can be rotated about its respective cylindrical axis. In order to adjust each partial beam individually, in particular at least two fourth cylindrical lenses are movable independently of one another, alternatively or additionally, for a simple adjustment, the at least two fourth cylindrical lenses are movable synchronously with one another. The at least one fourth cylindrical lens can be arranged such that the at least one partial beam is collimated behind the fourth cylindrical lens. Preferably, the at least one fourth cylindrical lens together with the at least one first cylindrical lens and the at least one second cylindrical lens form a lens system which as a whole is movable parallel to the optical axis, and the relative positions of the components of the lens system can be kept constant with respect to one another along the optical axis.

[0019] In a further advantageous embodiment of the invention, at least one fifth cylindrical lens is provided as a focusing lens, the cylindrical axis of which is oriented parallel to the cylindrical axis of the at least one first cylindrical lens and in particular forms a lens system together with the at least one first cylindrical lens, so that optical errors of the first cylindrical lens can be corrected by the fifth cylindrical lens, which is preferably arranged directly adjacent to the at least one first cylindrical lens.

[0020] Preferably, at least one sixth cylindrical lens is provided as a focusing lens, the cylindrical axis of which is oriented parallel to the cylindrical axis of the at least one first cylindrical lens, and can be arranged in the beam upstream of the at least one second cylindrical lens. The convex surface of the at least one sixth cylindrical lens can face the at least one first cylindrical lens. Alternatively, at least one seventh cylindrical lens can be provided as a concave lens, the cylindrical axis of which is oriented parallel to the cylindrical axis of the at least one first cylindrical lens, and can be arranged in the beam upstream of the at least one second cylindrical lens. The at least one seventh cylindrical lens, preferably together with the at least one sixth cylindrical lens and the at least one second cylindrical lens, constitutes a lens system for correcting optical errors. To that end, in particular the at least one sixth cylindrical lens and / or the at least one seventh cylindrical lens and / or the at least one second cylindrical lens can be translated parallel to the optical axis independently of one another.

[0021] In a further embodiment of the invention, a first prism is provided, the prism axis of which is arranged perpendicular to the base surface and is oriented parallel to the cylindrical axis of at least one first cylindrical lens. The first prism has a focusing optical effect, in particular on the laser beam, including its partial beams. In particular, the first prism has a polygonal base surface, which is preferably in the shape of an isosceles triangle, for example. Alternatively, the base surface of the at least one prism can be round, in particular elliptical. At least one surface of the at least one first prism can be oriented perpendicular to the optical axis. The at least one first prism can preferably be translated parallel to the optical axis and / or is arranged downstream of the at least one first cylindrical lens.

[0022] Preferably, at least one second prism is provided, the prism axis of which is oriented parallel to the cylindrical axis of the at least one first cylindrical lens. For example, the at least one second prism has a diffusive optical effect on the laser beam, including its partial beams. In addition, the at least one second prism can have a base surface corresponding to two assembled right-angled triangles. The second prism can be translated parallel to the optical axis. In an advantageous embodiment of the invention, the base surfaces of the first prism and the at least one second prism together correspond to a rectangle. In a particularly preferred embodiment, exactly one second prism is assigned to each partial beam, in particular the base surface of the second prism corresponds to a right-angled triangle. The at least two second prisms are movable independently of one another and / or the at least two second prisms are movable synchronously with one another. The at least one first prism and / or the at least one second prism may be disposed between the at least one first cylindrical lens and the at least one second cylindrical lens.

[0023] The beam splitter and / or the at least one cylindrical lens and / or the at least one prism can preferably be translated parallel to the optical axis in order to change parameters of the interference structure and / or to correct optical errors.

[0024] Furthermore, at least one beam expander is preferably provided for changing the beam cross section of the laser beam, including its partial beams, and / or for changing the structural period. The beam expander can be configured, for example, to change the interference angle of the partial beams, thereby changing the structural period of the interference pattern. For example, the at least one beam expander is formed by three cylindrical lenses and / or by a cylindrical lens with a first prism and at least one second prism. Since at least one of its components is movable, the beam expander is preferably configured as a variable beam expander. Functionally, the beam expander thus corresponds in particular to an optical expansion device of the laser beam, which expands the cross section of the laser beam when the magnification value is greater than 1 and reduces the cross section of the laser beam when the magnification value is between 0 and 1.

[0025] The interference pattern preferably has linear structural elements, the extension direction of which is respectively arranged parallel to the cylindrical axis of the first cylindrical lens. In addition, the interference pattern can have a user-defined, in particular variable, structural period in at least one direction, which structural period corresponds to the spacing between two adjacent structural elements. The interference pattern is preferably rectangular or elliptical, and the interference pattern can have a different extent in a first axis oriented parallel to the cylindrical axis of the first cylindrical lens than in a second axis arranged perpendicular to the cylindrical axis of the first cylindrical lens. The extent of the interference pattern and its structural period are variable, in particular by changing the optical components of the device according to the invention, preferably by changing the position and / or optical properties. In addition, the spatial position of the interference pattern is variable, in particular by moving at least one fourth cylindrical lens.

[0026] The spread of the interference pattern in a certain direction can be varied in particular by modifying at least one of the cylindrical lenses arranged with its cylindrical axis perpendicular to this direction, modification in this sense including a change in focal length and / or a change in position, for example the spread of the interference pattern in the y direction is possible by modifying the focal length of at least one of the cylindrical lenses arranged with its cylindrical axis parallel to the x direction and vice versa.

[0027] A beam shaping device is preferably provided, which is configured to vary the cross-sectional profile of the laser beam in a user-defined manner in order to affect the shape of the interference structure, the cross-sectional profile being variable in particular by diffraction effects. Particularly preferably, the beam shaping device is configured to form an elliptical or polygonal, in particular a rectangular, cross-sectional profile of the laser beam, in particular from a Gaussian spatial intensity distribution of the cross-sectional profile, the latter being referred to as a "top hat" or "flat-top" profile. By changing the cross-sectional profile of the laser beam, the shape of the interference pattern can be changed, for example a rectangular cross-sectional profile which can be obtained by the beam shaping device already mentioned gives rise to a rectangular shape of the interference pattern. The beam shaping device can be configured integrally with the beam splitter.

[0028] In a particularly preferred embodiment, a single first cylindrical lens and / or a single second cylindrical lens is provided in order to affect all partial beams by a single cylindrical lens. Alternatively, it is possible to replace each cylindrical lens by a lens system in order to correct optical errors. The laser beam, including the partial beams, can be oriented at least partially between at least one first cylindrical lens and at least one second cylindrical lens parallel to the optical axis, in particular collimated, or can have a divergence. The divergence can affect the size of the partial beam cross section in the interference region and thus the size of the interference pattern.

[0029] The method according to the invention is preferably carried out using the optical device according to the invention.

[0030] Further advantages and characteristics of the invention emerge from the claims and from the following description in which an embodiment of the invention has been explained in detail with reference to the drawings. [Brief description of the drawings]

[0031] [Figure 1] 2 shows an embodiment of the optical device of the present invention in the yz plane. [Diagram 2] 2 shows the embodiment of FIG. 1 in the xz plane. [Diagram 3] 2 shows an interference pattern obtained with the embodiment of FIG. 1. [Figure 4] 4 shows a further embodiment of the device of the present invention. [Figure 5a] 4 shows a further embodiment of the device of the present invention. [Figure 5b] 5b shows the embodiment of FIG. 5a where the beam splitter has been moved. [Figure 6] 6 shows the embodiment of FIG. 5 where the focal length of the second cylindrical lens is changed. [Figure 7] 4 shows a further embodiment of the optical device according to the invention comprising a third cylindrical lens. [Figure 8] 8 shows an interference pattern obtained with the embodiment of FIG. 7. [Figure 9] 8 shows the embodiment of FIG. 7 with the position of the third cylindrical lens changed. [Figure 10] 4 shows a further embodiment of the device of the present invention. [Figure 11a] 4 shows a further embodiment of the optical device of the invention comprising a fourth cylindrical lens. [Figure 11b] 11b shows the embodiment of FIG. 11a with components moved. [Figure 12] 4 shows a further embodiment of an optical device according to the invention comprising two fourth cylindrical lenses and a fifth cylindrical lens. [Figure 13] 13 shows the embodiment of FIG. 12 with the fourth cylindrical lens moved. [Figure 14a]4 shows a further embodiment of the optical device of the invention comprising sixth and seventh cylindrical lenses. [Figure 14b] 14b shows the embodiment of FIG. 14a with components moved. [Figure 15a] 4 shows a further embodiment of the optical device of the invention comprising a fifth and a sixth cylindrical lens. [Figure 15b] 15b shows the embodiment of FIG. 15a with components moved. [Figure 16a] 3 shows a further embodiment of the optical device according to the invention comprising a first prism; [Figure 16b] 16b shows the embodiment of FIG. 16a where the first prism has been moved. [Figure 17] 4 shows a further embodiment of the optical device according to the invention, comprising a second prism; [Figure 18a] 4 shows a further embodiment of the optical device according to the invention, which comprises two second prisms. [Figure 18b] 18b shows the embodiment of FIG. 18a where the prism has been moved. [Figure 19a] 3 shows a further embodiment of the optical device of the invention comprising two fourth cylindrical lenses and a prism. [Figure 19b] 19b shows the embodiment of FIG. 19a where the prism has been moved. [Figure 20] 2 shows the embodiment of FIG. 1 with a laser and a sample. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] FIG. 1 shows a schematic diagram of one embodiment of an optical device 10 of the present invention in a yz plane in a Cartesian coordinate system, in which the z-axis corresponds to the optical axis z of the present invention, and the x-axis and y-axis are each perpendicular to the z-axis and perpendicular to each other.

[0033] A laser 12, not shown in FIG. 1, emits a laser beam 8, which impinges on the beam splitter 1 in a collimated manner and is split into two partial beams 8.1, 8.2, which are finally deflected at the same angle to the optical axis z, i.e. axially symmetrically thereto, and each remain collimated. The beam splitter 1 is configured, for example, as a diffractive optical element in the form of a grid, so that the splitting of the laser beam 8 results from diffraction effects. Alternatively, the beam splitter 1 can be configured as a partially reflecting mirror. In this respect, the partial beams 8.1, 8.2 are deflected only in the y direction, while the partial beams 8.1, 8.2 are not offset in the x direction. Downstream of the beam splitter 1, the partial beams 8.1, 8.2 impinge on a first cylindrical lens 2, whose cylindrical axis ZA1 is oriented parallel to the x axis. The surface of the first cylindrical lens 2 facing the beam splitter 1 is configured convex in the yz-plane in FIG. 1, while the surface facing away from the beam splitter 1 is flat, so that the first cylindrical lens 2 has the shape of a plano-convex focusing lens. By the first cylindrical lens 2, both partial beams 8.1, 8.2, which impinge on it in a collimated manner, are respectively focused to a focal point, where the two focal points are respectively at the same distance to the first cylindrical lens 2. After passing through the respective focal points, the partial beams 8.1, 8.2 diverge and impinge on the second, plano-convex cylindrical lens 3, which here is configured flat on its surface facing the beam splitter 1 and convex on its surface facing away from the beam splitter 1. The cylindrical axis ZA2 of the second cylindrical lens 3 is oriented parallel to the x-axis, so that the cylindrical axis ZA1 of the first cylindrical lens 2 and the cylindrical axis ZA2 of the second cylindrical lens 3 are oriented parallel to each other.

[0034] The two partial beams 8.1, 8.2 are respectively collimated by a second cylindrical lens 3 and deflected relative to the optical axis z under a final interference angle θ toward the sample 13 to be processed (not shown in FIG. 1), so that the partial beams 8.1, 8.2 interfere with each other in an interference region 14 and form an interference pattern 15, in which the sample 13 is arranged, see FIG. 20. Due to the spatial energy distribution of the interference pattern 15 and the interaction of the laser beam with the sample material, a structuring of the sample 13 in the structure region 16 takes place, as shown on the basis of the interference pattern 15 in FIG. 3. The structure 9 of the sample 13 is formed by the interference pattern 15 with linear structure elements 15a and a predefined structure period Λ. The structure period will be described further below.

[0035] From FIG. 1 it can be seen that the partial beams 8.1, 8.2 are symmetrical with respect to the optical axis z. The distance d1 of the first cylindrical lens 2 from the second cylindrical lens 3 corresponds to the sum of the focal lengths of the two cylindrical lenses 2, 3. Since the cylindrical axes ZA1, ZA2 of the first and second cylindrical lenses 2, 3 are oriented parallel to one another, the laser beam 8, including its partial beams 8.1, 8.2, can be manipulated in the yz-plane independently of the xz-plane. This allows the geometry of the structure 9 obtained on the sample 13 to be manipulated in the y-axis independently of the x-axis, as will also be shown by the following examples of the invention. The interference angle θ shown in FIG. 1 relates to the yz-plane shown there, in which the division of the partial beams 8.1, 8.2 takes place as already described. Since the partial beams 8.1, 8.2 are focused between the first cylindrical lens 2 and the second cylindrical lens 3, the path difference of the partial beams 8.1, 8.2, i.e. the difference between the paths travelled by the partial beams 8.1, 8.2 respectively, is kept as small as possible in order to obtain a spatially largest possible interference region 14.

[0036] 2 shows the device 10 of FIG. 1 in the xz-plane, which is arranged perpendicular to the yz-plane of FIG. 1. Due to the nature of the beam splitter 1, the partial beams 8.1, 8.2 of the laser beam 8 are deflected only in the yz-plane, as already mentioned, so that the partial beams 8.1, 8.2 overlap in the xz-plane and cannot be seen separately there. Since the cylindrical axes ZA1, ZA2 of the first cylindrical lens 2 and the second cylindrical lens 3 are both oriented parallel to the x-axis, respectively, the partial beams 8.1, 8.2 are not refracted in the xz-plane by either the first cylindrical lens 2 or the second cylindrical lens 3. The laser beam 8, in particular its partial beams 8.1, 8.2, are collimated in the xz-plane and directed towards the interference region 14.

[0037] FIG. 3 also shows the interference pattern 15 obtained by the optical arrangement 10 of FIGS. 1 and 2 and the structure 9 in the structured area 16 of the sample 13 with linear structural elements 15a arranged side by side with a predefined, here fixed, structural period Λ, which are oriented parallel to the y axis and arranged adjacent to one another along the x axis. In the present invention, the structural period Λ represents the distance between two adjacent structural elements 15a. The interference pattern 15 arranged on the left in FIG. 3 is elliptical, the semi-axis in the x direction being larger than the semi-axis in the y direction. The formation of the structure 9 on the sample 13 is carried out by the interference of the partial beams 8.1, 8.2 as already mentioned. Depending on the application case, the sample surface facing the beam splitter 1 or the sample volume inside the sample 13 is processed. Due to the interaction of the laser beam with the sample material, the sample 13 is processed, for example by material removal based on an ablation process and / or by modification of the sample material, for example by polymerization.

[0038] Besides the elliptical interference pattern 15, a rectangular interference pattern 15, as shown on the right of FIG. 3, and a correspondingly shaped structure 9 of the sample 13 can be obtained by using, for example, a beam shaping device 17, which is configured integrally with the beam splitter 1. The beam shaping device converts the circular cross section of the impinging laser beam 8 into a rectangular cross section according to a normal Gaussian intensity distribution, which is also called a "top hat" or "flat-top" profile. The modified, rectangular cross section of the laser beam results in a rectangular interference pattern 15 in the interference region 14, which, as mentioned, causes a corresponding structuring of the sample 13. An enlarged area of ​​the interference pattern 15a is shown in the center of FIG. 3, from which it can be seen that the structural period Λ corresponds to the distance between two adjacent structural elements 15a.

[0039] The practical example of FIG. 4 substantially corresponds to the embodiment of FIGS. 1 and 2, where the focal length of the first cylindrical lens 2 has been changed in such a way that the foci of the partial beams 8.1, 8.2 are virtually located behind the second cylindrical lens 3, respectively, after passing through the first cylindrical lens 2. The path difference of the partial beams can be minimized, especially when using fs pulses, which leads to a spatially more elongated interference pattern. The same effect would also be caused by reducing the distance d1 of the second cylindrical lens 3 from the first cylindrical lens 2. The partial beams 8.1, 8.2 are no longer collimated behind the second cylindrical lens 3, respectively, but are focused at foci equally spaced between the second cylindrical lens 3 and the interference region 14. Behind the foci the partial beams 8.1, 8.2 respectively diverge and interfere in the interference region 14, as already mentioned.

[0040] In the embodiment of Fig. 5a, the beam splitter 1 and the first cylindrical lens 2 are exchanged in comparison with the embodiment of Fig. 1 in such a way that the laser beam 8 first hits the first cylindrical lens 2 and is then focused due to the optical action of the first cylindrical lens 1 as a focusing lens and hits the beam splitter 1. The distance d1 between the first cylindrical lens 2 and the second cylindrical lens 3 corresponds to the sum of the focal lengths of the two cylindrical lenses 2, 3, so that the partial beams 8.1, 8.2 are each focused behind the beam splitter 1 to a focal point in front of the second cylindrical lens 3. Behind the second cylindrical lens 3 the partial beams 8.1, 8.2 are each collimated in the same way as in Fig. 1 and refracted towards the interference region 14. In the embodiment of FIG. 5a, the beam splitter 1 is translatable along the optical axis, i.e. in the z-direction, so that by moving the beam splitter 1, the position at which the partial beams 8.1, 8.2, respectively, impinge on the second cylindrical lens 3 can be varied, as shown in FIG. 5b.

[0041] Thereby, the interference angle θ, at which the partial beams 8.1, 8.2 are refracted in the interference region 14 relative to the optical axis z, is also variable, which causes a structural period Λ of the structural elements 15a. Compared to the interference pattern 15 shown in Fig. 3, the interference pattern 15 shown on the right in Fig. 5a has a larger structural period Λ, since the structural elements 15a are arranged further apart from each other. The mobility of the beam splitter 1 is indicated by the double arrow.

[0042] In Fig. 5b, the beam splitter 1 has been moved closer to the second cylindrical lens 3 parallel to the optical axis z compared to Fig. 5a. As a result, the partial beams 8.1, 8.2 impinge on the second cylindrical lens 3 with a smaller radial spacing relative to the optical axis z. Furthermore, the partial beams 8.1, 8.2 are refracted by the second cylindrical lens into the interference region 14 with a smaller interference angle θ compared to Fig. 5a. Correspondingly, the structural elements 15a of the interference pattern 15 in Fig. 5b are spaced farther apart compared to Fig. 5a, and therefore the structural period Λ in Fig. 5b is greater than in Fig. 5a.

[0043] The embodiment of FIG. 6 is based on the embodiment of FIG. 5a, where the second cylindrical lens 3 is now at a larger distance d1 from the first cylindrical lens 2. For this, the first cylindrical lens 2 and / or the second cylindrical lens 3 are translatable along the optical axis z. By increasing the distance d1 between the first cylindrical lens 2 and the second cylindrical lens 3, the two partial beams 8.1, 8.2 are no longer collimated behind the second cylindrical lens 3 as in the embodiment of FIG. 5, but are now refracted into the interference region 14 so that they are focused, respectively. This is similar to what has already been described for the embodiment of FIG. 4. The resulting interference pattern 15, which is shown diagrammatically on the right of FIG. 6, has a smaller spread in the y direction compared to the interference pattern 15 of FIG. 5a. This is because, due to the changed arrangement of the cylindrical lenses 2, 3, the partial beams 8.1, 8.2 are focused more strongly in the y direction, but not in the x direction. The structural period Λ of the interference pattern 15 in FIG. 6 is larger than that in FIG. 5a but smaller than that in FIG. 5b.

[0044] The embodiment of Fig. 7 corresponds to the embodiment of Fig. 1, where a third cylindrical lens 11 is additionally arranged in front of the beam splitter 1, whose cylindrical axis ZA3 is parallel to the y-axis and thus oriented perpendicular to the cylindrical axes ZA1, ZA2 of the first and second cylindrical lenses 2, 3. In that respect, the third cylindrical lens 11 does not substantially influence the beam path in the yz-plane shown in the upper part of Fig. 7. Instead, the third cylindrical lens 11 focuses the laser beam 8, including the partial beams 8.1, 8.2, in the xy-plane shown in the lower part of Fig. 7, the focal length of the third cylindrical lens 11 corresponding to the distance d2 of the third cylindrical lens 11 to the interference region 14. Since the laser beam 8 is focused in the xz-plane, the interference pattern 15 obtained according to this embodiment, shown in FIG. 8, has a smaller spread in the x-direction compared to the interference pattern in FIG. 3, respectively, while the spread in the y-direction is unchanged, and the structural period Λ is not affected by the third cylindrical lens 11.

[0045] In the exemplary embodiment of Fig. 9, starting from the embodiment of Fig. 7, the third cylindrical lens 11 is moved parallel to the optical axis z closer to the beam splitter 1. As a result, the partial beams 8.1, 8.2 are not focused in the interference region 14 in the xz-plane as in the embodiment of Fig. 7, but have a greater spatial extent. This is manifested by a correspondingly enlarged interference region 14 in the x-direction. The behavior of the beam path in the yz-plane is substantially unaffected by the movement of the third cylindrical lens 11, in particular the interference angle θ corresponds to that of the embodiment of Fig. 7.

[0046] Starting from the embodiment of Fig. 7, the positions of the beam splitter 1 and the first cylindrical lens 2 can be exchanged, which is shown in the embodiment of Fig. 10, where the laser beam 8 first hits the third cylindrical lens 11 as before, but then the first cylindrical lens 2 and subsequently the beam splitter 1, which is movable along the optical axis z in order to change the structural period Λ of the structural elements as already mentioned. Compared to the interference pattern 15 of Fig. 8, the interference pattern 15 of Fig. 10 has a larger structural period Λ.

[0047] Starting from the embodiment of FIG. 7, in the embodiment of FIG. 11a, a fourth cylindrical lens 4 is additionally arranged between the first cylindrical lens 2 and the second cylindrical lens 3. The cylindrical axis ZA4 of the fourth cylindrical lens 4 is oriented parallel to the x-axis and thus parallel to the cylindrical axis ZA1 of the first cylindrical lens 2. In the yz-plane shown in the upper part of FIG. 11a, the fourth cylindrical lens 4 has a concave surface facing the beam splitter 1, while the surface facing away from the beam splitter 1 is designed flat. The fourth cylindrical lens 4 is therefore designed as a concave-plano diverging lens. After the fourth cylindrical lens 4, the two partial beams 8.1, 8.2 are each refracted away from the optical axis z, and the two partial beams 8.1, 8.2 then impinge on the second cylindrical lens 3 to be refracted in the direction of the interference region 14. The combination of the first cylindrical lens 2, the fourth cylindrical lens 4 and the second cylindrical lens 3 corresponds functionally to a beam expander 18, in which the first cylindrical lens 2, the fourth cylindrical lens 4 and the second cylindrical lens 3 are each translatable along the optical axis z independently of one another, thereby influencing not only the optical properties of the partial beams 8.1, 8.2 but also in particular the interference angle θ and thus also the structural period Λ of the interference pattern 15 shown on the right of Fig. 11a. In the xz-plane shown in the lower part of Fig. 11a, the beam path of this example substantially corresponds to that of Fig. 7, since the fourth cylindrical lens 4 has a biflat configuration in the xz-plane and therefore does not optically influence the beam path substantially.

[0048] Starting from Fig. 11a, in Fig. 11b the positions of the components of the beam splitter 18 have been changed: the first cylindrical lens 2 has been moved towards the beam splitter 1, and the fourth cylindrical lens 4 and the second cylindrical lens 2 away from the beam splitter 1, the movements being performed synchronously with each other. As a result, the interference angle θ in Fig. 11b has been reduced compared to that in Fig. 11a, which is reflected in a larger structural period Λ of the interference pattern 15 shown on the right of Fig. 11b.

[0049] In the embodiment of Fig. 12, starting from the embodiment of Fig. 1, a fifth cylindrical lens 5 is arranged as a converging lens immediately adjacent to the beam upstream of the first cylindrical lens 2, with its convex surface pointing towards the first cylindrical lens 2 and its cylindrical axis ZA5 oriented parallel to the cylindrical axis ZA1 of the first cylindrical lens 2. The fifth cylindrical lens 5 together with the first cylindrical lens 2 forms a lens system 19, which in particular corrects the optical errors of the first cylindrical lens 2. In comparison with the embodiment of Fig. 1, two fourth cylindrical lenses 4.1, 4.2 are additionally provided in the beam path between the first cylindrical lens 2 and the second cylindrical lens 3 as diverging lenses, respectively, whose cylindrical axes ZA4 are each oriented parallel to the x-axis and thus parallel to the cylindrical axis ZA1 of the first cylindrical lens 2. The two fourth cylindrical lenses 4.1, 4.2 are each configured plano-concave in the yz-plane, are arranged offset from one another in the y-direction and are respectively at the same distance from the first cylindrical lens 2 and from the second cylindrical lens 3. By using the two fourth cylindrical lenses 4.1, 4.2, the partial beams 8.1, 8.2 can be adjusted independently of one another before the second cylindrical lens 3 refracts the two partial beams 8.1, 8.2 towards the interference region 14, as already described. In the example of FIG. 12, the first fourth cylindrical lens 4.1 is assigned to the first partial beam 8.1 and the second fourth cylindrical lens 4.2 to the second partial beam 8.2. In the xz-plane shown in the lower part of FIG. 12, the two fourth cylindrical lenses 4.1, 4.2 are arranged one above the other and do not substantially affect the laser beam 8, since they are bi-flat in this respect.

[0050] In order to adjust the two partial beams 8.1, 8.2 independently of one another, the two fourth cylindrical lenses 4.1, 4.2 can be rotated in particular synchronously about their cylindrical axis ZA4, each parallel to the x-axis. FIG. 13 shows the embodiment of FIG. 12 with the fourth cylindrical lenses 4.1, 4.2 rotated in that respect. Besides, the two fourth cylindrical lenses 4.1, 4.2 can be translated in the x-, y- and / or z-directions, respectively, independently of one another. Due to the movement of the fourth cylindrical lenses 4.1, 4.2, the partial beams 8.1, 8.2 focused by the second cylindrical lens 3 on the sample 13 can be adjusted independently of one another. Misalignments can thereby be compensated, in particular the position of the interference pattern 15 on the sample 13 as well as its spread in the x- and y-directions can be influenced. In particular with the embodiment of FIG. 12 and FIG. 13, a particularly small spread of the interference pattern 15 in the y-direction and a particularly small structural period Λ can be obtained. It is important here that the partial beams 8.1, 8.2 are each refracted behind the second cylindrical lens 3 with an interference angle θ that is as large as possible towards the interference region 14. For this purpose, in the exemplary embodiments of figures 12 and 13, the beam splitter 1 is translatable along the optical axis z.

[0051] In the embodiment of Fig. 14a, in comparison with the embodiment of Fig. 12, a sixth cylindrical lens 6 as a converging lens and a seventh cylindrical lens 7 as a diverging lens are arranged between the two fourth cylindrical lenses 4.1, 4.2 and the second cylindrical lens 3, with their two cylindrical axes ZA6, ZA7 oriented parallel to the x-axis, respectively. The sixth cylindrical lens 6 is configured plano-convex in the yz-plane, and the seventh cylindrical lens 7 plano-concave, with the two flat surfaces facing the second cylindrical lens 3, respectively. After passing through the two fourth cylindrical lenses 4.1, 4.2, the two partial beams 8.1, 8.2, respectively, are collimated and oriented parallel to the optical axis z and impinge on the sixth cylindrical lens 6, which focuses the partial beams 8.1, 8.2 in the direction of the optical axis z, with the focal points virtually located behind the seventh cylindrical lens 7, respectively. Due to the plano-concave configuration of the seventh cylindrical lens 7, the partial beams 8.1, 8.2 are respectively diffused and refracted towards the third cylindrical lens 3, which focuses the partial beams 8.1, 8.2 in the interference region 14 under the interference angle θ as already mentioned. The sixth cylindrical lens 6, the seventh cylindrical lens 7 and the third cylindrical lens 3 are each translationally slidable along the optical axis z and functionally correspond to a variable beam expander 18. Here, by moving the cylindrical lenses 6, 7, 3 along the optical axis z, the structural period Λ of the interference pattern 15 can be changed, the mobility of the components being respectively indicated by double arrows. In the embodiment of FIG. 14a, the beam splitter 1 splits the laser beam 8 only in the y-direction. Since all cylindrical axes ZA1-ZA7 of cylindrical lenses 2, 3, 4.1, 4.2, 5, 6, 7 are oriented parallel to the x-axis, the beam path is barely affected in the xz-plane shown in the lower region of Fig. 14, while a relatively strong focusing occurs in the yz-plane. Correspondingly, the interference pattern 15 shown on the right of Fig. 14 is very thin in the y-axis, while it is barely affected in the x-direction.

[0052] In Fig. 14b, the positions of the sixth cylindrical lens 6, the seventh cylindrical lens 7 and the second cylindrical lens 3 have been changed in such a way that the partial beams 8.1, 8.2 are refracted into the interference region under a smaller interference angle θ compared to Fig. 14a. This is reflected in the structural period Λ of the interference pattern 15, which is enlarged compared to Fig. 14a, and whose position and shape are almost unchanged.

[0053] Fig. 15a shows an embodiment with a fifth cylindrical lens 5 as a focusing lens arranged in front of the beam splitter 1 in the direction of the beam path, which is configured plano-convex in the yz-plane shown in the upper region of Fig. 15a. The cylindrical axis ZA5 of the fifth cylindrical lens 5 is oriented parallel to the x-axis and thus parallel to the cylindrical axis ZA1 of the first cylindrical lens 2. Due to the presence of the fifth cylindrical lens 5, the laser beam 8 collimated in the yz-plane impinging on it is focused and deflected towards the beam splitter 1, whereby the laser beam 8 is split into two partial beams 8.1, 8.2 as already mentioned. Due to the focusing by the fifth cylindrical lens 5, the two partial beams 8.1, 8.2 are each focused at a focal point arranged symmetrically with respect to the optical axis z. After passing through the focal points, the two partial beams 8.1, 8.2 each impinge on a sixth cylindrical lens 6 as a focusing lens, whose cylindrical axis ZA6 is oriented parallel to the cylindrical axis ZA1 of the first cylindrical lens 2 and which is configured plano-convex in the yz-plane. The distance d3 of the fifth cylindrical lens 5 to the sixth cylindrical lens 6 corresponds to the sum of the two focal lengths, so that the partial beams 8.1, 8.2 each are collimated after passing through the sixth cylindrical lens 6. Since the partial beams 8.1, 8.2 impinge on the surface of the sixth cylindrical lens 6 obliquely, these partial beams are refracted into each other at a finite angle to the optical axis z after passing through the sixth cylindrical lens 6, so that the partial beams 8.1, 8.2 each are collimated, cross and subsequently impinge on the first cylindrical lens 2.

[0054] Due to the intersection of the two partial beams 8.1, 8.2, in Fig. 15a the first partial beam 8.1 is arranged downward and the second partial beam 8.2 is arranged upward behind the sixth cylindrical lens 6. After passing through the first cylindrical lens 2, the centers of gravity of the two partial beams 8.1, 8.2 are each oriented parallel to the optical axis z. Similar to the embodiment of Fig. 12, two fourth cylindrical lenses 4.1, 4.2 are provided behind the first cylindrical lens 2, where the first fourth cylindrical lens 4.1 is assigned to the upper second partial beam 8.2 and the second fourth cylindrical lens 4.2 is assigned to the lower first partial beam 8.1. After passing through the two fourth cylindrical lenses 4.1, 4.2, the two partial beams 8.1, 8.2 are each collimated and oriented parallel to the optical axis z and impinge on the second cylindrical lens 3, which refracts the two partial beams 8.1, 8.2 towards the interference region 14 in a known manner.

[0055] In FIG. 15a, the first cylindrical lens 2, the two fourth cylindrical lenses 4.1, 4.2 and the second cylindrical lens 3 together form a lens system 19 that is slidable along the optical axis z, the relative positions of the components of the lens system 19 do not change along the optical axis z, and therefore the components of the lens system 19 are synchronously movable. Furthermore, the beam splitter 1 is translatable along the optical axis z in order to affect in particular the structural period Λ with the movement of the lens system 19. The beam splitter 1 is arranged closer to the sixth cylindrical lens 6 in FIG. 15b compared to FIG. 15a. Furthermore, the two fourth cylindrical lenses 4.1, 4.2 are translatable in particular along the y axis in order to correct the position of the partial beams 8.1, 8.2 in the interference region 14 and to compensate for alignment errors, in particular so that the partial beams 8.1, 8.2 are always collimated behind the fourth cylindrical lenses 4.1, 4.2, respectively. In Fig. 15b, the two fourth cylindrical lenses 4.1, 4.2 are respectively moved along the y axis towards the optical axis z, i.e. closer to each other. The translational mobility of the components is indicated by the respective double arrows. Due to said movement of the components, the interference angle θ in Fig. 15b is smaller than in Fig. 15a, which is reflected in the correspondingly enlarged structural period Λ of the interference pattern 15. Since in the example of Fig. 15a all cylindrical axes ZA1-ZA6 of the cylindrical lenses 2, 3, 4.1, 4.2, 5, 6 are oriented parallel to each other, the laser beam 8, including its partial beams 8.1, 8.2, is optically almost unaffected in the xz-plane shown in the lower part of Fig. 15a, which also applies to the movement of the components evident in Fig. 15b.

[0056] The embodiment of FIG. 16a is a development of the embodiment shown in FIG. 7, in which a first prism 20 is additionally arranged between the first cylindrical lens 2 and the second cylindrical lens 3. The first prism 20 has an isosceles triangle as base A1, with two legs 21, 22 pointing towards the beam splitter 1. The prism axis PA1 of the first prism 20, which is arranged perpendicular to the base A1, is oriented parallel to the x-axis. The first prism 20 is arranged closer to the first cylindrical lens 2 than to the second cylindrical lens 3, so that the focal points of the partial beams 8.1, 8.2 are respectively between the first prism 20 and the second cylindrical lens 3. Since the surfaces of its legs 21, 22 of the first prism 20 are inclined with respect to the partial beams 8.1, 8.2, this causes focusing of the partial beams in the yz-plane, so that, as already mentioned, the path difference of the partial beams 8.1, 8.2 is kept as small as possible. Furthermore, the first prism 20 can be translated along the optical axis z, so that the structural period Λ of the interference pattern 15 can be changed. In FIG. 16b, the first prism 20 is moved in the direction of the second cylindrical lens 3 compared to FIG. 16a, which causes a reduction in the interference angle θ and thus an increase in the structural period Λ of the interference pattern 15. Furthermore, the first prism 20 can be rotated by 180° about the x-axis, so that the legs 21, 22 of the first prism 20 are directed towards the second cylindrical lens 3. Due to the arrangement, the first prism 20 has almost no effect on the beam path in the xz-plane, which corresponds substantially to the beam path shown in FIG. 7.

[0057] Starting from the embodiment of Figs. 16a and 16b, in the embodiment shown in Fig. 17, a second prism 23 is arranged in the beam path between the first prism 20 and the second cylindrical lens 3, in particular behind the focal points of the partial beams 8.1, 8.2. The base faces A2 of the second prism 23 correspond to two right-angled triangles connected together and are arranged parallel to each other, with their connected hypotenuses each arranged parallel to the y axis. The prism axis PA2 of the second prism 23 is arranged parallel to the x axis. Due to its arrangement and configuration, the second prism 23 causes the diffusion of the partial beams 8.1, 8.2 passing therethrough. The first prism 20 and the second prism 23 are each translatable along the optical axis z and, together with the third cylindrical lens 3, are in this embodiment a variable beam expander 18, by which the structural period Λ of the interference pattern 15 is variable, in particular by changing the interference angle θ. If only the second prism 23 is translated relative to the optical axis z, the interference angle θ and thus the structural period Λ are changed, but the spatial position of the interference region 14 does not change.

[0058] The second prism 23 can be replaced by two separate second prisms 23.1, 23.1, each of which can be translated parallel to the optical axis z, as shown in the example of FIG. 18a. The two second prisms 23.1, 23.2 are constructed and arranged symmetrically with respect to the optical axis z. The two second prisms 23.1, 23.2 each have a right-angled triangle with a base surface A. 21 ,A 22 The prism axis PA of the two prisms 23.1 and 23.2 is 21 ,PA 22are each arranged parallel to the x-axis. Alternatively, instead of the two prisms 23.1, 23.2, two edge plates can be provided in a corresponding configuration. The first second prism 23.1 is assigned to the first partial beam 8.1 and the second second prism 23.2 is assigned to the second partial beam 8.2. In FIG. 18b, starting from FIG. 18a, the first prism 20 has been shifted along the optical axis z towards the first cylindrical lens 2 and the two second prisms 23.1, 23.2 towards the second cylindrical lens 3, so that the interference angle θ in FIG. 18b is reduced compared to FIG. 18a.

[0059] Starting from the embodiment of Fig. 14b, in the embodiment of Fig. 19a, the sixth cylindrical lens 6 is replaced by a first prism 20 and the seventh cylindrical lens 7 by two second prisms 23.1, 23.2, which are still translatable along the optical axis z and, together with the third cylindrical lens 3, form a variable beam expander 18, as already mentioned. Due to its geometry, the first prism 20 has the same optical effect as the sixth cylindrical lens 6, and the same also applies to the two second prisms 23.1, 23.2 associated with the seventh cylindrical lens 7. The beam path of Fig. 19a therefore corresponds to that of Fig. 14b, whereby the interference patterns 15 obtained in each case are identical.

[0060] In FIG. 19b, starting from FIG. 19a, the first prism 20 and the two second prisms 23.1, 23.2 are moved closer to each other along the optical axis z, which causes an increase in the interference angle θ and thus also a reduction in the structural period of the interference pattern 15.

[0061] Figure 20 shows an embodiment according to figure 1 with a laser 12 as beam source, which as a diode-pumped solid-state laser emits a collimated pulsed laser beam as shown in figure 1 with a pulse duration in the fs range. On the right side of figure 20, in the already mentioned interference region 14 of the partial beams 8.1, 8.2, a sample 13 is arranged on its surface with a structuring 9 by an interference structure 15 as shown in figure 3. With such an arrangement of the optical components of the optical device according to the invention, the method according to the invention can be carried out.

Claims

1. An optical device (10) for interference structuring of a sample (13), comprising a laser (12) for emitting a laser beam (8), a beam splitter (1) for splitting the laser beam (8) into at least two partial beams (8.1, 8.2), at least one first cylindrical lens (2) and at least one second cylindrical lens (3) for refracting the at least two partial beams (8.1, 8.2) in the direction of an interference region (14), wherein the beam splitter (1) ), the at least one first cylindrical lens (2) and the at least one second cylindrical lens (3) are arranged in the beam path of the laser beam (8) such that the at least two partial beams (8.1, 8.2) of the laser beam (8) interfere with each other in the interference region (14) so ​​that a structure (9) with a linear structure element (15a) can be formed in a structure region (16) of the sample (13), and a cylindrical axis (ZA) of the at least one first cylindrical lens (2) is set to a value smaller than the value of ... １ ) is the cylindrical axis (ZA) of the at least one second cylindrical lens (3). ２ ) oriented parallel to the optical axis, 1. An optical arrangement, characterized in that at least one third cylindrical lens (11) is provided as a focusing lens, the cylindrical axis (ZA 3 ) of which is oriented perpendicular to the cylindrical axis (ZA 1 ) of the at least one first cylindrical lens (2) and perpendicular to the optical axis.

2. 2. The optical device according to claim 1, characterized in that the at least one third cylindrical lens (11) is arranged beam-upstream and / or beam-downstream of the beam splitter (1) and / or the distance of the interference region (14) to the at least one third cylindrical lens (11) substantially corresponds to its focal length.

3. At least one fourth cylindrical lens (4, 4.1, 4.2) is provided as a diffusing lens, the cylinder axis (ZA 4 ) of said at least one fourth cylindrical lens (4, 4.1, 4.2) is arranged parallel to the cylinder axis (ZA 1 ) of said at least one first cylindrical lens (2), and / or 3. The optical arrangement according to claim 1, wherein the at least one fourth cylindrical lens (4, 4.1, 4.2) is arranged beam-downstream of the at least one first cylindrical lens (2).

4. The at least one fourth cylindrical lens (4, 4.1, 4.2) is translatable in at least one axis (x, y, z) and / or has a cylindrical axis (ZA ４ ) and / or each partial beam (8.1, 8.2) is assigned exactly one fourth cylindrical lens (4.1, 4.2) and / or 4. Optical device according to claim 3, characterized in that at least two fourth cylindrical lenses (4, 4.1, 4.2) are movable independently of one another and / or synchronously with one another.

5. At least one fifth cylindrical lens (5) is provided as a focusing lens, the cylindrical axis (ZA ５ ) is the cylindrical axis (ZA) of the at least one first cylindrical lens (2). １ ) and forming a lens system (19) together with said at least one first cylindrical lens (2); and / or at least one sixth cylindrical lens (6) is provided as a focusing lens, the cylindrical axis (ZA 6 ) of which is oriented parallel to the cylindrical axis (ZA 1 ) of said at least one first cylindrical lens (2), said at least one sixth cylindrical lens being arranged in the beam upstream of said at least one second cylindrical lens (3); and / or 5. The optical device according to claim 1 , characterized in that at least one seventh cylindrical lens (7) is provided as a focusing lens, the cylindrical axis (ZA 7 ) of which is oriented parallel to the cylindrical axis (ZA 1 ) of the at least one first cylindrical lens (2), the at least one seventh cylindrical lens being arranged in the beam upstream of the at least one second cylindrical lens (3), the at least one first cylindrical lens (2) together with the at least one second cylindrical lens (3) and the at least one fourth cylindrical lens (4, 4.1, 4.2) and / or the at least one seventh cylindrical lens (7) together with the at least one second cylindrical lens (3) and the at least one sixth cylindrical lens (6) respectively form a lens system (19).

6. At least one first prism (20) is provided, the prism axis (PA １ ) is the cylindrical axis (ZA) of the at least one first cylindrical lens (2). １ ) and is oriented parallel to a surface of the at least one first prism (20) is oriented perpendicular to the optical axis (z); and / or 6. The optical device according to claim 1, characterized in that at least one second prism (23, 23.1, 23.2) is provided, the prism axis (PA2, PA21, PA22) of which is oriented parallel to the cylindrical axis (ZA1) of the at least one first cylindrical lens (2), and the base surface (A2, A21, A22) of the at least one second prism (23, 23.1, 23.2) together with the base surface (A1) of the at least one first prism (20) corresponds to a rectangle.

7. at least two second prisms (23, 23.1, 23.2) are movable independently of one another; and / or 7. The optical device according to claim 6, characterized in that the at least one first prism (20) and / or the at least one second prism (23, 23.1, 23.2) are arranged between the at least one first cylindrical lens (2) and the at least one second cylindrical lens (3).

8. the beam splitter (1) and / or the at least one cylindrical lens (2, 3, 11, 4, 4.1, 4.2, 5, 6, 7) and / or the at least one prism (20, 23, 23.1, 23.2) are translatable parallel to the optical axis (z); and / or 8. The optical arrangement according to claim 1, characterized in that at least one beam expander (18) is provided for changing the beam cross-section of the laser beam (8) and / or for changing the structural period (Λ), the at least one beam expander (18) being formed by three cylindrical lenses (3, 6, 7) and / or by a cylindrical lens (3) with a first prism (20) and at least one second prism (23, 23.1, 23.2).

9. 9. The optical device according to claim 1, wherein the interference region (14) has an interference pattern (15) with linear structural elements (15a), the interference pattern (15) having a user-defined, variable structural period (Λ) in at least one direction (x, y).

10. 10. The optical arrangement according to any one of claims 1 to 9, characterized in that a beam shaping device (17) is provided, the beam shaping device being configured such that a cross-sectional profile of the laser beam (8) is user-defined and variable, the beam shaping device (17) being configured to form an elliptical or polygonal cross-sectional profile of the laser beam (8).

11. A method for interference structuring a sample (13), comprising the steps of: providing a laser (12) for emitting a laser beam (8); splitting the laser beam (8) into at least two partial beams (8.1, 8.2); arranging at least one first cylindrical lens (2); and arranging at least one second cylindrical lens (3) in such a way that the at least two partial beams (8.1, 8.2) of the laser beam (8) are refracted in the direction of an interference region (14) such that the at least two partial beams (8.1, 8.2) of the laser beam (8) interfere with each other in the interference region (14) so ​​that a structure (9) with linear structure elements (15a) can be formed in a structure region (16) of the sample (13); and adjusting a cylindrical axis (ZA) of the at least one first cylindrical lens (2) so that the cylindrical axis (ZA) of the at least one first cylindrical lens (2) is set to a position perpendicular to the axis of the at least one first cylindrical lens (2). １ ) to the cylindrical axis (ZA) of the at least one second cylindrical lens (3). ２ 11. A method comprising the steps of: orienting the light source parallel to the light source; and wherein the method is performed by an optical device (10) according to any one of claims 1 to 10.

12. Use of an optical device (10) according to any one of the claims 1 to 10 for interference structuring of a sample (13), in particular a component.

Images