Abstract
A system (100, 300) for adapting a diameter of a photon beam (S, S) comprises: a first element (1) with a curved surface which bas a first and a second focus (F1, F2). The system may be set up such that the photon beam is focused into the first focus (F1), so that the photon beam is focused onto the second focus (F2) after reflection at the surface of the first element (1).
Claims
1. A system for adapting a diameter of a photon beam, comprising: a first element with a first curved surface which has a first focus and a second focus, wherein the system is configured such that the photon beam is focused into the first focus, so that the photon beam is focused onto the second focus after reflection at the first curved surface of the first element.
2. The system as claimed in claim 1, wherein the system further comprises a first output coupler, which collimates the photon beam to a first output diameter after reflection at the first output coupler.
3. The system as claimed in claim 2, wherein the first element and the first output coupler are arranged in relation to each other such that a focus of the first output coupler and the second focus of the first element are substantially in the same position.
4. The system as claimed in claim 2, wherein the first element and the first output coupler are arranged positionally fixed in relation to one another.
5. The system as claimed in claim 2, wherein the first output diameter is dependent on a numerical aperture of the photon beam focused into the first focus.
6. The system as claimed in claim 2, wherein the first output diameter is dependent on an angle of incidence at which the photon beam is focused into the first focus.
7. The system as claimed in claim 5, further comprising a means for varying the numerical aperture of the photon beam focused into the first focus and/or an angle of incidence at which the photon beam is focused into the first focus.
8. The system as claimed in claim 1, further comprising a first input coupler, wherein, when a collimated photon beam is received, the first input coupler focuses the collimated photon beam with an input diameter onto the first focus by reflection at the first input coupler.
9. The system as claimed in claim 8, wherein the collimated photon beam is directed onto different segments of a surface of the first input coupler.
10. The system as claimed in claim 2, wherein the first output diameter is greater than an input diameter of a collimated photon beam.
11. The system as claimed in claim 10, wherein the system is configured to allow at least two increases in the first output diameter with respect to the input diameter.
12. The system as claimed in claim 10, wherein an increase in the first output diameter with respect to the input diameter is by a factor of at least 1.4.
13. The system as claimed in claim 8, wherein the first element and the first input coupler are arranged positionally fixed in relation to each other.
14. The system as claimed in claim 1, wherein the first element comprises an elliptical mirror.
15. The system as claimed in claim 1, wherein the system further comprises a second element with a second curved surface including a third focus and a fourth focus, and wherein the photon beam reflected at the first element is focused into the third focus of the second element, so that the photon beam is focused onto the fourth focus of the second element after reflection at the second curved surface of the second element.
16. The system as claimed in claim 15, wherein the system further comprises a second output coupler, which collimates the photon beam to a second output diameter after reflection at the second element.
17. The system as claimed in claim 16, wherein the second element and the second output coupler are arranged in relation to each other such that a focus of the second output coupler and the second focus of the second element are substantially at the same position.
18. The system as claimed in claim 15, wherein the system further comprises a first output coupler and a second input coupler wherein the second input coupler is configured to receive the photon beam collimated by the first output coupler and to focus the photon beam onto the third focus of the second element by reflection at the second input coupler.
19. The system as claimed in claim 15, wherein the second element is configured to compensate at least partially for an unsymmetrical light distribution of the photon beam reflected by the first element.
20. A device for projecting comprising the system as claimed in claim 1.
21. A method for adapting a diameter of a photon beam comprising: directing an incident photon beam onto a first element comprising a curved surface, the first element having a first focus and a second focus, wherein the directing takes place in such a way that the received photon beam is focused into the first focus of the first element, with the directed photon beam being output as focused at the second focus, after reflection at the curved surface of the first element.
22. The method as claimed in claim 21, further comprising: collimating the photon beam reflected at the first element to a first output diameter, wherein the incident photon beam comprises a collimated photon beam with a first input diameter, and wherein directing the incident photon beam further comprises: varying a numerical aperture of the photon beam focused into the first focus and/or an angle of incidence at which the focused photon beam is focused into the first focus, so that the first output diameter varies.
23. A computer program comprising instructions which, when executed by a computer, causes the system of claim 1 to carry out a method for adapting a diameter of a photon beam comprising: directing an incident photon beam onto a first element comprising a curved surface, the first element having a first focus and a second focus, wherein the directing takes place in such a way that the received photon beam is focused into the first focus of the first element, with the directed photon beam being output as focused at the second focus, after reflection at the curved surface of the first element.
Description
4. BRIEF DESCRIPTION OF THE FIGURES
[0059] The detailed description that follows describes technical background information and exemplary embodiments of the invention with reference to the figures, which show the following:
[0060] FIG. 1 schematically illustrates in a side view a system of the invention, shown by way of example, for adapting a diameter of a photon radiation.
[0061] FIG. 2 schematically shows the beam distribution of the photon radiation as it passes through a system of the invention shown by way of example.
[0062] FIG. 3 schematically illustrates in a side view another system of the invention shown by way of example.
5. DETAILED DESCRIPTION OF THE FIGURES AND POSSIBLE EMBODIMENTS
[0063] FIG. 1 schematically illustrates in a side view a system 100, shown by way of example, for adapting a diameter of a photon radiation. The system 100 may in this case be designed for the adaptation of a photon radiation with any wavelength. For example, the photon radiation may comprise the light range visible to humans. For example, the photon radiation may in this case lie in a wavelength range of 400 nm to 800 nm (which includes the RGB color space). However, it is also conceivable that the concepts or features of the system 100 and the invention mentioned herein can also be applied to photon radiation in the (E and/or D) UV range and/or the (near) infrared range. Only a reflectivity of the respective reflecting surfaces of the system in the respective wavelength range must be provided. Irrespective of the respective wavelength range, the photon beam may be provided for example as a laser beam. The use of the word beam does not imply that it can be a continuous wave beam. Both a continuous wave photon beam and for example a pulsed photon beam can be used.
[0064] The system 100 in FIG. 1 may comprise a first element 1 for adapting the photon radiation. The first element 1 may in this case have a first focus F1 and a second focus F2. In an example, the first focus F1 and the second focus F2 may be designed such that a photon radiation which emanates from one focus and is reflected at the first element 1 subsequently enters the other focus. The photon radiation from one focus can therefore be projected onto the other focus. In one example, the first element 1 comprises an elliptical mirror, with the first focus F1 and the second focus F2 corresponding to the two focuses of the elliptical mirror. The elliptical mirror may in this case comprise a portion of a geometric ellipse, i.e. the ellipse of the elliptical mirror does not have to be completely formed geometrically. This can be seen for example in FIG. 1, with the first element 1 representing an elliptical mirror which is constructed from a partial portion of the ellipse represented by dashed lines.
[0065] The system 100 may also comprise a first input coupler E1. The first input coupler E1 can be used to receive a photon beam and to focus it onto the first focus F1 of the first element 1. The photon beam received at the first input coupler E1 can also be understood as an input of the system 100. In an example, the first input coupler E1 may be set up to receive a collimated photon beam which is collimated to a defined diameter, while this diameter can also be referred to as the input diameter. For the description of the system 100, reference is first made, by way of example, to the beam path of the first photon beam S, which is incident with the input diameter on the first input coupler E1. The first photon beam S may in this case comprise a radiation beam which comprises a number of partial beams, with the edge beams and the directional beam being shown in FIG. 1. The first photon beam S is in this case first incident on the first input coupler E1 as a collimated input beam with an input diameter. The first input coupler E1 may comprise for example a parabolic mirror (as shown in FIG. 1). The parabolic mirror may comprise a portion of a geometric parabola, i.e. the parabola of the parabolic mirror does not have to be completely formed geometrically. This can be seen for example in FIG. 1, with the first input coupler E1 representing a parabolic mirror which is constructed from a partial portion of the parabola represented by dashed lines. To focus the received photon radiation S, the first input coupler E1 (for example the parabolic mirror) may have a focus that is aligned with the first focus F1 of the first element. The position of the focus of the first input coupler E1 may substantially correspond to the position of the first focus F1 of the first element, so that these focuses spatially overlap completely (or at least partially). In the case of a parabolic mirror as the first input coupler E1, it should be mentioned that axially parallel beams, i.e. beams that are incident parallel to the ordinate (or the axis of symmetry or a guide line) of the geometrically/mathematically definable parabola, enter the focus of the parabolic mirror after the reflection at the parabolic mirror. The system 100 may accordingly be arranged in such a way that, when formed as a parabolic mirror, the first input coupler E1 receives the collimated first photon radiation S with the input diameter in this manner parallel to the axis, so that the received photon radiation is (mainly) diverted into the focus of the parabolic mirror. The first photon radiation S coupled in parallel to the axis may in this case comprise a planar wavefront. Since the focus of the first input coupler E1 (or the focus of its parabolic mirror) lies at the same position as the first focus F1 of the first element, the first photon radiation S is therefore automatically focused with the input diameter onto the first focus F1 of the first element 1. This photon radiation can subsequently be reflected at the first element 1, to then be focused into the second focus F2 of the first element 1. This defined refocusing can accordingly be used for deflecting a photon radiation in the system 100 or a system of the invention.
[0066] The system 100 may also comprise a first output coupler A1. The first output coupler A1 may in this case comprise for example a parabolic mirror (as shown in FIG. 1). The parabolic mirror may comprise a portion of a geometric parabola, i.e. the parabola of the parabolic mirror does not have to be completely formed geometrically. This can be seen for example in FIG. 1, with the first output coupler A1 representing a parabolic mirror which is constructed from a partial portion of the parabola represented by dashed lines. The first output coupler A1 may be set up to receive the radiation focused by the first element 1 at the second focus F2 and to collimate it to a first output diameter. For this purpose, the first output coupler A1 (for example constructed as a parabolic mirror) may have a focus that is aligned with the second focus F2 of the first element. In this case, the position of the focus of the first output coupler A1 may substantially correspond to the position of the second focus F2 of the first element, so that these focuses spatially overlap completely (or at least partially). In the case of a parabolic mirror as the first output coupler A1, it should be mentioned that focus beams, i.e. beams that emanate from the focus of the parabola and are incident on the surface of the parabolic mirror, are coupled out from the parabolic mirror in parallel with the axis after the reflection at the parabolic mirror. The overlapping mentioned of the second focus F2 and the focus of the first output coupler A1 therefore allows this axially parallel outcoupling to be ensured. This makes it possible, as can be seen in FIG. 1, to convert the first photon beam S into a collimated beam again and to couple it out as a collimated output beam with a first output diameter. The first photon radiation coupled out parallel to the axis may in this case comprise a planar wavefront.
[0067] In the example in FIG. 1, the first output diameter of the first photon beam S is in this case equal to the input diameter of the photon beam S. This is achieved by the fact that the photon beam S is substantially symmetrically incident on a region around the minor axis of the ellipse of the first element 1.
[0068] It should also be mentioned that in one example the parabolic mirror of the first input coupler E1 and the parabolic mirror of the first output coupler A1 can be described by the same parabola, just with different portions of the parabola (for example different legs of the parabola) being used for the first input coupler E1 and the first output coupler A1. The first input coupler E1 and the first output coupler A1 may be arranged symmetrically with respect to the first element 1. For example, the first input coupler E1 and the first output coupler may be arranged symmetrically with respect to a minor axis or major axis of the ellipse which is defined by the elliptical mirror of the first element 1.
[0069] As described, the system 100 can accordingly make it possible to divert the photon radiation in a targeted manner by a beam being transformed from a collimated state to a focused state, subsequently focused spatially offset and then returned to a defined collimated state without requiring a complex adjustment. The conversion of this deflecting unit by way of reflective elements (for example with the elliptical mirror as the first element 1, the parabolic mirror as the first input coupler E1 and/or the parabolic mirror as the first output coupler A1) can also make it possible that light transmission of the photon radiation through two media when it undergoes deflection in the system 100 can be avoided, so that corresponding aberration is likewise avoided (for example monochromatic and/or chromatic aberrations associated with lenses can be avoided).
[0070] For another example, a possible mechanism for adapting the diameter of the photon radiation in the system 100 is explained. The system 100 may for example be set up or used in such a way that the first output diameter of the photon beam coupled out at the first output coupler is greater than the input diameter of the photon beam coupled in at the first input coupler E1. For this magnification effect, reference is now made to the beam path of the second photon beam S shown in FIG. 1, in which the magnification effect occurs in contrast to the first photon beam S. The second photon beam S may in this case comprise a radiation beam which comprises a number of partial beams, while in FIG. 1 the first edge beam S1, the second edge beam S2 and the directional beam S3 are marked. The second photon beam S, axially parallel to the parabolic mirror of the first input coupler, in this case radiates onto a segment of the surface of the parabolic mirror of the first input coupler E1, so that the second photon beam S is focused onto the first focus F1 of the first element at a certain angle of incidence . The irradiated segment of the first input coupler E1 is different in the case of the second photon beam S from the irradiated segment in the case of the first photon beam S. A certain angle of incidence is therefore obtained for the second photon beam S, different from the angle of incidence of the first photon beam S, with which there is no magnification effect. The angle of incidence can be defined in this example as the angle between the directional beam of a photon beam and the line connecting the first and the second focus of the first element (i.e., the major axis of the ellipse, although other definitions are also possible). The angle of incidence results in a beam path which is further defined by the reflection of the second photon beam S at the first element 1 and the focusing onto the second focus F2. Due to the magnitude of the angle of incidence and the boundary conditions during the reflection at the first element 1, it is found that the numerical aperture NA2 of the second photon beam S at the second focus F2 is larger than the numerical aperture NA1 of the second photon beam S at the first focus F1. This larger second numerical aperture NA2 is subsequently incident on the surface of the first output coupler. The first output coupler A1 subsequently collimates the second photon beam S to the first output diameter. By increasing the numerical aperture NA2 at the second focus, it is shown in this example overall that the collimated output beam of the second photon beam S has a greater diameter than its collimated input beam.
[0071] In comparison, it should be mentioned that in the case of the first photon beam S no magnification effect occurs in the system 100, since there is no change in the numerical aperture during the reflection at the first element 1. Although the first (axially parallel) photon beam S has the same input diameter as the second photon beam S, the first photon beam S irradiates a different segment of the parabolic mirror of the first input coupler E1, resulting in a different angle of incidence at the first focus F1, which specifically does not cause any change in the numerical aperture at the second focus. For the first photon beam S, the numerical aperture NA1 at the first focus F1 is accordingly equal to the numerical aperture NA2 at the second focus F2. It should be noted that, for the first photon beam S, the angle of incidence is in this case chosen in such a way that the directional beam S3 of the second photon beam S is incident on a vertex of the minor axis of the ellipse which is formed by the elliptical mirror of the first element 1. The resulting beam path of the first photon beam S is therefore symmetrical with respect to the two focuses F1 and F2 (or the minor axis), so that there is no change in the numerical aperture at the focuses F1 and F2. It should also be mentioned that, in the example of FIG. 1, the first input coupler E1 and the first output coupler A1 are arranged symmetrically with respect to the minor axis of the ellipse, so that, with the same numerical aperture NA1 and NA2 of the first photon beam S, its input diameter is transformed directly to the first output diameter. In other words, the magnifying effect is caused by the oblique incidence of the second photon beam into the first element 1, so that the beam path no longer takes place symmetrically along the minor axis of the ellipse. The accompanying change of the numerical aperture at the focuses F1 and F2 can therefore be used to increase the output diameter of the photon beam with respect to the input diameter.
[0072] By parallel displacing of the incoming photon beam (for example by a mirror movable along an axis), the magnification of the system can therefore be varied.
[0073] It should be noted that a zoom system is typically defined from a magnification of 1/m to m. The zoom factor can be defined as: =m.sub.max/m.sub.min=m.sup.2, where m.sub.max and m.sub.min are typically the longest and shortest focal length of a zoom lens. In one example, the magnification of the system 100 can reach values that exceed the root of 10, for example greater than 4 (as already described herein). By the typical definition of a zoom lens, this accordingly corresponds to the magnification m of greater than root 10 (i.e. m at least 3.16), where the zoom factor m.sup.2 is then at least m.sup.2=10. In other examples, the zoom factor of the system 100 is at least 2, 3, 5, or at least 20.
[0074] However, as indicated in FIG. 1, the magnification in the case of the second photon beam S leads to an unsymmetrical light distribution of the partial beams S1, S2, S3. Thus it is indicated that the partial beams S2 and S3 in the collimated output diameter are at a greater distance from one another than the partial beams S1 and S2. In the system 100, although a magnification is accordingly performed in the case of the second photon beam S, an unsymmetrical light distribution of the partial beams is thereby introduced, which may for example represent a distortion. It should be mentioned here that, for the partial beams S1, S2, S3, there are different reflection angles at the first element 1. Thus for example, the edge beam S2 has the shortest distance of the partial beams from the second focus F2 after the reflection at the first element 1 and is therefore focused the strongest onto the second focus F2. The edge beam S1 has the longest distance of the partial beams from the second focus after the reflection at the first element 1 and is therefore focused the weakest onto the second focus F2.
[0075] The effect of the unsymmetrical light distribution in the case of a magnification is explained in more detail in FIG. 2. FIG. 2 schematically shows the beam distribution of the photon radiation as it passes through the system 100 of the invention shown by way of example. The beam distribution or arrangement of the partial beams of the second photon beam S is in this case schematically illustrated on the basis of simulation results. Shown on the one hand is the input beam distribution 201 of the collimated input beam of the second photon beam S before the incoupling into the system 100. The input beam distribution 201 is in this case shown in the x and y directions, while the path of the partial beams in the system 100 is shown in the z and y directions. The input beam distribution 201 may for example correspond to the beam distribution of a homogeneous light source which is used as the source for the second photon beam S. In this example, the input diameter of the collimated input beam is 3.2 mm, with the beam cross section being circular. It is also conceivable here to use any other form of beam cross section (for example rectangular, square, elliptical, etc.) as well as any other (largest) input diameter (for example at least 0.5 mm, at least 1 mm, at least 2 mm, at least 5 mm, and/or less than 10 mm, less than 5 mm, less than 2 mm, etc.). The output beam distribution 202 of the collimated output beam of the second photon beam S after passing through the system 100 with first element 1, input coupler E1 and output coupler A1 (which may be designed as described in relation to FIG. 1) is in this case shown in the x and y directions. It can be seen that in this case the first output diameter is approx. 30 mm, while by analogy with the input beam the beam cross section is circular. This accordingly indicates that, by way of example, the magnification in the system 100 has taken place in the x and y directions. In the example in FIG. 2, the incoupling (as described herein) accordingly takes place in such a way that a magnification factor of approx. ten occurs.
[0076] In an alternative example, the magnification may also only take place along one axis, for example the y axis. For this purpose, for example the mirrors of the first input coupler E1, the first element 1 and/or the first output coupler A1 may be produced as only curved in one dimension, so that the light can only be magnified in one dimension, for example the y axis. For example, the output beam would in this case be as wide in the x direction as the input beam in the x direction, while the diameter of the output beam in the y direction would be for example about ten times as large as the diameter of the input beam in the y direction (with a magnification factor of the system 100 of about ten). For this purpose, reference should also be made in advance to the beam distribution 302 in FIG. 3, which represents a corresponding beam distribution in the case of which the magnification only takes place along one axis. It can be seen that the enveloping form of the beam distribution 302 substantially represents an ellipse. Also in a system such as in FIG. 2, an output beam distribution of which the envelope substantially represents an ellipse can be generated by limiting the magnification along one axis (for example the y axis).
[0077] It should be noted that, according to the disclosure, a (substantially) symmetric beam magnification may therefore be generated (for example with an equal magnification along the x and y axes). Likewise, according to the disclosure, a (substantially) asymmetric beam magnification may be generated (for example with a magnification only along the y axis).
[0078] For certain applications, it may be necessary for example to generate a symmetrical beam magnification. It may be technically required here for example that the output beam is magnified symmetrically (as described herein). If for example the input beam has a (substantially) circular envelope of the intensity distribution, it may be required for example that the output beam also has a (substantially) circular envelope.
[0079] However, for certain applications it may also be necessary for example to generate an asymmetric beam magnification. It may be technically required for example that the output beam is magnified asymmetrically (as described herein). If for example the input beam has a (substantially) circular envelope of the intensity distribution, it may be required for example that the output beam has a (substantially) elliptical envelope. For example, this can ensure a higher light intensity of the output radiation, since the radiation is distributed (comparatively) over a smaller area than with a symmetrical magnification. For example, an asymmetric magnification may be advantageous when using the system in a projection device, while for example the elliptical output radiation can be further manipulated by way of the projection device. For example, the elliptical output radiation from the projection direction may be rasterized along a line.
[0080] The unsymmetrical light distribution of the partial beams (for the symmetrical magnification along the x and y axes) can also be read from FIG. 2, as can be seen from the greater distances of the partial beams at higher y values and the decreasing distances of the partial beams at lower y values. Also shown is the beam distribution in the y-z plane for ten partial beams, in which the asymmetry of the distances of the partial beams can likewise be seen schematically. No significant asymmetry can be seen here along the x axis (due to the optical structure). For example, this can be ensured by the fact that the beam path is formed symmetrically to the y-z plane.
[0081] FIG. 3 schematically illustrates in a side view another system 300 of the invention shown by way of example, which can compensate or minimize the asymmetry described with reference to FIG. 2. The system 100 described herein may in this case be included as a subsystem in the system 300. In FIG. 3 there can first be seen a photon beam input Si, which is diverted via a first deflecting mirror M1 to a first displacing mirror M2. The first displacing mirror M2 may in this case be displaced along the depicted y axis. The first displacing mirror M2 can be used to guide the photon beam input SI in a defined manner into a first subsystem G1, which may correspond to the system 100 in terms of structure and function. In this example, the first displaceable mirror M2 may introduce the photon beam input Si into the first subsystem G1, so that the first photon radiation S and also the second photon radiation S can be caused, depending on the position of the first displacing mirror M2. The displacing mirror can accordingly be understood as a means for varying, with more than two positions of the first displaceable mirror M2 being conceivable, while different photon radiations with different angles of incidence, and therefore magnifications, can be set for the first subsystem G1. In this respect, the first input coupler E1, the first element 1 and the first output coupler A1 of the first subsystem G1 (analogous to the system 100) can be seen in FIG. 3. From the first subsystem G1, the photon beam S (slightly magnified) or the photon beam S (more magnified, but also with a more unsymmetrical light distribution) can be coupled out with the first output diameter.
[0082] In the example from FIG. 3, this coupled-out photon radiation is subsequently diverted via a second deflecting mirror M3 to a second displacing mirror M4. The second displacing mirror M4 can be used to guide the photon radiation coupled out from the first subsystem G1 in a defined manner into a second subsystem G2 of the system 300. The second subsystem G2 may correspond to the system 100 in terms of structure and function. In this respect, a second input coupler E2, a second element 2 and a second output coupler A2 of the second subsystem G2 (analogous to the system 100 and the subsystem G1) can be seen in FIG. 3. In particular, here too the second displacing mirror M4 can adapt the radiation coupled out from the first subsystem G1 in such a way that it is incident on different segments of the surface of the second input coupler E2, so that different angles of incidence, and therefore accompanying magnifications, can be introduced to the photon radiation in the system 300 (as described herein). In one example, the second displacing mirror M4 and the first displacing mirror M2 may be coupled to one another. The coupling may in this case be designed in such a way that the first and second displacing mirrors M2, M4 for each subsystem G1, G2 cause the same magnification. In the example shown in FIG. 3, the coupling may in this case be such that the second displacing mirror M4 always moves in the same direction as the first displacing mirror M2, for example so that the photon beam is directed onto a segment of the second input coupler E2 which corresponds to the segment of the first input coupler E1 onto which the photon beam was directed. In this case, however, the second displacing mirror M4 may travel a multiple distance than in the comparison the first displacing mirror M2 (as indicated in FIG. 3, the displacing mirror M4 for the photon beam S is displaced further than in the comparison the displacing mirror M2, with respect to the mirror position in order to divert the photon beam S). For example, when there is a displacement of the first displacing mirror M2, the second displacing mirror M4 may travel a distance which is greater by a certain multiplicative factor than the distance that the first displacing mirror M2 travels. The zoom factor of the system 300 can accordingly be set over a single degree of freedom of movement and yet (at almost any wavelength) can be varied substantially without aberrations over a large range.
[0083] The total magnification of the system 300 can therefore be obtained from the multiplication of the magnification introduced at the first subsystem G1 by the magnification introduced at the second subsystem G2. The second subsystem G2 can therefore be regarded as a further magnification unit. The total magnification of the system 300 may comprise for example at least 5, at least 10 or at least 20, though higher total magnifications would also be conceivable. It is also conceivable that the system 300 comprises a zoom factor of at least 2, preferably at least 10, more preferably at least 50, most preferably at least 100.
[0084] In addition, the second subsystem G2 may however also (at the same time) compensate for the asymmetry of the light distribution which can occur with the magnification of the photon beam in the first subsystem G1 (as described herein). It should be mentioned that for this purpose the components in the system 300 should be configured for such a beam path in which the arrangement of the edge beams S1, S2 in the second subsystem G2 is reversed with respect to the arrangement of the edge beams S1, S2 in the first subsystem G1. The arrangement of the edge beams can in this case be considered to be reversed with respect to the incoupling of the edge beams into the respective subsystem. This is schematically shown in FIG. 3, in which the edge beams S1 and S2 are marked. In the first subsystem G1, the edge beam S1 is located in the portion between the focus of the first input coupler E1 and its reflection point at the first element 1 on the side of the photon beam S which is facing the first element 1. In the second subsystem G2, on the other hand, the edge beam S2 is located in the portion between the focus of the second input coupler E2 and its reflection point at the second element 2 on the side of the photon beam S which is facing the second element 2. This reversal of the edge beams S1, S2 when entering the second subsystem G2 can be explained for example in that, as a result of the beam path of the system 300, the photon radiation enters the second subsystem G2 mirrored, compared with when the photon radiation enters the first subsystem G1. This type of configuration can make it possible that the effect of the unsymmetrical light distribution of the first subsystem G1 is compensated (at least partially) by way of the second subsystem G2. This can be explained by the fact that the effect that causes the asymmetry of the distribution of the partial beams acts in the opposite direction in the second subsystem G2 due to the reflection of the photon radiation, so that the asymmetry of the distribution of the partial beams is minimized after passing the second subsystem G2. If the compensation mentioned does not take place, the parasitic effect described herein will increase the asymmetry of the light distribution still further.
[0085] The system 300 also comprises, after the second subsystem G2, a third displacing mirror M5, which is displaceable along the z direction. The third displacing mirror can therefore adapt the position of the photon beam coupled out from the second subsystem G2 on one plane. The photon beam coupled out from the system 300 may in this case also be referred to as the photon beam output SO. For example, depending on the magnification caused by the system 300, the third displacing mirror M5 can assume a position such that the photon beam output SO emitted by the system 300 appears centered on a point irrespective of the magnification.
[0086] The possible photon beam output SO of the system 300 is in this case given by way of example with the beam distribution 301 and the beam distribution 302.
[0087] The beam distribution 301 indicates the beam distribution in the case of a magnification and compensation of the photon beam input SI by way of the system 300 in the x and y directions. For the beam distribution 301 there is therefore a symmetrical beam magnification (as described herein). The symmetrical beam magnification may for example be present in both subsystems, so that as a result the photon beam output SO has a symmetrical beam magnification.
[0088] The beam distribution 302 in this case indicates the beam distribution in the case of a magnification and compensation of the photon beam input SI by way of the system only in the y direction. For the beam distribution 302 there is therefore an asymmetric beam magnification (as described herein). Thus, it can be seen that the envelope of the beam distribution 302 has an elliptical form (in contrast to the circular distribution of the radiation of the photon beam input SI, which is indicated in darker color). The asymmetric beam magnification may for example be present in both subsystems, so that as a result the photon beam output SO has an asymmetric beam magnification.
