Beam splitter, beam splitter system and use of a beam splitter

Abstract

A beam splitter comprises an input coupling structure configured to redirect an input beam to obtain a redirected input beam. A first reflective surface region and a second reflective surface region inclined relative to the first reflective surface region are provided. A beam splitting structure is arranged at an incline between the first reflective surface region and the second reflective surface region and is configured to split a light beam based on the redirected input beam to obtain a first partial beam and direct it onto the first reflective surface region, and to obtain a second partial beam and direct it onto the second reflective surface region.A first output beam of the beam splitter based on the first partial beam and a second output beam of the beam splitter based on the second partial beam have a substantially equal propagation delay compared to the input light beam.

Description

[0001] The present invention relates to beam splitters, for example, in which output beams of the beam splitters have a substantially equal propagation delay compared to an input light beam. Some of the embodiments described herein relate to beam splitters without temporal offset of the partial beams for a linear arrangement.

[0002] Beam splitters are used to split an input beam into at least a first and a second output beam. Prisms are commonly used for this purpose. For some applications, it is desirable for the resulting output beams to be similar or as similar as possible with respect to one or more properties or characteristics.

[0003] DE 10 2020 205 849 A1 relates to an arrangement of optical elements for the formation of structural patterns which can be formed with a compact optical structure for generating periodically pronounced intensities of laser radiation for structuring surfaces.

[0004] WO 2017 / 085618 A1 relates to an optical system with a device for generating a synthetic aperture.

[0005] US 4,009,940 A relates to a prism arrangement of bonded prisms.

[0006] An object of the present invention is to provide beam splitters and beam splitter systems which make it possible to obtain output beams with at least partially the same or at least similar propagation delay.

[0007] This problem is solved by the subject matter of the independent patent claims.

[0008] A key idea of the present invention is to implement output beams of a beam splitter, which can also be used in a beam splitter system, in such a way that the output beams have a substantially equal propagation delay compared to the input beam.

[0009] According to a first aspect of the present invention, this is achieved by deflecting an input beam at a coupling structure in order to direct it onto a beam splitting surface and to direct the resulting split light beams over as similar distances as possible and / or a similar or the same number of further deflecting surfaces.

[0010] According to one embodiment, a beam splitter comprises a coupling structure configured to deflect an input beam to obtain a deflected input beam. The beam splitter comprises a first reflective surface region and a second reflective surface region inclined relative to the first reflective surface region. Between the first reflective surface region and the second reflective surface region, a beam splitting surface is arranged that is inclined relative to the first reflective surface region and the second reflective surface region and is configured to split a light beam based on the deflected input beam to obtain a first partial beam and direct it onto the first reflective surface region. In addition, a second partial beam is obtained, which is directed onto the second reflective surface region.A first output beam of the beam splitter based on the first partial beam and a second output beam of the beam splitter based on the second partial beam have a substantially equal propagation delay compared to the input beam.

[0011] According to a further embodiment, a beam splitter comprises a beam splitting structure configured to split an input beam to obtain a first partial beam and to obtain a second partial beam. The beam splitter comprises a first reflective surface region inclined relative to the beam splitting structure and a second reflective surface region inclined relative to the first reflective surface region on the one hand and relative to the beam splitting structure on the other hand. The beam splitting structure is configured to direct the first partial beam onto the first reflective surface region and to direct the second partial beam onto the second reflective surface region.

[0012] A first output beam of the beam splitter based on the first partial beam and a second output beam of the beam splitter based on the second partial beam have a substantially equal propagation delay compared to the input beam.

[0013] According to one embodiment, a beam splitter system comprises at least a first beam splitter and a second beam splitter according to embodiments discussed herein, which are arranged serially one behind the other. That is, the output beams of the first beam splitter form input beams of the second beam splitter, which is configured to split each of the two input beams, thus providing a total of at least four output beams. This enables a spatial division of the output beams.

[0014] Further advantageous embodiments of the present invention are the subject of dependent patent claims.

[0015] Particularly advantageous embodiments of the present invention are explained below with reference to the accompanying drawings, in which: Fig. 1a-b are schematic side sectional views of a beam splitter according to an embodiment; Fig. 2 a schematic side sectional view of a beam splitter according to an embodiment, with a Fig. 1a-b modified arrangement of a coupling structure; Fig. 3 is a schematic side sectional view of a beam splitter according to an embodiment in which reflective structures are used instead of prisms; Fig. 4 is a schematic side sectional view of a beam splitter according to an embodiment of the present invention, in which the beam-deflecting regions can receive partial beams without the need for a coupling structure; Fig. 5a-b are schematic side sectional views of a beam splitter according to an embodiment, which, with respect to the beam guidance of the input beam, is comparable with the beam splitter of Fig. 4 is comparable but reflecting surfaces are used instead of prisms; Fig. 6 is a schematic perspective view of a beam splitter system according to an embodiment, for example, implementing a variant of a beam splitter system for a linear arrangement of the output beams; and Fig. 7 is a schematic perspective view of a beam splitter system according to an embodiment in which the second beam splitter is configured differently from the beam splitter in Fig. 6 is rotated by 90 degrees to provide, for example, a variant of a beam splitter system for a square arrangement of the output beams.

[0016] Before exemplary embodiments of the present invention are explained in more detail below with reference to the drawings, it is pointed out that identical, functionally identical or equivalent elements, objects and / or structures in the different figures are provided with the same reference numerals, so that the description of these elements shown in different exemplary embodiments is interchangeable or can be applied to one another.

[0017] The embodiments described below are described in conjunction with numerous details. However, embodiments may also be implemented without these detailed features. Furthermore, for clarity, embodiments are described using block diagrams instead of detailed illustrations. Furthermore, details and / or features of individual embodiments may be readily combined with one another, unless explicitly described otherwise.

[0018] Embodiments discussed herein relate to beam splitters with a beam splitting structure. A beam splitting structure that can be used in the context of embodiments discussed herein can be understood as a layer or a single-layer or multi-layer structure that may possibly have microstructures and / or nanostructures, for example so-called metastructures, that are designed to split an incoming light beam into two, possibly even multiple, partial beams.

[0019] The beam splitting structure can be passive or active. The input beam can be split according to one or more parameters. These include different polarizations, which can be separated into different beams, intensities, which can be separated into different partial beams, a spectral split, for example according to different wavelengths and / or a split of the angular momentum of the light. In other words, the phases, amplitudes and / or other relationships such as wavelength (frequency) of the incident electromagnetic wave can be separated. However, it is also conceivable that not only the intensity, polarization and / or wavelength, but also the angular momentum of the light is processed. This can be achieved, for example, by active structures orswitchable media, such as liquid crystal layers or vanadium dioxide layers, which are used to manipulate the incident light beam.

[0020] Embodiments of the present invention relate to light rays that are incident, split, or provided as outgoing light rays. In the context of the exemplary embodiments discussed herein, light is understood to mean electromagnetic radiation, which may, but not necessarily, be in the wavelength range visible to humans. It is readily possible to use exemplary embodiments described herein outside the visible wavelength range, for example in the infrared range and / or the ultraviolet range or in other wavelength ranges that are used, for example, for the optical transmission of information. Exemplary wavelength ranges here can comprise the wavelength range from at least 100 nm down to 1 mm, in whole or in part, for example in sections.

[0021] Embodiments described herein relate to beam splitters with reflective surface regions. Beam splitters according to the invention can, for example, comprise prisms or prism-like structures, i.e., transparent solid bodies, at whose interfaces reflection occurs, optionally with or without an arrangement of additional material layers. However, as also described in connection with embodiments discussed herein, the use of transparent or partially transparent bodies is not necessary. It is, for example, equally possible to provide a reflective surface or a reflective surface region without such bodies, for example by arranging a gas or vacuum between beam-splitting and / or reflective surfaces. One possible embodiment is, for example, a mirror arrangement or the like arranged around a beam splitting structure.

[0022] Some of the embodiments described herein relate to the use of one or more prisms or a prism structure. For example, a transparent material, such as glass, can be used as the material for the prism. Transparency may be wavelength-dependent, so structures that are transparent in certain wavelength ranges may comprise partially opaque or opaque materials in the wavelength range visible to humans, such as silicon materials for infrared applications or the like.

[0023] Fig. Figure 1a shows a schematic side sectional view of a beam splitter 10 according to one embodiment. The beam splitter comprises a coupling structure 12 configured to deflect an input beam 14 to obtain a deflected input beam 16. The coupling structure 12 can deflect the input beam 14 once or multiple times.

[0024] The beam splitter 10 comprises reflective surface regions 181 and 182 arranged at an angle to one another. A beam splitting structure 22 is arranged between the reflective surface regions 181 and 182, at least with respect to a path of the light beam, and is inclined relative to the reflective surface regions 181 and 182.

[0025] Preferably, a redirected input beam 16' strikes the beam splitting structure 22 and is split out there as a first partial light beam 241, for example, and reflected back, and a partial light beam 242 is transmitted. The arrangement is configured to direct the partial light beam 241 onto the reflective surface region 181, where it is reflected and redirected to provide a redirected partial light beam 24'1, which forms a basis for an output beam 261. In a preferred embodiment, the beam splitting structure 22 can be arranged at an angle bisecting an orientation of the reflective surface regions 181 and 182. This means that the beam splitting structure 22 can be arranged along an angle bisector of the inclination angle that results between the reflective surface regions 181 and 182.

[0026] The transmitted portion in the partial beam 242 is directed directly or indirectly onto the reflective surface region 182 to be reflected there and to provide a deflected partial light beam 24'2, on which a further output beam 262 of the beam splitter 10 is based. Although it is readily possible to obtain the partial beams 241 and 242 with different proportions with regard to the at least one split characteristic, for example approximately 70% intensity in one partial beam and a remaining 30% intensity in the other partial beam, preferred embodiments provide for the splitting to be approximately 50%, i.e., when two partial beams 241 and 242 are obtained, each with a proportion of 50%. Based on a corresponding configuration of the beam splitting structure 22, a higher number of beams can also be obtained.

[0027] The output beams 261 and 262 have a substantially equal propagation delay compared to the input beam 14. The propagation delay can be related to output surfaces 281 and 282, at which the output beams 261 and 262 exit from prism structures 321 and 322 of the beam splitter 10. Alternatively or additionally, the propagation delay can also be related to arrival at a receiver that receives both output beams 261 and 262.

[0028] In the illustrated configuration and with the input beam 14 arriving parallel to the direction 36, the beam splitter 10 can provide the output beams 261 and 262 substantially parallel to each other and / or parallel to the direction 36 or the input beam 14.

[0029] The coupling structure 12 may, for example, comprise a first prism region of the beam splitter, which comprises a deflection surface 34 which is inclined with respect to a direction 36 of the input beam 14 and with respect to the beam splitting surface 22.

[0030] Due to the wavy inclination angles and / or prism structures, the beam splitter 10 can be designed such that the direction 36 runs substantially parallel to the beam splitting structure 22, at least in one possible mode of operation of the beam splitter 10. The beam splitting structure 22 can, for example, be arranged at one or both interfaces of at least one of the prisms 321 and 322, i.e., between the prisms 321 and 322. This enables the use of prefabricated prisms and the arrangement of the beam splitting structure 22 at one or both interfaces before the two prisms 321 and 322 are joined together. The coupling structure 12 can comprise a further prism arranged on one of the sides of the prisms 321 or, alternatively, 322. A selection of an angle 38 between the direction 36 and the deflection surface 34 enables the adjustment of directions 361 and 362 of the output beams 261 and 262, respectively.For the sake of simplicity, the angle 38 can also be referenced to a normal or perpendicular 44, which can also be referred to as a surface normal to at least one layer of the beam splitting structure 22. The angle 38' can be at least 15 degrees and at most 75 degrees, preferably less with respect to a deviation from a 45-degree angle, for example at least 25 degrees and at most 65 degrees or at least 35 degrees and at most 55 degrees, preferably approximately 45 degrees. In other words, a deviation of up to 30 degrees is possible with respect to a value of 45 degrees to the normal 44 of the beam splitter surface 22.

[0031] Angles 461 and 462, at which the reflective surface areas 181 and 182 are inclined relative to the beam splitting structure 22, can be set or selected such that the output beams 261 and 262 run parallel to the direction 36 when the input beam is incident perpendicularly on a coupling side 48 of the coupling structure 12, which means that the directions 421 and 422 can possibly be parallel to each other and to the direction 36.

[0032] The beam splitter 10 can also be described such that the two prisms 321 and 322 together form an isosceles triangle in the cross-sectional view shown. The beam splitting structure 22 can be arranged at least on parts of the interface between the two prisms 321 and 322. Optionally, coatings 521 and 522 can be arranged to improve the reflection properties of the reflective surface regions 181 and 182. It is preferred if the coatings 521 and 522, if arranged, are arranged with the same properties so that the reflection in the reflective surface regions 181 and 182 is as similar as possible.

[0033] One possible requirement for beam splitters is that the input beam 14 and output light beams 261 and 262 run parallel to each other, at least in some configurations of the beam splitter 10. This is achieved in the illustrated implementation of a beam splitter by adjusting the angles 38 / 38' on the one hand and the angles 461 and 462 on the other hand, so that further reflection or beam deflection in a surface area 54 of the prism 321 results in the desired directional path.

[0034] While the coupling structure 12 can be referred to as the first prism region of the beam splitter 10, the prisms 321 and 322 can be referred to individually or in combination as the second prism region. It is preferred if the prism regions are directly adjacent to one another in order to avoid refraction or scattering effects due to different media on either side of the respective interface. The beam splitter 10 can be designed to direct the input beam 14 with the deflection surface 34 of the first prism region onto the deflection surface 54 of the second prism region, wherein the deflection region 54 in this embodiment is designed to direct the input beam or the deflected form thereof onto the beam splitting structure 22, which is also part of the second prism region.

[0035] The coupling side 48 can be arranged perpendicularly or non-perpendicularly with respect to the direction 36. According to a method used in connection with the Fig. 1b, the input side 48, according to one embodiment, has a first region 561 and a second region 562. By aligning the input beam 14 to the first region 561 or the second region 562, it is possible, for example, to control whether a beam splitting is carried out by the beam splitter or whether an output light beam is provided without splitting at the beam splitting surface 22. If, for example, the input beam 14 is shifted parallel along a positive x-direction to such an extent that the input beam 14 impinges away from the deflection surface 34 or the inclined side of the prism 12, for example opposite the deflection region 54 or shifted further along the positive x-direction, the deflection of the input beam 14 can be completely or partially omitted and, due to possibly parallel sides of the prism structure, the input beam can essentially emerge straight again from the overall prism structure.

[0036] This is in Fig. 1b, which shows the beam splitter 10 in the same perspective as the Fig. 1a and illustrates the effect of the beam splitter 10 when the position and / or orientation of a light source 58 is changed in different positions / orientations 58a, 58b and 58c. Compared to a beam splitter with the Fig. 1a, in a position 58a, by shifting the light source (position 58c) in such a way that the input beam 14 strikes the beam splitter 10 or the coupling structure 12 outside the region 561, in particular in the region 562, it can be adjusted whether the input beam 14 is deflected or not, so that, for example, an output light beam 263 can be obtained from the beam splitter 10 along an unchanged direction 36, which furthermore remains essentially undivided. As described with reference to the output light beam 263, the coupling side 48 can be configured to receive the input beam 14 and, upon arrival of the input beam in the region 561 of the coupling side 48, to split the light beam 16' based on the input beam by directing it onto the beam splitting structure 22.When the input beam 14 impinges on the region 562 of the coupling side 48, another output light beam 263 can be provided without splitting at the beam splitting surface.

[0037] In contrast, an orientation 58b of the light source 58 shows a tilt of the light source 58 about a z-axis by an angle 62, so that the input beam 14 strikes the deflection surface 34 at a changed angle. As a result, the deflection region 54 shifts towards a positive x-direction due to the law of refraction, whereby the angle of emergence of the deflected input beam 16' from the deflection region 54 can thereby also be changed, so that an angle of incidence of the deflected input beam 16' onto the beam splitting structure 22, the reflective surface region 181 and / or the reflective deflection region 182 is thereby also changed, whereby the output beams 261 and 262 can deviate from a parallel course and can be inclined at an angle 64 relative to one another.

[0038] This means that the beam splitter can be designed to provide the output beams 261 and 262 substantially parallel upon arrival of the input beam 14 on the coupling structure 12 with a reference direction 36, as shown in the Fig. 1a. The beam splitter can provide the output beams 261 and 262 inclined to one another when the input beam 14 arrives at the coupling structure 12 in a direction deviating from the reference direction 36.

[0039] The input beam 14 can be received from the direction 36, for example, as a reference direction perpendicular to a coupling side 48 of the coupling structure 12. The output beams 261, 262, and 263 can, at least when using the reference direction 36, be provided with a direction substantially parallel to one another and / or parallel to the direction 36. This can be deviated from as desired by tilting the light source 58, as described with reference to the position 58b.

[0040] As it is in Fig. As is clearly shown again in Figure 1b, the first prism region, which can be defined entirely or partially by the coupling side 48 and can also include subsequent regions of the prism 321 along the direction 36, can be designed such that the first prism region receives the input beam 14. The coupling side 48 can comprise regions 561 and 562, although additional regions are not excluded. The region 561 can be arranged opposite the deflection surface 34 along the direction 36 of the input beam 14, and the region 562 can be arranged offset perpendicular to the direction 36, i.e., in regions where the deflection surface 34 is not arranged opposite it.When the input beam arrives in the first region 561 of the coupling side 48, a splitting of the light beam can be effected and when the input beam 14 arrives in the region 562 of the coupling side 48, the input beam 14 can be guided undivided past the beam splitter structure 22, which does not exclude a different type of manipulation of the light beam.

[0041] Fig. 1b shows a further advantageous use of the beam splitter 10 and beam control options. While maintaining the reference direction 36, for example, perpendicular to the input side 48 and / or perpendicular to an exit side 66, a displacement of the light source 58 within the first region 561 can initially result in a position of the deflection region 54 also being shifted along the x-direction while maintaining the entrance angle and exit angle, whereby a region 681, in which the deflected input beam 16' strikes the beam splitting structure 22, can be shifted along the y-direction, which is represented by the region 682. As a result, the location at which the partial light beams 241 and 242 strike the reflective surface regions 181 and 182, respectively, can be shifted, whereby a distance 72 between the output beams 261 and 262 can be adjusted.Starting from position 58a, for example, when moving the light source 58 along the positive x-direction, the distance 72 can increase until the input beam 14 leaves the area 561 and impinges on the coupling structure 12 in the area 562, leaving the beam splitter 10 undivided. The receipt of the output light beam 263 as an undivided light beam is to be understood as an example; the output light beam 263 can be used for other purposes, for example, by arranging other beam-deflecting, beam-splitting, or beam-influencing elements.

[0042] As in Fig. 1b, the beam splitter 10 can be used to adjust the output beams 261 and 262 at the exit side 66 of the beam splitter with respect to the distance 72, so that a provided distance depends on a position at which the input beam 14 strikes the coupling structure 12.

[0043] The effects of the adjustable angle 64 and the adjustable distance 72 can be used individually or in combination.

[0044] In Fig. Figure 1b further clearly shows that the interface between the coupling structure 12 and the prism 321 can be used solely by connecting individual bodies, without exerting any beam-influencing effect. In some embodiments, it is also provided that the coupling structure 12 and at least the prism 321 are formed in one piece, i.e., integrally, thus avoiding the interface.

[0045] In other words, based on the Fig. 1a and Fig. In variant 1 shown in Figure 1b, an input beam 14 can be split into two partial beams 261 and 262. By cleverly defining the prism angles of the prism 12, for example, with regard to angles 38, 38', with respect to the input beam 14, the input beam 14 is totally reflected at the material-air interfaces and guided further to the beam splitter 22. The angle 38 can be set to the optimal angle for the beam splitter layer or beam splitter structure 22 so that the beam splitter 22 optimally splits the input beam. This angle can be influenced by the actual structure of the beam splitter 22, for example, the number of layers, the size of the structures, or the like. Mirror layers 521 and 522 are arranged on the cathetial surfaces, which can guide the two partial beams parallel to the output by adjusting the angle 46, based on the orientation of the light source.

[0046] By shifting the input beam 14 along the x-direction along the input surface, the distance 72 between the two partial beams 261 and 262 can be varied.

[0047] Furthermore, the angle 64 of the two partial beams 261 and 262 relative to each other can be adjusted via the angle of incidence 62 of the input beam 14. If, however, the input signal 14 is not to be split, it can also be sent through the element unprocessed, see position 58c of the light source 58.

[0048] In the Fig. 1a and Fig. The side sectional view shown in Figure 1b illustrates the use of a single input beam 14. However, the beam splitter 10 can easily be illuminated simultaneously with multiple input beams, such as spatially separated input beams that may be offset from one another along the x-direction and / or along the z-direction. This allows for multiple splitting and also increases the number of output beams accordingly.

[0049] Fig. 2 shows a schematic side sectional view of a beam splitter 20 according to an embodiment, which offers the same or similar advantages as the beam splitter 10, but has a different configuration. Compared to the beam splitter 10, the coupling structure 12 can be used to direct the deflected input beam 16 onto the beam splitting structure 22 without further deflection. The beam splitter 20 is illustrated such that it can comprise the coupling structure 12 as well as the prisms 321 and 322 and further prisms 741 and 742, wherein, for example, the prisms 741 and 321 can form a first side and the prisms 742 and 322 can form a second side of the second prism region of the beam splitter 20, between which the beam splitting structure 22 is arranged.The angles of the prisms 12, 32, and 74 can be adjusted to each other in such a way that the individual parts can be joined together as seamlessly as possible, which does not preclude an alternative implementation as a one-piece or integral structure for two or more of the described prisms. However, the joining allows the use of standard components and their simple and inexpensive joining. This also enables the use of different angles, for example for the coupling structure 12, which can be compensated for by appropriately designed adaptation structures in the form of the prisms 741 and 742, in order to still enable an alignment of the beam splitting structure 22 parallel to the direction 36 and / or the direction y.

[0050] The beam splitter 20 also makes it possible to direct the partial light beams 241 and 242 onto the reflective surface areas 181 and 182, respectively, in order to obtain the output beams 261 and 262.

[0051] Similar to the beam splitter 10, a displacement of the input beam 14 along the x-direction can be used to adjust the distance 72 between the output beams 261 and 262. Alternatively or additionally, a positioning of a light source (not shown) such that the input beam 14 impinges on the coupling structure 12 in the region 562 without being further directed onto the beam splitting structure 22 can be used to obtain the input beam 14 undivided at the output side 66.

[0052] In the Fig. 2, the beam splitter comprises a second prism region formed from the prisms 321, 322, 741 and 742, which adjoins the first prism region of the prism 12, wherein the beam splitter 20 is designed to direct the input beam 14 with the deflection surface 34 onto the beam splitting structure 22 within the scope of the described embodiment, wherein the beam splitting structure 22 is part of the second prism region.

[0053] In the context of the embodiments discussed herein, any interfaces can generally be provided with a layer that filters or manipulates the light. Unlike, for example, in the Fig. 1a and the Fig. As shown in Figure 1b, the reflective surface regions 181 and 182 can, for example, be interfaces between different media of the respective prism 321, 322 on the one hand and the external environment, such as air, vacuum, or the like, on the other. In one embodiment of the beam splitter 20, supporting coatings, such as coatings 52, can also be arranged in the region of the reflective surface regions 181 and / or 182, which may have reflective properties.

[0054] The Fig. Variant 2 shown in Figure 2 has the coupling prism 12 closer to the beam splitter layer or beam splitter structure 22. This allows a greater distance between the two partial beams 261 and 262 compared to the Fig. 1a and Fig. 1b shown first variant at the output.

[0055] Fig. 3 shows a schematic side sectional view of a beam splitter 30 according to an embodiment that describes a third variant of the invention discussed herein. Unlike beam splitters 10 and 20, reflective structures 761 to 764 can be used instead of prisms or their interfaces or coated surfaces to provide a beam path comparable to the beam path of beam splitter 10. Alternatively or additionally, a beam path corresponding to beam splitter 20 can also be fully or partially replicated using reflective structures 76 instead of prisms.One advantage of corresponding reflective structures may, for example, be the ability to adjust the angle 38 between the reflective structures 761 and 762, and thus between the deflection surfaces or deflection regions 34 and 54, for example by rotatably supporting the reflective structure 761 with respect to the reflective structure 762, or vice versa. The reflective structures 76 may have a reflective surface and / or be formed to be reflective due to a material structure.

[0056] In the same or similar manner, the reflective structure 763 can be rotatably mounted with respect to the reflective structure 764 in order to adjust angles 461 and / or 462 of the reflective surface regions 181 and / or 182 with respect to the beam splitting structure 22.

[0057] The reflective regions 761 and 762 can be inclined relative to the direction 36 of the input beam 14 and relative to the beam splitting surface 22 at a variable tilt angle to one another, the angle 38. This variable tilt angle 38 can enable manual and / or automated adjustment. According to one embodiment of the present invention, the beam splitter 30 comprises an actuator device configured to adjust the tilt angle in response to a control signal. The control signal can, for example, depend on the distance to be set between the output beams 261 and 262, whether the beams 261 and 262 should run parallel to one another or at an angle to one another, and / or to adjust an optimum beam splitting, for example with additional use of a sensor device to implement a control loop.

[0058] According to one embodiment of the present invention, the reflective structure 761 and / or 762 can, on the one hand, be mounted displaceably with respect to the beam-splitting structure 22 along the x-direction and / or y-direction and, if appropriate, be coupled to an actuator designed for the displacement. This allows an angle of incidence and / or incidence area of the light beam 16' on the beam-splitting structure 22 to be adjusted, even if the position of the light source 58 remains unchanged.

[0059] The possibility of allowing the input beam 14 to pass undivided past the beam-splitting structure 22 can also be realized with the beam splitter 30, for example by displacing the light source 58 along the positive x-direction and, if possible, by making the reflective structure 762 shorter than shown, as indicated by line 78, so that an intermediate region 82 is created through which the input beam 14 can pass. Alternatively, the reflective structure 762, like other reflective structures 761, 763, and / or 764 described herein, can be designed such that a mirroring or total reflection is only carried out upon oblique incidence on the structure, and, for example, a perpendicular incidence, similar to a prism surface, leads to total entry of the light beam.In this case, a displacement of the reflective structures 761 and 762 along the negative x-direction until the input beam 14 strikes the reflective structure 762, alternatively an opening of the angle 38 up to a value of approximately 90 degrees, that is, perpendicular to the direction 36, alone or in combination with a displacement of the light source 58 along the positive x-direction as well as a displacement of the light source 58 along the positive x-direction alone can be used to guide the input light beam 14 past the beam-splitting structure 22.

[0060] A coupling structure 12' of the beam splitter 30 comprises reflective or reflecting structures or regions 761 and 762 which are arranged inclined to one another and are inclined with respect to the direction 36 of the input beam 14 and with respect to the beam splitting structure 22, wherein the same values can be applied for the angle as in connection with the Fig. 1a and Fig. 1b. The beam splitter 30 may be configured to reflect the input beam 14 at the first reflective structure 761 and the second reflective structure 762 and direct it onto the beam splitting structure 22.

[0061] In other words, the principle of the second variant can be Fig. 2 also in the Fig. The third variant shown in Figure 3 can be realized with a mirror and beam splitter 22. Here, the input beam 14 is again guided through the angle 34 of the first mirror 761 to the beam splitter 22 and split. The partial beams 261 and 262 are output parallel to each other via the angle 46 of the second mirror 763 / 764. This mirror variant is advantageous, for example, when no dispersion is desired or for UV light or high-power applications.

[0062] Fig. 4 shows a schematic side sectional view of a beam splitter 40 according to an embodiment of the present invention, in which the beam-deflecting regions 181 and 182 can receive partial beams 241 and 242 without the need to use a coupling structure for this purpose, although this is still easily possible.

[0063] The beam splitter 40 includes the beam splitting structure 22, which is configured to split the input beam 14 to obtain the sub-beams 241 and 242. A reflective surface region 181, approximately disposed on the reflective structure 761, and a reflective surface region 182, approximately disposed on the reflective structure 762, are inclined relative to each other and each relative to the beam splitting structure 22. The beam splitting structure 22 is configured in this embodiment to direct the sub-beam 241 onto the reflective surface region 181 and to direct the sub-beam 242 onto the reflective surface region 182. The output beam 261 based on the sub-beam 241 and the output beam 262 based on the sub-beam 242 have substantially the same propagation delay relative to the input beam.This can be achieved by ensuring that the path length within the beam splitter 40, for example, starting from the optional light source 58 to a common reference plane, is the same. Such a reference plane is, for example, the exit side 66 in the beam splitters 10 and / or 20 and can also be viewed virtually in the beam splitter 40.

[0064] According to an embodiment of the beam splitter 40, which offers advantages in terms of propagation time equality, the reflective surface region 181 and the reflective surface region 182 are inclined by an angle 461, 462 of substantially the same amount with respect to the beam splitting structure 22 and face each other.

[0065] According to a further preferred but optional embodiment, the inclination angle 461 and / or the inclination angle 462 with respect to the beam splitting structure 22 is adjustable, for example, using actuators or providing manual adjustability, as described in connection with the beam splitter 30. According to one embodiment, a distance between the reflective regions 181 and / or 182 can be adjustable, which can enable the adjustability of the distance 70.

[0066] Fig. 5a shows a schematic side sectional view of a beam splitter 50 according to an embodiment, which is comparable to the beam splitter 40 with regard to the beam guidance of the input beam 14. In contrast to the description with regard to the use of the specular or reflective structures 761 and 762, prisms 321 and 322 can be joined together to form an interface 82, which, however, can possibly remain optically functionless. The beam-splitting structure 22 can be arranged on an entrance side and / or facing the optional light source 58, so that the input beam 14, at least in a reference orientation, strikes the beam splitting structure 22 substantially perpendicularly, so that the latter forms the partial beams 241 and 242 from the input beam 14. These partial beams can be formed on the reflective surface regions 181 and 182 of the prisms 321 and 322, respectively, in a similar way to that described in connection with the beam splitter 10 and / or 20.322, wherein an effect of the beam splitting structure 22 can be compensated for with regard to an output angle 481 and / or 482 exhibited by the partial beams 241 and 242 by designing the angles 461 and 462. The angles 841 and 842 can possibly be structurally determined, so that in order to obtain possibly parallel output beams 261 and 262, at least upon arrival of the input beam 14 from the reference direction 36, the latter can run parallel to one another.

[0067] Based on the Fig. 5b, an advantageous use of the beam splitter 50 is explained. Here, the optional light source 58 is inclined by an angle 86 relative to the reference direction 36, which, for example, leads to a situation similar to the orientation 58b of the Fig. 1b. The input beam 14 is thereby inclined on the one hand and, on the other hand, impinges on the beam splitting structure 22 at a changed position, wherein, due to the effect of the prisms 321 and 322, similar to a reflector, the output beams 261 and 262 are also inclined with respect to the reference direction 36, but can run along the opposite direction and, furthermore, still essentially parallel to one another.

[0068] The embodiments of beam splitters described herein can also be used in reverse to combine different partial beams, so that, for example, beams 261 and 262 traveling in the opposite direction are combined as a beam combiner.

[0069] This is particularly useful for coherent combination, where the identical path lengths of the partial beams are advantageous. For polarization combination, it is advantageous to guide the two partial beams into the element with their polarization perpendicular to each other. These beam splitters can also be cascaded, as described in connection with the beam splitter systems described herein. Fig. 4, Fig. 5a and Fig. 5b. The advantage of the system described herein is that the elements can be arranged, connected, and manufactured in any desired manner. For example, it is possible to place different dichroic beam splitters one behind the other to split a signal into any number of channels. Different patterns, such as linear or square patterns, of the output beams can also be generated, as described in connection with the beam splitter systems described herein. Furthermore, the beam spacings and angles can be adjusted as desired, as described herein.

[0070] Fig. 6 shows a schematic perspective view of a beam splitter system 60 according to an embodiment, which, for example, implements a variant of a beam splitter system for a linear arrangement of the output beams. The beam splitter system 60 comprises at least a first and a second beam splitter 101 and 102, which are connected in series, which can be understood to mean that the output beams 261 and 262 of the first beam splitter 101 can form input beams of the second beam splitter 102. Each of the beam splitters 101 and 102 can also be implemented as beam splitters 20, 30, 40, and / or 50.

[0071] The coupling structure of the beam splitter 102 can be configured to receive and redirect the input beam as a first input beam and simultaneously as a second input beam. The beam splitter 102 can be configured to provide first to fourth output light beams from the first and second input beams.

[0072] Based on receiving two input beams, the second beam splitter 102 can generate four or more output beams 26 11 , 26 12 , 26 21 and 26 22 provide, where the index 26 i,j the i-th output beam of the beam splitter 101 and the j-th output beam generated therefrom.

[0073] This shows a further advantage of the embodiments described herein. Thus, upon arrival of the input beam 14 in the region 582, the output light beam 263 can be directed to a beam splitter other than the beam splitter 102, for example, to obtain a different beam splitting, a different spatial orientation, as may be required in connection with the Fig. 7 or to benefit from other, possibly unchanged, optical properties of the light.

[0074] Fig. 7 shows a schematic perspective view of a beam splitter system 70 according to an embodiment in which the second beam splitter 102 is rotated by 90 degrees relative to the configuration of the beam splitter 60, for example to provide a variant of a beam splitter system for a square arrangement of the output beams.

[0075] While in the beam splitter system 60 the output beams 26 11 , 26 12 , 26 21and 26 22 While the beam splitters 101 and 102 can be arranged linearly next to one another, a 2x2 arrangement can be obtained with the beam splitter system 70, for example when viewing the output beams in a projection plane parallel to the x / z plane. Rotation of the beam splitters 101 and 102 relative to one another, for example about an axis parallel to the y-direction, can produce, for example, a diamond pattern or the like.

[0076] In other words, a beam splitter system as described herein can be used so that the four output beams, when projected in the plane perpendicular to a direction along which at least one light beam travels, form a one-dimensional pattern ( Fig. 6) or a two-dimensional pattern ( Fig. 7). The use of additional beam splitters allows for a higher number of output beams.

[0077] Beam splitting structures described herein can be configured to perform at least one of polarization splitting, intensity splitting, spectral splitting, for example, with respect to the wavelengths of the split beams, and angular momentum splitting. The beam splitting structure can be formed in a single layer or in multiple layers, with microstructures, nanostructures, such as metastructures, or the like being particularly suitable. According to one embodiment, the beam splitting structure comprises a surface grating, wherein one or more of the following options can be implemented: - discrete grids with trench and / or webs; - discrete gratings in several levels or multi-layer designs; - continuous surface gratings such as so-called sine gratings; - Meta-structures; - diffractive beam splitters - or more.

[0078] Alternatively or in addition to a so-called surface grating or a two-dimensional structure, three-dimensional structures can also be used, such as so-called volume Bragg gratings. A path difference between the two partial beams 241 and 242 can be adjusted by a left-right translation of the input beam, as described in connection with the Fig. 4, Fig. 5a and Fig. 5b. In these embodiments, an inclination of the input beam results in the same angular change of the output beam.

[0079] With the help of the beam splitters described herein, broadband, wavelength-specific (dichroic) and / or polarization-specific splitting of optical signals can be achieved so that the outgoing partial beams can travel parallel to each other and in the same direction as the input beam. The two partial beams, or output beams, ideally travel exactly the same path length through the material and interact with the same number of interfaces, whereby the temporal offset is negligible and no phase jump is induced. It is precisely this small propagation time difference that brings enormous advantages in optical signal processing and in coherent combination, i.e., as a combination element or as a signal splitting element. Embodiments can be readily used for both coherent and non-coherent light.

[0080] In addition, the angles and distances between the partial beams can be manipulated by adjusting the input beams (angle and position). Unlike lens-based approaches, the beam spacing can be changed independently of the diameter of the individual beams. This leads to better alignment or adaptation to an optical system and opens up new design possibilities.

[0081] The beam splitters described herein can be used wherever beam splitters or beam combiners are already used today, especially where a compact linear arrangement and the smallest possible temporal offset between the two partial beams is desired. This can be the case, for example, in laser communication as a beam splitter or laser combiner, telecommunications, quantum communication, materials processing, such as laser material processing, in the implementation of light sources, in optical signal processing, and / or, for example, in interferometric measurements.

[0082] In particular, it is conceivable for use in coherent combination, both for splitting the input signal into multiple optical amplifiers, such as fiber amplifiers, and for subsequently combining the signals. The property of minimal optical path length and phase difference between the partial beams is advantageous here.

[0083] In the spectral combination, the beam splitter can be used in its dichroic variant as well as in the coherent combination.

[0084] The beam splitter can be used for coupling into multi-core fibers with linear or rectangular core arrangements, as it allows independent control of the spacing and size of the output beams. Embodiments allow any size of input and output beams, provided the system is scaled accordingly. Collimated and non-collimated beam bundles can be used and / or generated. This means that the beam splitters described herein can also be used to focus or scatter light beams. The divergence of the beam bundles can be limited, which determines the size, diameter, or strength of the focusing / defocusing that the respective beam splitter can handle.

[0085] Embodiments overcome the previous disadvantage that there is currently no established design for beam splitters that directs input beams and output beams in the same direction and, ideally, does not cause any propagation time difference between the separated optical signals. Furthermore, one requirement may be to allow the partial beams to interact with the same number of interfaces, such as mirrors or the like, in order to minimize absorption losses and phase differences. The structures described herein provide a component that addresses precisely these problems. Furthermore, the component can be used to adjust the distance and divergence of the two partial beams from one another without affecting the properties of the individual beams. This is extremely helpful in the alignment and design of new optical systems.A further advantage of the embodiments described herein is the possibility of transmitting the beam through the component without beam splitting. This is particularly useful for reference signals.

[0086] Known solutions include broadband beam splitting, dichroic beam splitting, and polarization splitting. Currently, known beam splitting methods are based on birefringent materials or polarization splitter layers, interference filters, or gratings. None of these variants address all of the problems mentioned above. Either the partial beams travel in different spatial directions or they have different path lengths after splitting, which is partly equivalent, since different spatial directions and subsequent deflection can lead to different path lengths after rectification of the partial beams. This can lead to a temporal offset of optical signals.

[0087] Although some aspects have been described in connection with a device, it should be understood that these aspects also represent a description of the corresponding method, so that a block or component of a device can also be understood as a corresponding method step or as a feature of a method step. Analogously, aspects described in connection with or as a method step also represent a description of a corresponding block, detail, or feature of a corresponding device.

[0088] The above-described embodiments are merely illustrative of the principles of the present invention. It is understood that modifications and variations of the arrangements and details described herein will be apparent to others skilled in the art. Therefore, it is intended that the invention be limited only by the scope of the following claims and not by the specific details presented in the description and explanation of the embodiments herein.

Claims

[1] Beam splitter with: a coupling structure (12) configured to redirect an input beam (14) to obtain a redirected input beam (16); a first reflective surface region (181) and a second reflective surface region (182) inclined relative to the first reflective surface region (181); a beam splitting structure (22) arranged between the first reflective surface region (181) and the second reflective surface region (182) and inclined relative to the first reflective surface region (181) and relative to the second reflective surface region (182), which is configured to split a light beam based on the deflected input beam (16) to obtain a first partial beam (241) and direct it onto the first reflective surface region (181); and to obtain a second partial beam (242) and direct it onto the second reflective surface region (182); wherein a first output beam (261) of the beam splitter based on the first partial beam (241) and a second output beam (262) of the beam splitter based on the second partial beam (242) have a substantially equal propagation delay compared to the input beam (14); wherein the coupling structure (12) has an input side (48) configured to receive the input beam (14); wherein the coupling structure (12) is designed to cause a splitting of the light beam based on the input beam (14) upon arrival of the input beam (14) in a first region (561) of the coupling side (48); and to provide a third output light beam (263) without a split at the beam splitting structure (22) upon arrival of the input beam (14) in a second region (562) of the coupling side (48). [2] Beam splitter according to claim 1, which is configured to provide the first output beam (261) and the second output beam (262) substantially parallel. [3] Beam splitter according to claim 2, which is designed to provide the first output beam (261) and the second output beam (262) substantially parallel upon arrival of the input beam (14) on the coupling structure (12) with a reference direction (36); and to provide the first output beam (261) and the second output beam (262) inclined to one another upon arrival of the input beam (14) on the coupling structure (12) with a direction deviating from the reference direction (36). [4] Beam splitter according to one of the preceding claims, which is designed to provide the first output beam (261) and the second output beam (262) at an exit side (66) of the beam splitter with a distance (72) which is dependent on a position at which the input beam (14) strikes the coupling structure (12). [5] A beam splitter according to any one of the preceding claims, arranged to receive the input beam (14) from a first direction and to provide the first output beam (261), the second output beam (262) and the third output light beam (263) with a substantially parallel direction. [6] Beam splitter according to one of the preceding claims, wherein the first reflective surface region (181) and the second reflective surface region (182) are inclined to each other at an inclination angle; and the beam splitting structure (22) is arranged along an angle bisector of the inclination angle. [7] Beam splitter according to one of the preceding claims, wherein the coupling structure (12) comprises a first prism region of the beam splitter comprising a deflection surface (34) inclined with respect to a direction of the input beam (14) and with respect to the beam splitting structure (22). [8] A beam splitter according to claim 7, wherein the first prism region comprises the input side (48) configured to receive the input beam (14); wherein the coupling structure (12) comprises a coupling side (48) with a first region (561) and a second region (562); wherein the first region (561) is arranged opposite the deflection surface (34) along a direction of the input light beam and the second region (562) is arranged offset perpendicular to the direction of the input beam (14); wherein the beam splitter is designed to split the light beam when the input beam (14) arrives in the first region (562) of the coupling side (48); and wherein the beam splitter is designed to guide the input beam (14) undivided past the beam splitter surface when the input beam (14) arrives in the second region (562) of the coupling side (48). [9] Beam splitter according to claim 7 or 8, wherein the beam splitter comprises a second prism region adjacent to the first prism region; wherein the beam splitter is designed to direct the input beam (14) with the deflection surface (34) of the first prism region onto a deflection surface (54) of the second prism region, which is designed to direct the input beam (14) onto the beam splitting structure (22); wherein the beam splitting structure (22) is part of the second prism region. [10] Beam splitter according to claim 7 or 8, wherein the beam splitter comprises a second prism region adjacent to the first prism region; wherein the beam splitter is configured to direct the input beam (14) with the deflection surface (34) of the first prism region onto the beam splitting structure (22); wherein the beam splitting structure (22) is part of the second prism region. [11] Beam splitter according to one of claims 1 to 6, wherein the coupling structure (12) comprises a first reflective region (34) and an inclined second reflective region (54) which is inclined with respect to a direction of the input beam (14) and with respect to the beam splitting structure (22); wherein the beam splitter is configured to reflect the input beam (14) at the first reflective region (34) and the second reflective region (54) and to direct it onto the beam splitting structure (22). [12] Beam splitter according to claim 11, which is designed to effect beam splitting when the input beam (14) impinges on the first reflective region (34); and to guide the input beam (14) undivided past the beam splitting structure (22) when the input beam (14) impinges away from the first reflective region (34). [13] Beam splitter according to claim 11 or 12, wherein the first reflective region (34) and the second reflective region (54) are inclined to each other with a variable tilt angle relative to the direction of the input beam (14) and relative to the beam splitting structure (22). [14] Beam splitter according to claim 13, comprising an actuator device adapted to adjust the tilt angle in response to a control signal. [15] Beam splitter with: a beam splitting structure (22) configured to split an input beam (14) to obtain a first sub-beam (241) and to obtain a second sub-beam (242); a first reflective surface region (181) inclined relative to the beam splitting structure (22) and a second reflective surface region (182) inclined relative to the first reflective surface region (181) on the one hand and relative to the beam splitting structure (22) on the other hand; wherein the beam splitting structure (22) is configured to direct the first partial beam (241) onto the first reflective surface region (181); and to direct the second partial beam (242) onto the second reflective surface region (182); wherein a first output beam (261) of the beam splitter based on the first partial beam (241) and a second output beam (262) of the beam splitter based on the second partial beam (242) have a substantially equal propagation delay compared to the input beam (14); wherein a first angle of inclination of the first reflective surface region (181) with respect to the beam splitting structure (22) and / or a second angle of inclination of the second reflective surface region (182) with respect to the beam splitting structure (22) is adjustable. [16] Beam splitter according to claim 15, wherein the first reflective surface region (181) and the second reflective surface region (182) are inclined by a substantially equal angle with respect to the beam splitting structure (22) and face each other. [17] Beam splitter according to one of the preceding claims, wherein the beam splitting structure (22) is configured for at least one of: • a polarization split; • an intensity distribution; and • a spectral division • Angular momentum distribution is formed. [18] Beam splitter according to one of the preceding claims, wherein the coupling structure (12) is designed to receive the input beam (14) as a first input beam and to simultaneously receive and redirect a second input beam; wherein the beam splitter is designed to separate the first output beam (26) from the first and second input light beams. 11 ), the second output light beam (26 12 ), a third output light beam (26 21 ) and a fourth output light beam (26 22 ). [19] A beam splitter system comprising a first beam splitter according to any one of the preceding claims and a second beam splitter according to any one of the preceding claims arranged serially one behind the other; wherein the first output beam (261) and the second output beam (262) of the first beam splitter form input beams of the second beam splitter which is configured to provide at least four output beams. [20] A beam splitter system according to claim 19, wherein the four output beams, when projected into a plane perpendicular to a direction along which at least one of the output beams extends, form a one-dimensional pattern or a two-dimensional pattern. [21] Use of a beam splitter according to any one of claims 1 to 18 as a beam combiner.

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