Optical element, method for manufacturing an optical element and data glasses

Abstract

Optical element (100) and method for producing an optical element (100), wherein the optical element (100) comprises a plurality (104) of segments (102), wherein the plurality (104) of segments (102) is configured such that the plurality (104) of segments (102) forms an aperiodic pattern (106), in particular an aperiodic tessellation.

Description

State of the art

[0001] The present invention relates to an optical element and a method for manufacturing an optical element as well as to data glasses.

[0002] Recording methods for holographic-optical elements are generally based on techniques that generate coherent wavefronts with suitable aperture cones and angles for interference, and expose a corresponding interference pattern onto a suitable photosensitive material. Classic recording devices for capturing so-called analog holograms are based on conventional optical elements implemented for beam shaping / deflection. Analog holograms are typically recorded in a single exposure step using appropriately expanded wavefronts.

[0003] Compared to traditional analog holograms, holographic wavefront printing offers a unique opportunity to produce holographic-optical elements with particularly complex holographic structures. In this process, individual sub-holograms (hogels) within a matrix structure are exposed sequentially using a multi-stage exposure method. The size of a hogel, typically rectangular or square, varies between 50 µm and approximately 1 mm in edge length. With wavefront printing, the formation of a parasitic optical grating is unavoidable with conventional imaging methods. The holographic or optical function of each sub-hologram can be individually customized.

[0004] The shape of individual ridges, usually rectangular or square, and their arrangement in a matrix structure result in a periodic pattern, or periodic arrangement, a periodic parasitic optical grating. This amplifies parasitic diffraction effects at individual ridges, as perturbation orders of individual ridges constructively interfere with each other due to the periodic pattern.

[0005] Therefore, it is desirable to provide an optical element in which, for example, parasitic diffraction effects of the optical grating do not interfere constructively and which nevertheless has a high area utilization density. Disclosure of the invention

[0006] This is achieved through an optical element and a method for manufacturing an optical element.

[0007] The optical element comprises a multitude of segments of a predefined shape, arranged to form a predefined aperiodic pattern, in particular an aperiodic tessellation. A lattice structure is formed by the boundaries between adjacent segments. The individual segments, with their phase-matched boundaries, constitute a global optical component, for example, a holographic optical element. This component is characterized, for instance, by a global phase function based on the undisturbed contribution or interference of all individual segments within the multitude. In this context, the segments can be, for example, sections, tiles, substructures, or subelements.An aperiodic tessellation is an arrangement of shapes, such as segments, tiles, substructures, or sub-elements, on a surface that covers an area but does not exhibit a periodic pattern. This means that the pattern of the tiles or the grid structure does not repeat at regular intervals. This property distinguishes aperiodic tessellations from periodic ones, which are repeatable by translation or shift. The aperiodic pattern prevents the formation of a particularly parasitic optical grating and reduces constructive interference from disturbance orders, especially diffraction effects, which can be caused, for example, by the grid structure or the optical grating when the optical element is used. This improves, for example, the optical performance of the optical element, such as its transparency.Optical gratings are periodically arranged diffracting structures that deflect transmitted or reflected light into different diffraction orders.

[0008] It can be designed so that the numerous segments form the aperiodic pattern seamlessly and / or without overlap. This increases the area utilization density of the optical element, thereby improving diffraction efficiency and the overall quality of the optical element.

[0009] It may be provided that individual segments of the multitude of segments, particularly inner segments of the multitude, have the shape of a Penrose tile. In this context, inner segments are understood to be segments that are enclosed by other segments and, for example, do not belong to a boundary region of the aperiodic pattern or that do not complete the aperiodic pattern. Penrose tiles consist of two different shapes, for example, a kite and an arrow, or two different rhombuses. These shapes can fill a plane, for example, an aperiodic tessellation, without repeating any pattern.

[0010] It may be provided that individual segments of the multitude of segments, especially inner segments, have a uniform shape and / or size, particularly the shape of an Einstein tile. The uniform shape and size of the segments simplifies the manufacture of the optical element and reduces diffraction effects, which are more pronounced in smaller segments. The Einstein tile is a term from mathematics, specifically from surface tessellation. It refers to a special shape of tile, segment, or panel that enables aperiodic tessellation. This means that with this single tile shape or segment type, an area can be completely and seamlessly covered without creating a repeating pattern.Examples of this are shown in the publications “An aperiodic monotile” by David Smith, Joseph Samuel Myers, Craig S. Kaplan and Chaim Goodman-Strauss under arXiv:2303.10798, Cornell University and “An chiral aperiodic monotile” by David Smith, Joseph Samuel Myers, Craig S. Kaplan and Chaim Goodman-Strauss under arXiv:2305.17743, Cornell University.

[0011] The optical element can be designed as a diffractive optical element, with the multitude of segments representing a multitude of substructures of the diffractive optical element. Examples of diffractive optical elements (DOEs) include surface gratings, meta-optics, phase plates, and holographic optical elements (HOEs), such as volume holograms. Individual segments or substructures can exhibit different optical functions. Designing the optical element as a diffractive optical element enables broad technical applications in various fields, such as laser beam shaping, communications engineering, image display, and holography.

[0012] It can be provided that the optical element is a holographic-optical element and the multitude of segments is a multitude of Hogels, wherein, in particular, a single segment of the multitude of segments is designed as a single Hogel. Designing the optical element as a holographic-optical element enables, for example, applications in the technical field of data glasses or display technology.

[0013] The method for manufacturing an optical element comprises: providing a starting material; and generating a plurality of segments of a predetermined shape in the starting material, wherein the plurality of segments are arranged in a predetermined aperiodic pattern, in particular as an aperiodic tessellation.

[0014] It may be intended that the multitude of segments is generated in such a way that the aperiodic pattern is formed without gaps and / or without overlaps.

[0015] It may be provided that a Penrose tile shape is used for individual segments of the multitude of segments, especially for inner segments of the multitude of segments.

[0016] It may be provided that a uniform shape and / or size, in particular a shape of an Einstein tile, is used for individual segments of the multitude of segments, especially for inner segments of the multitude of segments.

[0017] In one example, the method involves determining the arrangement and / or optical function of the individual segments within a multitude of segments, depending on a predefined optical effect of the optical element. The multitude of segments is generated based on the arrangement and optical function of the individual segments. This makes it possible to efficiently manufacture the optical element with a complex optical effect, which is represented by the optical functions of the individual segments.

[0018] It may be provided that the optical element is a diffractive optical element and the multitude of segments is a multitude of sub-structures of the diffractive optical element.

[0019] It can be provided that the optical element is a holographic-optical element and the plurality of segments is a plurality of Hogel, wherein in particular a single segment of the plurality of segments is designed as a single Hogel, wherein individual Hogel of the plurality of Hogel are generated in the starting material, in particular a photosensitive material, in particular by means of a wavefront printer, in particular a spatial light modulator. This allows existing devices for receiving or exposing the holographic-optical element to be used.

[0020] The data glasses include the optical element as described above. This improves, in particular, the quality of content displayed by the optical element for a user, or a technical function, such as sensory function, to be performed by the optical element.

[0021] It may be possible for the optical element to be integrated into a lens of the data glasses.

[0022] Further details can be found in the drawing and the following description. The drawing shows: Fig. 1 a schematic representation of an optical element; Fig. 2a a schematic representation of an embodiment of the optical element; Fig. 2b a schematic representation of an embodiment of the optical element; Fig. 3a a schematic representation of a segment; Fig. 3b a schematic representation of an embodiment of the segment; Fig. 3c a schematic representation of an embodiment of the segment; Fig. 4a a flowchart of a process for manufacturing the optical element; Fig. 4b an embodiment of the method; Fig. 5 a schematic representation of a recording of the optical element; Fig. 6 a schematic representation of data glasses.

[0023] The Fig. Figure 1 shows a schematic representation of an optical element 100. The optical element 100 comprises a plurality 104 of segments 102, wherein the plurality 104 of segments 102 is configured such that it forms an aperiodic pattern 106, in particular an aperiodic tessellation. Individual segments 102 may have different optical functions. In this context, the optical element 100 is, for example, an element or component that has a specific or desired optical effect and is configured to influence a beam path and / or beams, such as light beams or laser beams.

[0024] It can be provided that the multitude 104 of segments 102 form the aperiodic pattern 106 without gaps and / or overlaps. Aperiodic patterns can be achieved, for example, by allowing gaps and / or overlaps of individual segments. However, this results in a low area utilization density of the optical element 100. In addition, aperiodic patterns can be realized, for example, by means of differently shaped segment types, whereby the number of differently shaped segment types may be limited.

[0025] It may be provided that individual segments 102 of the plurality 104 of segments 102, in particular inner segments 108 of the plurality of segments 102, have a Penrose tile shape. Penrose tiles are two or more differently shaped tile types. These tile types are anisotropic and have different sizes. Diffraction effects become more pronounced, especially with decreasing tile types; moreover, smaller tile types require higher positioning accuracies, for example, for the exposure of the optical element 100.

[0026] In the Fig. Figure 1 shows exemplary segments 110 that are assigned to or enclose a boundary region of the optical element 100. Depending on the given shape of the optical element 100, these boundary segments 110 can have a different shape than the inner segments 108.

[0027] It may be provided that individual segments 102 of the plurality 104 of segments 102, in particular inner segments 108 of the plurality of segments 102, have a uniform shape and / or size, in particular the shape of an Einstein tile. Fig. Figure 1 shows the optical element 100 with segments 102, which have an asymmetrical polygon shape and fulfill the criteria of the Einstein tile. Different orientations, such as rotations or reflections, are used to manipulate the image in the Fig. The segment type shown in Figure 1 achieves an aperiodic tiling. This results in the optical element 100 exhibiting a variation in its extent along specific spatial directions, thereby softening, reducing, or preventing aperture effects within the ensemble. This positively influences the transparency and optical performance of the optical element. The aperiodic tiling distributes radiation scattered by the optical element more homogeneously, whereas periodic patterns concentrate this radiation in specific spatial directions.

[0028] The Fig. Figure 2a shows a schematic representation of an embodiment of the optical element 100. This embodiment comprises segments 102 of an alternative segment type. This segment type enables aperiodic tiling by the plurality 104 of segments 102, in which a reflection of the individual segment 102 is not required.

[0029] The Fig. Figure 2b shows a schematic representation of an embodiment of the optical element 100. This embodiment comprises segments 102 of an alternative segment type. This segment type enables an aperiodic tiling by the plurality 104 of segments 102, which does not allow reflection of the individual segment 102.

[0030] The Fig. Figure 3a shows a single segment 102 of the segment type that is used for the optical element 100 according to the Fig. 1. This segment type has a polygon shape with 13 edges. This segment type is also called a "hat".

[0031] The Fig. Figure 3b shows a single segment 102 of the segment type that is used for the optical element 100 according to the Fig. 2a is used. This segment type has a polygon shape with 14 edges.

[0032] The Fig. Figure 3c shows a single segment 102 of the segment type that is used for the optical element 100 according to the Fig. 2b is used. This segment type has an abstract shape with rounded side lengths. This segment type can be called a "Spectre".

[0033] It can be provided that the optical element 100 is a diffractive optical element and the plurality 104 of segments 102 is a plurality of substructures of the diffractive optical element. These substructures can have different optical functions. The aperiodic pattern of the plurality 104 of segments 102 positively influences the transparency and / or the quality of the optical effect of the optical element 100. This allows, for example, the realization of highly transparent diffractive optical elements and diffractive optical elements with complex optical objective functions or optical effects with high quality.

[0034] It can be provided that the optical element 100 is a holographic-optical element and the plurality 104 of segments 102 is a plurality of Hogel. It can be provided that each segment 102 of the plurality of segments 104 is configured as an individual Hogel, or that an individual Hogel is formed by a group of individual segments 102. Particularly in the application area of ​​smart glasses, holographic-optical elements are used, for example, to display content for a user and / or for sensor applications of the smart glasses. By using the optical element 100, for example as a holographic-optical element, in smart glasses, the quality of these smart glasses and, in particular, the user experience is improved.

[0035] The Fig. Figure 4a shows a flowchart of a process 200 for the production of an optical element 100. The process 200 comprises providing 202 a starting material 2 ( Fig. 5) and generating 204 a plurality 104 of segments 102 in the starting material 2, such that the plurality 104 of segments 102 forms an aperiodic pattern 106, in particular an aperiodic tessellation. The starting material can be a photosensitive polymer, wherein the plurality 104 of segments 102 is generated in an exposure process 204.

[0036] It may be provided that the multitude 104 of segments 102 is generated in such a way 204 that the aperiodic pattern 106 is formed without gaps and / or without overlap.

[0037] It may be provided that for individual segments 102 of the plurality 104 of segments 102, in particular for inner segments 108 of the plurality of segments 102, a form of a Penrose tile is used.

[0038] It may be provided that for individual segments 102 of the plurality 104 of segments 102, in particular for inner segments 108 of the plurality of segments 102, a uniform shape and / or size, in particular a shape of an Einstein tile, is used.

[0039] The Fig. Figure 4b shows an embodiment of method 200. Method 200 can include determining 206 an arrangement 208 and / or an optical function 210 of the individual segments 102 of the plurality 104 of segments 102 in the plurality 104 of segments 102 depending on a predetermined optical effect 212 or optical target function of the optical element 100, wherein the plurality 104 of segments 102 is generated 204 depending on the arrangement 208 and the optical function 210 of the individual segments 102. The arrangement 208, for example, comprises a spatial arrangement of individual segments 102, which can include an orientation and position of the individual segments 102. Depending on the predetermined optical effect of the optical element 100, a specific optical function is determined for individual segments 102; this determination can be performed automatically or manually.

[0040] It may be provided that the segments 102 of the plurality 104 of segments 102 are generated sequentially depending on the arrangement 208 and the optical function 210.

[0041] It can be provided that the optical element 100 is a diffractive optical element and the plurality 104 of segments 102 is a plurality of sub-structures of the diffractive optical element.

[0042] The Fig. Figure 5 shows a schematic representation of the exposure of the optical element 100. The optical element 100, or the starting material 2, can be sequentially positioned 6, for example, for the sequential generation of a plurality 104 segments 102. The segments 102 can be generated 204 in the starting material 2 by means of an exposure beam 8, which is generated by an exposure device 4. The dashed lines in the Fig.The five indicated segments 102 represent segments 102 that have not yet been exposed by the exposure beam 8. These unexposed segments 102 exemplify the determined arrangement 208, which is to be exposed. The starting material 2 is positioned, for example, by means of a positionable recording device according to the determined arrangement 208 6, in order to expose the segments 102. The optical function 210 is implemented, for example, in the individual segment 102 by means of the exposure beam 8.

[0043] It can be provided that the optical element 100 is a holographic-optical element and the plurality 104 of segments 102 is a plurality 104 of holograms, wherein individual holograms of the plurality of holograms are generated in the starting material 2, in particular a photosensitive material, by means of an exposure device 4 in the form of a wavefront printer 4, in particular a spatial light modulator. It can be provided that each segment 102 of the plurality of segments 104 is configured as an individual hologram or that an individual hologram is formed by a group of individual segments 102. The holograms can also be referred to as sub-holograms. The spatial light modulator can be configured as a spatial light modulator (SLM). The exposure beam 8 comprises a reference beam and an object beam for the production of the optical element 100 as a holographic-optical element.The exposure beam 8 is adapted depending on the predefined optical function 210, for example in the form of a phase pattern, of the individual segment 102. The arrangement 208 of the segments 102, the position of the segments 102 in the optical element 100, and a phase pattern of the segments 102 can be determined in advance 206 and transferred to the wavefront printer 4 along with recording parameters. Adaptation of a holographic function or optical function 210 of a Hogel is achieved by adaptive optics, for example, by spatial light modulators. Further possibilities exist through transmissive, adaptive phase plates or deformable mirrors.

[0044] One shape of the segments 102 can be represented, for example, by an aperture device. In the wavefront printer 4, this can be achieved by an active area of ​​a wavefront-modulating component. In spatial light modulators, the shape of the segments 102 is represented, for example, by switching off pixels outside the active area, or by using adaptive apertures, which are placed between the modulating component and the source material 2.

[0045] The figure shows a schematic representation of a data glasses 300. The data glasses 300 comprise the optical element 100 as described above. The data glasses may include a projection device 304, which, in conjunction with the optical element 100, is configured to display content visible to a user 10.

[0046] It may be provided that the optical element 100 is integrated into a spectacle lens 302 of the data glasses 300. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited non-patent literature

[0000] “An aperiodic monotile” by David Smith, Joseph Samuel Myers, Craig S. Kaplan and Chaim Goodman-Strauss at arXiv:2303.10798, Cornell University

[0010] “An chiral aperiodic monotile” by David Smith, Joseph Samuel Myers, Craig S. Kaplan and Chaim Goodman-Strauss, available at arXiv:2305.17743, Cornell University

[0010]

Claims

[1] Optical element (100) wherein the optical element (100) comprises a plurality (104) of segments (102) of a predetermined shape, wherein the plurality (104) of segments (102) is arranged such that the plurality (104) of segments (102) forms a predetermined aperiodic pattern (106), in particular an aperiodic tessellation. [2] The optical element (100) according to claim 1, wherein the plurality (104) of segments (102) forms the aperiodic pattern (106) without gaps and / or overlaps. [3] The optical element (100) according to claim 1 or 2, wherein individual segments (102) of the plurality (104) of segments (102), in particular inner segments (108) of the plurality of segments (102), have a Penrose tile shape. [4] The optical element (100) according to one of claims 1 or 2, wherein individual segments (102) of the plurality (104) of segments (102), in particular inner segments (108) of the plurality of segments (102), have a uniform shape and / or size, in particular a shape of an Einstein tile. [5] The optical element (100) according to any one of claims 1 to 4, wherein the optical element (100) is a diffractive optical element and the plurality (104) of segments (102) is a plurality of sub-structures of the diffractive optical element. [6] The optical element (100) according to claim 5, wherein the optical element (100) is a holographic optical element and the plurality (104) of segments (102) is a plurality of Hogel, wherein in particular a single segment 102 of the plurality of segments (104) is designed as a single Hogel. [7] Method (200) for manufacturing an optical element (100), comprising: - Providing (202) a source material (2); - Generating (204) a plurality (104) of segments (102) of a given shape in the starting material (2), wherein the plurality (104) of segments (102) are arranged in a given aperiodic pattern (106), in particular as an aperiodic tessellation. [8] The method (200) according to claim 7, wherein the plurality (104) of segments (102) is generated (204) such that the aperiodic pattern (106) is formed without gaps and / or without overlaps. [9] The method (200) according to one of claims 7 or 8, wherein for individual segments (102) of the plurality (104) of segments (102), in particular for inner segments (108) of the plurality of segments (102), a Penrose tile shape is used. [10] The method (200) according to one of claims 7 or 8, wherein for individual segments (102) of the plurality (104) of segments (102), in particular for inner segments (108) of the plurality of segments (102), a uniform shape and / or size, in particular a shape of an Einstein tile, is used. [11] The method (200) according to any one of claims 7 to 10 comprising determining (206) an arrangement (208) and / or an optical function (210) of the individual segments (102) of the plurality (104) of segments (102) in the plurality (104) of segments (102) depending on a predetermined optical effect (212) of the optical element (100), wherein the plurality (104) of segments (102) is generated (204) depending on the arrangement (208) and the optical function (210) of the individual segments (102). [12] The method (200) according to any one of claims 7 to 11, wherein the optical element (100) is a diffractive optical element and the plurality (104) of segments (102) is a plurality of sub-structures of the diffractive optical element. [13] The method (200) according to claim 12, wherein the optical element (100) is a holographic optical element and the plurality (104) of segments (102) is a plurality (104) of Hogel, wherein in particular a single segment 102 of the plurality of segments 104 is designed as a single Hogel, wherein single Hogel of the plurality of Hogel are generated (204) in the starting material (2), in particular a photosensitive material, by means of a wavefront printer (4), in particular a spatial light modulator. [14] Data glasses (300) comprising the optical element (100) according to any one of claims 1 to 6. [15] The data glasses (300) according to claim 14, wherein the optical element (100) is integrated into a lens (302) of the data glasses (300).

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