Waveguide combiner, augmented reality and / or virtual reality headset and method for manufacturing the waveguide combiner

Abstract

The invention relates to a waveguide combiner (18a-h) for augmented reality and / or virtual reality headsets, in particular for data glasses (10a-h), which is at least configured to guide coupled light (12a-h) as a total reflection mode (TIR), with at least one waveguide core (14a-h) and with at least one waveguide sheath (16a-h) covering at least section of the waveguide core (14a-h). It is proposed that the waveguide cladding (16a-h) has a refractive index between 1.001 and 1.3, preferably between 1.007 and 1.24.

Description

State of the art

[0001] A waveguide combiner for augmented reality and / or virtual reality headsets, particularly for smart glasses, has already been proposed. This combiner is designed to guide coupled light as a total internal reflection (TIR) ​​mode, comprising at least one waveguide core and at least one waveguide cladding that covers at least part of the core (on both sides). The TIR light is coupled out of the waveguide combiner at a point in front of a view path of the AR / VR headset, thus converting it back from TIR reflection modes to transmitting modes. This can be achieved, for example, by tilted mirrors embedded in the waveguide (see, for example, products from tooz technologies), by surface relief gratings (see, for example, the Microsoft HoloLens 1 and 2 and products from Dispelix), or by holograms (see, for example, products from Tru-Life Optics).The two wave vector components k are crucial for the type of mode. x and k y of the light coupled into the waveguide combiner, where a surface normal of the waveguide combiner points in the z-direction, or the waveguide combiner is extended in an xy-plane. Its magnitude is less than the refractive index of the waveguide cladding multiplied by a quotient of 2π and λ. vac , can propagate the mode in the waveguide cladding. Light with wave vector components k x and k y greater than the refractive index of the waveguide cladding multiplied by the quotient of 2π and λ vac cannot propagate in the waveguide cladding. Are the wave vector components k x and k y however, it is also smaller than the refractive index of the waveguide core multiplied by the quotient of 2π and λ. vac, so the light can propagate in the waveguide core, meaning it is totally reflected within the waveguide combiner.

[0002] The dispersion relation for plane waves, rearranged to solve for k z is kz=(n2πλvac)2−kx2−ky2. In homogeneous media, light can propagate in all directions with the same magnitude of the wave vector. For a given k x and k y According to the formula above, k remains z only a fixed value, which depends on the respective refractive index n. Real solutions to the above formula only result if the term under the square root is positive, i.e., if the squares of k are equal to 1. x and k y together they are smaller than the square of the product of the refractive index and the quotient 2π / λ vac It follows that the larger the refractive index n, the larger the k. x and k y , which have a positive value of k zenable the propagation of k z allow.

[0003] The larger the k-spectrum guided in the waveguide combiner, the larger the k-spectrum coupled out into air can be for the observer. A large k-spectrum thus allows for a large field of view (FoV). In the prior art, an air gap is often used as the waveguide cladding. The refractive index in a vacuum is 1, and that of air under standard atmospheric conditions is 1.000292. A glass-air interface therefore allows for a relatively large TIR spectrum and thus also a relatively large field of view. However, the waveguide combiner usually also needs to be protected from mechanical contact (contamination, scratching). In the prior art, covers are placed in front of and behind the waveguide glass for this purpose. The waveguide and the cover must not touch to maintain the desired function – even under mechanical stress. The gap must therefore be designed with a minimum thickness, often 100 µm or more.Additionally, the cover must be stable against bending, i.e., it must have a minimum thickness, which can lead to a thick and heavy AR / VR headset and thus reduce user comfort.

[0004] Another known method for achieving a large refractive index difference between the waveguide core and cladding involves using waveguide cores made of high-refractive-index materials. Often, flint glasses, such as lanthanum-containing heavy flint glasses with a refractive index of up to slightly above 2, are used for this purpose. In holographic waveguides, where light is to propagate through input and output coupling structures, the usable k-spectrum is further limited by the refractive index of the holographic material. Holographic materials are typically only available with refractive indices significantly lower than 2. For example, photopolymers typically have an index of approximately 1.5. Silver halide films can reach approximately 1.65. If the waveguide core and the hologram have the same refractive index, no reflections occur when the waves pass between the materials.Compared to these high-refractive-index waveguide core materials, low-refractive-index waveguide cladding materials and / or relatively low-refractive-index optical adhesives with refractive indices of n = 1.35 to 1.45 are available in the prior art. This difference in refractive index compared to a high-refractive-index waveguide core can also allow TIR transmission of large fields without an air gap. However, the material selection in this case is very limited, and the high-refractive-index specialty materials can also be relatively expensive. Disclosure of the invention

[0005] The invention relates to a waveguide combiner for augmented reality and / or virtual reality headsets, in particular for data glasses, which is at least configured to guide coupled light as total reflection mode (TIR), with at least one waveguide core and with at least one waveguide sheath covering the waveguide core at least partially.

[0006] It is proposed that the waveguide cladding have a refractive index between 1.001 and 1.3, preferably between 1.007 and 1.24. This advantageously allows an acceptably large TIR-guided k-spectrum to be achieved even with relatively low-refractive-index waveguide core materials, which are advantageously inexpensive and readily available, such as ordinary glass. Furthermore, a particularly large guided k-spectrum can be advantageously achieved when using high-refractive-index waveguide core materials. In addition, the increased available k-space provided by the invention compared to known waveguide combiners can be advantageously used to shift the guided k-spectrum. Steeper angles of the TIR-guided beams are advantageously possible, which in particular enables shorter jump lengths of the TIR-guided beams for the same waveguide core thickness.Short hop lengths offer the advantage of a tighter coverage of the eye pupil of a user of data glasses equipped with a waveguide combiner by the rays exiting the waveguide combiner. In particular, the waveguide cladding is designed to be free of an air gap, preferably without one. Specifically, all refractive indices mentioned in this document refer to those of visible light with a wavelength of 590 nm and / or infrared light with a wavelength of 940 nm.

[0007] An AR headset is specifically designed for the computer-aided enhancement of reality perception by overlaying artificially generated image content with real-world images, preferably the immediate real-world environment of the AR system user. Examples of AR headsets include AR helmets or smart glasses, such as cycling glasses, diving masks, motorcycle goggles, aviator goggles, safety glasses, etc. Specifically, the real-world image overlaid by the (artificially generated) image content in the AR system is the image of the user's immediate surroundings, which the user would also perceive if they were to deactivate or remove the AR system. A VR headset, in particular, is a type of head-mounted display that provides users with a view into virtual reality. The light coupled into the waveguide combiner preferably includes the artificially generated image content and / or the virtual reality.The waveguide combiner is preferably designed to transmit / guide the artificial image generated and output by a light source over at least part of a path between the image generation and output unit and an eye plane of the augmented reality and / or virtual reality headset, in which, in an operating state, an eye of the user of the augmented reality and / or virtual reality headset is located.

[0008] The abbreviation TIR stands in particular for "Total Internal Reflection". The relevant physical principles of total internal reflection (TIR) ​​at interfaces are known to those skilled in the art. The waveguide core is preferably longitudinally extended. Preferably, the waveguide core has a cross-section perpendicular to its longitudinal extent, at least substantially constant. The cross-section can be round, oval, polygonal (e.g., trigonal), square, rectangular, pentagonal, hexagonal, etc. In particular, the longitudinal extent of the waveguide core is at least three times, preferably at least four times, more preferably at least five times, and most preferably at least ten times as large as a maximum transverse extent of the waveguide core perpendicular to it. In particular, the waveguide cladding completely covers the waveguide core, at least in the longitudinal direction.In particular, the waveguide cladding covers the waveguide core at its axial ends. However, it is also conceivable that the waveguide cladding is interrupted at one or more points on a surface of the waveguide combiner, for example, at coupling points where light can be coupled into the waveguide combiner, or at coupling points where light can be coupled out of the waveguide combiner. Preferably, the waveguide core and / or the waveguide cladding are plate-like. The terms "provided for" and / or "configured" are to be understood in particular as specifically programmed, designed, and / or equipped. The fact that an object is provided for and / or configured for a specific function is to be understood in particular as the object fulfilling and / or performing this specific function in at least one application and / or operating state.In particular, the waveguide cladding makes contact with the waveguide core over a large area.

[0009] If the waveguide core has a refractive index of 1.55 or less, a particularly simple and / or cost-effective design of the waveguide combiner can be advantageously achieved. Easily and inexpensively available waveguide core materials, such as ordinary fused silica (Foz) with a refractive index of 1.46, or polymethyl methacrylate (PMMA, commonly referred to as "Plexiglas") with a refractive index of 1.49, can be used, while still achieving a large guided k-spectrum. This allows for the advantageous development of a cost-effective and stable data glasses system. For example, in this case, the waveguide core material is SiO2 glass (fused silica). In particular, the waveguide core material differs from flint glass.

[0010] Alternatively, if the waveguide core is made of a high-refractive-index material, a particularly large guided k-spectrum can be advantageously achieved. This allows for a particularly large field of view for data glasses. Specifically, the term "high-refractive-index material" means a material with a refractive index of 1.56 or more, preferably 1.6 or more, more preferably 1.7 or more, and most preferably 1.9 or more. For example, the waveguide core material in this case is flint glass. In particular, the waveguide core material has a refractive index that is at least higher than the lowest known refractive index for flint glass. For example, the waveguide core material in this case is germanium dioxide (GeO2) or phosphate glass.

[0011] Furthermore, it is proposed that the waveguide cladding be formed at least partially, preferably completely, by a foam material, in particular a rigid foam. This allows advantageous refractive index values ​​for waveguide cladding materials to be achieved, which in particular enable a large guided k-spectrum and / or a large field of view. Advantageously, high robustness can be achieved despite low weight and without the need for particularly robust covers or the like. Moreover, a compact design can be advantageously achieved, especially compared to air-gap solutions, since such a waveguide cladding can be made particularly thin. In particular, rigid foam has a compression hardness of more than 50 kPa, preferably more than 100 kPa, more preferably more than 200 kPa, and most preferably more than 300 kPa.The foam material can completely surround the waveguide core, or at least cover the entire surface of its flat sides, or be applied to a surface of the waveguide core in a columnar and / or dimpled pattern. In this case, the foam material only covers a portion of the waveguide core's surface. For example, columns of foam material could be placed between the waveguide core and a cover. Alternatively, the columns could also form freestanding cylinders or a type of dimpled film on the surface of the waveguide core.

[0012] Furthermore, it is proposed that the waveguide cladding be formed at least partially, preferably completely, by an aerogel. This allows for advantageous refractive index values ​​for waveguide cladding materials, which in particular enable a large guided k-spectrum and / or a wide field of view. Advantageously, high robustness can be achieved despite low weight and without the need for particularly robust covers or the like. Moreover, a compact design can be advantageously achieved, especially compared to air-gap solutions, since such a waveguide cladding can be made particularly thin. The aerogel can completely surround the waveguide core or at least be applied to the entire surface of the waveguide core, either in a columnar and / or stud-like manner. In this case, the aerogel covers only a portion of the waveguide core's surface.For example, columns of aerogel could be inserted between the waveguide core and a cover. Alternatively, the columns could also form freestanding aerogel cylinders or a type of aerogel bubble sheet on the surface of the waveguide core. An aerogel is a highly porous solid in which more than 95%, preferably more than 97%, and preferably more than 99% of the volume consists of pores. Preferably, the aerogel is produced by a so-called sol-gel process, which is known to those skilled in the art. However, aerogels / foam materials produced by other methods are also conceivable. In particular, the aerogel has a refractive index between 1.007 and 1.24. Preferably, the aerogel has a refractive index of about 1.02. Preferably, the aerogel is silicate-based, aluminum-based, or plastic / bioplastic-based. More preferably, the aerogel is formed from a SiO2 base material or from a plastic / bioplastic base material.

[0013] If the foam material or aerogel is formed from a base material that is transparent as a solid, a high transparency of the aerogel waveguide cladding, e.g., for coupled-out light, can advantageously be achieved. Preferably, the inner diameters of at least a large proportion of the bubbles within the aerogel, preferably almost all or all bubbles within the aerogel, are significantly smaller than the wavelengths of the light to be guided in the waveguide combiner, in particular wavelengths of infrared and preferably also visible light.

[0014] Furthermore, it is proposed that the foam material or aerogel be formed in a film-like or plate-like / sheet-like form. This advantageously enables simple manufacturing, and in particular simple construction, of the waveguide combiner. Cost-effectiveness can be achieved. Joining the waveguide core and waveguide cladding can be advantageously simplified. The term "film-like" should be understood in particular as resembling a film. A film is, in particular, a thin, especially flexible, preferably homogeneous sheet structure. However, it is also conceivable that a film is not completely homogeneous, but has a recurring superstructure, as would be the case, for example, with a bubble wrap. The term "film-like" should also be understood to mean "mat-like."The term "plate-like / plate-like" should be understood in particular as referring to the nature of a plate / plate. A plate is, in particular, a thin, especially rigid, preferably homogeneous, planar structure. However, it is also conceivable that a plate is not completely homogeneous, but exhibits a recurring superstructure, as would be the case, for example, with a studded plate. Joining a waveguide core and a foil-like or plate-like / plate-like waveguide cladding can be achieved, for example, by simply layering an aerogel foil or an aerogel plate onto a waveguide core plate.

[0015] Additionally, it is proposed that the aerogel be grown onto the waveguide core. This allows for a simple and / or cost-effective manufacturing and / or construction process. In particular, in this case, precursors are first applied to the waveguide core, and then the coated waveguide core is dried using a supercritical aerogel process.

[0016] Alternatively, it is proposed that the aerogel be bonded to the waveguide core, particularly using an adhesive. This advantageously allows for simple and / or cost-effective manufacturing and / or construction. Specifically, the adhesive is designed to be water-soluble.

[0017] Furthermore, it is proposed that the aerogel be functionalized, for example, made hydrophobic, in a way that prevents the penetration of adhesive during bonding to the waveguide core. This advantageously avoids a change in the refractive index of the aerogel on a surface facing the waveguide core. It also advantageously ensures that the refractive index difference necessary for guiding the TIR modes at the interface between the waveguide core and the waveguide cladding corresponds to the refractive index difference between the waveguide core material and the aerogel, even after bonding. In particular, penetration of the water-soluble adhesive into the aerogel can be prevented if the aerogel is hydrophobic at least on one bonding side.

[0018] Furthermore, it is proposed that the waveguide cladding be formed, at least in sections, by a metamaterial and / or by photonic crystals. This advantageously allows for a large refractive index difference between the waveguide core and the waveguide cladding. This, in turn, advantageously enables the transmission of a large k-spectrum in the waveguide combiner. In particular, various metamaterials known to those skilled in the art (e.g., a so-called gradient-index metamaterial made of TiO2 nanostructures) or photonic crystals (e.g., so-called silica / air-photonic crystals) with refractive indices between 1.001 and 1.3, preferably between 1.007 and 1.24, are suitable.

[0019] Furthermore, the augmented reality and / or virtual reality headset, in particular the data glasses, is proposed to include at least the waveguide combiner. This advantageously enables a stable and / or lightweight construction. In addition, a large field of view can be achieved to advantage.

[0020] If the augmented reality and / or virtual reality headset has at least one lens in which the waveguide combiner is at least partially integrated, a stable and / or lightweight construction can be advantageously achieved.

[0021] Furthermore, a method for manufacturing the waveguide combiner is proposed, wherein the foam material or aerogel is applied to the waveguide core as a film or plate / sheet, or bonded to the waveguide core using an adhesive, or grown onto the waveguide core. Advantageously, this allows for the creation of a waveguide combiner with previously unattainable beneficial properties, particularly with regard to the achievable refractive index difference between the waveguide core and the waveguide cladding of the waveguide combiner.

[0022] The waveguide combiner, the augmented reality and / or virtual reality headset, and the method according to the invention are not limited to the application and embodiment described above. In particular, the waveguide combiner, the augmented reality and / or virtual reality headset, and the method according to the invention may, to achieve a functionality described herein, comprise a different number of individual elements, components, units, and process steps than those specified herein. Furthermore, values ​​within the specified limits of the value ranges stated in this disclosure are also considered disclosed and freely usable. drawing

[0023] Further advantages become apparent from the following description of the drawings. The drawings illustrate eight exemplary embodiments of the invention. The drawings, the descriptions, and the claims contain numerous features in combination. It is advantageous for those skilled in the art to also consider the features individually and combine them into meaningful further combinations.

[0024] They show: Fig. 1 a schematic representation of data glasses with a waveguide combiner, Fig. 2a a schematic cross-section through the waveguide combiner with a waveguide core and a waveguide cladding, Fig. 2b a schematic exploded view of the waveguide combiner, Fig. 2c a schematic cross-section through a curved waveguide combiner, Fig. 3 a schematic longitudinal section through a part of the waveguide combiner, Fig. 4 a schematic longitudinal section through a part of a waveguide combiner with an alternative decoupling device, Fig. 5 schematically depicts the behavior of the waveguide combiner in one of the wave vectors k x and k y spanned k-space, Fig. 6 a schematic cross-section through an alternative waveguide combiner with an alternative waveguide core and a waveguide cladding, Fig. 7 a schematic cross-section through a second alternative waveguide combiner with a waveguide core and a waveguide cladding, Fig. 8 a schematic cross-section through a third alternative waveguide combiner with a waveguide core and an alternative waveguide cladding, Fig. 9 a schematic cross-section through a fourth alternative waveguide combiner with a waveguide core and a second alternative waveguide cladding, Fig. 10 a schematic cross-section through a fifth alternative waveguide combiner with a waveguide core and a third alternative waveguide cladding, Fig. 11 a schematic cross-section through a sixth alternative waveguide combiner with a waveguide core and a fourth alternative waveguide cladding, Fig. 12 a schematic cross-section through a seventh alternative waveguide combiner with a waveguide core and a fifth alternative waveguide cladding and Fig. 13 a schematic flowchart of a method for manufacturing one of the waveguide combiners according to the invention. Description of the exemplary implementations

[0025] The Fig. Figure 1 schematically and exemplarily shows a pair of data glasses 10a. The data glasses 10a form an augmented reality and / or virtual reality headset. The data glasses 10a have an image generation and output unit 22a. The data glasses 10a have a waveguide combiner 18a. The data glasses 10a have a lens 20a. The waveguide combiner 18a is at least partially integrated into the lens 20a. The image generation and output unit 22a is designed to output an artificially generated image, which is coupled into the waveguide combiner 18a as light rays. The waveguide combiner 18a is configured to convert coupled light 12a (see Figure 1) into a spectacle. Fig. 3 or Fig. 4) to be conducted as Total Reflection Mode (TIR).

[0026] The Fig. Figure 2a schematically shows a cross-section through an exemplary waveguide combiner 18a. Fig. Figure 2b schematically shows an exploded view of the exemplary waveguide combiner 18a. The waveguide combiner 18a is flat and / or plate-like (flat waveguide). The waveguide combiner 18a has a waveguide core 14a. The waveguide core 14a is formed by a core plate. The waveguide core 14a has the shape of a flat plate. The waveguide combiner 18a has a waveguide cladding 16a. The waveguide cladding 16a covers the waveguide core 14a at least on its top and bottom surfaces. The waveguide cladding 16a completely covers the largest surfaces of the waveguide core 14a. The waveguide cladding 16a is formed by two cladding plates, which are arranged on opposite sides of the waveguide core 14a. The waveguide cladding 16a has the shape of two flat plates.The flat plates of the waveguide cladding 16a are essentially identical to each other, but could alternatively differ in shape and / or material. Alternatively, the waveguide combiner 18a could also be curved (curved waveguide, cf. ). Fig. 2c). In this case, the cladding plates and core plates have identical curvatures. The cladding plates and the core plate are manufactured with a curve and then joined. The waveguide core 14a and the waveguide cladding 16a are made of two substantially different materials. The waveguide core 14a and the waveguide cladding 16a are made of materials with substantially different refractive indices. The difference in refractive index between the waveguide core 14a and the waveguide cladding 16a is greater than 0.2, preferably greater than 0.3, and more preferably greater than 0.5. An interface 30a is formed between the waveguide core 14a and the waveguide cladding 16a. The waveguide cladding 16a has a refractive index between 1.001 and 1.3 (at λ = 940 nm), preferably between 1.007 and 1.24 (at λ = 940 nm). In the example shown, the waveguide cladding 16a has a refractive index of 1.02 (at λ=940nm).In this embodiment, the waveguide core 14a has a refractive index of 1.55 or less (at λ=940nm), but more than 1.3, preferably more than 1.35 (at λ=940nm). In the exemplary case shown, the waveguide core 14a has a refractive index of 1.46 (at λ=940nm). In the . Fig. 2 are examples of a k y -Direction 24a and a k x -Direction 26a of a wave vector of light 12a guided in the waveguide core 14a as TIR mode indicated.

[0027] The Fig. Figure 3 schematically and exemplarily shows a longitudinal section through a part of the waveguide combiner 18a. The waveguide combiner 18a has a decoupling device 28a. The decoupling device 28a deflects the light 12a guided in the waveguide core 14a such that it no longer strikes the interface 30a below the total internal reflection angle and is thus transmitted through the waveguide cladding 16a, i.e., it leaves the waveguide combiner 18a, e.g., in the direction of an eye of a user of the data glasses 10a. The decoupling device 28a can be implemented by roughening the surface of the waveguide cladding 16a and / or the waveguide core 14a, by an inserted component made of a special material, or in some other way. The decoupling device 28a can be configured as shown in the Fig. 3 shown in the waveguide sheath 16a or formed as part of the waveguide sheath 16a. Alternatively, the disconnector 28'a can also be arranged as in the Fig. 4 shown arranged in the waveguide core 14a or formed as part of the waveguide core 14a.

[0028] The waveguide sheath 16a is formed by a foam material. The waveguide sheath 16a is formed by a rigid foam. The waveguide sheath 16a is formed by an aerogel. The aerogel is formed from a base material which is transparent as a solid. In the exemplary embodiment of the Fig. In sections 2 to 4, the aerogel is formed in a film-like form and placed on a surface of the waveguide core 14a. Alternatively, the aerogel could also have grown directly onto the surface of the waveguide core 14a.

[0029] The Fig. Figure 5 schematically shows the behavior of the waveguide combiner 18a in one of the wave vectors k x and k y spanned k-space. This representation shows the set of k. x and k yVectors for which solutions to the dispersion relation mentioned in the introduction exist in air, in the waveguide core 14a, and in the waveguide cladding 16a. A core spectrum 40a is drawn in k-space, which represents light with k x and k y includes vectors that can propagate exclusively in the waveguide core 14a. Light with k x and k y Vectors in the region of the core spectrum 40a must be totally reflected upon striking a wall of the waveguide core. A surface spectrum 42a is drawn in k-space, which represents light with k x and k y includes vectors which can also propagate in the waveguide cladding 16a. Light with k x and k yVectors in the region of the cladding spectrum 42a would exit the waveguide core 14a upon striking a wall of the waveguide core 14a and enter the waveguide cladding 16a. However, a transition from the waveguide cladding 16a to air does not occur in the region of the cladding spectrum 42a. The region of the cladding spectrum 42a is irrelevant for the intended application, as the waveguide core 14a cannot retain these modes. A free-air spectrum 44a is shown in k-space, which represents light with k x and k y It includes vectors that can also propagate in air. Light with k x and k y Vectors in the free-air spectrum 44a would exit the waveguide cladding 16a upon encountering a wall of the waveguide cladding 16a and propagate into air. The coupler 28a has the task of separating a spectrum propagating in the waveguide core 14a (cf. TIR spectrum 46 in Fig. 5) to shift in such a way, i.e., their k x and / or k y To change vectors, this spectrum (cf. used spectrum 48 in Fig. 5) can also propagate in the air.

[0030] In the Fig. Figures 6 to 12 show further embodiments of the invention. The following descriptions and drawings are essentially limited to the differences between the embodiments, whereby, with regard to identically designated components, particularly those with the same reference numerals, reference is also generally made to the drawings and / or the description of the other embodiments, especially those of the Fig. 1 to 5, reference can be made. To distinguish the embodiments, the letter a is the reference numeral of the embodiment in the Fig. 1 to 5 are appended. In the exemplary embodiments of the Fig. In numbers 6 to 12, the letter a is replaced by the letters b to h.

[0031] The Fig. Figure 6 schematically and exemplarily shows a cross-section of an alternative waveguide combiner 18b with a waveguide cladding 16b and an alternative waveguide core 14b. The alternative waveguide core 14b is made of a high-refractive-index material. The alternative waveguide core 14b is made of a material with a refractive index greater than 1.56 (at λ = 940 nm). The one in the Fig. The exemplary waveguide core 14b shown has a refractive index of 1.7 (at λ=940nm).

[0032] The Fig. Figure 7 schematically and exemplarily shows a cross-section of a second alternative waveguide combiner 18c with a waveguide cladding 16c and a waveguide core 14c. The waveguide core material and the waveguide cladding material are, by way of example, identical to those of the waveguide combiner 18a. Fig. 2 to 5. The waveguide cladding 16c is formed by an aerogel. The aerogel is bonded to the waveguide core 14c. The aerogel is functionalized in a thin surface layer 32c of the waveguide cladding 16c. The aerogel is hydrophobized in a thin surface layer 32c of the waveguide cladding 16c. The functionalization / hydrophobization of the waveguide cladding 16c in the surface layer 32c prevents the penetration of adhesive when the waveguide cladding 16c is joined to the waveguide core 14c.

[0033] The Fig. Figure 8 schematically and exemplarily shows a cross-section of a third alternative waveguide combiner 18d with an alternative waveguide cladding 16d and a waveguide core 14d. The alternative waveguide cladding 16d is formed by a metamaterial.

[0034] The Fig. Figure 9 schematically and exemplarily shows a cross-section of a fourth alternative waveguide combiner 18e with a second alternative waveguide cladding 16e and a waveguide core 14e. The alternative waveguide cladding 16e is formed by a material with embedded photonic crystals.

[0035] The Fig. Figure 10 schematically and exemplarily shows a cross-section of a fifth alternative waveguide combiner 18f with a third alternative waveguide cladding 16f and a waveguide core 14f. The second alternative waveguide cladding 16f covers the waveguide core 14f only partially. The second alternative waveguide cladding 16f is formed by a plurality of column-like structures applied to a surface of the waveguide core 14f. The fifth alternative waveguide combiner 18f has a termination element 34f. The termination element 34f completely covers the waveguide cladding 16f. The termination element 34f protects the second alternative waveguide cladding 16f and the surfaces of the waveguide core 14f exposed between the column-like structures of the second alternative waveguide cladding 16f from contamination and / or damage.The column-like structures of the second alternative waveguide sheath 16f are formed by an aerogel.

[0036] It should be noted that the dimensions, in particular the relative sizes of the waveguide cladding 16 and the waveguide core 14, or the dimensions of structures such as the column-like formations or the like, are purely schematic in all drawings. In particular, outer layers / structures may be depicted as significantly larger or thicker than they actually are.

[0037] The Fig. Figure 11 schematically and exemplarily shows a cross-section of a sixth alternative waveguide combiner 18g with a fourth alternative waveguide cladding 16g and a waveguide core 14g. The third alternative waveguide cladding 16g only partially covers the waveguide core 14g. The third alternative waveguide cladding 16g is formed by a plurality of column-like structures applied to a surface of the waveguide core 14g. Spaces between individual column-like structures are open in the radial direction of the sixth alternative waveguide combiner 18g. The column-like structures of the third alternative waveguide cladding 16g are formed by an aerogel.

[0038] The Fig. Figure 12 schematically and exemplarily shows a cross-section of a seventh alternative waveguide combiner 18h with a fifth alternative waveguide cladding 16h and a waveguide core 14h. The fourth alternative waveguide cladding 16h has a plurality of studs. The fourth alternative waveguide cladding 16h is designed as a foil. The fourth alternative waveguide cladding 16h is designed as an aerogel studded foil. The studs of the fourth alternative waveguide cladding 16h are arranged on a side of the fourth alternative waveguide cladding 16h facing the waveguide core 14h.

[0039] The Fig.Figure 13 shows a schematic flowchart of a process for manufacturing one of the waveguide combiners 18 of the preceding embodiments. In at least one process step 36, the waveguide core 14 is provided. In at least one further process step 38, the waveguide cladding 16 is joined to the waveguide core 14. This joining is achieved by placing the aerogel as a film or plate onto the waveguide core 14, or by adhering it to the waveguide core 14 with an adhesive, or by growing it onto the waveguide core 14.

Claims

[1] Waveguide combiner (18a-h) for augmented reality and / or virtual reality headsets, in particular for data glasses (10a-h), which is at least designed to guide coupled-in light (12a-h) as a total reflection mode (TIR), with at least one waveguide core (14a-h) and with at least one waveguide cladding (16a-h) covering the waveguide core (14a-h) at least in sections, characterized by that the waveguide cladding (16a-h) has a refractive index between 1.001 and 1.3, preferably between 1.007 and 1.

24. [2] Waveguide combiner (18a; 18c-h) according to claim 1, characterized by that the waveguide core (14a; 14c-h) has a refractive index of 1.55 or less. [3] Waveguide combiner (18b) according to claim 1, characterized by that the waveguide core (14b) is made of a high-refractive material. [4] Waveguide combiner (18a-h) according to one of the preceding claims, characterized bythat the waveguide cladding (16a-h) is formed at least in sections by a foam material, in particular a rigid foam. [5] Waveguide combiner (18a-h) according to one of the preceding claims, characterized by that the waveguide cladding (16a-h) is formed at least in sections by an aerogel. [6] Waveguide combiner (18a-h) according to one of claims 4 or 5, characterized by that the foam material or the aerogel is formed from a base material which is transparent as a solid body. [7] Waveguide combiner (18a-e; 18h) according to one of claims 4 to 6, characterized by that the foam material or the aerogel is film-like or plate-like. [8] Waveguide combiner (18a-h) according to one of claims 5 or 6, characterized by that the aerogel is grown on the waveguide core (14a-h). [9] Waveguide combiner (18a-h) according to one of claims 5 to 7, characterized bythat the aerogel is glued to the waveguide core (14a-h). [10] Waveguide combiner (18c) according to claim 9, characterized by that the aerogel is functionalized, for example hydrophobized, in a way that prevents penetration of adhesive when joined to the waveguide core (14c). [11] Waveguide combiner (18d-e) according to one of claims 1 to 3, characterized by that the waveguide cladding (16d-e) is formed at least in sections by a metamaterial and / or by photonic crystals. [12] Augmented reality and / or virtual reality headset, in particular data glasses (10a-h), with at least one waveguide combiner (18a-h) according to one of the preceding claims. [13] Augmented reality and / or virtual reality headset according to claim 12, characterized by at least one spectacle lens (20a-h), wherein the waveguide combiner (18a-h) is at least partially integrated into the spectacle lens (20a-h). [14] Method for producing a waveguide combiner (18) according to one of claims 4 to 10, characterized by that the foam material or the aerogel is placed as a film or plate / plate on the waveguide core (14) or is glued to the waveguide core (14) by means of an adhesive or is grown on the waveguide core (14).

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