Method of producing an optical arrangement, optical arrangement and head-mounted display

Abstract

To produce a stacked optical arrangement (10) from a first optical component (12) and a second optical component (14), a dam-shaped barrier (22; 22, 28) is created in a surface (18) of the first optical component (12), an adhesive (24) is applied on the surface (18) of the first optical component (12) outside the created barrier (22; 22, 28), the first and second optical components (12, 14) are joined to each other in the stacked arrangement such that the adhesive (24) and the barrier (22; 22, 28) get in contact with the mutually facing surfaces (18, 20) of the first and second optical components (12, 14), and the adhesive (24) is cured to bond the first and second optical components (12, 14) to each other, wherein the airgap region (16) is arranged inside the barrier (22; 22, 28). Such optical arrangement (10) can be a part of a head-mounted display.

Description

Method of producing an optical arrangement, optical arrangement and head-mounted display

[0001] The invention relates to a method of producing an optical arrangement, the optical arrangement to be produced comprising a first optical component and a second optical component in stacked arrangement with an airgap region between mutually facing surfaces of the first and second optical components.

[0002] The invention further relates to an optical arrangement comprising a first optical component and a second optical component in stacked arrangement with an airgap region between mutually facing surfaces of the first and second optical components.

[0003] An optical arrangement according to the present invention may be used in head-mounted displays, such as comprised by data glasses, augmented-reality headsets, virtual-reality headsets, mixed-reality headsets or augmented-reality, virtual-reality or mixed-reality glasses, etc. In these examples of applications, one of the first and second optical components may be a waveguide, and the other of the first and second optical components may be a lens. Typically, the first and second optical components are arranged in a stacked arrangement, i.e. on top of each other, such that there is an airgap region between mutually facing surfaces of the first and second optical components. If one of the first and second optical components is a waveguide in which a light beam is guided based on total internal reflection, the airgap region ensures the condition for total internal reflection at the boundary surface of the waveguide to the airgap region. An optical arrangement according to the present invention may comprise more than two optical components in stacked arrangement, with or without additional airgaps between adjacent surfaces of the optical components.

[0004] It is to be understood that in the context of the present invention, the term “airgap” is to be understood not only as a gap filled with natural air, however it could also be filled with any gaseous fluid different from natural air. The pressure in the airgap can be very low in way that it can be considered as a vacuum gap as well. In another embodiment, the airgap can be filled with a low index material ensuring the condition oftotal internal reflection as provided by an air or vacuum gap, wherein the low index material can have some adhesive properties by itself, but does not have to.

[0005] WO 2024 / 008593 A1 discloses a method for producing an optical arrangement comprising an optical waveguide and a lens in stacked arrangement with an airgap between the waveguide and the lens. This known method requires a mask to be applied to the waveguide or the lens before applying an adhesive used for bonding the waveguide and lens to each other. The mask must be removed after hardening of the adhesive and bonding of the elements to each other which makes the removal complicated and could lead to a break of the mask, deformation of the mask or contamination of the mask. Thereby, the mask is an additional, single-use element to be manufactured separately that further requires a high-precision application and a complicated removal by means of different technological processes as compared to the adhesive deposition. The production process thus becomes more complicated and expensive.

[0006] US 11 243 398 B2 discloses an optical arrangement usable in a headmounted display. The optical arrangement comprises an optical waveguide having two opposite main faces for conducting light by total internal reflection, and at least one wafer facing one of the surfaces of the waveguide. Interposition means is provided in contact with said surface of the light conducting element and defines a gap optically isolating the waveguide.

[0007] US 20240142694 A1 discloses a stacked optical assembly comprising a first optical substrate, a second optical substrate and micro spacers positioned between the first and second optical substrates for maintaining a gap therebetween. The micro spacers can comprise layers of cured resin material formed by a 3D printing process, preferably, such that each layer is cured from a single droplet of the resin material. Such a gap-enabling technique provides for a compact and lightweight stacked optical assembly, but it is complicated and expensive.

[0008] It is an object of the present invention to provide a method of producing an optical arrangement as set forth in the outset which provides a simple and effectivetechnique for producing a stack of optical components, preferably a waveguide and a lens, with a controlled airgap in-between them.

[0009] It is a further object of the present invention to provide a corresponding optical arrangement and a head-mounted display comprising the corresponding optical arrangement.

[0010] According to the invention, a method of producing an optical arrangement is provided, the optical arrangement to be produced comprising a first optical component and a second optical component in stacked arrangement with an airgap region between mutually facing surfaces of the first and second optical components, the method comprising: providing the first and second optical components; creating a dam-shaped barrier in a peripheral region of a surface of the first optical component at least in part along a peripheral length of the first optical component; applying an adhesive on the surface of the first optical component in the peripheral region outside the created barrier; joining the first and second optical components to each other in stacked arrangement by applying a joining force to the stacked arrangement such that the adhesive and the barrier get in contact with the mutually facing surfaces of the first and second optical components; and curing the adhesive to bond the first and second optical components to each other, wherein the airgap region is arranged inside the barrier.

[0011] The present invention is based on the idea to create a dam-shaped barrier in a peripheral region of a surface of one of the first and second optical components. The barrier is beneficial at least for the reason that the barrier helps or even ensures toavoid that adhesive used for bonding the optical components to each other gets into the airgap region inside the barrier. Thus, the barrier facilitates applying the adhesive for bonding in a controlled manner, because when the barrier has been created, the adhesive used for bonding the first and second optical components to each other is applied in the peripheral region outside the created barrier. Thus, one function of the dam-shaped barrier is to limit the area of the adhesive and, thus, to avoid that the adhesive is applied or leaks to the airgap region inside the barrier. A further benefit of the dam-shaped barrier is that the barrier may also define a height of the airgap region between the mutually facing surfaces of the optical components. While the dam-shaped barrier serves as a separating means to define the airgap region, the adhesive provides bonding and optionally peripheral sealing of the stacked arrangement.

[0012] The barrier may have a height from the surface of the first optical component in a range from 0.01 to about 0.3 mm. The height of the barrier may be about 0.2 mm, preferably about 0.1 mm, most preferably 0.05 mm.

[0013] The advantages of the present invention include a simple and effective technological process of embodying an airgap region in an optical arrangement having a stacked structure by creating the dam-shaped barrier between the mutually facing surfaces of the first and second optical components. The method according to the invention does not require any pre-manufactured elements, such as a mask, to be applied between the stacked optical components and removed therefrom after hardening the adhesive and bonding the components to each other.

[0014] The term “curing” is used herein synonymously for “hardening”.

[0015] One of the first and second optical component preferably is a waveguide, and the other one of the first and second optical components is a lens with or without optical power, for example a prescription lens (Rx lens).

[0016] The dam-shaped barrier may be created by a variety of techniques and may have a variety of configurations, in particular according to embodiments as indicated in the dependent claims and as described herein.

[0017] In an embodiment, the barrier may be created in a closed-loop configuration along the peripheral length of the first optical component. In the closed-loop configuration, the dam-shaped barrier has the shape of a closed ring without openings therein.

[0018] In a further embodiment, the joining force to be applied for joining the first and second optical components to each other in the stacked arrangement corresponds to the force of gravity. Thereby, with this embodiment only the force of gravity is required to join the first and second optical components to each other, for example, the joining is occurred naturally when the components are put in contact with each other during a certain time, without applying any extra force, which enables a simpler and cost- effective production.

[0019] In another embodiment, the barrier may be created in an open-loop configuration having at least one opening along the peripheral length of the first optical component. In this embodiment, the dam-shaped barrier has the shape of a ring which is open at one or more locations along the length of the barrier.

[0020] Both of the afore-mentioned embodiments with the closed and openloop configurations of the barrier have advantages. The closed-loop configuration is beneficial as the function of limiting the adhesive from the airgap region is achieved without further measures. The open-loop configuration is beneficial if one of the optical components is an optical waveguide having a portion extending beyond the circumference of the other optical component, as will be described further below.

[0021] In a further embodiment, the barrier is created to be compressible when, during said joining, the joining force is applied to the stacked arrangement of the first and second optical components.

[0022] The advantage of this embodiment is that it facilitates applying the adhesive for bonding, because the dam-shaped barrier may be created with a height above the surface of the first optical component which is larger than the height of the adhesive to be applied after the barrier has been created. It may be difficult to deposit the adhesive exactly to the height level of the dam-shaped barrier or even a bit higher with a small meniscus. In this embodiment, therefore, the adhesive for bonding the optical components to each other may be deposited with a height level lower than the height of the created barrier so that the risk that the adhesive gets over and across the barrier into the airgap region is reduced. Due to the compressibility of the barrier under the applied joining forces upon joining the optical components to each other, the surfaces of the first and second optical components can be brought into contact with the adhesive for proper bonding the first and second optical components to each other.

[0023] In a further embodiment, said creating the barrier comprises applying a curable material, e.g. in liquid form, on the surface of the first optical component and curing said material to form the barrier.

[0024] This embodiment is particularly advantageous as the dam-shaped barrier can be created by the same technological process as used for applying and / or curing the adhesive for bonding the first and second optical components to each other. In this embodiment, adhesive material may be deposited to the surface of the first optical component in at least two stages, wherein the adhesive deposited at the first stage is cured to create the dam-shaped barrier, and the adhesive deposited at the second stage is used for bonding the optical components into the stacked arrangement.

[0025] Accordingly, in a further embodiment, the barrier is created from a same material as the adhesive for bonding the first and second optical components to each other, or is created from a different material than the adhesive for bonding the first and second optical components to each other, wherein the different material may have a same or different viscosity as compared to the viscosity of the adhesive for bonding the first and second optical components to each other. Preferably, the different material has a viscosity higher than the viscosity of the adhesive for bonding the first and second optical components to each other.

[0026] In a further embodiment, the barrier is created from two or more different materials, a first material of which is applied for forming a lower part of the barrier, and at least a second material of which is applied for forming an upper part of the barrier, wherein preferably the first material has after curing a viscosity or hardness higher or an elasticity lower than those of the second material.

[0027] In this embodiment, the dam-shaped barrier may comprise a bottom part or layer of a higher viscosity or hardness material, e.g. an adhesive material with a higher viscosity or hardness, to form a non-compressible part of the barrier, and a top part or layer of a lower viscosity or hardness material, which may also be an adhesive material, to form a compressible part of the barrier. Numerous other implementations of the barrier made of different materials are equally possible.

[0028] For example, an adhesive material for creating the barrier may be applied to the surface of the first optical component and then it is cured or hardened by known means and methods to create the barrier of required height and form. It is to be understood that the barrier material is not limited to an adhesive material, and the barrier can be made of any other materials having or providing required properties, such as a rubber or a polymer.

[0029] Preferably, the barrier material or materials is / are of a liquid form to be deposited to the surface of the first optical component by the same or similar technological process as the one for applying the adhesive for bonding the components to each other. Preferably, both materials, the barrier material and the adhesive material for bonding the components to each other, are curable with ultraviolet (UV) light, i.e. light having shorter wavelengths than visible light, and most preferably with UV light of the same or similar wavelength, in order to further simplify and reduce the time and cost expenditure of the method.

[0030] In a further embodiment, the barrier is a first barrier, and the method further comprises creating a second barrier in the peripheral region of the surface of the first optical component at least in part along a peripheral length of the first optical component,wherein said second barrier is created outside the first barrier and spaced apart from the first barrier, the method further comprising applying the adhesive in a space between the first and second barriers.

[0031] This embodiment is advantageous as the area for depositing the adhesive for bonding the first and second components to each other is even better defined by the space between the two barriers. Thus, the adhesive for bonding the first and second optical components is limited in a more defined manner and depositing the adhesive for bonding is further facilitated.

[0032] The second barrier may be created in a closed-loop configuration, or in an open-loop configuration having at least one opening along the peripheral length of the first optical component. Also, the first barrier may be created in closed-loop configuration, while the second barrier is created in open-loop configuration, or vice versa, or both barriers are created in closed-loop configuration or both barriers are created in open-loop configuration.

[0033] In particular, one or more openings in the second, i.e. , outer damshaped barrier, has / have the advantage that a surplus of the adhesive for bonding the optical components to each other may be discharged through the opening(s) of the second barrier and does not get into the airgap region over and across the first barrier.

[0034] In a further embodiment, the second barrier may be created to be compressible when, during said joining, the joining force is applied to the stacked arrangement of the first and second optical components.

[0035] As in the corresponding embodiment according to which the first barrier preferably is created to be compressible, this embodiment too has the advantage to enable a better control of the deposition of the adhesive in the space between the first and second barriers in order to ensure that no adhesive gets into the airgap region. A further advantage again is that the compressibility of the second barrier as well as of the first barrier provides that the mutually facing surfaces of the optical components come intoproper contact with the adhesive for bonding the optical components to each other when applying the joining force, and thus a proper sealing effect and protection of the airgap region is achieved.

[0036] In a further embodiment, said second barrier may be created with a height from the surface of the first optical component, which is larger than the height of the first barrier.

[0037] In this embodiment, the second barrier may advantageously serve as an alignment structure for a precise alignment of the second optical component with respect to the first optical component when joining the optical components to each other.

[0038] In this context, it is further preferred if the second barrier is created with an internal contour matching with an outer contour of the second optical component.

[0039] Thus, the second barrier can be advantageously used not only for limiting the adhesive arrangement for bonding the components to each other, but also as a seat within the contour of the second dam-shaped barrier for receiving and aligning the second optical component with respect to the first optical component. In other words, the internal contour of the second barrier with higher walls then those of the first barrier may effectively define a mounting space for the second optical component so that simple placing of the second optical component into said mounting space provides the precise alignment of the second optical component with respect to the first optical component in the stacked structure.

[0040] In a further embodiment, the method further comprises removing the second barrier after the adhesive has been cured to bond the first and second optical components to each other.

[0041] Here it is advantageous that the optical arrangement can be produced with a slim design. The second barrier may be removed by any appropriate means, such as mechanical cutting.

[0042] In particular, it is preferred according to another embodiment that the second barrier is created from a material which is peelable, in particular from a peelable adhesive. It is advantageous here that removal of the second barrier can be easily accomplished by peeling.

[0043] In yet another embodiment, the adhesive applied in the peripheral region outside the barrier or between the first and second barriers comprises a material which is peelable, such as a peelable adhesive, so that the adhesive arrangement bonding the first and second optical components to each other can be destroyed, for example, by peeling. This embodiment enables disassembling the optical arrangement after its production without damaging the first and second optical components, for example, for replacing one of the first and second optical components by a new one. Moreover, in another embodiment the first barrier comprises a material which is peelable, such as a peelable adhesive, for example, the same peelable adhesive as used in the second barrier and / or the adhesive arrangement between the barriers. In this case each of the first and second barriers and the adhesive arrangement between them can be destroyed, for example, by peeling, after the producing of the optical arrangement according to the present invention. This enables disassembling the optical arrangement fully after its production without damaging the first and second optical components, for example, for replacing one of the first and second optical components by a new one.

[0044] In an embodiment, one of the first and second optical components is an waveguide, wherein a waveguiding region of the waveguide (i.e. its region used for guiding the light) extends from the airgap region beyond the barrier, wherein the barrier is created with an opening in a region of overlap with the waveguiding region.

[0045] This embodiment is an example of an open-loop configuration of the barrier. When two barriers are created as described above, preferably the first barrier and the second barrier are created with an opening in each case in the region of overlap with the waveguiding region.

[0046] The opening in the barrier or barriers serves to maintain as far as possible total internal reflection conditions in the overlap region of the barrier / barriers with the waveguiding region of the waveguide. The barrier material may have a refractive index which might be too high for maintaining the internal reflection condition. Thus, it is preferred that the barrier is “interrupted” in the region where the optically used region of the waveguide passes across the barrier.

[0047] At that, the barrier, in particular the first barrier, may be created with curved edges at the opening to seal the waveguiding region from the adhesive used for bonding the first and second optical components to each other.

[0048] In this context, the opening in the first and / or second barrier may be closed with an insert comprising a material with a low refractive index or a high reflectivity as compared with those of the waveguiding region.

[0049] Here it is advantageous, that the airgap region may be sufficiently sealed by the insert, while the insert comprises a material, at least in its part contacting the surface of the optical waveguide, having a refractive index low enough or a reflectivity high enough to maintain as far as possible the total internal reflection conditions in the waveguide.

[0050] Alternatively, the opening in the first and / or second barrier may be left open instead of closing the opening with an insert as described above, and thus the conditions for total internal reflection are maintained without further measures.

[0051] In another embodiment, it is also possible that the barrier itself is created in a region of overlap with the waveguiding region at least at a bottom of the barrier with a material having a low refractive index or a high reflectivity, or with an insert comprising a material with a low refractive index or a high reflectivity as compared with those of the waveguiding region.

[0052] In this embodiment, the barrier, in particular the first and / or the second barrier, can be created in closed-loop configuration, without the need to be created with an opening in the overlap region with the waveguiding region, as the bottom of the barriers) is made from a material having a low refractive index or a high reflectivity so that the total internal reflection conditions in the overlap region with the waveguiding region are maintained as far as possible.

[0053] In a further embodiment, the method may further comprise, before creating the barrier, applying a mask on the surface of the first optical component, said mask having one or more line-shaped openings defining the shape of the barrier to be created, the method further comprising applying a material into the one or more openings to create the barrier.

[0054] In this embodiment, a mask is applied to the surface of the first optical component, wherein the mask has one or more openings (also referred to as blanks) which define the shape of the barrier or barriers. The openings may have a line-shape and / or a series of line segments. The dam-shaped barrier or barriers are created by depositing a barrier material, such as an adhesive, into the openings of the mask. By an optional process step, the surplus barrier material can be removed e.g. by wiping with a squeegee over the mask, to provide a further improvement and repeatability of the barrier height precision. After hardening of the barrier(s), but before bonding the optical components to each other, the mask can be removed in a simple manner. The use of the mask as described allows creating the barrier(s) with a controlled and precise shape. The height as well as the form of each barrier in the plan view are defined by the corresponding openings in the mask. Depending on the barrier material properties, the shape and dimensions of the mask are easier to control than the same of the barrier material itself when being deposited on the surface of the first optical component without mask, especially when the barrier to be created has a high aspect ratio, as a geomentrical structure. The mask is removed from the surface of the first optical component before applying the adhesive for bonding the optical components to each other, in particular without breaks and significant deformations and so the mask can be reused.

[0055] According to a further aspect of the present invention, an optical arrangement is provided, comprising a first optical component and a second optical component in a stacked arrangement with an airgap region between mutually facing surfaces of the first and second optical components, further comprising a dam-shaped barrier in a peripheral region of the mutually facing surfaces of the first and second optical components at least in part along a peripheral length of the first and second optical components, and a bonding region in the peripheral region outside the barrier in which the first and second optical components are bonded to each other by an adhesive, the barrier being in contact with the mutually facing surfaces of the first and second optical components and surrounding the airgap region.

[0056] Preferably, the optical arrangement according to the invention is produced by the method according to the invention.

[0057] In an embodiment, the barrier of the optical arrangement is formed from a curable material applied on the surface of the first optical component in a closed loop configuration, or in an open loop configuration having at least one opening along the peripheral length of the barrier.

[0058] In another embodiment, one of the first and second optical components of the optical arrangement is a waveguide, wherein a waveguiding region of the waveguide extends from the airgap region beyond the barrier, wherein the barrier comprises in a region of its overlap with the waveguiding region at least at a bottom of the barrier a material having a high reflectivity or a low refractive index as compared with those of the waveguiding region, or an opening accommodating an insert that comprises a material with a low refractive index or a high reflectivity as compared with those of the waveguiding region.

[0059] In yet another embodiment, the barrier is a first barrier, and the optical arrangement further comprises a second barrier in the peripheral region of the surface of the first optical component at least in part along a peripheral length of the first optical component, wherein said second barrier is arranged outside the first barrier and spacedapart from the first barrier, and the bonding region with the adhesive corresponds to a space between the first and second barriers. At that, the second barrier can have a closed loop configuration, or an open loop configuration having at least one opening along the peripheral length of the first optical component.

[0060] In a further embodiment the second barrier has a height from the surface of the first optical component, which is larger than the height of the first barrier, and / or has an internal contour matching with an outer contour of the second optical component.

[0061] It would be appreciated by those skilled in the art that the optical arrangement according to the invention may have the corresponding embodiments and provide the same advantages as the method according to the invention.

[0062] According to a further aspect of the present invention, provided is a head-mounted display comprising the optical arrangement according to the invention, in particular, the one produced by the method according to the invention. It would be appreciated by those skilled in the art that the head-mounted display according to the invention may have corresponding embodiments and provide the same advantages as the method according to the invention.

[0063] Further features and advantages of the invention will become apparent from the following description and the accompanying drawings.

[0064] Embodiments of the invention are shown in the drawings and will be described below with reference to the drawings. In the drawings:

[0065] Fig. 1 shows schematically a cross-section of an optical arrangement in an intermediate stage of producing the optical arrangement according to an embodiment of the present invention;

[0066] Fig. 2 shows schematically a cross-section of an optical arrangement in an intermediate stage of producing the optical arrangement according to another embodiment of the present invention;

[0067] Fig. 3 shows schematically a cross-section of an optical arrangement in an intermediate stage of producing the optical arrangement according to yet another embodiment of the present invention;

[0068] Fig. 4 shows schematically a partial perspective view of an optical arrangement in an intermediate stage of producing the optical arrangement according to another embodiment of the present invention;

[0069] Fig. 5 shows schematically a partial perspective view of an optical arrangement in an intermediate stage of producing the optical arrangement according to another embodiment of the present invention;

[0070] Fig. 6 shows schematically a top plan view of a surface of a first optical component of an optical arrangement with an adhesive applied in a space between two dam-shaped barriers according to an embodiment of the present invention;

[0071] Fig. 7 shows schematically an example of mask used for creating two dam-shaped barriers in a method of producing an optical arrangement according to an embodiment of the present invention;

[0072] Fig. 8 shows schematically a plan view of a first optical component of an optical arrangement with two open-loop barriers and an insert in a region of overlap of the barriers with a waveguiding region according to another embodiment of the present invention;

[0073] Fig. 9 shows a plan view of a first optical component of an optical arrangement with two open-loop barriers and an insert of different form in a region ofoverlap of the barriers with a waveguiding region according to yet another embodiment of the present invention; and

[0074] Fig. 10 shows a plan view of a first optical component of an optical arrangement with two open-loop barriers one of which has curved edges to seal the adhesive from a waveguiding region according to another embodiment of the present invention.

[0075] Fig. 1 shows schematically a cross-section of an optical arrangement according to an embodiment of an aspect of the invention labelled with general reference numeral 10. The optical arrangement 10 comprises a first optical component 12 and a second optical component 14. In a method of producing the optical arrangement 10 according to an embodiment of another aspect of the invention, the first optical component 12 and the second optical component 14 are to be bonded to each other in a stacked arrangement with an airgap region 16 of longitudinal dimension L between mutually facing surfaces 18 and 20 of the first optical component 12 and the second optical component 14. Fig. 1 shows the optical components 12 and 14 separated from each other, i.e. before being joined and bonded to each other.

[0076] The first and second optical components 12 and 14 may be any type of optical components. The first optical component 12 may be an optical waveguide, and the second optical component 14 may be a lens, e.g. an Rx lens. However, it is to be understood that the first optical component 12 may be a lens, e.g. an Rx lens, and the second optical component 14 may be a waveguide. It is also possible that the first and second optical components 12 and 14 are both waveguides, or both lenses, etc. For simplicity of the following description and without limiting the scope of the invention, the first optical component 12 will be referred to as an optical waveguide in some embodiments, and the second optical component 14 will be referred to as a lens in some embodiments.

[0077] The surface 18 of the first optical component 12 may be planar. The surface 20 of the second optical component 14 may be planar as well, without limiting the invention to planar surfaces of the first and second optical components 12, 14 as the surfaces might be of different shapes, for example, comprising convex and / or concavesurfaces. Non-planar surfaces 18, 20 can be intended for providing the first optical component 12 and / or the second optical component 14 with an optical power. In case when one of the first and second optical components 12, 14 is an optical waveguide, opposite surfaces of the optical waveguide designed for conducting light by total internal reflection can be planar or non-planar, in part or in full. The present invention is equally applicable and provides the same benefits in cases when at least one of the first and second optical components 12, 14 is a planar waveguide or a curved waveguide.

[0078] Next, a method of producing the optical arrangement 10 according to an embodiment of the invention will be described. Initially, the first and second optical components 12 and 14 are provided as separate parts.

[0079] A dam-shaped barrier 22 is created in a peripheral region of the surface 18 of the first optical component 12 at least in part along a peripheral length of the first optical component 12.

[0080] The dam-shaped barrier 22 may be in the form of a closed or open loop on the surface 18 of the first optical component 12. Examples of closed and open loop configurations of the barrier 22 will be described below in more detail. In general, the barrier 22 has a shape of a line.

[0081] The airgap region 16 is defined as a region inside the barrier 22, i.e. surrounded by the barrier 22. The airgap region 16 has a height hawhich is defined by the height of the barrier 22 when the first and second optical components 12 and 14 are bonded to each other. The height haof the barrier 22 may be about 0.2 mm, preferably about 0.1 mm and most preferably 0.05 mm. The thickness of the barrier 22 in a plane perpendicular to the height hamay be in the same or similar range as the height ha.

[0082] After the barrier 22 has been created, an adhesive 24 used for bonding the optical components 12, 14 to each other is applied on the surface 18 of the first optical component 12 in the peripheral region outside the created barrier 22. The adhesive may be of a type known in the art for bonding optical components to each other. The adhesive24 may be dispensed on the surface 18 with an adhesive dispensing tool (not shown) as known in the art. The adhesive 24 is limited by the barrier 22 in the inward direction towards the airgap region, i.e. in direction to the center area of the optical component 12. After applying the adhesive 24, the second optical component 14 is joined to the first optical component in a stacked arrangement, i.e. to form a stack structure, wherein a joining force (illustrated by an arrow 26) is applied to the stacked arrangement, such that the adhesive 24 and the barrier 22 come into contact with the mutually facing surfaces 18 and 20 of the first and second optical components 12 and 14. When joining the first and second optical components 12, 14 to each other, the barrier 22 serves as a separating means to define the airgap region 16, while the adhesive 24 provides bonding and optionally peripheral sealing of the stack structure. Due to the barrier 22, the adhesive 24 does not get into the airgap region 16.

[0083] When the first and second optical components 12 and 14 are joined to each other, the adhesive 24 is cured to bond the first and second optical components 12, 14 to each other. The region where the adhesive 24 bonds the optical components 12, 14 to each other is also referred to as a bonding region.

[0084] As it may be difficult to deposit the adhesive 24 exactly to the right level as the height of the barrier 22 or a bit higher of that with a small meniscus, it is preferred that the created barrier is configured, such as made of a suitable material, to be compressible under the applied joining force, and the sealing effect to the airgap region 16 is ensured by the abutting of the second optical component 14 to the barrier 22 with certain compression of the barrier 22, before the second optical component 14 gets in contact with the adhesive 24. On the left side of Fig. 1, the barrier 22 is shown in a noncompressed state, before being compressed, with a height which is larger than the required height haof the airgap region 16 to be formed when the first and second optical components 12 and 14 are bonded to each other. The height hadefining the height of the airgap region 16 corresponds to the height of the barrier 22 in compressed state. The barrier 22 is shown on the left side with a height which is larger than the height haby an amount hc. When the first and second optical components 12 and 14 are joined to each other by applying the joining force (arrow 26), the barrier 22 will be compressed by the amount hc. On the right side in Fig. 1, the barrier 22 is shown when being compressed tothe compressed state. It would be appreciated for those skilled in the art that the barrier 22 is to be created with a constant or essentially constant height along its length, and the parts of the barrier 22 are shown on the left and right sides in Fig. 1 with different heights only for explanatory purposes to illustrate possible states of the barrier 22 before and after the compression.

[0085] A surplus of the adhesive 24, if any, can be removed from the circumference of the stack arrangement comprising the first and second optical components 12, 14 by any suitable means, such as being peeled or trimmed, to ensure a required form of the stacked arrangement of the optical components 12, 14.

[0086] The dam-shaped barrier 22 can be made of any appropriate material or materials, including the same adhesive material as a material of the adhesive 24 used for bonding the optical components 12, 14 to each other, or an adhesive material with the same, similar or a different viscosity as compared with the viscosity of the adhesive 24. Preferably, the material of the barrier 22 has a higher viscosity than the viscosity of the adhesive 24.

[0087] It is also possible to create the barrier 22 as being made of two or more different materials. For example, the barrier 22 can comprise a part such as a layer of one material while the rest of the barrier 22 is made of another material. The barrier 22 may comprise a bottom part or layer of a high viscosity adhesive to form a non-compressible part of the barrier 22, and a top part or layer of a lower viscosity adhesive to form a compressible part of the barrier 22, for example. Numerous other implementations of the barrier 22 made of different materials are equally possible.

[0088] In an embodiment, the barrier 22 may be made of an adhesive material which is applied in liquid form to the surface 18 of the first optical component 12, and then it is cured or hardened by known means and techniques to create the barrier 22 of the required height and form. The material of the barrier 22 is not limited to an adhesive material. The barrier 22 may be made of any other materials having or providing required properties, such as a rubber or a polymer. However, it is preferred if the material of thebarrier 22 is of a liquid form which can be deposited on the surface 18 by the same or similar technological process as the one for applying the adhesive 24 used for bonding the optical components 12, 14 to each other to the surface 18 of the optical component 12.

[0089] When the material of the barrier 22 is applied as a liquid curable material on the surface 18 of the optical component 12, it is preferred if the material of the barrier 22 and the adhesive 24 used for bonding the optical components 12, 14 to each other can be cured with UV light, and most preferably with UV light of the same or similar wavelength.

[0090] Fig. 2 shows schematically another embodiment of an optical arrangement according to the present invention, wherein those elements which are identical, comparable or similar to elements in Fig. 1 are denoted with the same reference numerals as in Fig. 1. In this embodiment, a second dam-shaped barrier 28 in addition to the barrier 22, that thereby is hereinafter referred to as a first barrier, is created in the peripheral region of the surface 18 of the first optical component 12 at least in part along a peripheral length of the first optical component 12. The second barrier 28 is created outside the first barrier 22, i.e., farther away from the center of the first optical component 12. Further, the second barrier 28 is spaced apart from the first barrier 22 such that the adhesive 24 used for bonding the optical components 12, 14 to each other may be deposited in a space between the first and second barriers 22, 28. Thus, the adhesive 24 is limited on both sides by the barriers 22 and 28. However, also in this case it is still required to control the amount of adhesive 24 deposited between the barriers 22, 28 quite well to ensure that no surplus of the adhesive 24 is getting into the airgap region 16. Therefore, here it is preferred as well to have a compressible barrier material at least in the first barrier 22, preferably in the first and the second barriers 22, 28, for proper sealing effect and protection of the airgap region 16.

[0091] The second barrier 28 may have a closed loop or open loop configuration. The open-loop configuration of the second barrier 28 is beneficial as it allows a surplus of the adhesive 24, if any, discharging from the space between the first and second barriers 22, 28 to an outside of the second barrier 28 through one or more open-ings in the second barrier 28, thus preventing the adhesive 24 from getting into the airgap region 16.

[0092] Similar to the embodiment described above with referent to Fig. 1 , it is preferred here that both the barriers 22, 28 are configured, such as made of a suitable material or materials, to be compressible under the applied joining force. On the left side of Fig. 2, the barriers 22, 28 are shown in a non-compressed state, before being compressed, with a height which is larger than the required height haof the airgap region 16 to be formed when the first and second optical components 12 and 14 are bonded to each other. The height hadefining the height of the airgap region 16 corresponds to the height of the barriers 22, 28 in a compressed state. The barriers 22, 28 are shown on the left side with a height which is larger than the height haby an amount hc. When the first and second optical components 12 and 14 are joined to each other by applying the joining force (arrow 26), the barriers 22, 28 will be compressed by the amount hc. On the right side in Fig. 2, the barriers 22, 28 are shown when being compressed to the compressed state. It would be appreciated for those skilled in the art that each of the barriers 22, 28 is to be created with a constant or essentially constant height along its length, and the parts of the barriers 22, 28 are shown on the left and right sides in Fig. 2 with different heights only for explanatory purposes to illustrate possible states of the barriers 22, 28 before and after the compression.

[0093] Fig. 3 shows schematically another embodiment of the optical arrangement 10 which is a modification of the embodiment in Fig. 2. Elements of the optical arrangement 10 in Fig. 3 which are identical, comparable or similar to elements in the embodiment in Fig. 2 are denoted with the same reference numerals as in Fig. 2. In the embodiment of Fig. 3, the second barrier 28 is created with a height above the surface 18 of the first optical component 12 which is larger than the height of the first barrier 22. Further, the second barrier 28 is provided with an internal contour that matches with an outward shape of the second optical component 14. Thus, the second barrier 28 can be beneficially used not only for limiting the adhesive 24, but also as an alignment means for aligning the second optical component 14 in the plan view precisely within the contour of the second barrier 28. In other words, the second barrier 28 can be designed to define a seat S to fit the second optical component 14 enhancing and simplifying the alignment ofthe second optical component 14, e.g., a lens, with the first optical component 12, e.g., an optical waveguide, thus simplifying the assembly procedure. After stacking and bonding and optionally sealing the stack structure comprising the first and second optical components 12, 14 with the adhesive 24, the second barrier 28 can be removed by any appropriate means to provide a slim design of the stacked structure of the optical arrangement 10, such as mechanical cutting. It is preferred if the second barrier 28 is created from a peelable material, such as a peelable adhesive, to facilitate the removal of the second barrier 28 by peeling.

[0094] At that, each of the barriers 22, 28 can be configured, such as made of a suitable material or materials, to be compressible under the applied joining force. Though, in the given embodiment, it is preferable to have the first barrier 22 being compressible under the applied joining force, similar to the embodiment described above with referent to Fig. 1.

[0095] Fig. 4 and Fig. 5 show schematically further embodiments of the optical arrangement 10 according to the present invention. Elements of the optical arrangements 10 in Fig. 4 and Fig. 5, which are identical, comparable or similar to elements in the previous embodiments, are denoted with the same reference numerals as in the previous embodiments.

[0096] In an application of the optical arrangement 10 in head-mounted displays, e.g. data glasses, etc. it is common that the optical arrangement comprises an optical waveguide which has an input coupling structure and an output coupling structure as known to those skilled in the art. The input coupling structure is designed to couple an image light, e.g. from a display, into the optical waveguide. The image light coupled into the waveguide propagates by total internal reflection at interfaces of the waveguide to surroundings, e.g. to air. The output coupling structure is designed to couple the light propagated in the optical waveguide out of the waveguide in an eyebox direction to project the image to the user’s eye or eyes. The region of the waveguide where the image light is guided, from the input coupling structure and to the output coupling structure, may be referred to as the waveguiding region. Those skilled in the art would appreciate that the rest of the waveguide, i.e. a non-waveguiding part of the waveguide, can essentially havethe same structure as the waveguiding region, but it is not critical for a proper operation of the optical arrangement 10 in such devices as data glasses and head-mounted displays, to have the non-waveguiding part of the waveguide optically isolated from its surroundings, so the non-guiding part may have or may not have an airgap around it.

[0097] Both Figs. 4 and 5 illustrate embodiments of the optical arrangement of the present invention in a semi-assembled state when the joining of the first and second optical components 12, 14 is in process. In these embodiments the second optical component 14 is a lens, such as a prescription lens having an optical power in accordance with a viewer’s prescription, and the first optical component 12 is an optical waveguide having an input coupling structure 30 and an output coupling structure 32. As shown in each of Figs. 4 and 5, there are the dam-shaped first and second barriers 22, 28 in a peripheral region of a surface of the waveguide 12 and the adhesive 24 in a space between the first and second barriers 22, 28. In the embodiment of Fig. 4, the airgap region 16 inside an inward contour of the first barrier 22 includes the input coupling structure 30 as well as the output coupling structure 32. In the embodiment of Fig. 5, only the output coupling structure 32 is arranged within the airgap region 16 inside the contour of the first barrier 22, while the input coupling structure 30 is arranged outside the airgap region 16, and more exactly outside an outward contour of the second barrier 28. The method of producing an optical arrangement according to the invention as described above is applicable to both the embodiments of Fig. 4 and 5 and provides all the described advantages in both these embodiments as well as in any other configuration of an optical waveguide that is designed to be stacked with a lens or other optical element.

[0098] Fig. 6 shows schematically another embodiment of the present invention where a first optical component 12 is prepared for joining with a second optical component (not shown for the sake of simplicity) to produce an optical arrangement 10, namely: the dam-shaped first and second barriers 22, 28 are created in a peripheral region of a surface of the first optical component 12 and the adhesive 24 is deposited in a space between the first and second barriers 22, 28. Elements of the embodiment in Fig. 6 which are identical, comparable or similar to elements in the previous embodiments are denoted with the same reference numerals as in the previous embodiments. In the embodiment of Fig. 6, the second barrier 28 is created in the form of an open loop barrier with at leastone, here a plurality of openings 34. The openings 34 form outlets for discharging a surplus of the adhesive 24 before the adhesive 24 is cured or hardened, especially, during the joining of the first and second optical components to each other in stacked arrangement by applying a joining force, when the adhesive 24 and the barriers 22, 28 get in contact with adjacent, mutually facing surfaces of the first and second optical components. Thereby, it is ensured that any surplus of the adhesive 24 can get out through the openings 34 of the second barrier 28 and does not enter the airgap region 16 through the first barrier 22.

[0099] Fig. 7 schematically shows a mask 40 which may be applied in an embodiment of the method according to the invention for creating the first barrier 22 and / or the second barrier 28. The mask 40 is applied to the surface 18 of the first optical component 12 before creating the barrier 22 or barriers 22, 28, to define the shape of the barrier 22 or the barriers 22, 28. The mask 40 can be designed to define a pattern for the barrier 22 or the barriers 22, 28 by having one or more openings or blanks 42, 44, which for example have a line shape and / or are configured as a series of openings. The openings or blanks 42, 44 essentially have the shape of the barrier 22 and / or the second barrier 28 to be created, i.e. inward shapes of the openings or blanks 42, 44 correspond to outward shapes of the first barrier 22 and / or the second barrier 28. Thereby, the barrier 22 or barriers 22, 28 can be created by depositing a barrier material, such as an adhesive, into the openings 42, 44 of the mask 40. By an optional process step, the surplus barrier material can be removed by wiping with a squeegee over the mask 40, to provide a further improvement and repeatability of the barrier height precision. After the barrier 22 or barriers 22, 28 have been created (e.g. by curing the barrier material), but before bonding the optical components 12, 14 to each other in a stack structure, the mask 40 can be removed in a simple manner. The use of the mask 40 as described allows creating the barrier 22 or barriers 22, 28 of a controlled and precise shape. The height as well as the form of each barrier 22 and / or 28 in the plan view are defined by the corresponding openings or blanks 42, 44 in the mask 40. Depending on the barrier material properties, the shape and dimensions of the barrier material when using the mask are easier to control than the shape and dimensions of the barrier material when the barrier material is deposited on the surface 18 of the optical component 12 without using the mask, especially in the case of high aspect ratio of the barrier to be created, as a geometrical structure.At that, the mask 40 in the present embodiment can be removed from the surface 18 without breaks and significant deformations and so can be reused.

[0100] Further embodiments of optical arrangements 10 according to the present invention will be described below with reference to Figs. 8 - 10. In Fig. 8 - 10, elements of the optical arrangements which are identical, comparable or similar to elements of the previously described embodiments are labelled with the same reference numerals as in the previous embodiments. In particular, the embodiments of Fig. 8 - 10 are preferred refinements of the embodiment of Fig. 5. Reference is also made to the description above with respect to Fig. 4 and 5.

[0101] In each of Figs. 8 - 10, only the first optical component 12 of the optical arrangement 10 is shown, while the second optical component 14 has been omitted for the sake of simplicity. In each of the illustrated embodiments, the first optical component 12 is an optical waveguide having an input coupling structure 30 and an output coupling structure 32. Correspondingly, as it is mentioned above, the second optical component can be a lens, such as a prescription lens having an optical power in accordance with a viewer’s prescription. In each case, the dam-shaped first and second barriers 22, 28 are created in a peripheral region of a surface of the waveguide 12 and the adhesive 24 is deposited in a space between the first and second barriers 22, 28. At that, in each of the embodiments of Figs. 8 - 10 the input coupling structure 30 is arranged outside the airgap region 16, similar to the embodiment described above with reference to Fig. 5. The output coupling structure 32 in turn is arranged inside the airgap region 16. In this case, there is a waveguiding region 52 of the optical waveguide extending from the input coupling structure 30 to the output coupling structure 32 through an overlap region 50 in which the waveguiding region 52 would pass below contours of the barriers 22, 28 and the adhesive 24, if they have a closed-loop configuration. As described above, it is required to provide, as far as possible, total internal reflection conditions for a guided image light in all the waveguiding region 52 of the waveguide 12. Unfortunately, most common adhesive materials or other materials that can be beneficially used to create the barrier 22 or barriers 22, 28 and the adhesive 24 for bonding the optical components 12, 14 to each other have higher refractive indices and / or lower reflectivity that would violate the conditions of total internal reflection in the region of their overlap with the waveguiding region52, i.e. in the overlap portion 50. Therefore, it can be desired to create the first barrier 22 and / or the second barrier 28 at least in the overlap region 50 with a material, part or insert having or providing certain optical properties, such as providing a low refractive index or a high reflectivity in the region 50 of overlap with the waveguiding region 52 as compared with a refractive index and reflectivity of the waveguiding region 52. To this end, in an embodiment, the barrier 22 or barriers 22, 28can be created in the region 50 of overlap with the waveguide at least at a bottom of the barrier 22 or barriers 22, 28 with a material having a low refractive index or a high reflectivity, or with an insert 54 comprising a material with a low refractive index or a high reflectivity as compared with those of the waveguiding region 52.

[0102] As per embodiments of the present invention, the barriers 22, 28 (and also the adhesive arrangement 24) can be provided with an insert or part 54 in the overlap region 50, for example, as shown in Figs. 8 and 9. In general, the first and / or the second barriers 22, 28 can comprise one or more parts or inserts 54 of different material or materials in the overlap region 50 as compared with material or materials of the remaining portions of the barriers 22, 28, wherein the different material or materials have a desired low refractive index or high reflectivity. It would be appreciated by those skilled in the art that Figs. 8 and 9 illustrate the insert 54 as a separate element of a shape different from the shapes of the barriers 20, 28 only for illustrative purposes, without implying any limitations to the scope of the invention. In further embodiments, such parts or inserts 54 of different material or materials may be arranged only in a bottom part of the barrier 22 or the barriers 22, 28, for example constituting a lower layer of the barrier 22 or the barriers 22, 28 in the overlap region 50 of its overlap with the waveguiding region 52. The said lower layer can comprise a very thin layer of a low index material or a high reflective coating. In an embodiment, such high reflective coating or low index material layer is applied to the surface of the first optical component 12 (e.g. the optical waveguide) by well known vacuum deposition processes (CVD or PVD), but any other application techniques can be used within the scope of the invention.

[0103] In another embodiment, the first barrier 22 and / or the second barrier 28 can be made as open-loop barriers having an opening 53 in the overlap region 50 so that there is also provided an airgap to ensure the total internal reflection inside the waveguidein this region, as illustrated for example in Figs. 8 - 10. The opening 53 in the barrier 22 or barriers 22, 28 in the overlap region 50 can be left unsealed as shown in Fig. 10. In yet other embodiments, there may be provided an insert 54 of another material, such as a material with a low refractive index or a high reflectivity, to close and / or seal the opening in the first barrier 22 and / or the second barrier 28 as shown in Figs. 8 and 9.

[0104] The described embodiments are not limited by any form, material and / or technique of application of the insert or inserts 54 that can be used in the overlap region 50, i.e., in the overlap of the barrier 22 or the barriers 22, 28 and the adhesive 24 with the waveguiding region 52. For example, the insert 54 can have such a form in the plan view to contact with and effectively seal the opening 53 in each of the first barrier 22, the adhesive 24 and the second barrier 28, as shown in Fig. 9. Preferably, the insert 54 can be created by depositing a suitable material in the area of the opening 53 in the first and second barriers 22, 28 and in the adhesive 24 after the first and / or second barriers 22, 28 have been created, and / or after or before depositing the adhesive 24 between the barriers 22, 28.

[0105] Alternatively or in addition to the above, in order to seal the opening 53 and thereby the waveguiding portion 52 in the overlap region 50 from any adhesive leakages, the first barrier 22 and / or the second barrier 28 can be made of a specific form to close the space between the barriers 22, 28 in the overlap region 50 from the adhesive 24, for example, as illustrated in Fig. 10. To this end, as shown in Fig. 10, the first barrier 22 may have edges 55 in the region of the opening 53 which are curved and connect to the second barrier 28, thereby sealing the opening 53 from the adhesive 24. The embodiment of Fig. 10 and the embodiments of Figs. 8 - 9 can be beneficially used in combination with each other as well.

[0106] The method according to the invention described with reference to all embodiments above provides significant improvement and benefits in the production of optical stacked structures embedding airgaps as compared to the state of art technologies. Optical arrangements that can be produced by the described method in accordance with another aspect of the invention implement said improvement and provide essentially the same benefits as the described method. A head-mounted display, such as a smart ordata glasses, comprising such optical arrangement, for example, the one produced by the described method according to yet another aspect of the present invention, also implements the improvement and provides essentially the same benefits.

Claims

Claims1. Method of producing an optical arrangement (10), the optical arrangement (10) to be produced comprising a first optical component (12) and a second optical component (14) in stacked arrangement with an airgap region (16) between mutually facing surfaces (18, 20) of the first and second optical components (12, 14), the method comprising: providing the first and second optical components (12, 14); creating a dam-shaped barrier (22; 22, 28) in a peripheral region of a surface (18) of the first optical component (12) at least in part along a peripheral length of the first optical component (12); applying an adhesive (24) on the surface (18) of the first optical component (12) in the peripheral region outside the created barrier (22; 22, 28); joining the first and second optical components (12, 14) to each other in stacked arrangement by applying a joining force to the stacked arrangement such that the adhesive (24) and the barrier (22; 22, 28) get in contact with the mutually facing surfaces (18, 20) of the first and second optical components (12, 14); and curing the adhesive (24) to bond the first and second optical components (12, 14) to each other, wherein the airgap region (16) is arranged inside the barrier (22; 22, 28).

2. Method of claim 1 , wherein the barrier (22) is created in a closed loop configuration, or in an open loop configuration having at least one opening along the peripheral length of the barrier (22; 22, 28).

3. Method of claim 1 or 2, wherein the joining force corresponds to the force of gravity.

4. Method of any one of claims 1 to 3, wherein said barrier (22; 22, 28) is created to be compressible when, during said joining, the joining force is applied to the stacked arrangement of the first and second optical components (12, 14).

5. Method of any one of claims 1 to 4, wherein said creating the barrier (22; 22, 28) comprises applying a curable material on the surface (18) of the first optical component (12) and curing said material to form the barrier (22; 22, 28).

6. Method of any one of claims 1 to 5, wherein said barrier (22; 22, 28) is created from a same material as the adhesive (24) for bonding the first and second optical components (12, 14) to each other, or is created from a different material than the adhesive (24) for bonding the first and second optical components (12, 14) to each other, wherein the different material has a same or different viscosity as compared to the viscosity of the adhesive (24) for bonding the first and second optical components (12, 14) to each other, preferably the different material has a viscosity higher than the viscosity of the adhesive (24) for bonding the first and second optical components (12, 14) to each other.

7. Method of any one of claims 1 to 6, wherein the barrier (22; 22, 28) is created from two or more different materials, a first material of which is applied for forming a lower part of the barrier (22; 22, 28), and at least a second material of which is applied for forming an upper part of the barrier (22; 22, 28), the first and second materials having different viscosity or hardness at least after curing.

8. Method of claim 7, wherein the first material has after curing a viscosity or hardness higher or an elasticity lower than those of the second material.

9. Method of any one of claims 1 to 8, wherein the barrier (22; 22, 28) is a first barrier (22), and the method further comprises creating a second barrier (28) in the pe-ripheral region of the surface (18) of the first optical component (12) at least in part along a peripheral length of the first optical component (12), wherein said second barrier (28) is created outside the first barrier (22) and spaced apart from the first barrier (22), and applying the adhesive (24) in a space between the first and second barriers (22, 28).

10. Method of claim 9, wherein said second barrier (28) is created in a closed loop configuration, or in an open loop configuration having at least one opening (34) along the peripheral length of the first optical component (12).

11. Method of claim 9 or 10, wherein said second barrier (28) is created to be compressible when, during said joining, the joining force is applied to the stacked arrangement of the first and second optical components (12, 14).

12. Method of any one of claims 9 to 11 , wherein said second barrier (28) is created with a height from the surface (18) of the first optical component (12), which is larger than a height of the first barrier (22).

13. Method of any one of claims 9 to 12, wherein said second barrier (28) is created with an internal contour matching with an outer contour of the second optical component (14).

14. Method of any one of claims 9 to 13, further comprising removing said second barrier (28) after the adhesive (24) has been cured to bond the first and second optical components (12, 14) to each other.

15. Method of any one of claims 1 to 14, wherein the adhesive (24) and / or the barrier(22; 22, 28) comprises a material which is peelable, such as a peelable adhesive.

16. Method of any one of claims 1 to 15, wherein one of the first and second optical components (12, 14) is a waveguide, wherein a waveguiding region (52) of the waveguide extends from the airgap region (16) beyond the barrier (22; 22, 28),wherein the barrier (22; 22, 28) is created with an opening (53) in a region (50) of its overlap with the waveguiding region (52).

17. Method of claim 16, wherein the barrier (22; 22, 28) is created with curved edges (55) at the opening (53) to seal the waveguiding region (52) from the adhesive (24).

18. Method of claim 16 or 17, further comprising closing the opening (53) with an insert (54) comprising a material with a low refractive index or a high reflectivity as compared with those of the waveguiding region (52).

19. Method of any one of claims 1 to 15, wherein one of the first and second optical components (12, 14) is a waveguide, wherein a waveguiding region (52) of the waveguide extends from the airgap region (16) beyond the barrier (22; 22, 28), wherein the barrier (22; 22, 28)) is created in a region (50) of its overlap with the waveguiding region (52) at least at a bottom of the barrier (22; 22 28) with a material having a high reflectivity or a low refractive index as compared with those of the waveguiding region (52), or with an insert (54) comprising a material with a low refractive index or a high reflectivity as compared with those of the waveguiding region (52).

20. Method of any one of claims 1 to 19, further comprising, before creating the barrier (22; 22, 28), applying a mask (40) on the surface (18) of the first optical component (12), said mask (40) having one or more line-shaped openings (42, 44) defining the shape of the barrier (22; 22, 28) to be created, and applying a material into the one or more openings to create the barrier (22; 22, 28).

21. Optical arrangement, comprising a first optical component (12) and a second optical component (14) in a stacked arrangement with an airgap region (16) between mutually facing surfaces (18, 20) of the first and second optical components (12, 14), further comprising a dam-shaped barrier (22; 22, 28) in a peripheral region of the mutually facing surfaces (18, 20) of the first and second optical compo-nents (12, 14) at least in part along a peripheral length of the first and second optical components (12, 14), and a bonding region in the peripheral region outside the barrier (22; 22, 28) in which the first and second optical components (12, 14) are bonded to each other by an adhesive (24), the barrier (22; 22, 28) being in contact with the mutually facing surfaces (18, 20) of the first and second optical components (12, 14) and surrounding the airgap region (16).

22. Optical arrangement of claim 21 , wherein the barrier (22,22, 28) is formed from a curable material applied on the surface (18) of the first optical component (12) in a closed loop configuration, or in an open loop configuration having at least one opening along the peripheral length of the barrier (22; 22, 28).

23. Optical arrangement of claim 21 or 22, wherein one of the first and second optical components (12, 14) is a waveguide, wherein a waveguiding region (52) of the waveguide extends from the airgap region (16) beyond the barrier (22; 22, 28), wherein the barrier (22; 22, 28) comprises in a region (50) of its overlap with the waveguiding region (52) at least at a bottom of the barrier (22; 22 28) a material having a high reflectivity or a low refractive index as compared with those of the waveguiding region (52), or an opening (53) accommodating an insert (54) that comprises a material with a low refractive index or a high reflectivity as compared with those of the waveguiding region (52).

24. Optical arrangement of any one of claims 21 to 23, wherein the barrier (22; 22, 28) is a first barrier (22), and the optical arrangement further comprises a second barrier (28) in the peripheral region of the surface (18) of the first optical component (12) at least in part along a peripheral length of the first optical component (12), wherein said second barrier (28) is arranged outside the first barrier (22) and spaced apart from the first barrier (22), and the bonding region with the adhesive (24) corresponds to a space between the first and second barriers (22, 28).

25. Optical arrangement of claim 24, wherein the second barrier (28) has a closed loop configuration, or an open loop configuration having at least one opening (34) along the peripheral length of the first optical component (12).

26. Optical arrangement of claim 24 or 25, wherein the second barrier (28) has a height from the surface (18) of the first optical component (12), which is larger than the height of the first barrier (22), and / or has an internal contour matching with an outer contour of the second optical component (14).

27. A head-mounted display comprising an optical arrangement produced according to the method of any one of claims 1 to 20.

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