WO2024052536A1

WO2024052536A1 - Functionalised waveguide

Info

Publication number: WO2024052536A1
Application number: PCT/EP2023/074744
Authority: WO
Inventors: Viktor Schuetz; Petr Vojtisek; Yi ZHONG
Original assignee: Carl Zeiss Jena Gmbh
Priority date: 2022-09-08
Filing date: 2023-09-08
Publication date: 2024-03-14
Also published as: DE102022122789A1

Abstract

The invention relates to a functionalised waveguide, wherein the waveguide (1) has a transparent main body (6) with a front side (7) and a rear side (8), wherein the main body (6) has a coupling-in region (4) and a coupling-out region (5) spaced apart therefrom in a first direction (5), wherein the coupling-in region (4) comprises a diffractive structure (12) which deflects at least a portion of the radiation (L1), which comes from an object (9) and strikes said structure, in such a manner that the deflected portion is propagated as coupled-in radiation in the main body (6) through reflections up to the coupling-out region (5) and strikes the coupling-out region (5), wherein on the front side (7) and/or rear side (8) an anti-reflection layer (13, 14) is formed which transmits interference radiation, which would strike the diffractive structure (12) only after a reflection on the front side (7) and/or rear side (8), to the front side (7) and/or rear side (8) and thus suppresses the reflection on the front side (7) and/or rear side (8).

Description

Functionalized waveguide

The present invention relates to a functionalized waveguide that can be used, for example, in a detector system or a screen.

Transparent surfaces made of glass or plastic, such as windows or windshields in cars, have a transparent base body and generally only serve to protect people or objects from environmental influences such as wind, temperature, particles or radiation.

There is increasing interest in providing such a transparent base body that provides additional optical functionality.

It is therefore the object of the invention to provide a transparent base body with additional optical functionality.

The invention is defined in the independent claims. Advantageous embodiments are specified in the dependent claims.

In the functionalized waveguide according to the invention, an anti-reflection layer is formed on the front and/or back, which suppresses reflection of the interfering radiation on the front and/or back, in particular by transmitting the interfering radiation on the front and/or back. As a result, for example, undesirable ghost images (or double images) of the object or other undesirable effects of interference radiation can be prevented or at least significantly reduced by means of the functionalized waveguide. Preferably, 100% or at least 90% or more than 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% of the interference radiation is transmitted on the front and/or back , whereby the desired suppression of the reflection of the interference radiation on the front and/or back is achieved.

A (eg partially transparent) coupling region and a coupling region spaced therefrom in a first direction can be provided or formed in the transparent base body. The coupling-in area can have a diffractive structure, with which the transparency of the coupling-in area is maintained under normal viewing over a large angle and wavelength range. Only part of the radiation striking a front side of the transparent base body can be redirected by means of the transparent coupling-in area in such a way that the deflected part propagates as coupled-in radiation in the base body through reflection up to the coupling-out area and hits the coupling-out area.

The reflections can in particular be total internal reflections on the front and/or back of the transparent base body. However, it is also possible for reflective layers or coatings or partially reflective layers or coatings to be provided for this purpose.

The front and back of the transparent base body can be designed as flat surfaces. For example, the transparent base body can be designed as a plane-parallel plate.

However, it is also possible for the front and/or the back to be curved.

The transparent base body can be made of glass and/or plastic. It can be in one piece or have a multi-layer structure.

In particular, the transparent base body can be transparent to radiation or light from the visible wavelength range. Furthermore, there may be transparency for the near infrared and/or the infrared range.

The decoupling region of the transparent base body can deflect at least part of the coupled-in radiation striking it in such a way that the deflected part emerges from the base body. This is preferably done via the front or back of the transparent base body.

The coupling-in area and the coupling-out area can be designed in such a way that, in addition to the deflection, they do not produce an optical imaging function. However, it is also possible for the coupling-in area and/or the coupling-out area to provide an optical imaging function in addition to the deflection and thus bring about an optical imaging. For example, the optical imaging function can realize the function of a converging lens or diverging lens, a concave or convex mirror, the curved surfaces (centered or decentered) can be spherically curved, aspherically curved surfaces or free-form surfaces.

The diffractive structure of the coupling region can be implemented as a buried diffractive structure, as a diffractive structure between two substrates or as a diffractive structure formed on the front or back.

Furthermore, the decoupling area can have a diffractive structure. The diffractive structure of the decoupling area can be designed as a buried diffractive structure or as a diffractive structure on the front or back.

A reflective or transmissive volume hologram can be provided as the diffractive structure of the coupling-in area or the coupling-out area. Furthermore, it is possible for the diffractive structure of the coupling-out or coupling-in area to be a transmissive or reflective relief grating.

If the coupling region is designed as a (reflective or transmissive) relief grating, it is preferred not to form the anti-reflection layer directly on the relief grating. For example, the relief grid can be formed on the front of the transparent base body and the anti-reflection layer on the back of the transparent base body (or vice versa).

If the coupling region is designed as a (reflective or transmissive) volume hologram, the anti-reflection layer can be formed directly on the volume hologram. In particular, the volume hologram can be designed as a stack of several individual volume holograms, with each individual volume hologram being optimized for a predetermined wavelength. For example, three individual volume holograms can be optimized for wavelengths from the red, green or blue wavelength range. When the volume hologram is formed as a stack of several individual volume holograms, the anti-reflection layer is preferably formed as the first or last layer of such a stack.

The anti-reflection layer can preferably be designed so that it is transmissive (preferably only) for the predetermined wavelengths for which the diffractive structure (eg the volume hologram) of the coupling region is designed. The anti-reflection layer can thus have a transmissivity that is designed for the acceptance characteristic of the diffractive structure of the coupling region (or the volume hologram(s). The acceptance characteristic is understood here in particular to mean that for certain directions or angles of incidence there are certain wavelength spectra that are diffracted by the diffractive structure. In other words, the acceptance characteristic here means in particular that the diffractive structure in Depending on the angle of incidence, only certain wavelength spectra or only radiation with certain wavelengths diffracts.

Furthermore, it is possible for the anti-reflection layer to be designed as a broadband anti-reflection layer which is (preferably only) transmissive in the entire predetermined angle of incidence range for all wavelengths used.

The anti-reflection layer can be formed as a single layer or as a multi-layer system (for example as a multi-layer system, as an interference layer system and/or as a moth-eye anti-reflection layer).

The anti-reflection layer can be designed for an angle of incidence range of, for example, 80°-100°.

The anti-reflection layer can in particular be designed in such a way that it does not influence the radiation coupled into the base body from the diffractive structure of the coupling-in region in such a way that it does not propagate through reflections to the coupling-out region. One can also say that the optical properties, the dimensions and/or positioning of the anti-reflection layer are selected such that the radiation coupled into the base body from the diffractive structure of the coupling-in region can propagate through reflections to the coupling-out region.

For example, the dimensions and/or positioning of the anti-reflection layer can be selected so that the coupled-in radiation does not hit the anti-reflection layer. This can be easily achieved, for example, in the case in which the anti-reflection layer is formed on the back of the base body and the diffractive structure of the coupling region is formed on the front of the base body. Furthermore, this can be easily implemented, for example, in the case in which the anti-reflection layer is formed on the front of the base body and the diffractive structure of the coupling region is formed on the back of the base body. In this case, it is advantageous, for example, if the dimension of the diffractive structure of the coupling region in the first direction is in the range of 5-15 mm or 5-10 mm. The dimension of the anti-reflection layer in the first direction can preferably be equal to or smaller than the dimension of the diffractive structure of the coupling region in the first direction.

Furthermore, it is advantageous if the dimension of the diffractive structure of the coupling-in region in the first direction is selected so that the radiation coupled into the base body from the diffractive structure of the coupling-in region does not strike the diffractive structure of the coupling-in region again after a first reflection in the base body. This can be done, for example, by a suitable choice of the dimension of the diffractive structure of the coupling area in the first direction can be achieved. Advantageous values are, for example, in the range of 5-15 mm or 5-10 mm.

The diffractive structure of the coupling region can be designed so that only the radiation coming from the object, which hits the diffractive structure at an angle from a predetermined angle of incidence range, is diffracted by the diffractive structure and thereby redirected, the optical properties of the anti-reflection layer (s) are chosen so that the anti-reflection layer(s) transmit/transmit radiation that strikes the anti-reflection layer(s) at an angle that lies in the predetermined angle of incidence range.

One can also say that the predetermined angle of incidence range defines a field of view. The anti-reflection layer(s) is/are preferably designed so that they are transmissive for at least this field of view.

The predetermined angle of incidence range can be rotationally symmetrical.

Alternatively, the predetermined angle of incidence range may not be rotationally symmetrical. The predetermined angle of incidence range in a first plane (x-z plane), which is spanned by a perpendicular to the diffractive structure and a perpendicular to both the first direction and the perpendicular to the diffractive structure, can be larger than in a second plane (y-z plane), which is spanned by the perpendicular to the diffractive structure (12) and the first direction.

The ratio is preferably not greater than 2:1 or not greater than 3:2.

The predetermined angle of incidence range can, for example, be in the range from 40° to 120° and in particular be 40°, 50°, 60°, 70°, 80°, 90°, 100°, 1 10° or 120°. In particular, the predetermined angle of incidence range can be symmetrical to the perpendicular to the diffractive structure. Thus, the predetermined angle of incidence range can be, for example, any range from +/- 20° to +/- 60° and in particular a range from -20° to 20°, -25° to 25°, -30° to 30°, -35 ° to 35°, -40° to 40°, -45° to 55°, -50° to 50°, -55° to 55° or from -60° to 60°.

The anti-reflection layer or the anti-reflection layers can be implemented in a wide variety of variants. On the one hand, the anti-reflection layer can be formed or consist in the simplest form of a single layer, for example of MgFz (for example on spectacle lenses), and in more complex versions of several 10 to 100 layers, for example as in high-performance anti-reflection coatings on optics in ultra-short-pulsed lasers . Example materials are TiO ₂ and SiO ₂ . The anti-reflection layer can be made planar and/or can also be implemented on additionally structured surfaces. Examples of this include so-called moth-eye structures and/or pyramidal surfaces, such as those realized on monocrystalline silicon solar cells. Typically, adapted anti-reflection layers can be designed and optimized using software solutions known to those skilled in the art.

The anti-reflection layer preferably completely covers the diffractive structure of the coupling region. For this purpose, the anti-reflection layer can have the same size as the diffractive structure or be larger (for example 5-10% larger).

The decoupling area can also have a mirror surface, a prism and/or a reflective or transmissive Fresnel structure. These variants can be provided as an alternative to the diffractive structure or in addition to the diffractive structure of the output region.

Furthermore, a detector system with a functionalized waveguide according to the invention (including all further developments) is provided. The detector system can have a detector onto which the part of the radiation deflected by the decoupling area hits. The detector can be connected to the front or back of the base body. In particular, there may be a direct connection.

The detector system can in particular be designed as a camera, so that a recording (e.g. a single image, several images or a video) of the object can be carried out.

Furthermore, the detector system can be designed such that at least one optically imaging element is arranged in the area between the detector and the front or back. It is also possible for the area between the detector and the front or back to be free of imaging optical elements. In other words, the radiation coupled out from the decoupling area hits the detector without having passed through further optically imaging elements. In this case, it is advantageous if the decoupling area has an optical imaging property in addition to the deflection.

The functionalized waveguide can be designed to perform infinite-infinity imaging. However, it is also possible for it to perform a finite-infinity mapping, an infinite-finite mapping or a finite-finite mapping.

The detector system can of course also be designed in such a way that at least one optically imaging element is arranged between the detector and the front or back. Furthermore, a projection system or a screen with a functionalized waveguide according to the invention (including all further developments) is provided. In particular, the functionalized waveguide according to the invention can, for example, be arranged with the back of the transparent base body on a front side of a screen (e.g. connected to it), so that light to be emitted from the screen via its front side enters the back of the base body via the back of the base body in order to display a predetermined image, runs up to the front of the base body and exits over the front of the base body. For example, the part of the light from the screen that hits the anti-reflection layer is transmitted through the anti-reflection layer, which can prevent unwanted stray light.

The system formed in this way from waveguide and screen can be designed, for example, as a stand-alone screen (e.g. a screen for a computer), as a laptop screen, as a mobile phone, as a tablet, etc.

The screen can be developed in such a way that the detector system described (in particular with the camera functionality described) is provided. This allows the object (e.g. a person looking at the screen) to be recorded. This can be realized, for example, by recording a person looking at the screen looking into the eyes of the person shown on the screen with whom the video call is being carried out, for example during a video call (or video conference), so that a natural Impression created during video telephony. It is essential for this that the recording direction of the camera is, for example, perpendicular to the front of the screen, which is possible with the screen according to the invention due to the functionalized waveguide. This is advantageous compared to known solutions in which the camera is arranged on the edge of the screen or in the screen frame, whereby a person looking at the screen is recorded at an angle from above, below or from the side. This creates the well-known effect that the person being recorded appears to look past you.

In the area of the decoupling area or section, the screen can, for example, have no LCD elements (or other image-generating elements) or is, for example, transparent. In particular, the decoupling area or section can be in an area in which no image information is generated by the screen. It is also possible that no part of the screen is formed in the area of the output area or section.

This makes it possible, for example, to ensure that the part of the coupled-in radiation that is deflected by the decoupling area hits the detector. It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or alone, without departing from the scope of the present invention.

The invention will be explained in more detail below using exemplary embodiments with reference to the accompanying drawings, which also reveal features essential to the invention. These embodiments are for illustrative purposes only and are not to be construed as limiting. For example, a description of an embodiment including a plurality of elements or components should not be construed to mean that all of these elements or components are necessary for implementation. Rather, other embodiments may also contain alternative elements and components, fewer elements or components, or additional elements or components. Elements or components of different embodiments may be combined with one another unless otherwise specified. Modifications and variations described for one of the embodiments may also be applicable to other embodiments. To avoid repetition, the same or corresponding elements in different figures are designated with the same reference numerals and are not explained more than once. Of the figures show:

1 is a side view of an embodiment of a detector system according to the invention;

FIG. 2 is a top view of the waveguide 1 from FIG. 1;

3 shows a schematic representation of the spectrally resolved, angle-dependent deflection efficiency of the transmissive volume hologram of the coupling region 4;

4 shows a schematic representation of the deflection efficiency for three different angles of incidence depending on the wavelength;

5 shows a side view of a detector system with a waveguide without an anti-reflection layer;

Fig. 6 is a schematic enlarged representation of the coupling area of the side view of Fig. 5;

7 shows a side view of a further embodiment of the detector system according to the invention;

8 is a side view of a detector system with a waveguide without an anti-reflection layer;

9 shows a side view of a further embodiment of the detector system according to the invention, and Fig. 10 is a side view of a further embodiment of the detector system according to the invention.

The views according to FIGS. 1 and 2 show an embodiment of the waveguide 1 according to the invention together with a detector system 2 in order to realize a camera 3.

For this purpose, the waveguide 1 comprises a coupling-in region 4 and a coupling-out region 5 spaced therefrom in a first direction (here along the y-axis) and can be designed as a plane-parallel plate 6 with a flat front side 7 and a flat back side 8. The plane-parallel plate 6, which can also be referred to as the base body 6, is formed from a transparent material, such as glass or plastic.

The detector system 2 and the lower part of the plate 6 with the decoupling area 5 can be arranged in a housing G, which is only shown schematically in FIG. 1, so that it is not obvious to a user at first glance that it is a camera 3 . A control unit S can be provided in the housing, which can control the execution of a recording and, for example, has a processor P and a memory M.

With the camera 3, an object 9 can be imaged in such a way that light beams emanating from the object 9 (a light beam L1 is shown as a representative) enter the plate 6 via the front 7 and are redirected by the coupling area 4 in such a way that they hit the back 8 at such an angle that total internal reflection takes place. Thus, the light bundles L1 are guided by internal total reflection on the front 7 and back 8 to the decoupling area 5, which causes a deflection towards the back 8, so that the light bundles L1 emerge from the plate 6 via the back 8. Of course, it is also possible to coat the front and back sides 7, 8 with a reflective or partially reflective coating (not shown in FIGS. 1 and 2), so that the guidance of the light bundles in the plate 6 from the input to the output area 4, 5 occurs through reflections on the reflective or partially reflective coating.

Using a lens 10 of the detector system 2, the light bundles L1 are then focused onto a detector 11 of the detector system 2, so that the desired image of the object 9 can be recorded using the detector 11. In Fig. 1, the representation of the imaging properties of the lens 10 is purely schematic. The detector system 2 can also be designed so that no lens 10 is required. It is possible, for example, for the decoupling area 5 to provide a desired imaging function (in addition to beam deflection). The coupling region 4 can, for example, have a transmissive volume hologram 12, which has a wavelength selectivity that is dependent on the angle of incidence, so that it has a high level of transparency over a large angle and wavelength range. This means that only a portion of the light beams L1 emanating from the object 9 and striking the coupling region 4 (or the transmissive volume hologram 12) are redirected in the manner described. Other light bundles from the object 9 propagate through the coupling area 4 (or through the transmissive volume hologram 12) and emerge from the plate 6 via the back 8. The coupling area 4 can therefore be described as partially transparent.

3 shows schematically the spectrally resolved, angle-dependent deflection efficiency for the transmissive volume hologram 12 of the coupling region 4 as a function of the angle of incidence (in the y-z plane) of the corresponding light bundle, with the wavelength in pm along the x-axis and the wavelength along the y -Axis the angle of incidence is plotted in °. 4 shows the deflection efficiency for the angles of incidence + 20°, 0° and - 20°, with the wavelength in nm plotted along the x-axis and the efficiency plotted along the y-axis.

From Fig. 3 and 4 it can be seen that the transmissive volume hologram 12 of the coupling area 4 deflects radiation from the spectral range from 392 nm to 398 nm (Azentrai = 395 nm ± 3 nm) with high efficiency for an angle of incidence of -20 ° and thus coupled into the plane-parallel plate 6. For an angle of incidence of 0° there is a high efficiency for the spectral range from 528 nm to 536 nm (Azentrai = 532 nm ± 4 nm) and for an angle of incidence of +20° there is a high coupling efficiency for the spectral range from 600 nm to 610 nm ( Azentrai = 605 nm ± 5 nm).

The coupling area 4 additionally has an anti-reflection layer 13 (FIGS. 1 and 2), which is designed in such a way that it emits light beams (a light beam L2 is shown as a representative), which come from the object 9, for example, and lead to an undesirable ghost image on the detector 11 would be transmitted, so that they emerge from the plate 6 via the back 8 and therefore cannot hit the detector 11. Without the anti-reflection layer 13, part of the light bundles L2 would be reflected back towards the front side 7 at the back side 8 - air interface, as shown schematically in FIG. 5. To simplify the illustration, the back-reflected part of the light bundle is shown offset in the y-direction in FIG.

From this back-reflected part of the light bundle L2, which hits the volume hologram 12 during the formation of the waveguide in FIG. 5, a certain proportion is reflected at the air-front interface 7 and redirected by the volume hologram 12, as shown schematically in FIG . This deflected part of the light bundle L2 is then in the same way how the deflected part of the light bundle L1 is guided to the decoupling section 5 and decoupled, so that an undesirable ghost image is generated.

6 shows, schematically enlarged, how the undesired ghost image can occur for an object 9'. Light rays L2i and L2z pass through the volume hologram 12 (without being deflected), are reflected at the air-back interface 8 (a first virtual image 9h is generated by the reflection at the air-back interface 8), and pass through the volume hologram 12 again , are reflected at the air-front interface 7 (a second virtual image 9'2 is generated by the reflection at the air-front interface 7) and are then deflected by the volume hologram 12 so that they are in the plate 6 to the decoupling area 5 be guided. These light rays L2i and L2z thus generate a second virtual image 9'2, which appears as a ghost image offset from the object 9' by twice the distance d from the front 7 to the back 8.

By providing the anti-reflection layer 13 according to Figures 1 and 2, such an undesirable ghost image is greatly reduced, since the light rays L2, L2i and L22 are transmitted by means of the anti-reflection layer 13 (FIG. 1) and are therefore no longer reflected at the air-back interface 8 .

7 shows a modification of the embodiment according to FIGS. 1 and 2. In the embodiment of FIG. 7, an anti-reflection layer 14 is formed on the front side 7 in front of the volume hologram 12. This prevents unwanted ghost images that can come from light beams (a light beam L3 is shown as a representative) that enter the plate 6 via the back 8 and run through the volume hologram 12. A part of these light bundles would then be reflected at the front surface 7 - air (as shown schematically in FIG. 8) and in turn hit the volume hologram 12, which would redirect part of it in the manner shown in FIG. 8, whereby this Light in the plate 6 would be guided to the coupling-out section 5 and would be coupled out by means of the coupling-out section 5 and would lead to the undesirable ghost image. However, due to the anti-reflection layer 14 on the front 7, the light bundles L3 are transmitted (FIG. 7), so that such ghost images can be prevented.

In the embodiment of the waveguide 2 according to the invention shown in FIG. 9, this is applied to a screen 20 which sits in a housing 21 in which the detector system 2 is also accommodated. The system formed in this way can be designed, for example, as a stand-alone screen (eg a screen for a computer), a laptop screen, a mobile phone, a tablet, etc. The representation in Fig. 9 is purely schematic and in particular not true to scale. The back side 8 of the base body 6 is connected (for example glued) to a front side 22 of the screen 20, so that the light (L3, L4) emitted by the screen 20 via its front side 22 is transmitted through the back side 8 to produce a predetermined image on the screen 20 enters the transparent base body 6, runs in this to the front 7 and exits via the front 7, so that a viewer can perceive the image generated by the screen 20. This light L3, L4 emitted by the screen 20 could, for example, lead to undesirable stray light in the area of the coupling-in area 4. However, since the anti-reflection layer 14 is provided, any light rays L3 that may lead to stray light are transmitted and thus emerge from the base body 6 via the front side 7. Thus, the light emitted by the screen 20 does not lead to any undesirable stray light and there is no undesirable reduced brightness in the image generated by the screen 20 in the area of the coupling area 4.

In the area of the decoupling section 5, the screen 20 has, for example, no LCD elements or is, for example, transparent, so that the light bundles L1 deflected by the decoupling section 5 can be focused by the lens 10 onto the detector 11. The decoupling section 5 can thus be located in an area in which no image information is generated by the screen 20 (it should be noted that the representation in FIG. 9 is schematic and not true to scale).

10 shows a modification of the embodiment according to FIGS. 1 and 2, in which an anti-reflection layer 14 according to FIG. 4 is provided in addition to the anti-reflection layer 13, so that suppression of undesirable ghost images due to light bundles L2 and L3 can be prevented.

The light bundles L2, L3 shown in FIGS. 1, 2, 7, 9 and 10 each strike the front side 7 and back side 8 perpendicularly. Of course, the anti-reflection layers 13, 14 can be designed for a predetermined angle of incidence range of the light bundles L2, L3. This predetermined angle of incidence range can be, for example, 80°-100°. In particular, under the angle of incidence, the angle of the light beam L2 becomes the plumb line to the front (i.e. 0° in Fig. 1) or the angle of the light beam L3 becomes the plumb line to the back (i.e. 0° in Fig. 7) in the respective yz level (hereinafter also referred to as the second level). The angle of incidence range in the xz plane (hereinafter also referred to as the first plane) can be the same size (then there is a rotationally symmetrical angle of incidence range) or larger than the angle of incidence range in the yz plane, with a ratio of not greater than 2:1 or 3:2 can be present. The predetermined angle of incidence range is preferably symmetrical to the respective perpendicular, so that with a predetermined angle of incidence range of, for example, 80°, the range from -40° to 40° is covered. The waveguide 1 according to FIGS. 1, 2, 7, 9 and 10 can be designed such that neither the coupling-in region 4 nor the coupling-out region 5 has an imaging function. In this case, the waveguide 1 has an infinite-infinity configuration. One can also say that the waveguide 1 performs an infinite-infinity mapping. The detector 11 can be, for example, a CCD detector or a CMOS detector.

Since the coupling region 4 has the transmissive volume hologram 12, the coupling by means of the transmissive volume hologram 12 leads to a dispersion within the coupled spectral range for every angle. If the coupling-out area 5 has a transmissive volume hologram designed in the same way as the coupling-in area 4, the dispersion caused by the coupling-in area 4 is compensated for and all spectral components are deflected again into the corresponding angle.

As an alternative to the described infinite-infinity configuration of the waveguide 1, the coupling-in region 4 and/or the coupling-out region 5 can, for example, have an imaging function in the form of a lens function or concave mirror function. As a result, finite-infinity, infinite-finite or finite-finite imaging configurations can be realized using the waveguide 1. In the coupling area 4, this can be used, for example, to record an object 9 that is positioned so close to the waveguide 1 that it can no longer be optically assumed to be an infinitely distant object. In the decoupling region 5, an implementation of such a lens or concave mirror function makes it possible to convert the decoupled angular spectrum into a spatial distribution in the focal plane of this implemented lens or mirror function. In this case, the lens 10 can be omitted, for example. In this case one can say that the detector system 2 has the detector 11 as well as the lens and/or concave mirror function of the decoupling area 5. Since the lens 10 can be omitted, the detector 11 can be positioned and/or attached, for example, directly on the back 8 of the waveguide 1, whereby a very high degree of integration, a minimal volume and a high level of robustness can be achieved.

The described reflective volume holograms for the coupling-in region 4 and the coupling-out region 5 can, for example, be produced in such a way that a photosensitive volume holographic material 12, which is integrated into the waveguide 1, is exposed to a reference wave with a wavelength of 532 nm, which is at an angle of incidence of 0 ° incident on the front side 7 and exposed to a signal wave with the same wavelength, which is incident on the back side 8 at an angle of incidence of 60°, the reference wave and the signal wave coming from the same Lasers come from so that an interference field or interference volume is created via the photosensitive volume holographic material and corresponding refractive index modifications can form there. Photosensitive glasses, dichromate gelatins or photopolymers can be used as photosensitive volume holographic materials. These can, for example, be applied to a PC film (polycarbonate film) and exposed accordingly. The film can then be laminated onto a substrate for the waveguide 1 to produce the waveguide 1. The film can, for example, only be laminated in the area of the coupling-in area 4 and the coupling-out area 5. Alternatively, full-surface lamination over the entire waveguide surface is possible, with the corresponding coupling-in and coupling-out functions simply being exposed in the coupling-in and coupling-out areas. To protect the volume holograms, it makes sense to apply another substrate to the laminated volume hologram. A layer stack with the following basic structure is thus realized: transparent substrate, putty or adhesive layer, volume hologram, putty or adhesive layer, transparent substrate.

Claims

Claims Functionalized waveguide, wherein the waveguide (1) has a transparent base body (6) with a front (7) and a back (8), the base body (6) having a coupling-in region (4) and a coupling-out region spaced therefrom in a first direction (5), wherein the coupling region (4) comprises a diffractive structure (12) which deflects at least a part of the radiation (L1) coming from an object (9) and striking it in such a way that the deflected part appears as coupled radiation in the base body (6) propagated by reflections to the decoupling area (5) and hits the decoupling area (5), which deflects at least part of the coupled-in radiation hitting it in such a way that the deflected part emerges from the base body (6), whereby at the An anti-reflection layer (13, 14) is formed on the front (7) and/or back (8), the interference radiation which only hits the diffractive structure (12) after a reflection on the front (7) and/or back (8). would be transmitted on the front (7) and/or back (8) and thus the reflection on the front (7) and/or back (8) is suppressed. Waveguide according to claim 1, wherein a first anti-reflection layer (13, 14) is formed on the front side (7). Waveguide according to claim 1 or 2, wherein a second anti-reflection layer (13, 14) is formed on the back side (8). Waveguide according to one of the above claims, wherein the anti-reflection layer (s) (13, 14) completely covers the diffractive structure (12). Waveguide according to one of the above claims, wherein the first anti-reflection layer (13, 14) and / or the second anti-reflection layer (13, 14) are designed to transmit the radiation (L1) coming from the object (9) to be detected. 6. Waveguide according to one of the above claims, wherein the diffractive structure (12) is designed as a transmissive or reflective volume hologram.

7. Waveguide according to one of the above claims, wherein the optical properties, the dimensions and / or positioning of the anti-reflection layer (s) (13, 14) are selected such that the diffractive structure (12) of the coupling region ( 4) radiation coupled into the base body (6) can propagate through reflections to the decoupling area (5).

8. Waveguide according to one of the above claims, wherein the dimension of the diffractive structure of the coupling region in the first direction is selected such that the radiation coupled into the base body (6) from the diffractive structure (12) of the coupling region (4) after a first Reflection in the base body (6) does not hit the diffractive structure (12) of the coupling area (4) again.

9. Waveguide according to one of the above claims, wherein the diffractive structure (12) of the coupling region (4) is designed so that only the radiation coming from the object (9) which is at an angle from a predetermined incidence angle range onto the diffractive structure (12 ) hits, is deflected by the diffractive structure (12), the optical properties of the anti-reflection layer (s) (13, 14) being selected so that the anti-reflection layer (s) (13, 14) transmit/transmit radiation which is below a Angle hits the anti-reflection layer (s) (13, 14), which is in the predetermined angle of incidence range.

10. Waveguide according to claim 9, wherein the predetermined angle of incidence range is rotationally symmetrical.

11. Waveguide according to claim 9, wherein the predetermined angle of incidence range is in a first plane (xz plane), which is spanned by a perpendicular to the diffractive structure (12) and a perpendicular to both the first direction and to the perpendicular to the diffractive structure, is larger than in a second plane (yz plane), which is spanned by the perpendicular to the diffractive structure (12) and the first direction, with preferably a ratio of not greater than 2:1 or 3:2. Waveguide according to one of the above claims, wherein the anti-reflection layer (s) is/are designed such that it is/are transmissive for the predetermined wavelengths for the diffractive structure (12) of the coupling region (4). Waveguide according to one of the above claims, wherein the anti-reflection layer(s) is/are designed such that they have/have a transmissivity designed for the acceptance characteristic of the diffractive structure (12) of the coupling region (4). Waveguide according to one of claims 1 to 11, wherein the anti-reflection layer (s) is / are designed so that it is / are transmissive for all wavelengths used in the entire predetermined angle of incidence range of the diffractive structure (12) of the coupling region (4). Detector system with a functionalized waveguide (1) according to one of the above claims. Detector system according to claim 15, wherein the detector system has a detector (2) onto which the part of the radiation deflected by the decoupling region (5) hits. Detector system according to claim 15 or 16, wherein the detector system has a screen (20) with a front side (22) which can emit light (L3, L4) over the front side (22) to display an image, the base body (6) also its back (8) is attached to the front (22) of the screen, so that the light (L3, L4) coming from the screen (20) runs through the base body (6) and over the front (7) of the base body (6). emerges, whereby the part (L3) of the light (L3, L4) coming from the screen (20) that hits the anti-reflection layer (13, 14) is transmitted by it.