Color-mixing laser module device, RGB laser module, and smart glasses

Abstract

The invention relates to a color-mixing laser module device (72a-d), in particular for use in smart glasses (10a-d), comprising a layer structure (22a-d) which is designed at least for an at least partly spatially separated internal guiding of at least one first laser signal (12a-d) having a first light color and at least one second laser signal (14a-d) having a second light color which substantially differs from the first light color, preferably a red laser signal (16a-d), a green laser signal (18a-d), and a blue laser signal (20a-d), said layer structure having a first layer (24a-d) with a respective spatially separated coupling region (26a-d, 28a-d, 30a-d) for the first laser signal (12a-d) and for the second laser signal (14a-d), preferably for the red laser signal (16a-d), for the green laser signal (18a-d), and for the blue laser signal (20a-d), and a second layer (32a-d) with at least one common color-mixing decoupling region (34a-d) for the first laser signal (12a-d) and the second laser signal (14a-d), preferably the red laser signal (16a-d), the green laser signal (18a-d), and the blue laser signal (20a-d).

Description

[0001] Description

[0002] Color-mixing laser module device, RGB laser module and data glasses

[0003] State of the art

[0004] Laser modules, for example as light sources in smart glasses, typically consist of three or more laser diodes, associated collimating lenses, a dichroic mirror, and a pair of optical (anamorphic) prisms. Each laser diode emits a beam of visible light with an elliptical cross-section in the colors red, green, and blue. The collimating lenses limit the extent of these light beams. The limited light beams are then combined by the dichroic mirror and, with the prism pair or a pair of cylindrical lenses, transformed into a common, circular beam profile. The resulting circular beam, especially one consisting of all three RGB colors, typically has a diameter on the order of several hundred micrometers. Using one or more micromirrors, an image can be generated from this beam by scanning.The specific coloring of individual pixels in the image is achieved through the temporal modulation of the individual laser diodes.

[0005] Laser modules of this type are highly efficient, but require considerable effort in adjusting all optical components. Additionally, the required micro-optics significantly determine the module's size and weight, making integration into everyday eyeglass models difficult.

[0006] Disclosure of the invention: A color-mixing laser module device, particularly for use in data glasses, is disclosed, comprising a layer structure configured for at least a spatially separated internal routing of at least one first laser signal with a first light color and at least one second laser signal with a second light color substantially different from the first light color, preferably a red laser signal, a green laser signal, and a blue laser signal, which has a first layer with a spatially separated coupling area for each of the first laser signal and the second laser signal, preferably for the red laser signal, the green laser signal, and the blue laser signal, and which has a second layer with at least one common color-mixing output coupling area for the first laser signal and the second laser signal, preferably the red laser signal.The green and blue laser signals are combined, and this is proposed. This allows for advantageous design properties. Minimization of laser modules can be advantageously achieved, thereby reducing installation space and / or weight. This can advantageously improve suitability for smart glasses. Furthermore, the adjustment of optical components of the laser module can be advantageously simplified or at least partially eliminated. Chromatic aberrations can also be advantageously kept low.

[0007] The color-mixing laser module device is designed, in particular, for mixing laser signals from several, preferably at least three, differently colored laser sources. In particular, the color-mixing laser module device is configured as an RGB color-mixing laser module device. The layer structure is, in particular, plate-like. The layer structure is, in particular, configured as a stacking of planar layers. Preferably, the extent of the layer structure in both directions perpendicular to a stacking direction of the layer structure is significantly greater than in the direction of the stacking direction. In particular, "significantly greater" is understood to mean at least twice as large, preferably at least three times as large, preferably at least five times as large, and most preferably at least ten times as large. In particular, the layer structure is designed to be rigid. In particular, the layer structure is configured differently from a film.Each coupling region is preferably designed to couple a laser beam from a different light source. Preferably, the first layer has at least three coupling regions for laser beams of different colors. At least two of the coupling regions are arranged on different sides of the first layer, preferably sides that are at least substantially perpendicular to each other or at least substantially opposite each other. In particular, the coupling regions are arranged in a side region of the first layer. Specifically, the coupling regions are arranged on sides of the first layer that are non-parallel to each other, preferably at least substantially perpendicular to a principal plane of extension of the layer structure.The term "essentially perpendicular" here is intended to define, in particular, an orientation of a direction relative to a reference direction, wherein the direction and the reference direction, especially when viewed in a projection plane, enclose an angle of 90° and the angle has a maximum deviation of, in particular, less than 8°, advantageously less than 5°, and most advantageously less than 2°. A "principal extension plane" of a building unit is understood to be, in particular, a plane that is parallel to a largest side face of a smallest imaginary cuboid that just completely encloses the building unit, and in particular passes through the center of the cuboid.

[0008] In particular, the coupling regions are non-overlapping. Specifically, the first layer completely overlaps the second layer and / or vice versa. In particular, the second layer, preferably the entire layer structure, has only a single common color-mixing output coupling region. Specifically, all laser signals coupled into the first layer (apart from scattered light) exit the layer structure via the common color-mixing output coupling region(s) of the second layer. Specifically, the light colors red, green, and blue are mixed in the output coupling region. Specifically, each of the laser signals has a different primary color, e.g., red, green, blue, or yellow. Preferably, the different light colors of the laser signals are additive primary colors, e.g., red, green, and blue. Alternatively, however, it is also conceivable that the light colors are subtractive primary colors, e.g.,Cyan, magenta, and yellow, or other miscible colors. In particular, the color-mixing laser module device is designed to generate white light from laser signals of single-color light sources by color mixing in at least one operating state. In particular, "white" or white light is not a color of light within the meaning of the invention, especially not the first color of light and not the second color of light. In particular, the color-mixing laser module device is designed as a white-light-generating laser module device. In particular, the color-mixing laser module device is designed as a white-light-generating laser module device by color mixing several colors of light. In particular, the wavelength of the red laser signal for which the layer structure is optimized is in a range between 630 nm and 650 nm. Preferably, the wavelength of the red laser signal for which the layer structure is optimized is approximately 638 nm.In particular, the wavelength of the green laser signal for which the layer structure is optimized lies in a range between 530 nm and 550 nm. Preferably, the wavelength of the green laser signal for which the layer structure is optimized is approximately 532 nm. In particular, the wavelength of the blue laser signal for which the layer structure is optimized lies in a range between 440 nm and 460 nm. Preferably, the wavelength of the blue laser signal for which the layer structure is optimized is approximately 455 nm.

[0009] Furthermore, it is proposed that the first layer be formed by an integrated photonic integrated circuit (PIC) / integrated optics. This allows for advantageous design properties. Advantageously, miniaturization of laser modules, particularly with regard to weight and volume, can be achieved. Advantageously, simple and mass-producible manufacturing is enabled. In particular, the integrated photonic circuit replaces the functions of the dichroic mirror and the prism pair of the laser module described above, which is known from the prior art.

[0010] Furthermore, it is proposed that spatially separated waveguides for the first laser signal and for the second laser signal, preferably for the red laser signal, the green laser signal, and the blue laser signal, are integrated into the first layer. This advantageously allows for optimized merging of the laser signals, particularly the primary-colored laser signals. Preferably, aberrations, e.g., due to material transitions / refractive index transitions, are avoided as far as possible. In particular, the integrated photonic circuit / integrated optics form a waveguide chip with the multiple waveguides. The first layer, especially the waveguide chip, can be transparent in the stacking direction of the layer structure (e.g., made of SiO2).Alternatively, the first layer, in particular the waveguide chip, can also be made of a material that is at least partially opaque, for example, a material with a silicon substrate. In particular, the waveguides do not intersect. In particular, the waveguides do not overlap. In particular, the waveguides do not touch. In particular, the waveguides run separately from each other. In particular, at least two of the waveguides of the first layer run non-parallel to each other.

[0011] In this context, it is further proposed that each waveguide in the first layer has at least one separate coupler, in particular a separate coupler structure, which is configured to couple light guided in the respective waveguide from the first layer towards the second layer. This advantageously allows for optimized merging of the laser signals, especially the primary-colored laser signals. It also advantageously enables miniaturization of laser modules, particularly with regard to weight and volume. Specifically, the coupler couples the light out of the first layer in the stacking direction. The couplers are arranged away from an edge region of the first layer, in particular the layer structure, and away from the second layer, in particular an edge region of the layer structure.In particular, the couplers are integrated into the interior of the first layer. Specifically, the couplers extend over a planar area that runs at least substantially parallel to the main plane of extension of the layer structure.

[0012] If each of the couplers includes a grating coupling structure, particularly one adapted to the respective light color, efficient and / or structurally simple coupling can be advantageously achieved. When using a grating coupling structure, polishing the waveguides is advantageously unnecessary. Each coupler preferably includes an adiabatic taper in addition to the grating coupling structure. Alternative couplers, e.g., holographic couplers, are also conceivable. If the separate couplers are designed such that the coupled light signals are deflected towards the second layer in such a way that the coupled light signals overlap at least to a large extent, preferably almost completely, within the second layer, good color mixing can advantageously be achieved. A white laser signal can also be advantageously generated by color mixing.The superposition takes place, in particular, at a location within a holographic-optical element integrated into the second layer. The light signals coupled out from the first layer / waveguides are superimposed as precisely as possible in the second layer. Since a separate coupler is provided in the first layer for each color of light, its grating properties, in particular, can be advantageously tuned precisely to the respective wavelength, the required coupling angle, and / or the required numerical aperture. Chromatic errors can thus be advantageously minimized by the precise superposition achieved.

[0013] Furthermore, it is proposed that each waveguide includes a coupling structure connected to the respective coupling region, preferably designed as a taper coupler. This allows advantageous coupling and / or light-guiding properties of the first layer to be achieved. The laser signal generated by the laser sources is coupled directly into the waveguide chip via the respective coupling structure, in particular via the respective taper coupler. Taper couplers are also specifically called spot-size converters. Taper converters are able to convert the larger free-space propagating laser modes into laser modes that can propagate in the respective waveguides. A taper coupler is specifically designed by a waveguide that widens in a plane, preferably in a layer plane of the first layer. By tapering, i.e.,Increasing the width of the waveguide particularly strengthens the light limitation and reduces the size of a propagating mode until it is comparable to a fundamental mode of the respective waveguide.

[0014] It is further proposed that the first layer be transparent at least in a viewing direction parallel to a planned extraction direction of the extraction area, in particular in a direction parallel to a stacking direction of the layer structure, or have an aperture / recess that overlaps with the extraction area in the viewing / stacking direction. This advantageously allows for the simple recording of a hologram integrated into the second layer, especially when the first and second layers are already assembled. It also advantageously enables the simple fabrication of the layer structure. The aperture / recess forms, in particular, a window in an opaque second layer through which (transmission) illumination of the hologram integrated into the second layer can occur.

[0015] Furthermore, it is proposed that the second layer comprises at least the holographic-optical element (HOE). This advantageously enables optimized merging of the laser signals, particularly the primary-colored laser signals. Minimization of laser modules, especially with regard to weight and volume, is also advantageously achieved. In particular, the HOE is embedded in the second layer. The HOE can be surrounded on both sides by transparent material of the second layer or covered on only one side by transparent material of the second layer. Particularly in the latter case, the HOE can be located on a side of the second layer facing the first layer or on a side of the second layer facing away from the first layer. The HOE is specifically designed for beam shaping of the coupled-out light signal.The HOE is specifically designed for collimating the extracted light signal. The HOE is specifically designed for combining the wavelengths of the different colored laser signals. "Designed" and / or "configured" should be understood to mean specifically programmed, designed, and / or equipped. The fact that an object is designed and / or configured for a specific function should be understood to mean that the object fulfills and / or performs this specific function in at least one application and / or operating state. The second layer can be formed from a combination of a hologram carrier layer and the HOE. Alternatively, the second layer can also be formed entirely by the HOE. In particular, the laser signals extracted by the grid extraction structures, which may be divergent, are collimated by the HOE.In particular, compared to the use of a collimating lens, as is the case, for example, in the prior art described above, the use of the HOE offers the advantage that wavefront errors of an outcoupler / grating outcouple structure can be corrected by means of the HOE, which is preferably freeformable in a module-specific manner. Furthermore, the considerable mass of three collimating lenses is advantageously saved.

[0016] Furthermore, it is proposed that the holographic-optical element possesses an optical function that generates at least a collimation of at least one of the light signals directed onto the output coupling area and / or at least a deflection of at least one of the light signals directed onto the output coupling area parallel to a stacking direction of the layer structure. This advantageously enables good color mixing. Advantageously, a white light laser signal can also be generated through color mixing. Advantageously, suitability for display in smart glasses, e.g., for a virtual retinal display, can be achieved, which in particular generates the image by scanning the output light signals onto the retina of a user's eye using a MEMS scanner.In particular, the respective grid output coupling structures of the waveguides each generate divergent laser beams, which are then collimated by one optical function of the HOE or by a single HOE. Specifically, the HOE can be configured as a single HOE with a single optical function that collimates and deflects light of a single wavelength. Alternatively, the HOE can be configured as a multiplex HOE with several optical functions, each collimating and deflecting light of different wavelengths. It is also conceivable that several HOEs with different optical functions, e.g., one collimating and one deflecting function for each of the light colors, are integrated into the second layer.

[0017] Furthermore, it is proposed that the second layer comprises at least one second holographic-optical element, which is arranged above or below the holographic-optical element in the stacking direction of the layer structure, or which is superpositioned with the holographic-optical element in a common hologram layer. The second holographic-optical element preferably has an optical function that generates at least a collimation of at least one further light signal directed towards the output coupling area and / or at least a deflection of at least one further light signal directed towards the output coupling area parallel to a stacking direction of the layer structure. The respective holographic-optical elements interact with only one of the differently colored light signals each. This advantageously allows for good color mixing.Advantageously, a white light laser signal can also be generated through color mixing. In particular, the second layer features a number of holographic-optical elements, corresponding to a number of light colors that can be coupled into the first layer, with each HOE interacting with a different light color. These holographic-optical elements can be stacked in the second layer or superimposed in a common holographic material / in a common hologram plate integrated into or forming the second layer.

[0018] Furthermore, it is proposed that the holographic-optical element forms a transmission hologram. This advantageously allows for a high signal strength of the coupled-out light signal.

[0019] Alternatively, it is proposed that the holographic-optical element forms a reflection hologram. This advantageously allows for high resistance to stray light.

[0020] Furthermore, an RGB laser module with the color-mixing laser module device and with at least one red laser source, at least one green laser source, and at least one blue laser source, and / or smart glasses, in particular an AR headset, with a laser projector incorporating the RGB laser module, is proposed. This advantageously allows for a compact, in particular small, and / or lightweight design of the RGB laser module and / or the smart glasses. "Smart glasses" are understood to mean, in particular, a wearable device (head-mounted display) by means of which information can be added to a user's field of vision. Preferably, smart glasses enable augmented reality and / or mixed reality applications. Smart glasses are also commonly referred to as smart glasses.The color-mixing laser module device, the RGB laser module, and / or the data glasses according to the invention are not to be limited to the application and embodiment described above. In particular, the color-mixing laser module device, the RGB laser module, and / or the data glasses according to the invention may, to achieve a functionality described herein, have a different number of individual elements, components, and units than that specified herein. Furthermore, values ​​within the specified limits of the value ranges stated in this disclosure are also to be considered disclosed and freely usable.

[0021] drawing

[0022] Further advantages become apparent from the following description of the drawings. The drawings illustrate four exemplary embodiments of the invention. The drawings, the descriptions, and the claims contain numerous features in combination. It is advantageous for those skilled in the art to also consider the features individually and combine them into meaningful further combinations.

[0023] They show:

[0024] Fig. 1 shows a schematic view of data glasses with a laser projector comprising an RGB laser module.

[0025] Fig. 2 shows a schematic representation of the RGB laser module with laser sources and a color-mixing laser module device.

[0026] Fig. 3 shows a schematic representation of a section of a first layer of a layer structure of the color-mixing laser module device,

[0027] Fig. 4 shows a schematic representation of a perpendicular section through the layer structure with the first layer and with a second layer.

[0028] Fig. 5 shows a schematic representation of an exemplary arrangement of optical components for recording holographic-optical elements of the second layer; Fig. 6 shows a schematic representation of an exemplary setup of the second layer.

[0029] Fig. 7 shows a schematic representation of a first layer and a second layer of a layer structure of a first alternative color-mixing laser module device,

[0030] Fig. 8 shows a schematic representation of a perpendicular section through a layer structure of a second alternative color-mixing laser module device,

[0031] Fig. 9 shows a schematic representation of an exemplary arrangement of optical components for receiving at least one holographic-optical element of the second alternative color-mixing laser module device and

[0032] Fig. 10 shows a schematic representation of a layer structure of a third alternative color-mixing laser module device with a first layer and a second layer.

[0033] Description of the exemplary implementations

[0034] Figure 1 shows a schematic view of a pair of smart glasses 10a. The smart glasses 10a include a virtual retinal scan display. The smart glasses 10a form an AR headset. The smart glasses 10a include a laser projector 80a. The laser projector 80a generates an artificial image, which is superimposed by the retinal scan display onto a real image perceived by a user 82a of the smart glasses 10a through the lenses of the smart glasses 10a. The laser projector 80a is integrated into a temple 112a of the smart glasses 10a.

[0035] The laser projector 80a includes an RGB laser module 70a. The RGB laser module 70a emits a color-modulated laser beam. The laser projector 80a includes a MEMS scan mirror system 84a. The MEMS scan mirror system 84a generates the artificial image on the retina 86a of the user 82a of the data glasses 10a by scanning the color-modulated laser beam of the RGB laser module 70a line by line.

[0036] Figure 2 shows a schematic representation of the RGB laser module 70a. The RGB laser module 70a includes a red laser source 74a. The red laser source 74a emits a first laser signal 12a with a first color of light. The first laser signal 12a is a red laser signal 16a. The RGB laser module 70a includes a green laser source 76a. The green laser source 76a emits a second laser signal 14a with a second color of light. The second laser signal 14a is a green laser signal 18a. The RGB laser module 70a includes a blue laser source 78a. The blue laser source 78a emits a third laser signal 88a with a third color of light. The third laser signal 88a is a blue laser signal 20a.

[0037] The RGB laser module 70a comprises a color-mixing laser module device 72a. The color-mixing laser module device 72a is intended for use in the data glasses 10a. The color-mixing laser module device 72a includes a layer structure 22a. The layer structure 22a has a first layer 24a. The layer structure 22a, in particular at least the first layer 24a of the layer structure 22a, is configured for spatially separated internal routing of at least the first laser signal 12a with the first light color, the second laser signal 14a with the second light color, which is substantially different from the first light color, and the third laser signal 88a with the third light color, which is substantially different from both the first and second light colors. The first layer 24a has a first coupling area 26a for the first laser signal 12a. The first layer 24a has a second coupling area 28a for the second laser signal 14a.The first layer 24a has a third coupling area 30a for the third laser signal 88a. The coupling areas 26a, 28a, and 30a are spatially separated from one another. The coupling areas 26a, 28a, and 30a are not adjacent to each other. The coupling areas 26a, 28a, and 30a are each arranged on different, preferably differently oriented, side edge surfaces 90a of the first layer 24a. The laser sources 74a, 76a, and 78a each shine approximately perpendicularly onto their respective coupling areas 26a, 28a, and 30a of the layer structure 22a. The laser sources 74a, 76a, and 78a are arranged laterally around the layer structure 22a. The laser sources 74a, 76a, and 78a are each configured as laser diodes with emission spectra corresponding to the respective light colors.

[0038] The first layer 24a is formed by an integrated photonic circuit. The first layer 24a has a first waveguide 36a for the first laser signal 12a. The first layer 24a has a second waveguide 38a for the second laser signal 14a. The first layer 24a has a third waveguide 40a for the third laser signal 88a. The waveguides 36a, 38a, and 40a, in particular the first waveguide 36a, the second waveguide 38a, and the third waveguide 40a, are each completely spatially separated from one another. The waveguides 36a, 38a, and 40a are integrated / embedded in the first layer 24a. The waveguides 36a, 38a, 40a carry the respective laser signals 12a, 14a, 88a in a plane of the first layer 24a / perpendicular to a stack direction 64a of the layer structure 22a.

[0039] The layer structure 22a has a second layer 32a. The second layer 32a is arranged above the first layer 24a in the stacking direction 64a. The first layer 24a is transparent in a viewing direction 56a parallel to a designated output coupling direction 58a of a common color-mixing output coupling area 34a of the second layer 32a / parallel to the stacking direction 64a. The second layer 32a is also transparent in the viewing direction 56a / in the stacking direction 64a. The first waveguide 36a has a first output coupler 42a. The first output coupler 42a is configured to couple the first laser signal 12a from the first waveguide 36a in the direction of the second layer 32a / in the stacking direction 64a. The second waveguide 36a has a second output coupler 44a.The second output coupler 44a is configured to couple the second laser signal 14a from the second waveguide 38a towards the second layer 32a / in the stacking direction 64a. The third waveguide 40a has a third output coupler 46a. The third output coupler 46a is configured to couple the third laser signal 88a from the third waveguide 40a towards the second layer 32a / in the stacking direction 64a. The output couplers 42a, 44a, and 46a are completely spatially separated from one another. The output couplers 42a, 44a, and 46a lie in a plane that runs parallel to a principal extension plane of the layer structure 22a. Each of the waveguides 36a, 38a, 40a has at least one separate decoupling device 42a, 44a, 46a in the first layer 24a, which is each configured to decouple light guided in the respective waveguide 36a, 38a, 40a from the waveguide 36a, 38a, 40a.The output couplers 42a, 44a, 46a are each configured as separate and differently designed output coupling structures. Each output coupler 42a, 44a, 46a comprises a grid output coupling structure adapted to the respective light color of the respective waveguide 36a, 38a, 40a. The separate output couplers 42a, 44a, 46a are each configured such that the light signals 48a, 50a, 52a coupled through them are deflected towards the second layer 32a in such a way that these coupled light signals 48a, 50a, 52a almost completely overlap within the second layer 32a. The overlap occurs at a location where a holographic-optical element 62a, 66a of the layer structure 22a is arranged in the second layer 32a.

[0040] The second layer 32a has exactly one common color-mixing output coupling area 34a for the first laser signal 12a, the second laser signal 14a, and the third laser signal 88a. The second layer 32a has exactly one common color-mixing output coupling area 34a for the red laser signal 16a, the green laser signal 18a, and the blue laser signal 20a.

[0041] Figure 3 schematically shows a section of the layer structure 22a in a region of the first waveguide 36a. The first waveguide 36a has a coupling structure 54a. The coupling structure 54a is configured as a taper coupler. The coupling structure 54a connects to the first coupling region 26a of the first waveguide 36a. Each of the subsequent waveguides 38a, 40a also has its own coupling structure 54a, configured as a taper coupler and connected to the respective coupling regions 28a, 30a.

[0042] Figure 4 shows a schematic representation of a perpendicular section through the layer structure 22a with the first layer 24a and the second layer 32a. The second layer 32a comprises a first holographic-optical element 62a. The first holographic-optical element 62a has a first optical function which collimates the first light signal 48a directed onto the output coupling area 34a. The first optical function of the first holographic-optical element 62a also deflects the first light signal 48a directed onto the output coupling area 34a in a direction parallel to the stack direction 64a of the layer structure 22a. The second layer 32a comprises a second holographic-optical element 66a.The second holographic-optical element 66a has a second optical function which generates a collimation of the second light signal 50a directed onto the output coupling area 34a. The second optical function of the second holographic-optical element 66a also generates a deflection of the second light signal 50a directed onto the output coupling area 34a in a direction parallel to the stacking direction 64a of the layer structure 22a. The second layer 32a comprises a third holographic-optical element 92a. The third holographic-optical element 92a has a third optical function which generates a collimation of the third light signal 52a directed onto the output coupling area 34a. The third optical function of the third holographic-optical element 92a also generates a deflection of the third light signal 52a directed to the output coupling area 34a in a direction parallel to the stacking direction 64a of the layer structure 22a.All holographic-optical elements 62a, 66a, 92a are designed as transmission holograms. After passing through the second layer 32a, all light signals 48a, 50a, 52a, in particular all light beams exiting the second layer 32a, are collimated and aligned parallel to the stacking direction 64a of the layer structure 22a / perpendicular to a surface plane of the layer structure 22a. The respective holographic-optical elements 62a, 66a, 92a each interact with only exactly one of the differently colored light signals 48a, 50a, 52a.

[0043] Figure 5 schematically shows an exemplary setup for recording the holographic-optical elements 62a, 66a, 92a. To generate precise interference patterns in the holographic-optical elements 62a, 66a, 92a, coherent light in the form of a laser beam emitted by a recording laser 94a is used. The laser beam is split by means of a beam splitter 96a and used to generate both a reference light and an object light. The couplers 42a, 44a, 46a are used to generate the reference light. The object light is a plane wavefront, which is generated by means of a telescope 98a (a combination of a concave lens and a convex lens) and directed perpendicularly through the transparent first layer 24a. The reference light is superimposed on the object light on a photosensitive element, which after exposure forms the holographic-optical elements 62a, 66a, 92a.The resulting interference patterns modulate the local refractive index within the holographic material, thereby recording the relative phase (between the plane wavefront and the reference wave). Since the holograms of the holographic-optical elements 62a, 66a, 92a were already recorded with the couplers 42a, 44a, 46a of the waveguides 36a, 38a, 40a of the first layer 24a, the reconstruction with the reference wave by diffraction at the recorded interference pattern produces an exact copy of the object wave.

[0044] Figure 6 schematically shows an exemplary structure of the second layer 32a. In the case shown in Figure 6, the second layer 32a comprises a common hologram layer 110a. The common hologram layer 110a encompasses all three holographic optical elements 62a, 66a, and 92a together. The three holographic optical elements 62a, 66a, and 92a are combined in a single multiplex hologram. The three holographic optical elements 62a, 66a, and 92a are superimposed to form a single hologram. For this purpose, the three interference patterns were recorded one on top of the other on the same hologram plate.

[0045] Figures 7 to 10 show three further embodiments of the invention. The following descriptions and drawings are essentially limited to the differences between the embodiments, whereby, with regard to identically designated components, particularly those with the same reference numerals, reference may also be made to the drawings and / or the description of the other embodiments, especially Figures 1 to 6. To distinguish the embodiments, the letter "a" is appended to the reference numerals of the embodiment in Figures 1 to 6. In the embodiments of Figures 7 to 10, the letter "a" is replaced by the letters "b" to "d".

[0046] Figure 7 shows a schematic representation of a first layer 24b and a second layer 32b of a layer structure 22b of a first alternative color-mixing laser module device 72b. The second layer 32b comprises a first holographic-optical element 62b, a second holographic-optical element 66b, and a third holographic-optical element 92b. The holographic-optical elements 62b, 66b, and 92b are arranged one above the other in separate hologram layers 100b, 102b, and 104b. An intermediate layer 106b and 108b are arranged between each pair of hologram layers 100b, 102b, and 104b. The holographic-optical elements 62b, 66b, and 92b are arranged one above the other in a stacking direction 64b of the layer structure 22b.

[0047] Figure 8 shows a schematic representation of a perpendicular section through a layer structure 22c of a second alternative color-mixing laser module device 72c, comprising a first layer 24c and a second layer 32c. The second layer 32c includes at least one holographic-optical element 62c. This holographic-optical element 62c is configured as a reflection hologram. Figure 9 schematically shows an exemplary arrangement for imaging the holographic-optical element 62c of the second alternative color-mixing laser module device 72c. The components used correspond to those already described in connection with Figure 5. In contrast to Figure 5, the hologram is now shown being imaged from above, i.e., from a side of the second layer 32c opposite the first layer 24c.When using an RGB laser module 70c with the second alternative color-mixing laser module device 72c, the light coupled out from the first layer 24c is collimated and propagated through the transparent layers 24c, 32c of the layer structure 22c (downwards in the drawing of Fig. 8).

[0048] Figure 10 shows a schematic representation of a layer structure 22d of a third alternative color-mixing laser module device 72d, comprising a first layer 24d and a second layer 32d. The first layer 24d is opaque. The first layer 24d has an aperture. The first layer 24d has a recess 60d. The second layer 32d has a common color-mixing output coupling area 34d. The aperture / recess 60d overlaps the layer structure 22d in a viewing direction 56d and in a stacking direction 64d. The aperture / recess 60d allows the exposure of the second layer 32d, when recording holographic optical functions to generate at least one holographic-optical element 62d (as depicted in Figures 5 or 9), despite the opacity of the first layer 24d.

Claims

Claims 1. Color-mixing laser module device (72a-d), in particular for use in data glasses (10a-d), comprising a layer structure (22a-d) configured for at least a spatially separated internal guiding of at least a first laser signal (12a-d) with a first light color and at least a second laser signal (14a-d) with a second light color substantially different from the first light color, preferably a red laser signal (16a-d), a green laser signal (18a-d) and a blue laser signal (20a-d), which has a first layer (24a-d) with a spatially separated coupling area (26a-d, 28a-d, 30a-d) for each of the first laser signal (12a-d) and for the second laser signal (14a-d), preferably for the red laser signal (16a-d), for the green laser signal (18a-d) and for the blue laser signal (20a-d),and which has a second layer (32a-d) with at least one common color-mixing output coupling area (34a-d) for the first laser signal (12a-d) and the second laser signal (14a-d), preferably the red laser signal (16a-d), the green laser signal (18a-d) and the blue laser signal (20a-d).

2. Color-mixing laser module device (72a-d) according to claim 1 , characterized in that the first layer (24a-d) is formed by an integrated photonic circuit.

3. Color-mixing laser module device (72a-d) according to claim 1 or 2, characterized in that a spatially separated waveguide (36a-d, 38a-d, 40a-d) for the first laser signal (12a-d) and for the second laser signal (14a-d), preferably for the red laser signal (16a-d), for the green laser signal (18a-d) and for the blue laser signal (20a-d), is integrated into the first layer (24a-d).

4. Color-mixing laser module device (72a-d) according to claim 3, characterized in that each of the waveguides (36a-d, 38a-d, 40a-d) in the first layer (24a-d) has at least one separate coupler (42a-d, 44a-d, 46a-d), in particular a separate coupler structure, which is at least configured to couple light guided in the respective waveguide (36a-d, 38a-d, 40a-d) out of the respective waveguide (36a-d, 38a-d, 40a-d) of the first layer (24a-d) in the direction of the second layer (32a-d).

5. Color-mixing laser module device (72a-d) according to claim 4, characterized in that each of the couplers (42a-d, 44a-d, 46a-d) comprises a grid coupler structure, in particular adapted to the respective light color.

6. Color-mixing laser module device (72a-d) according to claim 4 or 5, characterized in that the separate couplers (42a-d, 44a-d, 46a-d) are designed such that the respective coupled light signals (48a-d, 50a-d, 52a-d) are deflected in the direction of the second layer (32a-d) in such a way that the coupled light signals (48a-d, 50a-d, 52a-d) overlap at least to a large extent, preferably almost completely, within the second layer (32a-d).

7. Color mixing laser module device (72a-d) according to one of claims 3 to 6, characterized in that each of the waveguides (36a-d, 38a-d, 40a-d) comprises a coupling structure (54a-d) adjoining the respective coupling area (26a-d, 28a-d, 30a-d) and preferably designed as a taper coupler.

8. Color-mixing laser module device (72a-d) according to one of the preceding claims, characterized in that the first layer (24a-d) is transparent at least in a viewing direction (56a-c) parallel to a provided output coupling direction (58a-c) of the output coupling area (34a-c) or is transparent with the output coupling area (34d) in the viewing direction (56d) / in a stacking direction (64d) of the layer structure (22d) has an overlapping aperture / recess (60d).

9. Color-mixing laser module device (72a-d) according to one of the preceding claims, characterized in that the second layer (32a-d) comprises at least one holographic-optical element (62a-d) 10. Color-mixing laser module device (72a-d) according to claim 9, characterized in that the holographic-optical element (62a-d) has an optical function which generates at least a collimation of at least one of the light signals (48a-d, 50a-d, 52a-d) directed onto the output coupling area (34a-d) and / or at least a deflection of at least one of the light signals (48a-d, 50a-d, 52a-d) directed onto the output coupling area (34a-d) parallel to a stacking direction (64a-d) of the layer structure (22a-d).

11. Color-mixing laser module device (72a-d) according to claim 9 or 10, characterized in that the second layer (32a-d) has at least one second holographic-optical element (66a-d) which is arranged in the stacking direction (64b) of the layer structure (22b) above or below the holographic-optical element (62b) or which is in a common hologram layer (110a; 110c-d) with the holographic-optical element (62a;62c-d) is superpositioned, wherein the second holographic-optical element (66a-d) preferably has an optical function that generates at least a collimation of at least one further light signals (48a-d, 50a-d, 52a-d) directed onto the output coupling area (34a-d) and / or at least a deflection of at least one further light signals (48a-d, 50a-d, 52a-d) directed onto the output coupling area (34a-d) parallel to a stacking direction (64a-d) of the layer structure (22a-d), wherein the respective holographic-optical elements (62a-d, 66a-d) interact only with one of the differently colored light signals (48a-d, 50a-d, 52a-d) each.

12. Color-mixing laser module device (72a-b; 72d) according to one of claims 9 to 11, characterized in that the holographic-optical element (62a-b, 66a-b; 62d, 66d) is a transmission hologram trains.

13. Color-mixing laser module device (72a-d) according to one of claims 9 to 11, characterized in that the holographic-optical element (62c, 66c) forms a reflection hologram.

14. RGB laser module (70a-d) with a color-mixing laser module device (72a-d) according to one of the preceding claims and with at least one red laser source (74a-d), at least one green laser source (76a-d) and at least one blue laser source (78a-d).

15. Data glasses (10a-d), in particular AR headset, with a laser projector (80a-d) comprising an RGB laser module (70a-d) according to claim 14.

Images