Led-driven metasurface RGB laser module & actively controlled variable aperture single mode metasurface laser enabled by µ-led arrays

Abstract

A light emitting device is provided including a wavelength conversion structure configured to convert electromagnetic radiation of a first wavelength in to an electromagnetic radiation of a second wavelength; a plurality of light sources, wherein at least one light source is configured to emit an electromagnetic radiation of the first wavelength, wherein the plurality of light sources are arranged on or above the wavelength conversion structure; and an optical metastructure configured as optical cavity comprising a resonance frequency at about the second wavelength.

Description

[0001] LED-DRIVEN METASURFACE RGB LASER MODULE & ACTIVELY CONTROLLED VARIABLE APERTURE SINGLE MODE METASURFACE LASER ENABLED BY p- LED ARRAYS

[0002] Description

[0003] This disclosure generally relates to laser modules.

[0004] Currently, (RGB) laser modules are made by means of edge emitter lasers and some optics for beam collimation and beam combining. R. Contractor, et al., Nature, 608 (7924) , 692-698 (2020) , and US15 / 767520 disclose a large aperture single mode lasing as a comparative example.

[0005] Some properties of a laser device are highly desirable but very difficult to achieve each by itself:

[0006] - Compactness (geometrically) : Due to the need to having an optical cavity with sufficient gain;

[0007] - Variable aperture: To be able to actively control the area in which the laser illuminates typically requires additional external optics;

[0008] - Single mode: If the aperture is large enough, typically the laser operates in the multimode regime which causes a complex wavefront that may be difficult to use for certain applications;

[0009] - Stable output polarization unaffected by temperature changes and / or electronic jitters: Typical vertical cavity surface emitting lasers (VCSEL) may not be accessible to control precisely the output polarization due to the inherent symmetry of the structure that can support multiple modes of different polarizations; and

[0010] - Chiral emission: Typically to obtain chiral laser light, additional external optical components are necessary.

[0011] Alignment of three laser diodes with optics is a time consuming and expensive process. Furthermore, expensive and relatively large optical components may be required. It is an obj ective of the invention to provide a laser source having an improved compactness and being more cost ef fective .

[0012] In one aspect , a light emitting device is provided including a wavelength conversion structure configured to convert electromagnetic radiation of a first wavelength into an electromagnetic radiation of a second wavelength; a plurality of light sources , wherein at least one light source is configured to emit an electromagnetic radiation of the first wavelength, wherein the plurality of light sources are arranged on or above the wavelength conversion structure ; and an optical metastructure configured as optical cavity comprising a resonance frequency at the second wavelength or at about the second wavelength . Note , the electromagnetic radiation of the first wavelength may be incoherent .

[0013] In another aspect , a method to manufacture a light emitting device is provided, the method including : forming a wavelength conversion structure configured to convert electromagnetic radiation of a first wavelength in to an electromagnetic radiation of a second wavelength; forming a plurality of light sources , wherein each light source is configured to emit an electromagnetic radiation of the first wavelength, wherein the plurality of light sources are arranged on or above the wavelength conversion structure ; and forming an optical metastructure configured as optical cavity including a resonance frequency at the second wavelength or at about the second wavelength .

[0014] In the drawings , like reference characters generally refer to the same parts throughout the di f ferent views . The drawings are not necessarily to scale , emphasis instead generally being placed upon illustrating the principles of the invention . In the following description, various aspects of the invention are described with reference to the following drawings , in which : FIG.1 shows a cross-sectional view of a light emitting device;

[0015] FIG.2A to FIG.2C show schematic views of a light emitting device ;

[0016] FIG.3A to FIG.3C show schematic views of a light emitting device ;

[0017] FIG.4 shows a cross-sectional view of a light emitting device ;

[0018] FIG.5 shows a cross-sectional view of a light emitting device ;

[0019] FIG.6A to FIG.6E show diagrams illustrating a chirality of light emitted by a light emitting device;

[0020] FIG.7A to FIG.7C show diagrams illustrating a chirality of light emitted by a light emitting device;

[0021] FIG.8 shows a cross-sectional view of a light emitting device;

[0022] FIG.9A to FIG.9B show schematic views of a light emitting device ;

[0023] FIG.10A to FIG.10B show schematic views of a light emitting device ;

[0024] FIG.11 shows a cross-sectional view of a light emitting device;

[0025] FIG.12 shows a cross-sectional view of a light emitting device;

[0026] FIG.13 shows a cross-sectional view of a light emitting device;

[0027] FIG.14A shows a cross-sectional view of a light emitting device;

[0028] FIG.14B shows a spectral diagram; and

[0029] FIG.15 shows a flow diagram of a method to manufacture a light emitting device.

[0030] The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and aspects in which the disclosure may be practiced. One or more aspects are described in sufficient detail to enable those skilled in the art to practice the disclosure. Other aspects may be utili zed and structural , logical , and electrical changes may be made without departing from the scope of the disclosure . The various aspects described herein are not necessarily mutually exclusive , as some aspects can be combined with one or more other aspects to form new aspects . Various aspects are described in connection with methods and various aspects are described in connection with devices . However, it may be understood that aspects described in connection with methods may similarly apply to the devices , and vice versa . Throughout the drawings , it should be noted that like reference numbers are used to depict the same or similar elements , features , and structures . Throughout the drawings , it should be noted that proportions are not necessary to scale and that the si ze of features may be emphasi zed for ease of illustration .

[0031] I llustratively, in one aspect , a micro light emitting diode (p-LED) pumped laser is provided based on a resonant metasurface .

[0032] Note , a metasurface ( also denoted as optical metastructure ) may be characteri zed by a nanostructured surface having a plurality of optical nano-elements causing an optical resonance . The resonance may not be caused by the geometry of a single optical nano-element , but it is a collective phenomenon of optically coupled optical nano-elements .

[0033] Further note that light may be any kind of electromagnetic radiation in the spectrum of visible and invisible electromagnetic radiation, including ultraviolet (UV) radiation, near infrared ( IR) radiation and middle infrared radiation .

[0034] A high Q- factor metasurface ( Q>103) may be doped with an active material . Thus , high Q- factor metasurface may act as a cavity and a gain medium for a laser at the same time . Lasing can be achieved due to bound states in the continuum (BIC ) resonance responses in the metasurface. The high Q-factor metasurface may cause a giant field enhancement in the gain medium.

[0035] An array of p-LED may be used to optically pump the resonant metasurface. Thus, using the high Q-factor metasurface, an efficient laser with controllable polarization emission can be achieved. The polarization can be a linear polarization or a chiral polarization for example. The polarization may depend on the symmetry of the metasurface. A laser utilizing the high Q-factor metasurface can be a single mode laser with a large mode area. Further, the laser mode area may be controllable by turning on and off pLEDs in the array.

[0036] Note, a metasurface (also denoted as optical metastructure) may be characterized by a nanostructured surface having a plurality of optical nano-elements causing an optical resonance. The resonance may not be caused by the geometry of a single optical nano-element, but it is a collective phenomenon of optically coupled optical nano-elements. Further note, an absorption peak of a metasurface may occur at a frequency where a metamaterial absorbs the maximum amount of electromagnetic energy. This peak may be at or near the resonance frequency, but it is specifically characterized by the materials ability to convert incoming energy into other forms, such as heat, rather than reflecting or transmitting it. In contrast, a resonance frequency of a metamaterial is the frequency at which the metamaterials structure naturally oscillates with the greatest amplitude. At this frequency, the material can store and transfer energy very efficiently due to constructive interference of waves within the structure. Thus, while the resonance frequency is about the efficient oscillation of the material, the absorption peak is about the metamaterials ability to absorb energy. Thus, the absorption peak of a metamaterial and the resonance frequency of the metamaterial are distinct phenomena . FIG.l illustrates a schematic cross-sectional view of a pumped laser source 100 (also denoted as laser module 100, light emitting device 100, p-LED pumped laser source 100) having an optical pump source 102, e.g. a light emitting diode (LED) 102, e.g. a p-LED 102, (also denoted as light source 102, plurality of light sources 102, or array of light sources 102) and a resonant metasurface (also denoted as optical cavity) 104.

[0037] The optical pump source 102 may include or be a p-LEDs array.

[0038] The resonant metasurface 104 may be formed of a laser active material. The laser active material may be arranged for a specific laser wavelength of the optical pump source 102 directly in the BIC resonant metasurface 104. The LED 102 may pump the laser active material inside the metasurface 104.

[0039] The high Q-factor of the resonant metasurface 104 may cause that the resonant metasurface 104 acts as an optical cavity through the BIC mode with large near-field enhancement that the metasurface supports. This way, the pumped laser source 100 may be formed having an improved geometric compactness.

[0040] Alternatively, or in addition, as illustrated in FIG.4, the lasing area can be controlled by the amount of p-LED pixels of the optical pump source 102 being turned on. This allows a variable aperture through the p-LED array that pumps the active metasurface.

[0041] Alternatively, or in addition, the number of BIC modes supported by the metasurface can be independent of the pumped area. Thus, a single mode operation can be ensured by designing the metasurface to only support one single BIC mode at the target lasing wavelength. Hence, a single mode operation can be maintained even when using a large surface area of the pumped laser. Alternatively, or in addition, the shape and symmetry of the optical nano-elements of the metasurface sets the output polarization of the pumped laser source 100. Thus, the polarization of the pumped laser source 100 is adjusted on a hardware-level. Hence, there may be only one single BIC mode that emission can couple to at the lasing wavelength.

[0042] Alternatively, or in addition, the structure of the pumped laser source 100 may inherently provide a stable output polarization that is unaffected by any one of temperature changes and electronic jitters.

[0043] Alternatively, or in addition, the symmetry of the optical nano-elements of the metasurface may set the polarization of the output light, e.g. linear or chiral polarization, as illustrated in FIG.2 and FIG.4.

[0044] Alternatively, or in addition, the structure of the pumped laser source 100 may provide an actively tuned aperture area, e.g. see FIG .4.

[0045] Alternatively, or in addition, the structure of the pumped laser source 100 may provide a single mode operation regardless of area.

[0046] Alternatively, or in addition, the structure of the pumped laser source 100 may provide an improved compactness.

[0047] In other words, the pumped laser source may include an optical pump source, e.g. p-LED pumped array, and a resonant metasurface (also denoted as metastructure) . This allows to simultaneously achieve at least two or more of: a single mode laser with large emission area, a stable linear and chiral polarization output dictated by the geometry / symmetry of the dielectric-metasurface (see also FIG.2 and FIG.3) , an active control of a laser mode area, e.g. while maintaining a single mode simply by choosing which p-LEDs are turned on in the array (e.g. see FIG.4) , and a geometrical compactness due to being able to have the effective optical cavity responsible for lasing only at the metasurface.

[0048] Alternatively, or in addition, the structure of the pumped laser source 100 may provide a stable control of the polarization of the emitted laser light, e.g. chiral polarization light emission vs. linear polarization light emission, see FIG.2 and FIG.3.

[0049] Alternatively, or in addition, the structure of the pumped laser source 100 may provide that a resonance linewidth and a polarization, e.g. chiral polarization or linear polarization, of the metasurface can be easily tuned by the symmetry broken parameters of the unit cell of the optical nano-elements of the metasurface, e.g. see a and 0 illustrated in FIG.2 and FIG.3.

[0050] Alternatively, or in addition, the structure of the pumped laser source 100 may provide that the wavelength of operation of metasurfaces can flexibly be tuned by proper scaling the dimension of the individual unit cell of the optical nanoelements of the metasurface and their periodicity. Thus, the the pumped laser source 100 simplifies the design process.

[0051] Alternatively, or in addition, the structure of the pumped laser source 100 may utilize any one of an available laser active material according to a desired laser frequency, and any one of an available p-LED of the corresponding wavelength. Thus, by combining a laser active material and a corresponding p-LED, the pumped laser source 100 can be configured for a very broad range of frequencies.

[0052] FIG.2 illustrates a schematic cross-sectional view of a pumped laser source 100. Illustratively, FIG.2 shows a pumped laser source 100 pumped with an array of p-LEDs based on chiral BIC resonant metasurfaces. Using a BIC resonant metasurfaces one can achieve a chiral lasing emission with a degree of polarization (DOP) of near unity (see also FIG.5) , as also illustrated in Zhang et al., Science 377, 1215-1218 (2022) .

[0053] The high Q-factor (Q>103) metasurface may achieve lasing due to a giant field enhancement. The underlying physics of high Q-factor metasurface can be understood from quasi-bound states in the continuum (quasi-BIC) . The Q-factor of the metasurface can be easily tuned by symmetry-broken parameters, e.g. a and 0 shown in FIG.2. The unit cell of the optical nano-elements of the chiral metasurface may not be superimposed onto its mirror image (i.e., without any mirror symmetry) .

[0054] FIG.7A and FIG.7B show that a metasurface chiral lasing may be obtained when pumped above threshold. Thus, the laser emission may exhibit a very small divergence angle as illustrated in FIG.7C.

[0055] FIG.3 illustrates a schematic cross-sectional view of a pumped laser source 100. Here, in comparison to FIG.2, the symmetry of the metasurface, e.g. the unit-cell, may be broken only 0 (see FIG.3, a = 0°) to achieve linear polarization emission. Note that the quality factor of the metasurface can be tuned by symmetry-broken parameter 0.

[0056] FIG.4 illustrates a schematic cross-sectional view of a pumped laser source 100. Here, in comparison to the examples above, the p-LEDs pumping area is tunable and can provide active control of laser mode area.

[0057] FIG.5 illustrates a schematic cross-sectional view of a pumped laser source 100. Here, in comparison to the examples above, the BIC resonant metasurface includes an evanescent coupling with gain medium. FIG.8 illustrates a schematic cross-sectional view of a pumped laser source 100. In various examples, a laser module 100 is provided including two or more optical channels 802, 804 (e.g. lasers sources) , e.g. three or more, each having a wavelength different from the others, e.g. red, green and blue, e.g. combined in a single component.

[0058] Each optical channel 802, 804 may include a metasurface and can be made in a very compact form, e.g. having a size of about ~ 100 x 100 pm2. Thus, the laser sources can be arranged very close to each other. Hence, the laser module can be formed as a compact module, e.g. less than 1 x 0.5 x 0.5 mm3.

[0059] Pre-collimated beams of the optical channel 802, 804 may have a divergence of less than a few degrees e.g. ~ 2°, for a quasi-bound states in the continuum (BICs) metasurface.

[0060] The light emitting device 100 may provide single mode laser beams. The light emitting device 100 may provide laser beams having a large area (cross section) .

[0061] The light emitting device 100 may include for example three pump sources 102-1, 102-2, 102-3 (see also e.g. FIG.9B) , e.g. LED chips, e.g. p-LED chips, which can optically pump different specially designed active metasurfaces (also denoted as optical metastructure) . The metasurfaces may be stacked above one another, as illustrated in FIG.14.

[0062] These metasurfaces may be doped with active fluorescent materials that can lase when they are sufficiently pumped beyond a certain threshold. Each pump source 102-1, 102-2, 102-3 may be emitting with a specific spectrum which may coincide with the absorption spectrum of the corresponding doped active laser material. The emission wavelength of the active material in each wavelength converting structure may be designed to coincide with the resonant wavelength of a quasi-bound state in the continuum (QBIC) that is supported by each optical metastructure.

[0063] A large array may mimic an infinite lattice array, and thus allows to achieve a high Q-factor metasurface (e.g., Q > 1000) . A typical dimensions may be in a range of 100 pm x 100 pm (or even smaller) to achieve a reasonably large Q-factor (Q >1000) for lasing.

[0064] Therefore, it is possible to integrate three light sources

[0065] 102-1, 102-2, 102-3, e.g. in a row of a length of less than

[0066] 1 mm.

[0067] For example, flip-chip mini-LEDs with an area less than the metasurface can be used as a pump source 102-1, 102-2, 102-3 under each metasurface 204. The emitted laser 112 out of each metasurface 204 is relatively collimated (less than a few degrees, e.g., about 2°, for a quasi-BIC metasurface. Note that the collimation angle can be improved by engineering the dispersion of the metasurface and operating at the Gamma-point) realizing highly collimated beam (~0.1°) .

[0068] Thus, the light emitting device 100 can be provided very compact in size, and very cost effective.

[0069] There may be no need for a laser alignment in the light source 100, e.g. laser diode to photonic integrated circuit (PIC) or optic for example.

[0070] The light emitting device 100 may provide scalability of beam cross-section by increasing the area of metasurface or by integrating several pieces together. Since three laser beams are pre-collimated and very close to each other, providing a beam combiner is simplified. The polarization of each laser may be defined based upon the metasurface design. This provides more possibilities for different applications. For example, one can bend one laser beam while let the other one passing through the optic, based on the polarization.

[0071] Further, a laser wavelength (light colour) may not be changed by increasing the intensity of pumping light 106 in order to increase the laser intensity. This is especially important in case of image applications.

[0072] Further, one can attach the metasurface directly on top of an LED to get the minimum thickness if needed. In this case a black matrix can optically separate light sources from each other to prevent any optical cross-talk between them, as illustrated in FIG.9. This may be important if two adjacent channels use equal wavelengths as pump source.

[0073] FIG.10 illustrates a variation in which light sources 102 are arranged in a cavity (reflector) for the sake of better light extraction. Here the reflector prevents optical cross-talk as well .

[0074] In principle, the optical metastructure may be configured to support a Mie electric (or magnetic) resonance mode at the pump wavelength. This may increase pump light absorption. In such case, the optical pump efficiency may be enhanced by additionally pre-collimating the LED incoming to the metasurface to enhance the pump light absorption. Thus, as illustrated in FIG.11, adding a lens effect on a cladding material may improve coupling pump light into the optical cavity 104. Additional collimation can also be applied for the output laser beam on top side of the cladding (FIG.12) to enhance system optics performance.

[0075] Here, adding a lens effect on top of the cladding (material of the first substrate, e.g. SiO2, as described in more detail below) may diverge separate beams and overlap their spots on burning point. Afterwards a diffractive optic can be used for combining beams and make a single beam.

[0076] FIG.13 illustrates a variation in which the laser output of two side optical channels are bent (through surface structuring of top side of cladding surface) toward inside to meet the laser beam of the middle optical channel. Thus, in a laser spot at a certain distance of the optical metastructure, all three laser beams of the optical channels meets each other (also denoted as burning point or focal point) . A diffractive optic in the focal point may create a single laser beam (beam combiner) .

[0077] Another possibility is to arrange different optical metastructures, illustrated in FIG.14, by stacking the optical metastructures on top of each other and pump them with different light sources 102-1, 102-2, 102-3. Each two optical metastructures are transparent or at least partially transparent to the third wavelength for each of the optical channels .

[0078] The light sources 102-1, 102-2, 102-3 may optionally include an electrothermal element for thermally adjust the eigenfrequency of the metastructure and / or adjust the laser active material to tune or adjust the second wavelength.

[0079] In other words, referring to FIG.l to FIG.15:

[0080] FIG.l shows a cross-sectional view of a light emitting device 100. The light emitting device 100 may include an optical cavity 104 and a plurality of light sources 102.

[0081] At least one pump source 102 may be configured to emit a electromagnetic radiation of a first wavelength 106.

[0082] The light sources 102 may be spaced apart by a distance 108 from each other. The distance may be in a range from about 0.1 pm to about 300 pm. At least a subset of the light sources 102 may be light emitting diodes. The light emitting diode may have a size of less than about 100 x 100 pm2 (also denoted as p-LEDs) , respectively, for example. The light sources 102 may be arranged in a shared plane adjacent to each other.

[0083] The optical cavity 104 may include a wavelength conversion structure 202 (e.g. a layer doped with laser active material, e.g. Pr3+) and an optical metastructure 204 (e.g. formed of TiO2) , as illustrated in FIG.2A. FIG.2B shows a schematic cross-sectional view and FIG.2C shows a schematic cross- sectional side view of a unit cell 206 of the optical cavity 104.

[0084] The wavelength conversion structure 202 may be configured to convert electromagnetic radiation of the first wavelength 106 into an electromagnetic radiation of a second wavelength 112. The plurality of light sources 102 may be arranged on or above the wavelength conversion structure 202.

[0085] The optical metastructure 204 may be configured as optical cavity and may be configured to include a resonance frequency at about the second wavelength 112 or at the second wavelength 112. The optical metastructure 204 may be configured having a Q factor of more than 1000.

[0086] The wavelength conversion structure 202 and the optical metastructure 204 may be stacked above one another in the optical path of the plurality of light sources 102.

[0087] The light emitting device 100 may include a first substrate 110. The first substrate 110 may include any one of the wavelength conversion structure 202 or the optical metastructure 204 embedded therein, e.g. arranged therein or integrated therein. The first substrate 110 may be formed of a material having a first refractive index and the optical metastructure 204 may be formed having a second refractive index larger than the first refractive index at least for the second wavelength 112.

[0088] The plurality of light sources 102 may be formed on a shared surface of the first substrate 110.

[0089] The wavelength conversion structure 202, the plurality of light sources 102, and the optical metastructure 204 may be integrated in a shared layer stack.

[0090] As illustrated in FIG.2A to FIG.2C, the optical metastructure 204 may include a plurality of optical nano-elements 204. The optical nano-elements 204 may be configured for emitting chiral polarized electromagnetic radiation 112.

[0091] Another example of the light emitting device 100 is illustrated in the schematic cross sectional side view in FIG.3A. FIG.3B shows a schematic cross-sectional view and FIG.3C shows a schematic cross-sectional side view of a unit cell 206 of the optical cavity 104. Here, the optical nanoelements 204 may be configured for emitting linear polarized electromagnetic radiation 112.

[0092] Further, e.g. as illustrated in FIG.2A, the light emitting device 100 may include an optical filter 208 in the light path of the optical metastructure 204. The optical filter 208 may be configured to block electromagnetic radiation of the first wavelength 106, e.g. absorb, reflect, or convert. The optical filter 208 may be arranged at an emission surface of the light emitting device 100, for example.

[0093] The wavelength conversion structure 202 and the optical metastructure 204 may be integrated in a shared layer, as illustrated in FIG.2A to FIG.4. Alternatively, the wavelength conversion structure 202 and the optical metastructure 204 may be integrated in separated layers stacked in a shared light path, as illustrated in FIG.5. Illustratively, the light emitting device 100 is an array of light sources 102 pumped laser based on BIC resonant optical metastructures 204 with an evanescent coupling with gain medium.

[0094] The light emitting device 100 may further include a controller configured to control at least a first subset 404 (in FIG.4 illustrated as turned on) of the plurality of light sources 102 independent from a second subset 402 (in FIG.4 illustrated as turned off) of the plurality of light sources 102, as illustrated in a cross-sectional view in FIG.4. This way, the emission of electromagnetic radiation of the second wavelength 112 can be controlled, e.g. to generate a predetermined illumination pattern (also denoted as structured light) . In other words, the controller may provide an active control by defining a tunable pumping area by turning on / off subsets 402, 404 of the light source array, and thus generates a tunable laser mode area.

[0095] FIG.6A to FIG.6E show diagrams illustrating a chirality of light emitted by a light emitting device according to Zhang et al., Science 377, 1215-1218 (2022) . FIG.6A shows a top view and FIG.6B shows a side view of a metastructure. FIG.6C illustrates a left circular polarization (LCP) angledependent emission spectra of the metastructure of FIG.6A to FIG.6B, and FIG.6D illustrates right circular polarization (RCP) angle-dependent emission spectra of the metastructure of FIG.6A to FIG.6B. FIG.6E illustrates a degree of polarization (DOS) of the metastructure of FIG.6A to FIG.6B FIG.7A to FIG.7C show diagrams illustrating a chirality of light emitted by a light emitting device according to Zhang et al., Science 377, 1215-1218 (2022) of the metastructure of FIG.6A to FIG.6B. FIG.7A illustrates an emission spectra in the normal direction for chiral lasing of LCP (solid lines) and RCP (dashed lines) after a threshold, while FIG.7B shows the same emission spectra before a threshold. FIG.7C shows a far-field angular intensity distribution of the chiral laser having a metastructure illustrated in FIG.6A to FIG.6B

[0096] FIG.8 shows a cross-sectional view of a light emitting device 100. The light emitting device 100 can be configured to have at least a first optical channel 802 and a second optical channel 804. The first optical channel 802 may be configured to differ in at least one characteristic from the second optical channel 804.

[0097] For example, the first optical channel 802 may be configured to emit LCP second electromagnetic radiation 112-1, and the second optical channel 804 may be configured to emit RCP second electromagnetic radiation 112-2.

[0098] As another example, the first optical channel 802 may be configured to emit a chiral polarized, e.g. any one of LCP or RCP, second electromagnetic radiation 112-1, and the second optical channel 804 may be configured to emit linear polarized second electromagnetic radiation 112-2.

[0099] As another example, the first optical channel 802 may be configured to emit a second electromagnetic radiation 112-1 of a first color, e.g. a first color bin, and the second optical channel 804 may be configured to emit a second electromagnetic radiation 112-2 of a second color, e.g. a second color bin, different from the first color.

[0100] Thus, the plurality of pump source 102 as discussed above may include at least a first pump source 102-1 and a second pump source 102-2. Note that there may be more than two light sources, e.g. 102-N with N being an integer. Applicationspecific, the first pump source 102-1 and the second pump source 102-2 may be configured to emit first electromagnetic radiations 106-1, 106-2 of different color.

[0101] Application-specific, a first optical cavity 104-1 and a second optical cavity 104-2 each having a wavelength conversion structure and an optical metastructure, e.g. as discussed above, may be configured to generate second electromagnetic radiation of the respective wavelength or polarization, e.g. having a corresponding wavelength conversion structure and an optical metastructure.

[0102] The light emitting device 100 may be configured to generate a coherent light of a predefined color, e.g. white light, by combining the second electromagnetic radiations of optical channels. FIG.9A shows a schematic cross-sectional side view and FIG.9B shows a schematic cross-sectional top view of a light emitting device 100. Here, the light emitting device 100 may include at least a first pump source 102-1 associated with a first optical cavity 104-1 configured to emit a second electromagnetic radiation of a first colour bin, e.g. red (R) light, a second pump source 102-2 associated with a second optical cavity 104-2 configured to emit a second electromagnetic radiation of a second colour bin, e.g. green (G) light, and a third pump source 102-3 associated with a third optical cavity 104-3 configured to emit a second electromagnetic radiation of a third colour bin, e.g. blue (B) light.

[0103] Note, each of the light sources 102-1, 102-2, 102-3 may be a blue light emitting diode (LED) respectively. Thus, the first optical cavity 104-1 may include a wavelength converting material configured to convert blue light into red light, and the optical metastructure may be configured to have an optical resonance for the red light. Accordingly, the second optical cavity 104-2 may include a wavelength converting material configured to convert blue light into green light, and the optical metastructure may be configured to have an optical resonance for the green light. Correspondingly, the third optical cavity 104-3 may be free of a wavelength converting material, and the optical metastructure may be configured to have an optical resonance for the blue light. However, any other combination may also be useable depending on the desired application and considering quantum efficacy,

[0104] For example, the light emitting device 100 may include a first pump source 102-1 emitting red light and a first optical cavity 104-1 free of wavelength converting material and an optical metastructure having an optical resonance for the red light. The second pump source 102-2 may emit blue light and the first optical cavity 104-1 may include a wavelength converting material configured to convert blue light into green light, and the optical metastructure may be configured to have an optical resonance for the green light. Accordingly, the third light source may emit blue light, and the third optical cavity 104-3 may be free of a wavelength converting material, and the optical metastructure may be configured to have an optical resonance for the blue light.,

[0105] At least a subset of the light sources 102 and the wavelength conversion structure 202 may be configured to generate a white light when combined.

[0106] The light emitting device 100 having the optical cavity 104 may emit highly collimated second electromagnetic radiations 112-1, 112-2, 112-3, e.g. having a narrow beam angle in a range from about 0.1° to about 5°, e.g. in a range from about 2 ° to about 3 ° .

[0107] For example, the light emitting device 100 may include a black structure (also denoted as black matrix, e.g. a black epoxy) laterally adjacent to at least one of the light sources 102, e.g. to improve the narrow beam angle. The light emitting device 100 may include a second substrate 902 . The light sources 102 may be arranged on the second substrate 902 . The second substrate 902 may be a printed circuit board ( PCB ) . The light sources 102 may be electrically coupled to the printed circuit board .

[0108] Thus , the light emitting device 100 may include a first substrate 110 . The first substrate 110 includes any one of the wavelength conversion structure 202 or the optical metastructure 204 ( see FIG . 2 ) of the optical cavity 104 . The first substrate 110 may be arranged on or above the second substrate 902 .

[0109] An interspacer structure 904 may be arranged between the first substrate 110 and the second substrate 902 . The interspacer structure 904 may be configured as the black matrix may be arranged between the first substrate 110 and the second substrate 902 . The interspacer structure 904 may be arranged between adj acent light sources 102 . The interspacer structure 904 may be configured to optically isolate adj acent light sources 102 .

[0110] An optical filter 208 may embedded in the first substrate 110 or may be arranged thereon, as illustrated in FIG . 9A. Alternatively, or in addition, a dichroic mirror 906 may be embedded in the f irst substrate 110 or may be arranged thereon, as illustrated in FIG . 9A.

[0111] Alternatively, or in addition, the interspacer structure 904 may include tapered structure 1002 as illustrated in FIG . 10A to FIG . 10 . FIG . 10A shows a schematic cross-sectional side view and FIG . 10B shows a schematic cross-sectional top view of a light emitting device 100 . The light sources 102 may be arranged in a tapered structure 1002 respectively . The tapered structure 1002 may be configured as reflector for at least the first wavelength, respectively . For example , the tapered structure 1002 may be formed of a white matrix, e . g . a white epoxy, or a metal, e.g. additionally as a heat sink for thermal management.

[0112] The first substrate 110 may include a first surface facing the light sources 102. The first surface may include a first optical structure 1102 respectively arranged in a light path of a pump source 102-1, 102-2, 102-3. FIG.11 shows a schematic cross-sectional side view of a light emitting device 100 having a first optical structure 1102. The first optical structure 1102 may be separated by a distance from the pump source 102, respectively. The first optical structure 1102 may be a Fresnel lens pattern or metastructure, e.g. a metagrating, for example.

[0113] The first optical structure 1102 may add a lens effect on the first surface of the first substrate 110. This may improve a coupling to pump light into the optical cavity 104, and thus may improve an extraction of electromagnetic radiation of the second wavelength 112.

[0114] Alternatively, or in addition as illustrated in FIG.12, the first substrate 110 may include a second surface opposite to a surface facing the light sources 102, and the second surface may include a second optical structure 1202 respectively arranged in a light path of a pump source 102-1, 102-2, 102-2. The second surface may be a light emission surface of the light emitting device 100.

[0115] The second optical structure may be a collimating optic, e.g. any one of an optical metastructure, a Fresnel lens, or a microlens array (MLA) .

[0116] In other words, the first substrate 110 includes a first surface facing the light sources 102 and a second surface opposite to the first surface, wherein at least one of the first surface and the second surface includes an optical structure 1102, 1202 respectively arranged in a light path of a pump source 102-1, 102-2, 102-3. The optical structures 1102, 1202 of at least a subset of light sources 102 of the plurality of light sources 102 may be configured to focus the light to a shared focal point 1306, as illustrated in the schematic cross-sectional side view in FIG.13. The light emitting device 100 may include an optical element 1302 arranged in the shared focal point. The optical element 1302 may be any one of a diffractive optic, e.g. a grating, e.g. a metagrating .

[0117] The optical element 1302 may generate a combined beam 1304, e.g. generate a collimated, combined beam of coherent electromagnetic radiations of the second wavelengths.

[0118] Thus, optical structures 1102, 1202 may diverge beams of the optical channels and overlap their spots on a common focal point (also denoted as burning point) . Afterwards the optical element 1302, e.g. a diffractive optic, may combine beams and generate a single beam 1302.

[0119] In the examples above, optical cavities 104-1, 104-2, 104-3 for the pump source 102, 102-2, 102-3 have been arranged adjacent to each other. However, alternatively or in addition, optical cavities 104-1, 104-2, 104-3 may be stacked above one another as illustrated in the schematic cross- sectional view in FIG.14A. Note that there are various combinations of the arrangement of optical cavities possible based on the examples described above.

[0120] For example, the metastructure may be a first metastructure 1402 and the light emitting device 100 may further include a second metastructure 1404, 1406 arranged on or above the first metastructure 1402.

[0121] The second metastructure 1404 may be configured to include a resonance at about a third wavelength. Third wavelength may be the any one of the first wavelength 106 or another wavelength di f ferent from the first wavelength 106 and the second wavelength 112 . Thus , each optical metastructure 1402 , 1404 , 1406 may be getting pumped at a speci fic wavelength (Xdome-i with i being an integer , as illustrated in FIG . 14B ) and lases at its corresponding wavelength (Xi ) . Other optical metastructures may be transparent at third wavelength .

[0122] The first metastructure 1402 and the second metastructure 1404 may be spaced apart from each other . The first metastructure 1402 and the second metastructure 1404 may be embedded in a shared substrate . The first metastructure 1402 and the second metastructure 1404 may be arranged in a shared light path of at least one light source .

[0123] Alternatively, or in addition, the first metastructure 1402 may be arranged in a third substrate 110- 1 and second metastructure 1404 may be arranged in a fourth substrate 110- 1 , wherein third substrate 110- 1 and the fourth substrate 110-2 form the first substrate 110 , for example . The third substrate 110- 1 and the fourth substrate 110-2 may be stacked above one another .

[0124] Thus , the light beam 1410 emitted by the light emitting device 100 , can already be collimated having a narrow band angle as described above , without an additional optical element .

[0125] Note that there may be a shared tapered interspacer structure 1002 for more than one pump source 102 , as illustrated in FIG . 14A.

[0126] FIG . 15 shows a flow diagram of a method to manufacture a light emitting device , see also FIGs . l to 14 .

[0127] The method 1500 of manufacturing a light emitting device 100 , may include forming 1502 a wavelength conversion structure 202 configured to convert electromagnetic radiation of a first wavelength 106 into an electromagnetic radiation of a second wavelength 112 ; forming 1504 a plurality of light sources 102 , wherein each light source may be configured to emit an electromagnetic radiation of the first wavelength 106 , wherein the plurality of light sources 102 may be arranged on or above the wavelength conversion structure 202 ; and forming 1506 an optical metastructure 204 may be configured as optical cavity may include a resonance frequency at about the second wavelength 112 .

[0128] A first substrate 110 may include any one of the wavelength conversion structure 202 or the optical metastructure 204 embedded therein . The first substrate 110 may be formed of a material having a first refractive index and the optical metastructure 204 has a second refractive index larger than the first refractive index at least for the second wavelength 112 .

[0129] The plurality of light sources 102 may be formed on a shared surface of the first substrate 110 .

[0130] Alternatively, or in addition, the light sources 102 may be formed by depositing epitaxial layers , wherein the epitaxial layers may be formed on the first substrate 110 .

[0131] Alternatively, or in addition, the plurality of light sources 102 may be arranged on the first substrate 110 , e . g . using a pick-and-place method .

[0132] Alternatively, or in addition, the first substrate 110 may be formed on or above the plurality of light sources 102 .

[0133] The method may further include any feature as described for the device above .

[0134] In the following some examples are described, which relate to what is described herein and shown in the figures . Example 1 is a light emitting device , including a wavelength conversion structure configured to convert electromagnetic radiation of a first wavelength in to an electromagnetic radiation of a second wavelength; a plurality of light sources , wherein at least one light source is configured to emit an electromagnetic radiation of the first wavelength, wherein the plurality of light sources are arranged on or above the wavelength conversion structure ; and an optical metastructure configured as optical cavity including a resonance frequency at about the second wavelength .

[0135] Note , the metastructure includes a nanostructured surface having a plurality of optically coupled nano-elements causing the collective optical resonance .

[0136] In Example 2 , the subj ect matter of Example 1 can optionally include that the optical metastructure is configured having a Q factor of more than 1000 .

[0137] In Example 3 , the subj ect matter of any one of Examples 1 to 2 can optionally include that the wavelength conversion structure and the optical metastructure are stacked above one another in the optical path of the plurality of light sources .

[0138] In Example 4 , the subj ect matter of any one of Examples 1 to 2 can optionally include that the wavelength conversion structure and the optical metastructure are integrated in a shared layer .

[0139] In Example 5 , the subj ect matter of any one of Examples 1 to

[0140] 4 can optionally include that the wavelength conversion structure , the plurality of light sources , and the optical metastructure are integrated a shared layer stack .

[0141] In Example 6 , the subj ect matter of any one of Examples 1 to

[0142] 5 can optionally further include a first substrate , wherein the first substrate includes any one of the wavelength conversion structure or the optical metastructure embedded therein .

[0143] In Example 7 , the subj ect matter of Example 5 can optionally include that the first substrate is formed of a material having a first refractive index and the optical metastructure has a second refractive index larger than the first refractive index at least for the second wavelength .

[0144] In Example 8 , the subj ect matter of any one of Examples 6 to

[0145] 7 can optionally include that the plurality of light sources are formed on a shared surface of the first substrate .

[0146] In Example 9 , the subj ect matter of any one of Examples 1 to

[0147] 8 can optionally include that the optical metastructure includes a plurality of optical nano-elements , wherein the optical nano-elements are configured for emitting linear polari zed electromagnetic radiation .

[0148] In Example 10 , the subj ect matter of any one of Examples 1 to 8 can optionally include that the optical metastructure includes a plurality of optical nano-elements , wherein the optical nano-elements are configured for emitting chiral polari zed electromagnetic radiation .

[0149] In Example 11 , the subj ect matter of any one of Examples 1 to 10 can optionally further include an optical filter in the light path of the optical metastructure , wherein the optical filter is configured to block, e . g . absorb or reflect , electromagnetic radiation of the first wavelength .

[0150] In Example 12 , the subj ect matter of Example 11 can optionally include that the optical filter is arranged at an emission surface of the light emitting device . In Example 13 , the subj ect matter of any one of Examples 1 to

[0151] 12 can optionally further include a controller configured to control at least a first subset of the plurality of light sources independent from a second subset of the plurality of light sources .

[0152] In Example 14 , the subj ect matter of any one of Examples 1 to

[0153] 13 can optionally further include a black structure laterally adj acent to at least one of the light sources .

[0154] In Example 15 , the subj ect matter of any one of Examples 1 to

[0155] 14 can optionally include that at least a subset of the light sources are light emitting diodes .

[0156] In Example 16 , the subj ect matter of Example 15 can optionally include that the light emitting diode have a si ze of less than about 100 x 100 pm2 , respectively .

[0157] In Example 17 , the subj ect matter of any one of Examples 1 to

[0158] 16 can optionally include that the light sources are arranged in a shared plane adj acent to each other .

[0159] In Example 18 , the subj ect matter of any one of Examples 1 to

[0160] 17 can optionally include that the plurality of light sources includes at least a first light source configured to emit light of a first color bin and a second light source configured to emit light of a second color bin, wherein the first color bin is di f ferent from the second color bin .

[0161] In Example 19 , the subj ect matter of any one of Examples 1 to

[0162] 18 can optionally include that at least a subset of the light sources and the wavelength conversion structure are configured to generate a white light when combined .

[0163] In Example 20 , the subj ect matter of any one of Examples 1 to

[0164] 19 can optionally further include a second substrate , wherein the light sources are arranged on the second substrate . In Example 21 , the subj ect matter of Example 20 can optionally include that the second substrate is a printed circuit board .

[0165] In Example 22 , the subj ect matter of Example 21 can optionally include that the light sources are electrically coupled to the printed circuit board .

[0166] In Example 23 , the subj ect matter of any one of Examples 20 to 22 can optionally further include a first substrate , wherein the substrate includes any one of the wavelength conversion structure or the optical metastructure , wherein the first substrate is arranged on or above the second substrate .

[0167] In Example 24 , the subj ect matter of Example 23 can optionally further include an interspacer structure arranged between the first substrate and the second substrate .

[0168] In Example 25 , the subj ect matter of Example 24 can optionally include that the interspacer structure is configured as a black matrix arranged between the first substrate and the second substrate .

[0169] In Example 26 , the subj ect matter of any one of Examples 24 to 25 can optionally include that the interspacer structure includes tapered structures , wherein a light source is arranged in a tapered structure respectively .

[0170] In Example 27 , the subj ect matter of Examples 26 can optionally include that the tapered structure is configured as reflector for at least the first wavelength .

[0171] In Example 28 , the subj ect matter of any one of Examples 23 to 27 can optionally include that the interspacer structure is arranged between adj acent light sources . In Example 29 , the subj ect matter of any one of Examples 23 to 28 can optionally include that the interspacer structure is configured to optically isolate adj acent light sources .

[0172] In Example 30 , the subj ect matter of any one of Examples 6 to 29 can optionally include that the first substrate includes a first surface facing the light sources , wherein the first surface includes a first optical structure respectively arranged in a light path of a light source .

[0173] In Example 31 , the subj ect matter of Example 30 can optionally include that the first optical structure is separated by a distance from the light source , respectively .

[0174] In Example 32 , the subj ect matter of any one of Examples 30 to 31 can optionally include that the first optical structure is a Fresnel lens pattern .

[0175] In Example 33 , the subj ect matter of any one of Examples 6 to 29 can optionally include that the first substrate includes a second surface opposite to a surface facing the light sources , wherein the second surface includes a second optical structure respectively arranged in a light path of a light source .

[0176] In Example 34 , the subj ect matter of Example 33 can optionally include that the second optical structure is a Fresnel lens pattern .

[0177] In Example 35 , the subj ect matter of any one of Examples 33 to 34 can optionally include that the second surface is a light emission surface of the light emitting device .

[0178] In Example 36 , the subj ect matter of any one of Examples 6 to 35 can optionally further include an optical filter embedded in the first substrate . In Example 37 , the subj ect matter of Example 36 can optionally include that the optical filter is not exposed on an emission surface of the substrate .

[0179] In Example 38 , the subj ect matter of any one of Examples 6 to 37 can optionally further include a dichroic mirror embedded in the first substrate .

[0180] In Example 39 , the subj ect matter of Example 38 can optionally include that the dichroic mirror is not exposed on an emission surface of the substrate .

[0181] In Example 40 , the subj ect matter of any one of Examples 6 to 39 can optionally include that the first substrate includes a first surface facing the light sources and a second surface opposite to the first surface , wherein at least one of the first surface and the second surface includes an optical structure respectively arranged in a light path of a light source ; and wherein the optical structures of at least a subset of light sources of the plurality of light sources is configured to focus the light to a shared focal point .

[0182] In Example 41 , the subj ect matter of Example 40 can optionally further include an optical element arranged in the shared focal point .

[0183] In Example 42 , the subj ect matter of Example 41 can optionally include that the optical element is any one of a di f fractive optic, e . g . a grating, e . g . a metagrating .

[0184] In Example 43 , the subj ect matter of any one of Examples 1 to 42 can optionally include that the metastructure is a first metastructure and the light emitting device further includes a second metastructure arranged on or above the first metastructure . In Example 44 , the subj ect matter of Example 43 can optionally include that the second metastructure is configured to include a resonance at about a third wavelength, wherein the third wavelength is the any one of the first wavelength or another wavelength di f ferent from the first wavelength and the second wavelength .

[0185] In Example 45 , the subj ect matter of any one of Examples 43 to 44 can optionally include that the first metastructure and the second metastructure are spaced apart from each other .

[0186] In Example 46 , the subj ect matter of any one of Examples 43 to 45 can optionally include that the first metastructure and the second metastructure are embedded in a shared substrate .

[0187] In Example 47 , the subj ect matter of any one of Examples 43 to 46 can optionally include that the first metastructure and the second metastructure are arranged in a shared l ight path of at least one light source .

[0188] In Example 48 , the subj ect matter of any one of Examples 43 to 47 can optionally include that the first metastructure is arranged in a third substrate and second metastructure is arranged in a fourth substrate , wherein third substrate and the fourth form the first substrate .

[0189] In Example 49 , the subj ect matter of Example 48 can optionally include that third substrate and the fourth are stacked above one another .

[0190] Example 50 is method of manufacturing a light emitting device , including forming a wavelength conversion structure configured to convert electromagnetic radiation of a first wavelength in to an electromagnetic radiation of a second wavelength; forming a plurality of light sources , wherein each light source is configured to emit an electromagnetic radiation of the first wavelength, wherein the plurality of light sources are arranged on or above the wavelength conversion structure ; and forming an optical metastructure configured as optical cavity including a resonance frequency at about the second wavelength .

[0191] In Example 51 , the subj ect matter of Example 50 can optionally further include a first substrate , wherein the substrate includes any one of the wavelength conversion structure or the optical metastructure embedded therein .

[0192] In Example 52 , the subj ect matter of any one of Examples 50 to 51 can optionally include that the first substrate is formed of a material having a first refractive index and the optical metastructure has a second refractive index larger than the first refractive index at least for the second wavelength .

[0193] In Example 53 , the subj ect matter of any one of Examples 50 to 52 can optionally include that the plurality of light sources are formed on a shared surface of the first substrate .

[0194] In Example 54 , the subj ect matter of any one of Examples 50 to 53 can optionally include that the light sources are formed by depositing epitaxial layers , wherein the epitaxial layers are formed on the first substrate .

[0195] In Example 55 , the subj ect matter of any one of Examples 50 to 53 can optionally include that the plurality of light sources are arranged on the first substrate , e . g . using a pick-and-place method .

[0196] In Example 56 , the subj ect matter of any one of Examples 50 to 53 can optionally include that the first substrate is formed on or above the plurality of light sources . The method may further include any feature as described for the device above.

[0197] Example 57 is a wearable display device, e.g. an augmented reality glass or a virtual reality glass. The wearable display device includes a light emitting device of any one of Examples 1 to 49, and a waveguide structure optically coupled to the light emitting device. The waveguide structure may be a planar waveguide, e.g. having a bend shape.

[0198] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any example or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other examples or designs .

[0199] The words "plurality" and "multiple" in the description or the claims expressly refer to a quantity greater than one. The terms "group (of) ", "set [of] ", "collection (of) ", "series (of)", "sequence (of)", "grouping (of)", etc., and the like in the description or in the claims refer to a quantity equal to or greater than one, i.e. one or more. Any term expressed in plural form that does not expressly state "plurality" or "multiple" likewise refers to a quantity equal to or greater than one.

[0200] The term "connected" can be understood in the sense of a (e.g. mechanical, optical and / or electrical) , e.g. direct or indirect, connection and / or interaction. For example, several elements can be connected together mechanically such that they are physically retained (e.g., a plug connected to a socket) and electrically such that they have an electrically conductive path (e.g., signal paths exist along a communicative chain) .

[0201] While the above descriptions and connected figures may depict optical device components as separate elements, skilled persons will appreciate the various possibilities to combine or integrate discrete optical functions into a single element . Such may include combining two or more components from a single component . Conversely, skilled persons will recogni ze the possibility to separate a single element into two or more discrete elements , such as splitting a single component into two or more separate component .

[0202] It is appreciated that implementations of methods detailed herein are exemplary in nature , and are thus understood as capable of being implemented in a corresponding device . Likewise , it is appreciated that implementations of devices detailed herein are understood as capable of being implemented as a corresponding method . It is thus understood that a device corresponding to a method detailed herein may include one or more components configured to perform each aspect of the related method .

[0203] All acronyms defined in the above description additionally hold in all claims included herein .

[0204] While the disclosure has been particularly shown and described with reference to speci fic embodiments , it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims . The scope of the disclosure is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced . Reference Numeral List

[0205] 100 light emitting device

[0206] 102, 102-1, 102-2, 102-3 light source

[0207] 104, 104-1, 104-2 optical cavity

[0208] 106, 106-1, 106-2 electromagnetic radiation of first wavelength

[0209] 108 lateral distance

[0210] 110, 110-1, 110-2 first substrate

[0211] 112, 112-1, 112-2 electromagnetic radiation of second wavelength

[0212] 202 optical metastructure

[0213] 204 wavelength conversion structure

[0214] 206 unit cell of an optical metastructure

[0215] 208 optical filter structure

[0216] 402, 404 subsets of light sources

[0217] 802, 804 optical channels

[0218] 902 second substrate

[0219] 904 interspacer structure

[0220] 906 optical element - dichroic mirror, optical filter

[0221] 1002 tapered structure

[0222] 1102, 1202 optical structure

[0223] 1302 optical element

[0224] 1304,1402 combined beam

[0225] 1306 focal point

[0226] 1402, 1404, 1406 optical metastructure

[0227] 1500, 1502, 1504, 1506 method and method steps

Claims

CLAIMS1 . A light emitting device , comprising : a wavelength conversion structure configured to convert electromagnetic radiation of a first wavelength into an electromagnetic radiation of a second wavelength; a plurality of light sources , wherein at least one light source is configured to emit an electromagnetic radiation of the first wavelength, wherein the plurality of light sources are arranged on or above the wavelength conversion structure ; and an optical metastructure configured as optical cavity comprising a resonance frequency at about the second wavelength, wherein the metastructure comprises a nanostructured surface having a plurality of optically coupled nano-elements causing the collective optical resonance .2 . The light emitting device of claim 1 , wherein the optical metastructure is configured having a Q factor of more than 1000 .3 . The light emitting device of claim 1 or 2 , wherein the wavelength conversion structure and the optical metastructure are integrated in a shared layer .4 . The light emitting device of any one of claims 1 to 3 , further comprising a first substrate , wherein the first substrate comprises any one of the wavelength conversion structure or the optical metastructure embedded therein, wherein the first substrate is formed of a material having a first refractive index and the optical metastructure has a second refractive index larger than the first refractive index at least for the second wavelength .

5. The light emitting device of claim 4 , wherein the plurality of light sources are formed on a shared surface of the first substrate .

6. The light emitting device of any one of claims 1 to 5 , wherein the optical metastructure comprises a plurality of optical nano-elements , wherein the optical nanoelements are configured for any one of emitting linear polari zed electromagnetic radiation or for emitting chiral polari zed electromagnetic radiation .7 . The light emitting device of any one of claims 1 to 6 , further comprising an optical fi lter in the light path of the optical metastructure , wherein the optical filter is configured to block electromagnetic radiation of the first wavelength .8 . The light emitting device of any one of claims 1 to 7 , further comprising a controller configured to control at least a first subset of the plurality of light sources independent from a second subset of the plurality of light sources .

9. The light emitting device of any one of claims 1 to 8 , wherein at least a subset of the light sources are light emitting diodes , wherein each light emitting diode has a si ze of less than about 100 x 100 pm2 .10 . The light emitting device of any one of claims 1 to 9 , wherein the plurality of light sources comprises at least a first light source configured to emit light of a first colour bin and a second light source configured to emit light of a second colour bin, wherein the first colour bin is di f ferent from the second colour bin .11 . The light emitting device of any one of claims 1 to 10 , further comprising : a second substrate , wherein the light sources are arranged on the second substrate , wherein the second substrate is a printed circuit board, wherein the light sources are electrically coupled to the printed circuit board .12 . The light emitting device of any one of claims 1 to 11 , comprising a first substrate , wherein the first substrate comprises any one of the wavelength conversion first structure or the optical metastructure , a second substrate , wherein the light sources are arranged on the second substrate , and an interspacer structure arranged between the first substrate and the second substrate .13 . The light emitting device of claim 12 , wherein the interspacer structure is configured as a black matrix .14 . The light emitting device of any one of claims 12 to 13 , wherein the interspacer structure includes tapered structures , wherein a light source is arranged in a tapered structure respectively .15 . The light emitting device of any one of claims 4 to 14 , wherein the first substrate comprises a first surface facing the light sources and a second surface opposite to the first surface , wherein at least one of the first surface and the second surface comprises an optical structure respectively arranged in a light path of a light source .16 . The light emitting device of claim 15 , wherein the optical structures of at least a subset of light sources of the plurality of light sources isconfigured to focus the light to a shared focal point ; and further comprising an optical element arranged in the shared focal point .17 . The light emitting device of any one of claims 1 to 16 , wherein the metastructure is a first metastructure and the light emitting device further comprises a second metastructure arranged on or above the first metastructure , wherein the second metastructure is configured to comprise a resonance at about a third wavelength, wherein the third wavelength is the any one of the first wavelength or another wavelength di f ferent from the first wavelength and the second wavelength .18 . A wearable display device , comprising : a light emitting device of any one of claims 1 to 17 , and a waveguide structure optically coupled to the light emitting device .19 . A method of manufacturing a light emitting device , the method comprising : forming a wavelength conversion structure configured to convert electromagnetic radiation of a first wavelength into an electromagnetic radiation of a second wavelength; forming a plurality of light sources , wherein each light source is configured to emit an electromagnetic radiation of the first wavelength, wherein the plurality of light sources are arranged on or above the wavelength conversion structure ; and forming an optical metastructure configured as optical cavity including a resonance frequency at about the second wavelength, wherein the metastructure comprises a nanostructured surface having a plurality of optically coupled nanoelements causing the collective optical resonance .20 . The method of claim 19 , wherein the light sources are formed by depositing epitaxial layers , wherein the epitaxial layers are formed on the first substrate

Images