optoelectronic devices

Abstract

An optoelectronic device (1) is identified, comprising at least one emitter (2) configured to emit electromagnetic radiation (3) in the ultraviolet spectral range, and at least one optical element (4) configured to redirect the electromagnetic radiation (3) towards an external surface (5) such that the external surface (5) is uniformly illuminated.

Description

[Technical Field]

[0001] As used herein, optoelectronic devices are specified. Summary of the Invention [Problem to be solved by the invention]

[0002] At least one object of certain embodiments is to identify an optoelectronic device for uniformly illuminating an external surface with electromagnetic radiation. [Means for solving the problem]

[0003] According to at least one embodiment, the optoelectronic device includes at least one emitter configured to emit electromagnetic radiation in the ultraviolet spectral range. For example, the emitter emits electromagnetic radiation in the wavelength range of 100 nm to 400 nm. Preferably, the emitter emits electromagnetic radiation in the UV-C spectral range, which is in the wavelength range of 100 nm to 280 nm. In particular, the emitter is configured to convert electrical current into electromagnetic radiation during operation.

[0004] According to at least one embodiment, an optoelectronic device includes at least one optical element configured to redirect electromagnetic radiation to an external surface so as to uniformly illuminate the external surface, for example, by refraction, reflection, diffraction, scattering, and / or interference of the electromagnetic radiation.

[0005] Here and below, an external surface is "uniformly" illuminated if the intensity of the electromagnetic radiation varies across the illuminated external surface by at most 40%, preferably at most 20%, particularly preferably at most 10%. In other words, the difference between the maximum and minimum intensity of the electromagnetic radiation in different areas of the illuminated external surface is no more than 40%, preferably no more than 20%, particularly preferably no more than 10% of the average intensity of the electromagnetic radiation across the illuminated surface.

[0006] According to a preferred embodiment, the optoelectronic device comprises: at least one emitter configured to emit electromagnetic radiation in the ultraviolet spectral range; and at least one optical element configured to redirect the electromagnetic radiation onto the exterior surface such that the exterior surface is uniformly illuminated.

[0007] The optoelectronic devices described herein have the advantage of providing uniform area illumination while achieving a slim profile. For example, the distance between the optoelectronic device and the external surface may be less than the length and / or width of the external surface to be uniformly illuminated by electromagnetic radiation. Furthermore, the distance between the optoelectronic device and the external surface may be less than the distance between two emitters of the optoelectronic device. Furthermore, the optical element may reduce the number of emitters required for uniform area illumination compared to an optoelectronic device without the optical element, thereby reducing the cost of the optoelectronic device.

[0008] Uniform area illumination is advantageous for UV disinfection applications. In optoelectronic devices for UV disinfection applications, when emitters directly illuminate an external surface and no optical elements for redirecting electromagnetic radiation are positioned between the emitters and the external surface, the lateral distance between different emitters is approximately equal to the longitudinal distance between the emitters and the illuminated surface to achieve uniform area illumination. Here, "lateral" refers to the direction parallel to the external surface, and "vertical" refers to the direction perpendicular to the external surface.

[0009] When the available space for placing an optoelectronic device is vertically constrained, for example in a compact air conditioning unit, a large number of emitters may be required to achieve uniform area illumination along with a small vertical distance between the emitters and the external surface. In this case, the illumination intensity required for sterilization applications may be significantly exceeded and / or the cost of the optoelectronic device may be high due to the large number of emitters required. Advantageously, the optoelectronic devices described herein enable a reduced number of emitters while keeping the vertical distance between the emitters and the external surface as small as possible.

[0010] According to at least one embodiment of the optoelectronic device, the emitter is a semiconductor light emitting diode. In particular, the semiconductor light emitting diode comprises a semiconductor layer stack having a pn junction for converting electrical current into electromagnetic radiation. For example, the semiconductor layer stack comprises a III / V compound semiconductor material.

[0011] III / V compound semiconductor materials contain at least one element from group 3, such as B, Al, Ga, or In, and one element from group 5, such as N, P, or As. In particular, the term III / V compound semiconductor materials includes a group of binary, ternary, or quaternary compounds that contain at least one element from group 3 and at least one element from group 5. Furthermore, III / V semiconductor materials may contain one or more dopants.

[0012] The semiconductor stack preferably includes or is made of a nitride compound semiconductor material. The nitride compound semiconductor material is a group III / V compound semiconductor material containing nitrogen, such as In. x Al y Ga 1-x-y N(0≦x≦1, 0≦y≦1 and x+y≦1).

[0013] According to at least one embodiment, the optoelectronic device comprises at least two emitters, the distance between the two emitters being at least twice, preferably at least five times, the smallest distance between one of the emitters and the external surface. In particular, the distance between the two emitters is the lateral distance, i.e., the distance in a direction parallel to the external surface. Furthermore, the smallest distance between one of the emitters and the external surface is preferably the longitudinal distance, i.e., the distance in a direction perpendicular to the external surface.

[0014] According to at least one embodiment of an optoelectronic device, the optical element comprises a light guide having an inlet surface and an outlet surface for electromagnetic radiation, the outlet surface being at least twice, preferably at least ten times, larger than the inlet surface. The inlet surface and / or outlet surface may be flat or curved. In particular, during operation of the optoelectronic device, electromagnetic radiation is introduced into the light guide via the inlet surface and extracted from the light guide via the outlet surface. In particular, the area of the outlet surface is at least twice, preferably at least ten times, larger than the area of the inlet surface.

[0015] In particular, the light guide comprises or consists of a material that is at least partially transparent to the electromagnetic radiation emitted by the emitter, for example the light guide comprises fused silica.

[0016] A light guide may be, for example, quasi-one-dimensional or quasi-two-dimensional. Here and hereinafter, "quasi-one-dimensional" refers to a light guide whose spatial extent in one direction is much greater than its spatial extent in two complementary, orthogonal directions. For example, the spatial extent in one direction is at least ten times greater than the spatial extent in the other two directions. Here and hereinafter, "quasi-two-dimensional" refers to a light guide whose spatial extent in one direction is much less than its spatial extent in two complementary, orthogonal directions. For example, the spatial extent in one direction is at most ten times less than the spatial extent in the other two directions.

[0017] For example, the light guide may have a cylindrical or thin sheet shape. The cross section of the cylinder may be, for example, circular, semicircular, elliptical, rectangular, or square. Here, the cross section preferably refers to the shape of the base of the cylinder. In particular, the light inlet surface corresponds to one or both of the flat bases at opposite ends of the cylinder, and the light outlet surface corresponds to the lateral outer surface of the cylinder. Preferably, the lateral outer surface connects the two bases at opposite ends of the cylinder.

[0018] According to at least one embodiment of the optoelectronic device, the light extraction surface has a structuring such that the electromagnetic radiation is scattered from the light guide. In particular, the electromagnetic radiation is diffusely scattered from the light guide. For example, the electromagnetic radiation propagates inside the light guide parallel to the light extraction surface. In order to extract the electromagnetic radiation from the light guide, the light extraction surface comprises a structuring, for example in the form of a roughening. In particular, the light extraction surface comprises a plurality of recesses.

[0019] The characteristics of a single recess described below apply to most of the recesses, preferably to all of them. Preferably, the depth of the recess in a direction perpendicular to the light extraction surface is greater than the wavelength of the electromagnetic radiation, so that the electromagnetic radiation is diffusely scattered in the recesses. Different recesses may have different shapes or may have the same shape within manufacturing tolerances. The shape of the recesses may be random, for example, columnar, cuboidal, or pyramidal, or may be regular. In particular, the recesses are randomly or regularly distributed over the entire light extraction surface. The surface of the light guide opposite the light extraction surface may also be structured as described above.

[0020] According to at least one embodiment of the optoelectronic device, the structuring is configured to compensate for intensity gradients of the electromagnetic radiation within the light guide, such that the intensity of the extracted electromagnetic radiation is uniform across the light extraction surface. In particular, the intensity of the electromagnetic radiation may decrease along the light guide with increasing distance from the light extraction surface, resulting in intensity gradients within the light guide.

[0021] For example, the area density of recesses in the light extraction surface may increase with increasing distance from the light ingestion surface, such that electromagnetic radiation is more strongly scattered from the light guide at increasing distances from the light ingestion surface, and the distance between the light extraction surface and the external surface may decrease with increasing distance from the light ingestion surface to compensate for intensity gradients within the light guide.

[0022] According to at least one embodiment of an optoelectronic device, the optical element includes light-scattering particles embedded in a transparent matrix material. In particular, the light-scattering particles change the propagation direction of at least a portion of electromagnetic radiation propagating within the optical element. Preferably, the light-scattering particles have an average size equal to or less than the wavelength of the electromagnetic radiation.

[0023] Preferably, the light scattering particles are distributed along the light guide such that the intensity of the extracted electromagnetic radiation is uniform across the light extraction surface, e.g., the number of light scattering particles per volume increases with increasing distance from the light incoupling surface.

[0024] The matrix material may comprise glass, such as quartz glass. In particular, the transparent matrix material is at least partially transparent to the electromagnetic radiation generated by the emitter during operation. For example, the matrix material absorbs up to 10% of the electromagnetic radiation coupled into the light guide after an optical path length of about 10 mm.

[0025] The matrix material may include a plurality of bubbles. In particular, the bubbles are closed cavities within the matrix material, preferably filled with air. For example, the bubbles change the propagation direction of at least a portion of the electromagnetic radiation propagating within the optical element. Preferably, the average size of the bubbles is equal to or less than the wavelength of the electromagnetic radiation. In particular, the bubbles can scatter electromagnetic radiation in a manner similar to or equivalent to that of scattering particles.

[0026] According to at least one embodiment of the optoelectronic device, the optical element comprises a reflective element. For example, the reflective element comprises or consists of a reflective surface coating and / or a mirror. The reflective element may be planar or curved. For example, the reflective element comprises a surface coating on a portion of the light extraction surface of the light guide. In particular, the reflective surface coating comprises a metal, such as aluminum.

[0027] For example, the reflective surface may have no focal point, one focal point, or at least two focal points. The reflective surface may have multiple focal points. In particular, the reflective surface may have multiple regions or sections, each having a separate focal point. For example, the multiple focal points may be closely spaced along a line to form a focal line. The focal line may be straight or curved. A curved focal line may be a curve in a two-dimensional plane or in three-dimensional space. The multiple focal points may be arranged in a two-dimensional plane without forming a focal line. For example, an emitter may be located at at least one focal point, or an emitter may be located offset from at least one focal point, or an emitter may be located offset from all focal points of the reflective surface.

[0028] According to at least one embodiment of an optoelectronic device, the emitter and reflective element do not overlap the external surface in a plan view of the external surface and / or in a side view of the external surface. In particular, here and hereinafter, "plan view" refers to a view along a direction perpendicular to the external surface, and "side view" refers to a view along a direction parallel to the external surface.

[0029] For example, a fluid may flow across or parallel to the exterior surface and the electromagnetic radiation emitted by the optoelectronic device may be configured to sterilize the fluid. Positioning the optoelectronic device so that it does not overlap the exterior surface allows the fluid to flow unimpeded by the optoelectronic device.

[0030] According to at least one embodiment of the optoelectronic device, the area of the external surface is at least 10 times, preferably at least 20 times, the area of the reflective surface of the reflective element. Thus, the optoelectronic device is preferably small compared to the external surface.

[0031] According to at least one embodiment of the optoelectronic device, the reflective surface is a free-form surface. In particular, the shape of the reflective surface is configured so that the electromagnetic radiation emitted by the emitter is redirected to the external surface and the external surface is uniformly illuminated. Preferably, the free-form surface is curved. For example, the free-form surface has different curvatures along different directions. In particular, the free-form surface may have a shape that is not hyperbolic, parabolic, or spherical.

[0032] According to at least one embodiment of the optoelectronic device, the exterior surface has an aspect ratio greater than 2, preferably greater than 5, and the reflective element collimates the electromagnetic radiation along the minor axis of the exterior surface and homogenizes the intensity profile of the electromagnetic radiation along the major axis of the exterior surface. Here and hereinafter, "aspect ratio" refers to the ratio between the maximum diameter and the minimum diameter of the exterior surface. Furthermore, "major axis" refers to the direction in which the diameter is greatest, and "minor axis" refers to the direction in which the diameter is smallest.

[0033] In particular, the collimated electromagnetic radiation propagates substantially parallel with a small beam divergence across the minor axis, e.g., a beam divergence of at most 30°, preferably at most 20°, and particularly preferably at most 10°. In other words, the electromagnetic radiation propagates within a pyramid with an opening angle across the minor axis of at most 10°. Furthermore, a uniform intensity profile along the major axis provides a uniform surface illumination.

[0034] Furthermore, a fluid cooling system is specified, in particular the fluid cooling system comprises the optoelectronic device described above, and all features of the optoelectronic device are also disclosed for the fluid cooling system and vice versa.

[0035] According to at least one embodiment, a fluid cooling system includes the above-described optoelectronic device. In particular, the optoelectronic device is configured to prevent the formation of a film of biological material on a portion of the fluid cooling system due to irradiation with ultraviolet electromagnetic radiation. Furthermore, the optoelectronic device may at least partially sterilize a fluid flowing through the fluid cooling system during operation. For example, the electromagnetic radiation emitted by the optoelectronic device during operation inactivates or destroys at least 70%, preferably at least 90%, and particularly preferably at least 99% of bacteria and / or viruses in the fluid flowing through the fluid cooling system.

[0036] According to at least one embodiment, the fluid cooling system includes at least two cooling fins arranged parallel to one another and configured to cool a fluid flowing between the two cooling fins, and electromagnetic radiation emitted by the optoelectronic device irradiates the fluid between the two cooling fins during operation. In particular, for example, the two cooling fins have a lower temperature than the fluid. Preferably, the fluid may be air flowing between the two cooling fins. The fluid may also be a liquid flowing between the cooling fins. For example, the fluid cooling system is an air conditioning system.

[0037] In at least one embodiment of the fluid cooling system, the optoelectronic device is disposed outside a volume defined by two cooling fins, e.g., the two cooling fins have the same shape, and in this case, the two cooling fins partially enclose a volume defined by, e.g., the area of the cooling fins and the distance between the two cooling fins.

[0038] The fluid cooling system may comprise a plurality of cooling fins arranged parallel to one another, in which case the optoelectronic device may be located outside the volume spanned by the plurality of cooling fins, advantageously such that the optoelectronic device does not impede the flow of fluid between the cooling fins.

[0039] According to at least one embodiment of the fluid cooling system, the external surface illuminated by electromagnetic radiation during operation corresponds to a cross section of the volume through which the fluid flows, in particular the cross section being arranged perpendicular to the main plane of extension of the cooling fins.

[0040] According to at least one embodiment of the fluid cooling system, the optoelectronic device is positioned between two cooling fins such that the external surface that is irradiated by electromagnetic radiation during operation corresponds to a major surface of at least one of the two cooling fins.

[0041] Further advantageous embodiments and further embodiments of the optoelectronic device and fluid cooling system will become apparent from the following exemplary embodiments described in conjunction with the figures. [Brief explanation of the drawings]

[0042] [Figure 1] 1 shows a schematic cross-sectional view of an optoelectronic device according to an embodiment. [Figure 2] 1 illustrates a schematic intensity distribution of electromagnetic radiation at an external surface according to one embodiment. [Figure 3] 1A-1D show schematic cross-sectional views of fluid cooling systems according to different illustrative embodiments; [Figure 4] 1A-1D show schematic cross-sectional views of fluid cooling systems according to different illustrative embodiments; [Figure 5] 1A-1D show schematic cross-sectional views of fluid cooling systems according to different illustrative embodiments; [Figure 6] 1A-1D show schematic cross-sectional views of fluid cooling systems according to different illustrative embodiments; [Figure 7] 1A-1D show schematic cross-sectional views of fluid cooling systems according to different illustrative embodiments; [Figure 8] 10A-10C show different schematic cross-sectional views of a fluid cooling system according to further exemplary embodiments; [Figure 9] 10A-10C show different schematic cross-sectional views of a fluid cooling system according to further exemplary embodiments; [Figure 10]10A-10C show different schematic cross-sectional views of a fluid cooling system according to further exemplary embodiments; [Figure 11] 10A-10C show different schematic cross-sectional views of a fluid cooling system according to further exemplary embodiments; [Figure 12] 10A-10C show different schematic cross-sectional views of a fluid cooling system according to further exemplary embodiments; [Figure 13] 10A-10C show different schematic cross-sectional views of a fluid cooling system according to further exemplary embodiments; [Figure 14] 10A-10C show different schematic cross-sectional views of a fluid cooling system according to further exemplary embodiments; [Figure 15] 10A-10C show different schematic cross-sectional views of a fluid cooling system according to further exemplary embodiments; [Figure 16] 10A-10C show different schematic cross-sectional views of a fluid cooling system according to further exemplary embodiments; [Figure 17] 10A-10C show different schematic cross-sectional views of a fluid cooling system according to further exemplary embodiments; DETAILED DESCRIPTION OF THE INVENTION

[0043] In the figures, elements having the same, similar or equivalent effect are provided with the same reference numerals. The figures and the proportions of the elements shown therein are not to be considered true to scale. Rather, individual elements may be shown exaggeratedly large for better representation and / or better understanding.

[0044] The optoelectronic device 1 according to the example of Fig. 1 comprises a plurality of emitters 2 arranged on a main surface of a carrier 15. The emitters 2 are light-emitting diodes that emit electromagnetic radiation 3 in a direction preferably perpendicular to the main surface of the carrier 15. In particular, the emitters 2 are configured to uniformly illuminate an outer surface 5 arranged parallel to the main surface of the carrier 15 at a distance D2 from the emitters 2.

[0045] In order to uniformly illuminate the external surface 5, the lateral distance D1 between adjacent emitters 2 is approximately equal to the distance D2 between the emitters 2 and the external surface 5. When the external surface 5 has a given area that needs to be uniformly illuminated by the electromagnetic radiation 3, the distance D2 between the emitters 2 and the external surface 5 depends on the number of emitters 2 in the optoelectronic device 1. In particular, when the number of emitters 2 is small, the distance D1 between the emitters 2, i.e., the distance D2 between the emitters 2 and the external surface 5, needs to be large in order to uniformly illuminate the external surface 5.

[0046] If the maximum distance D2 between the emitter 2 and the external surface 5 is limited by mechanical constraints, multiple emitters 2 may be required to uniformly illuminate the external surface 5, increasing the cost of the optoelectronic device 1. Furthermore, the intensity of the electromagnetic radiation 3 at the external surface 5 may exceed the illumination intensity required for sterilization.

[0047] 2 shows a contour plot of the general irradiance distribution of electromagnetic radiation 3 on the irradiated external surface 5 as a function of the x and y coordinates of the external surface 5. In particular, the irradiance distribution corresponds to the configuration shown in FIG. 1, where the distance D2 between the emitter 2 (not shown) and the external surface 5 is smaller than the distance D1 between adjacent emitters 2. Therefore, the irradiance distribution on the external surface 5 is not uniform. In particular, the irradiance at the position of maximum irradiance of electromagnetic radiation 3 is about 10 times greater than the position on the external surface 5 where the irradiance of electromagnetic radiation 3 is lowest. In particular, sterilization may be ineffective at positions on the external surface 5 where the irradiance of electromagnetic radiation 3 is too low.

[0048] 3, the fluid cooling system 12 according to the exemplary embodiment comprises an optoelectronic device 1 and a plurality of cooling fins 13. The optoelectronic device 1 is disposed outside a volume spanned by the plurality of cooling fins 13.

[0049] In the following figures, the orientation of various elements will be described using a Cartesian coordinate system having mutually orthogonal x, y, and z coordinates. In particular, Figure 3 shows a schematic cross-sectional view of the fluid cooling system 12 in the xz plane. The cooling fins 13 have a main extension plane parallel to the yz plane, while the exterior surface 5 is parallel to the xy plane and corresponds to the side of the volume spanned by the cooling fins 13.

[0050] Electromagnetic radiation 3 is emitted by the optoelectronic device 1, preferably in opposite directions in the z direction, and can propagate between cooling fins 13. The optoelectronic device 1 comprises an optical element 4 in the form of a light guide 6 arranged between two emitters 2, which are light-emitting semiconductor light-emitting diodes. In operation, the two emitters 2 emit electromagnetic radiation 3 in the UV-C spectral range. The electromagnetic radiation 3 is coupled into the light guide 6 via two light-intake surfaces 7 at either end of the light guide 6. The light-intake surfaces 7 are arranged parallel in the yz direction.

[0051] The light guide 6 may be a quasi-one-dimensional column extending in the x-direction, or a quasi-two-dimensional thin sheet extending in the x- and y-directions. In particular, the spatial extent of the light guide 6 in the x-direction between the two emitters 2 is at least ten times greater than the thickness of the light guide 6 in the z-direction.

[0052] The light extraction surface 8 of the light guide 6 extends in the x-direction and is arranged parallel to the propagation direction of the electromagnetic radiation 3 within the light guide 6. In order to extract the electromagnetic radiation 3 from the light guide 6 via the light extraction surface 8, the light extraction surface 8 is provided with a structured portion 9. In particular, the structured portion 9 has a plurality of recesses 16 in the light extraction surface 8. The recesses 16 are configured to scatter the electromagnetic radiation 3 propagating inside the light guide 6, thereby changing the direction of travel of the electromagnetic radiation 3. In particular, the electromagnetic radiation 3 is scattered preferably in a direction perpendicular to the light extraction surface 8 so that it can be extracted from the light guide 6. The recesses 16 can have any shape and have a depth in the z-direction that is equal to or greater than the wavelength of the electromagnetic radiation 3.

[0053] The light extraction surface 8, and therefore the recesses 16, are arranged on the side of the light guide 6 facing the cooling fins 13. The recesses 16 are distributed on the light extraction surface 8 in such a way that the external surface 5 is uniformly illuminated by the electromagnetic radiation 3.

[0054] The fluid cooling system 12 according to the exemplary embodiment of Fig. 4 comprises an optoelectronic device 1 with a light guide 6 as described in relation to the exemplary embodiment of Fig. 3. Furthermore, a reflective element 10 is arranged on the side of the light guide 6 opposite the structured portion 9. Furthermore, instead of a second emitter 2, a further reflective element 10 is arranged on the side of the light guide 6 opposite the light intake surface 7. The reflective element 10 comprises a metallic surface coating of the light guide 6 configured to reflect electromagnetic radiation 3 propagating inside the light guide 6 and incident on the reflective element 10. The reflective element 10 increases the efficiency of the optoelectronic device 1 by redirecting a larger portion of the electromagnetic radiation 3 generated by the emitter 2 towards the external surface 5.

[0055] The fluid cooling system 12 according to the exemplary embodiment of Figure 5 comprises a plurality of optoelectronic devices 1 arranged adjacent to each other in an x-direction parallel to an external surface 5. In particular, the optoelectronic devices 1 correspond to the optoelectronic devices 1 described with respect to the embodiment of Figure 3. By arranging a plurality of such optoelectronic devices 1 on the external surface 5, the intensity of the electromagnetic radiation 3 can be increased or the intensity of the electromagnetic radiation 3 can be kept constant while increasing the area of the external surface 5.

[0056] 6 shows a schematic cross-sectional view in the xz plane of a fluid cooling system 12 according to a further exemplary embodiment. The fluid cooling system 12 comprises a plurality of cooling fins 13 having a main plane of extension parallel to the yz plane and a plurality of optoelectronic devices 1 arranged outside the volume spanned by the cooling fins 13. Electromagnetic radiation 3 emitted by the plurality of optoelectronic devices 1 propagates in the opposite direction to the z direction, preferably parallel to the main plane of extension of the cooling fins 13.

[0057] The optoelectronic devices 1 are structurally identical, and only one of the optoelectronic devices 1 will be described in detail below. The optoelectronic device 1 comprises an emitter 2 in the form of a semiconductor light-emitting diode and an optical element 4. The optical element 4 has a material that is transparent to the electromagnetic radiation 3 emitted by the emitter 2 and redirects the electromagnetic radiation 3 by refraction towards an external surface 5, where the external surface 5 extends in the x and y directions.

[0058] The optical element 4 has a light inlet surface 7 that is hemispherical, parabolic, ellipsoidal, or free-form, and a planar light outlet surface 8 that is located opposite the light inlet surface 7. The light outlet surface 8 is located parallel to the external surface 5 and extends in the x and y directions. The light inlet surface 7 is concave, forming a through hole in the center of the optical element 4. The emitter 2 is located within the through hole and emits electromagnetic radiation preferably in the opposite direction, the z direction. In particular, the optical element 4 is configured to redirect electromagnetic radiation 3 emitted by the emitter 2 at a large exit angle off the z axis toward the external surface 5.

[0059] Also, a reflective or partially reflective coating can be applied to the central region of the light inlet surface 7 , which makes the intensity of the electromagnetic radiation 3 more evenly distributed at the light outlet surface 8 .

[0060] The fluid cooling system 12 according to the exemplary embodiment shown in Figure 7 comprises a plurality of cooling fins 13 and optoelectronic devices 1 arranged as described with respect to the exemplary embodiment of Figure 6. Each optoelectronic device 1 comprises an emitter 2 and an optical element 4.

[0061] In contrast to the exemplary embodiment described in connection with Fig. 6, the emitter 2 emits electromagnetic radiation 3 in the x-direction, and the optical element 4 comprises a prism. The prism has a light inlet surface 7 parallel to the yz-plane and a light outlet surface 8 parallel to the xy-plane, i.e., the external surface 5. The prism redirects the electromagnetic radiation from the light inlet surface 7 to the light outlet surface 8, for example via total internal reflection at the boundary between the prism and the ambient atmosphere outside the prism. The area of the light outlet surface 8 is at least two times larger than the area of the light inlet surface 7.

[0062] 8 shows a schematic cross-sectional view in the xz plane of a fluid cooling system 12 according to a further exemplary embodiment, similar to the exemplary embodiment described in relation to Fig. 3. In particular, the optical element 4 comprises a cylindrical light guide 6 extending in the x direction and two emitters 2 arranged on opposite bottom surfaces of the cylinder. The bottom surface is parallel to the yz plane and configured as a light collection surface 7 of the light guide 6.

[0063] In contrast to the exemplary embodiment described in connection with Fig. 3, the light extraction surface 8 has a structuring 9 along the entire periphery of the light guide 6, such that the electromagnetic radiation 3 is extracted from the light guide 6 in all directions. In particular, the electromagnetic radiation 3 also leaves the light guide 6 in a direction away from the external surface 5. In order to redirect the electromagnetic radiation 3 towards the external surface 5, the optical element 4 further comprises a reflective element 10 in the form of a plane mirror which extends parallel to the xy-plane and thus parallel to the external surface 5. The reflective element 10 is arranged on the side of the light guide 6 opposite the external surface 5.

[0064] Figure 9 shows a different schematic cross-sectional view along the yz plane of the fluid cooling system 12 according to the exemplary embodiment of Figure 8. In particular, multiple columnar light guides 6 extend in the x direction and corresponding emitters 2 are arranged parallel to each other, so that the outer surface 5 is uniformly illuminated in the y direction as well.

[0065] 10 shows a schematic cross-sectional view in the xz plane of a fluid cooling system 12 according to a further exemplary embodiment, similar to the exemplary embodiment described in connection with FIG. 8 . In contrast to the embodiment of FIG. 8 , the reflective element 10 is not a plane mirror, but rather has the form of a reflective surface coating applied to the cylindrical light guide 6 in the region of the light extraction surface 8. In particular, the reflective surface coating 10 is applied to the half circumference of the cylindrical light guide 6 facing away from the external surface 5. The reflective surface coating comprises aluminum. Thus, the reflective element 10 redirects the electromagnetic radiation 3 towards the external surface 5.

[0066] 10 further shows a fluid 14, in particular air, flowing between the cooling fins 13. The optoelectronic device 1 is positioned so that the fluid 14 can flow through the optoelectronic device 1 with as little obstruction as possible.

[0067] Figure 11 shows a different schematic cross-sectional view along the yz plane of the fluid cooling system 12 according to the exemplary embodiment of Figure 10. In particular, since the columnar light guides 6 extend in the x direction and the corresponding emitters 2 are arranged parallel to each other, the outer surface 5 is uniformly illuminated in the y direction as well. Furthermore, the fluid 14 can flow unimpeded between the columnar light guides 6 and through the optoelectronic device 1.

[0068] 12 shows a schematic cross-sectional view in the xz plane of a fluid cooling system 12 according to a further exemplary embodiment. In contrast to the embodiment described in relation to FIG. 8 , a plurality of cylindrical light guides 6, together with a corresponding emitter 2, are arranged between each pair of cooling fins 13, with each light guide 6 extending in the z direction. In this way, the optoelectronic device 1 is arranged inside a volume spanned by the plurality of cooling fins 13, and the electromagnetic radiation 3 is directly incident on the main surfaces of the cooling fins 13. Therefore, in this exemplary embodiment, no reflective element 10 is required, and the external surface 5 uniformly illuminated by the electromagnetic radiation 3 is the main surface of each cooling fin 13, which extends parallel to the yz plane.

[0069] Figure 13 shows a different schematic cross-sectional view along the xy plane of the fluid cooling system 12 according to the exemplary embodiment of Figure 12. In particular, a plurality of columnar light guides 6 extend in the z direction, and corresponding emitters 2 are arranged parallel to each other between each pair of cooling fins 13, such that the outer surface 5 is uniformly illuminated in the y direction as well.

[0070] 14 shows a schematic cross-section in the xz plane of a fluid cooling system 12 according to a further embodiment, comprising a plurality of cooling fins 13 having a main extension surface extending parallel to the yz plane. The external surface 5 is a side surface extending parallel to the xy plane of the volume spanned by the plurality of cooling fins 13. The optoelectronic device 1 comprises an emitter 2 and an optical element 4 in the form of a reflective element 10, each emitter 2 having exactly one corresponding reflective element 10. The emitter 2 irradiates electromagnetic radiation 3 in the z direction onto a reflective surface 11 of the corresponding reflective element 10. The reflective element 10 reflects the electromagnetic radiation 3 emitted by the corresponding emitter 2 towards the external surface 5.

[0071] In a plan view of the external surface 5 in the z direction, the emitter 2 and the reflective element 10 do not overlap with the cooling fins 13. Furthermore, in a side view along the x and / or y directions, the emitter 2 and the reflective element 10 do not overlap with the cooling fins 13. In this way, the flow of the fluid 14 is not impeded by the optoelectronic device 1.

[0072] Each reflective element 10 has a size equivalent to that of the corresponding emitter 2. In particular, the area of the reflective surface 11 of each reflective element 10 is much smaller than the area of the external surface 5. For example, the area of the external surface 5 is at least 10 times larger than the area of the reflective surface 11 of each reflective element 10.

[0073] The reflective surface 11 of each reflective element 10 is a free-form surface that is neither a sphere, a paraboloid, nor a hyperboloid, and in particular, the shape of the free-form surface is optimized so that the electromagnetic radiation 3 emitted by the emitter 2 uniformly illuminates the external surface 5.

[0074] Figure 15 shows a different schematic cross-sectional view along the yz plane of the fluid cooling system 12 according to the exemplary embodiment of Figure 14. The reflective surface 11 is concave and redistributes the electromagnetic radiation 3 mainly in the y direction of the outer surface 5. Preferably, the reflective element 10 collimates the electromagnetic radiation 3 in the x direction, allowing it to propagate deeper between the cooling fins 13 in the opposite z direction, thereby sterilizing the fluid 14 flowing between the cooling fins 13.

[0075] Figure 16 shows a schematic cross-sectional view in the xz plane of a fluid cooling system 12 according to a further exemplary embodiment, similar to the exemplary embodiment described in relation to Figures 14 and 15. In contrast to the exemplary embodiment of Figure 14, the emitter 2 emits electromagnetic radiation 3 in the z direction towards the reflective surface 11 of the corresponding reflective element 10. The emitter in Figure 16 has a reflective surface 11 with the same or similar shape as the reflective element 10 described in relation to the exemplary embodiment of Figure 14.

[0076] The reflective element 10 reflects the electromagnetic radiation 3 towards a further reflective element 10 which is a planar mirror extending parallel to the external surface 5 in the xy plane. The mirror further reflects the electromagnetic radiation 3 towards the external surface 5. The mirror may be a planar mirror or may be a mirror having a roughened reflective surface 11 configured to provide diffuse reflection of the incident electromagnetic radiation 3.

[0077] Figure 17 shows a different schematic cross-sectional view along the yz plane of the fluid cooling system 12 according to the exemplary embodiment of Figure 16. Similar to the embodiment described in relation to Figure 15, the reflective element 10 is configured to collimate the electromagnetic radiation 3 in the x direction.

[0078] The present invention is not limited to the exemplary embodiments described above, but encompasses any novel feature and any combination of features, including any combination of features described in the claims and any combination of features described in the embodiments.

[0079] This patent application claims priority from German patent application DE 102022118392.0, the disclosure of which is incorporated herein by reference. [Explanation of symbols]

[0080] 1. Optoelectronic devices 2 Emitter 3. Electromagnetic Radiation 4 Optical Elements 5. External Surface 6 Light guide 7 Light intake surface 8 Light extraction surface 9 Structuring part 10 Reflective element 11 Reflective surface 12 Fluid Cooling System 13 Cooling fins 14 Fluid 15 Career 16 Recess D1 Distance between adjacent emitters D2 Distance between emitter and external surface

Claims

1. at least one emitter (2) configured to emit electromagnetic radiation (3) in the ultraviolet spectral range; at least one optical element (4) configured to redirect said electromagnetic radiation (3) towards said external surface (5) so that said external surface (5) is uniformly illuminated; An optoelectronic device (1).

2. The emitter (2) is a semiconductor light-emitting diode. An optoelectronic device (1) according to claim 1.

3. It comprises at least two emitters (2), and the distance (D1) between the two emitters (2) is at least twice the minimum distance (D2) between one of the two emitters (2) and the external surface (5), An optoelectronic device (1) according to claim 1 or 2.

4. The optical element (4) comprises a light guide (6) having a light inlet surface (7) and a light outlet surface (8) for the electromagnetic radiation (3), The light extraction surface (8) is at least twice as large as the light intake surface (7), An optoelectronic device (1) according to any one of claims 1 to 3.

5. The light extraction surface (8) has a structuring (9) so that the electromagnetic radiation (3) is scattered from the light guide (6). An optoelectronic device (1) according to claim 4.

6. the structuring (9) compensates for intensity gradients of the electromagnetic radiation (3) within the light guide (6) so that the intensity of the extracted electromagnetic radiation (3) is uniform across the light extraction surface (8). An optoelectronic device (1) according to claim 5.

7. The optical element (4) comprises light-scattering particles embedded in a transparent matrix material. An optoelectronic device (1) according to any one of claims 1 to 6.

8. The optical element (4) comprises a reflective element (10). An optoelectronic device (1) according to any one of claims 1 to 7.

9. the emitter (2) and the reflective element (10) do not overlap the external surface (5) in a plan view of the external surface (5) and / or in a side view of the external surface (5); An optoelectronic device (1) according to claim 8.

10. the area of said external surface (5) is at least 10 times the area of the reflective surface (11) of said reflective element (10); An optoelectronic device (1) according to claim 8 or 9.

11. The reflecting surface (11) is a free-form surface. An optoelectronic device (1) according to claim 10.

12. said outer surface (5) having an aspect ratio greater than 2; The reflecting element (10) collimates the electromagnetic radiation (3) along the minor axis of the external surface (5) and homogenizes the intensity profile of the electromagnetic radiation (3) along the major axis of the external surface (5). An optoelectronic device (1) according to any one of claims 8 to 11.

13. An optoelectronic device (1) according to any one of claims 1 to 12, at least two cooling fins (13) arranged parallel to one another and configured to cool a fluid (14) flowing between said two cooling fins (13); Electromagnetic radiation (3) emitted by the optoelectronic device (1) irradiates the fluid (14) between the two cooling fins (13) during operation. A fluid cooling system (12).

14. The optoelectronic device (1) is arranged outside the volume defined by the two cooling fins (13), the external surface (5) illuminated by the electromagnetic radiation (3) during operation corresponds to the cross section of the volume through which the fluid (14) flows; The fluid cooling system (12) of claim 13.

15. the optoelectronic device (1) is arranged between the two cooling fins (13) such that the outer surface (5) illuminated by the electromagnetic radiation (3) during operation corresponds to at least one main surface of the two cooling fins (13); The fluid cooling system (12) of claim 13.

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