Component and assembly for analyzing a medium

Abstract

A component (1) is provided, comprising a photodetector (2), a wavelength-selective element (3), and an interaction region (4). The interaction region (4) is arranged within the wavelength-selective element (3), the photodetector (2) is arranged adjacent to the wavelength-selective element (3), and the interaction region (4) is configured to receive a medium. Further, an assembly (10) comprising a component (1) is provided.

Description

[0001] 2024PF00913 November 21, 2025

[0002] P2024, 1015 WO N - 1 -

[0003] Description

[0004] COMPONENT FOR ANALYZING A MEDIUM AND ASSEMBLY

[0005] The present disclosure relates to a component for analyzing a medium and to an assembly.

[0006] It is an obj ect to provide a component for efficiently analyzing a medium. A further obj ect is to provide an assembly with a component .

[0007] According to at least one embodiment of the component, the component comprises a photodetector . The photodetector can be configured to detect electromagnetic radiation. This can mean that, during operation of the component or of the photodetector, the photodetector detects electromagnetic radiation. For example, the photodetector is configured to detect electromagnetic radiation of a predetermined wavelength or of a predetermined wavelength range . For instance, the photodetector is or comprises a photodiode .

[0008] According to at least one embodiment of the component, the component comprises a wavelength-selective element . The wavelength-selective element can also be referred to as a filter, in particular as an optical filter . For instance, the wavelength-selective element is configured to transmit a certain wavelength or certain wavelengths of electromagnetic radiation impinging on the wavelength-selective element through the wavelength-selective element . Electromagnetic radiation of a different wavelength can be reflected by the wavelength-selective element .2024PF00913 November 21, 2025

[0009] P2024, 1015 WO N - 2 -

[0010] According to at least one embodiment of the component, the component comprises an interaction region. Within the interaction region, electromagnetic radiation passing through the wavelength-selective element can interact with a medium, e . g. a gas, inside the interaction region. For instance, absorption for gas detection or gas analysis takes place in the interaction region.

[0011] The interaction region can be arranged upstream from the photodetector, for instance by means of electromagnetic radiation spreading in the component . In other words, the photodetector can be arranged downstream of the interaction region. This can mean that electromagnetic radiation passing through the wavelength-selective element and / or the interaction region can impinge on the photodetector or can be detected by the photodetector .

[0012] According to at least one embodiment of the component, the interaction region is arranged within the wavelength-selective element . For instance, the interaction region is defined and / or bound by the wavelength-selective element .

[0013] According to at least one embodiment of the component, the photodetector is arranged adj acent to the wavelength-selective element . In other words, the photodetector is not arranged within the wavelength-selective element . For instance, the photodetector is directly adj acent to the wavelength-selective element . Alternatively, a spacer can be arranged between the wavelength-selective element and the photodetector .

[0014] According to at least one embodiment of the component, the interaction region is configured to receive a medium. For2024PF00913 November 21, 2025

[0015] P2024, 1015 WO N 3

[0016] instance, the medium is or comprises a gas or a gas mixture or a liquid material . This can mean that the interaction region is configured to receive a gas . It is possible, that the interaction region is in direct contact with the medium, e . g. the gas, surrounding the component . It is possible that the gas comprises CO2 . For instance, the component is configured to detect CO2and / or to determine a CO2concentration of the medium.

[0017] In at least one embodiment, the component comprises a photodetector, a wavelength-selective element and an interaction region, wherein the interaction region is arranged within the wavelength-selective element, the photodetector is arranged adj acent to the wavelength-selective element, and the interaction region is configured to receive a medium.

[0018] An idea is to provide a component which can be suitable for or used for gas detection or gas analysis . For instance, the component is configured to detect gas, e . g. CO2, using absorption of electromagnetic radiation. Due to the wavelength-selective element the absorption-based gas analysis can be performed with resolutions smaller than impinging electromagnetic radiation, e . g. emitted by a light source or a laser light source outside the component .

[0019] The component can be configured for detecting gas components and / or gas concentrations within gas mixtures . For this, for example, wavelength ranges smaller than typical laser emission bandwidths are required. The wavelength or wavelength range entering the interaction volume and interacting with the medium can be selected or defined by means of the wavelength-selective element . The wavelength-2024PF00913 November 21, 2025

[0020] P2024, 1015 WO N - 4 -

[0021] selective element can be a passive wavelength filter . Thus, the component comprises a low complexity. The component can be scalable in regard of the interaction region. The wavelength-selective element can be easily manufactured for any desired wavelength or wavelength ranges . Thus, the component comprises a high adaptability for the analysis or detection of desired gases or gas components .

[0022] For example, only wavelengths which are required for the analysis and / or detection of components of the medium, e . g. the gas, may be emitted and / or only photodetectors corresponding to interaction regions in which electromagnetic radiation of the required wavelengths interacts with the medium may be operated. The component can be energy efficient and / or cost efficient .

[0023] A further idea is to have a component which is compatible with common surface-mounting technology, SMT, packages, e . g. surface-mounted devices, SMDs . This can mean that the component comprises an expansion, for instance a spatial extension, which is suitable for SMT packages . For example, the component can be particularly small . For instance, a size, in particular a spatial or lateral extension of the component or of an assembly comprising the component can be between 50 pm and 500 mm, inclusive, for example, between and including 100 pm and 100 mm or, in particular, between 200 pm and 10 mm, inclusive . For example, in case the assembly comprises an unpackaged VCSEL die with the component, e . g. also referred to as stacked filter, on top, the size of the component and / or the assembly is limited by a suitable die size, for instance around a few 100 pm.2024PF00913 November 21, 2025

[0024] P2024, 1015 WO N - 5 -

[0025] According to at least one embodiment of the component, the wavelength-selective element forms an optical cavity with a predetermined resonant wavelength. The interaction region can be formed by the optical cavity. This can mean that the interaction region is comprised by a Fabry-Perot-cavity or comprises or is a Fabry-Perot-cavity. Electromagnetic radiation with the resonant wavelength, for example only electromagnetic radiation with the resonant wavelength, can pass through the wavelength-selective element, interact with the medium within the interaction region, in particular the optical cavity, and / or is detected by the photodetector .

[0026] Electromagnetic radiation with the resonant wavelength may travel multiple times through the optical cavity, in particular the interaction region. In other words, electromagnetic radiation may circulate within the optical cavity .

[0027] A thickness of the optical cavity and / or the interaction region can be X / 2 or a multiple thereof, wherein X is the wavelength, in particular the resonant wavelength.

[0028] The amount of runs of a ray of electromagnetic radiation, e . g. a light ray, through the optical cavity of a Fabry-Perot-interf erometer can correlate with a quality factor, also referred to as Q-factor . The Q-factor is a measure of the quality of a resonator and describes how many times electromagnetic radiation or light is reflected back and forth between mirrors forming the resonator .

[0029] The Q-factor can be calculated according to

[0030]

[0031] 2024PF00913 November 21, 2025

[0032] P2024, 1015 WO N - 6 -

[0033] For a Fabry-Perot-interf erometer , the Q-factor can also be expressed in terms of finesse and free spectral range :

[0034]

[0035] wherein F is the finesse, indicating how many times the electromagnetic radiation is reflected on average before leaving the resonator, AA is the free spectral range and A is the resonant wavelength.

[0036] For example, assuming R~0.999, AA = 0.2nm and A~2000nm, it follows that F~3000 and Q~107. R can be the reflectivity. A finesse F~3000 can mean that the light circulates at least approximately 3000 times within the cavity prior to leaving the resonator . Thus, the interaction with the electromagnetic radiation and the medium within the interaction region can be improved by a factor of approximately 3000.

[0037] An advantage of this embodiment is that an interaction length, e . g. a path of the electromagnetic radiation inside the interaction region, is prolonged. It is possible, that the interaction between the medium to be analyzed, e . g. the gas or gas mixture, and the electromagnetic radiation is maximized or at least improved. For example, this is advantageous in absorption spectroscopy, in particular in gas detection relying on absorption.

[0038] According to at least one embodiment of the component, the wavelength-selective element comprises a first reflector and a second reflector . For instance, the first reflector and the second reflector are arranged on opposing sides of the interaction region. The first reflector and / or the second reflector can be configured to reflect at least a portion of2024PF00913 November 21, 2025

[0039] P2024, 1015 WO N - 7 -

[0040] electromagnetic radiation impinging on the respective reflector .

[0041] According to at least one embodiment of the component, the first and / or second reflector comprises a dielectric mirror . The dielectric mirror can comprise a high refractive index material . Additionally or alternatively, the dielectric mirror can comprise a low refractive index material . It is possible that the dielectric mirror comprises or consist of at least one high refractive index material and at least one low refractive index material, which are alternatingly arranged .

[0042] For instance, the high refractive index material is or comprises titanium dioxide, niobpentoxide (Nb2Os) , tantalum pentoxide (Ta2Os) and / or hafnium dioxide (HfCy) . The low refractive index material is or comprises silicon dioxide, for example . A thickness of the first and / or second reflector can be a quarter wavelength, e . g. X / 4, or a multiple thereof . The wavelength can be understood as the resonant wavelength.

[0043] According to at least one embodiment of the component, the photodetector comprises silicon or InGaAs / InP . For instance, in case the photodetector comprises or is based on silicon, the photodetector can be configured to detect electromagnetic radiation with wavelengths from approximately 600 nm to approximately 900 nm. In case the photodetector comprises or is based on InGaAs / InP, the photodetector can be configured to detect electromagnetic radiation within the IR region or within the NIR region. For example, these materials can comprise high quantum efficiencies for the respective wavelength ranges . Alternatively or additionally, the photodetector can comprise or can be based on indium2024PF00913 November 21, 2025

[0044] P2024, 1015 WO N 8

[0045] arsenide, InAs, indium antimonide, InSb, gallium antimonide, GaSb, and / or indium gallium arsenide, InGaAs . For example, the photodetector comprising or being based on these materials can be configured to detect electromagnetic radiation within the IR region.

[0046] However, the photodetector can additionally or alternatively be based on other material and / or be configured to detect electromagnetic radiation in any wavelength range of the electromagnetic spectrum. The photodetector can be configured to detect the electromagnetic radiation interacting with the medium within the interaction region. This can mean that the photodetector is configured to detect at least the resonant wavelength of the optical cavity. For this, the photodetector can be formed of a suitable material .

[0047] According to at least one embodiment, the component comprises a plurality of photodetectors . For example, the plurality of photodetectors is configured to detect electromagnetic radiation passing through the wavelength-selective element .

[0048] The plurality of photodetectors can be configured to detect electromagnetic radiation originating from a common interaction region. In other words, multiple photodetectors, for example at least three or at least nine photodetectors, e . g. a plurality of photodetectors, can be assigned to one interaction region. For example, adj acent interaction regions have different resonant frequencies from each other . The transmission wavelength of the cavities or an interaction region is a function of the angle of incidence . For example, assuming under phi = 0° , a first light is transmitted, then, under phi > 0° , a second light with a shorter wavelength than the first light is transmitted. By having multiple2024PF00913 November 21, 2025

[0049] P2024, 1015 WO N 9

[0050] photodetectors for one interaction regions, spectrally closely spaced characteristic emission peaks of the elements or gases under investigation or to be detected can be divided among the photodetectors, for example . Thereby, the number of photodetectors can be arbitrary. For example, the number of separately detectable spectral peaks increases with the number of photodetectors . This can mean that the resolution can be enhanced for larger numbers of photodetectors . For instance, different wavelengths are transmitted in different directions . Thus, for example, the spatial separation due to the transmission of slightly different wavelengths in different directions can be used to place photodetectors at suitable locations . By this, for instance, a higher wavelength resolution of the component can be achieved.

[0051] For instance, the photodetectors of the at least three photodetectors, the at least nine photodetectors or the plurality of photodetectors can be arranged spaced apart from each other . For example, the photodetectors of the plurality of photodetectors can be laterally spaced apart from each other . It is possible, that the photodetectors assigned to one interaction region can be arranged laterally spaced apart from each other .

[0052] Alternatively, each photodetector of the plurality of photodetectors can be uniquely assigned to one interaction region .

[0053] The plurality of photodetectors can be arranged in a common plane .

[0054] According to at least one embodiment of the component, the component comprises at least one further interaction region,2024PF00913 November 21, 2025

[0055] P2024, 1015 WO N 10

[0056] wherein the further interaction region is laterally spaced apart from the interaction region, and wherein at least one photodetector is uniquely assigned to each interaction region .

[0057] The interaction region and the further interaction region can be linked to each other via the medium. This can mean that the interaction region and the further interaction region are configured to receive a common medium. In other words, the medium within the interaction region can be equal or at least approximately equal to the medium within the further interaction region.

[0058] For example, the interaction region and the at least one further interaction region can each be assigned at least three photodetectors . Thereby, each photodetector can be assigned to at most one interaction region of the interaction region and the at least one further interaction region.

[0059] According to at least one embodiment of the component, a resonant wavelength of the further interaction region differs from a resonant wavelength of the interaction region. This can mean that the further interaction region is adapted such that electromagnetic radiation with a wavelength different from the electromagnetic radiation interacting with the medium in the interaction region interacts with the medium in the further interaction region.

[0060] According to at least one embodiment of the component, the interaction region comprises a plurality of optical cavities which are arranged spaced apart from each other . This can mean that electromagnetic radiation interacting with the medium in a plurality of optical cavities can be detected by2024PF00913 November 21, 2025

[0061] P2024, 1015 WO N 11

[0062] a common photodetector . For instance, at least two optical cavities or a plurality of cavities can be stacked along a vertical direction. The vertical direction extends at least approximately perpendicular to a main extension plane of the component . For instance, the interaction region and the detector are arranged one after the other along the vertical direction .

[0063] Furthermore, an assembly is provided. The assembly can preferably comprise the component described herein. This means all features disclosed for the component are also disclosed for the assembly and vice-versa .

[0064] According to at least one embodiment of the assembly, the assembly comprises a component . The component can be a component described herein.

[0065] According to at least one embodiment of the assembly, the assembly comprises a light source . The light source can comprise or consist of a laser, e . g. a semiconductor laser, or an LED. For instance, the light source is configured to emit at least approximately coherent and / or parallel light .

[0066] The light source is configured to provide electromagnetic radiation with a suitable spectral linewidth, e . g. a suitable laser linewidth. Suitable can thereby mean that the spectral linewidth covers relevant absorption bands of particles or molecules of interest . It is possible that the light source is configured to cover a required spectral linewidth at least via an operating point adjustment .

[0067] For example, to differentiate between CO2 and H2O in a gas mixture and / or for determining or measuring the respective2024PF00913 November 21, 2025

[0068] P2024, 1015 WO N - 12 -

[0069] concentrations within the gas mixture a spectral linewidth of approximately 14 nm is required. For example, a laser comprising a suitable spectral linewidth for this purpose is PLPT9 450D_E A01. Further, for instance, a wavelength resolution of approximately 0.5 nm is suitable to distinguish between CO2 and H2O and measure the respective concentrations . The desired wavelength resolution can be adjusted and / or ensured by means of the number of interaction regions and the number of the respective wavelength-selective elements of the component . The suitable selectivity of the wavelength-selective elements can also be realized with Q-factors around 5000 or of at least 5000. Typical Q-factors can be much larger .

[0070] According to at least one embodiment, the light source is configured to emit electromagnetic radiation towards the component, such that, during operation of the assembly, at least a portion of the electromagnetic radiation emitted by the light source interacts with the medium in the interaction region of the component and impinges on the photodetector . For example, the portion of the electromagnetic radiation interacting with the medium and impinging on the photodetector can correspond to the resonant wavelength of the interaction region formed or comprised by the optical cavity. For example, the electromagnetic radiation spreads along a well-defined preferred direction and impinges on the component, for instance on the wavelength-selective element of the component .

[0071] In at least one embodiment of the assembly, the assembly comprises a component and a light source . For instance, the light source is configured to emit electromagnetic radiation towards the component, such that, during operation of the2024PF00913 November 21, 2025

[0072] P2024, 1015 WO N - 13 -

[0073] assembly, at least a portion of the electromagnetic radiation emitted by the light source interacts with the medium in the interaction region of the component and impinges on the photodetector .

[0074] According to at least one embodiment of the assembly, the light source is configured to emit parallel electromagnetic radiation .

[0075] According to at least one embodiment of the assembly, the light source comprises a radiation outcoupling side and the component is in direct contact with the radiation outcoupling side of the light source .

[0076] According to at least one embodiment, the assembly further comprises an optical element . The optical element can be configured to direct the electromagnetic radiation emitted by the light source to the component . The component and the light source can be arranged on the same side of the optical element .

[0077] According to at least one embodiment of the assembly, the light source comprises a laser . It is possible that the light source comprises a VCSEL or an edge-emitting laser . This means, the component is compatible with a plurality of light sources or lasers . Laser can be configured to provide parallel or at least approximately parallel electromagnetic radiation .

[0078] According to at least one embodiment, the assembly is a gas sensor . For instance, the assembly is configured to detect or analyze elements in the medium, e . g. a gas mixture, or to2024PF00913 November 21, 2025

[0079] P2024, 1015 WO N - 14 -

[0080] detect concentrations of elements included in the gas mixture .

[0081] Further advantages and advantageous designs and further developments of the component and the assembly will become apparent from the following exemplary embodiments, which are described below in association with the figures .

[0082] Figure 1 shows a component and an assembly according to an exemplary embodiment .

[0083] Figures 2 and 3 show components according to further exemplary embodiments .

[0084] Figures 4, 5 and 6 show components and assemblies according to exemplary embodiments .

[0085] Identical, similar or equivalent elements are marked with the same reference signs in the figures . The figures and the proportions of the elements represented in the figures among each other are not to be considered as true to scale . Rather, individual elements may be oversized for better representability and / or comprehensibility. Identical or effectively identical components and parts might be described only with respect to the figures where they occur first .

[0086] Their description is not necessarily repeated in successive figures .

[0087] Figure 1 shows a component 1 according to an exemplary embodiment . The component 1 comprises a photodetector 2, a wavelength-selective element 3 and an interaction region 4.2024PF00913 November 21, 2025

[0088] P2024, 1015 WO N - 15 -

[0089] The interaction region 4 is arranged within the wavelength-selective element 3. This can mean, shown here, that the wavelength-selective element 3 comprises a first reflector 8 and a second reflector 9. Then, the first reflector 8 and the second reflector 9 can be arranged on opposing sides of the interaction region 4. In other words, the interaction region 4 is arranged between the first reflector 8 and the second reflector 9. The first reflector 8 and / or the second reflector 9 can comprise or consist of a dielectric mirror .

[0090] For instance, shown here, the wavelength-selective element 3 forms an optical cavity 7 with a predetermined resonant wavelength, and the interaction region 4 is formed by the optical cavity 7 or corresponds to the optical cavity 7. This can mean that the interaction region 4 is a Fabry-Perot-cavity. A thickness of the interaction region 4 corresponds to a distance between the first reflector 8 and the second reflector 9. The thickness of the interaction region 4 can be the extension of the interaction region 4 along the vertical direction. The interaction region 4 can be formed as a recess in a layer 17 arranged between the first reflector 8 and the second reflector 9.

[0091] For example, the component 1 comprises at least one further interaction region 5. The further interaction region 5 is arranged spaced apart from the interaction region 4 . In particular, the further interaction region 5 is arranged laterally spaced apart from the interaction region 4.

[0092] "Laterally" thereby means along a lateral direction. The lateral direction can extend at least approximately in parallel to a main extension plane of the component . The lateral direction can be at least approximately perpendicular to the vertical direction. For example, a resonant2024PF00913 November 21, 2025

[0093] P2024, 1015 WO N - 16 -

[0094] wavelength of the further interaction region 5 differs from a resonant wavelength of the interaction region 4. This can mean that the interactions regions 4, 5 have different thicknesses from each other .

[0095] The photodetector 2 is arranged adj acent to the wavelength-selective element 3. This can in particular mean that the photodetector 2 is not arranged between the first reflector 8 and the second reflector 9. The photodetector 2 can be arranged on the side of the second reflector 9 facing away from the interaction region 4. The component 1 can comprise a plurality of photodetectors 2. The plurality of photodetectors 2 can be configured to detect electromagnetic radiation passing through the wavelength-selective element / s 3. For instance, at least one photodetector 2 is uniquely assigned to each interaction region 4, 5. The photodetectors 2 can be arranged on a common substrate 16. For instance, the photodetectors 2 are embedded in the common substrate 16.

[0096] A medium 6 is arranged within the interaction region 4. For instance, the interaction region 4 is completely filled with the medium 6. The medium 6 can be or can comprise a gas . For example, the medium 6 is a gas mixture .

[0097] The circular arrow indicates that electromagnetic radiation 15 circulates in the interaction region 4 and / or the optical cavity 7 .

[0098] Electromagnetic radiation 15 is directed towards the component 1. The electromagnetic radiation 15 impinging on the component 1 can be at least approximately parallel . For example, the electromagnetic radiation 15 extends2024PF00913 November 21, 2025

[0099] P2024, 1015 WO N - 17 -

[0100] perpendicular or at least approximately perpendicular to the main extension plane of the component 1.

[0101] The electromagnetic radiation 15 impinges on the component 1 on the side of the wavelength-selective element 3, e . g. of the first reflector 8, facing away from the photodetector 2. This can mean that the component 1 is configured to receive electromagnetic radiation 15 from the side of the wavelength-selective element 3 facing away from the photodetector 2 .

[0102] Figure 1 further shows a graph of a schematic laser spectrum 14, 15 and a schematic reflectance of the wavelength-selective elements 3. The dotted line shows an exemplary laser spectrum.

[0103] On the x-axis the wavelength is plotted in nm. The y-axis shows the reflectance in % . For example, shown here, the reflectance comprises a minimum, e . g. a local or global minimum, overlapping with the laser spectrum. The wavelength, at which the reflectance comprises a minimum can be the resonant wavelength of one of the interaction regions 4, 5. Shown here, the solid line has a minimum overlapping with the laser spectrum. The dashed lines indicate two different minima of reflectance spectrums, e . g. of different wavelength-selective elements 3.

[0104] The solid and dashed reflectance spectra show the reflectance for phi = 0° . Thereby, phi can correspond to the angle at which the electromagnetic radiation travels through the optical cavity 7 or in the interaction region 4, 5. Phi = 0° can mean that the electromagnetic radiation travels through the optical cavity 7 perpendicular to the first reflector 8 and the second reflector 9. Phi can depend on the angle of2024PF00913 November 21, 2025

[0105] P2024, 1015 WO N - 18 -

[0106] incidence of the electromagnetic radiation impinging on the component .

[0107] In case electromagnetic radiation does not impinge perpendicular on the component 1, phi may be larger than 0° . Then, the three shown reflectance minima may be shifted to smaller wavelengths . Thus, the resonant wavelength of the interaction regions 4, 5 may depend on the angle of incidence of the electromagnetic radiation 15.

[0108] Figure 2 shows a component 1 according to a further exemplary embodiment . The component 1 shown here differs from the component 1 shown in Figure 1 in that each interaction region 4, 5 comprises at least two optical cavities 7 or, for example, a plurality of optical cavities 7. The optical cavities 7 of each interaction region 4, 5 can be stacked along the vertical direction z . Between two adj acent optical cavities 7 of a common interaction region 4, 5 an intermediate layer 19 can be arranged. In other words, the intermediate layer 19 can be arranged between two adj acent cavities 7 in the vertical direction z . For example, the intermediate layer 19 can comprise or consist of the same material as the layer 17.

[0109] For instance, a stack comprising the optical cavities 7 can be monolithically . This can mean that the intermediate layer 19 and / or the layer 17 comprise a material of one of the elements of a distributed Bragg reflector, DBR, forming the reflectors 8, 9 or one of the reflectors 8, 9 of the component 1. For instance, the intermediate layer 19 and / or the layer 17 comprise or consist of SiCy or Nb2Os . For example, the intermediate layer 19 can be thick compared to a layer of the same material within the reflector 8, 9.2024PF00913 November 21, 2025

[0110] P2024, 1015 WO N - 19 -

[0111] Alternatively, the optical cavities 7 of a common interaction region 4, 5 can be formed separately. For instance, as a distance between the stacked optical cavities 7 in the component 1 is relatively uncritical, the parts of the component 1 comprising the optical cavities 7 can be glued together, for instance using a transparent silicone glue, to form the stack. Alternatively, the parts comprising the optical cavities 7 can be bonded together .

[0112] The plurality of optical cavities 7 of a common interaction region 4, 5 each comprise the same or at least approximately the same resonant wavelength. Thus, the interaction between the electromagnetic radiation 15 and the medium 6 can be enhanced .

[0113] Figure 3 shows a component 1 according to an exemplary embodiment . The exemplary embodiment shown here differs from the exemplary embodiment of the component shown in Figure 1 in that for each interaction region 4, 5 multiple photodetectors 2 are assigned. For instance, the photodetectors 2 of one interaction region 4, 5 are configured detect electromagnetic radiation 15 of different angles of incidence . Thus, each photodetector 2 of the photodetectors 2 assigned to the same interaction region 4, 5 may detect a different resonant wavelength of the interaction region 4, 5. As shown in Figure 1, the resonant wavelength can depend on the angle of incidence of the electromagnetic radiation 15.

[0114] A spacer 18 can be arranged between the wavelength-selective element / s 3 and the photodetector / s 2. For instance, the spacer 18 is transparent or translucent for the2024PF00913 November 21, 2025

[0115] P2024, 1015 WO N 20

[0116] electromagnetic radiation 15. Due to the spacer 18 the electromagnetic radiation 15 leaving the interaction region 4, 5 can spread, such that it can impinge on multiple laterally spaced photodetectors 2. For example, a thickness of the spacer 18 can be between and including 50 pm and 200 mm, for example between and including 100 pm and 100 mm or between and including 200 pm and 50 mm. It is also possible, that the thickness of the spacer 18 is at most 10 mm, at most 5 mm or at most 1 mm. For instance, assuming a detector minimum pixel size of around 50 pm and a necessary resolution of 0.5 nm with around 10° divergence, a thickness of the spacer 18 can be around 250 pm. However, for example, higher resolution may require a thicker spacer .

[0117] The graph shown in Figure 3 essentially corresponds to the graph shown in Figure 1 . In contrast to the graph shown in Figure 1, the reflectance spectrum shown here comprises multiple minima, for instance two further minima, around the first reflectance minimum. For example, the further minima may indicate variations of the reflectance minimum due to different angles at which the electromagnetic radiation travels through the optical cavity 7 or in the interaction region 4, 5. For instance, for phi not equal to 0° , a variation of the reflectance minimum is expected to fluctuate closely around the value obtained for phi = 0° . In the exemplary embodiment of the component 1 of Figure 3, the wavelengths of the three reflectance minima of the solid line shown may interact with the medium 6 in a common interaction region 4, 5. For instance, in this case, one reflectance minimum is obtained for phi = 0° , whereas the two further reflectance minima are obtained for phi > 0° .2024PF00913 November 21, 2025

[0118] P2024, 1015 WO N 21

[0119] Figure 4 shows a component 1 and an assembly 10 comprising the component 1 according to an exemplary embodiment .

[0120] The assembly 10 further comprises a light source 11. The light source 11 is configured to emit electromagnetic radiation 15 towards the component 1. During operation of the assembly 10, at least a portion of the electromagnetic radiation 15 emitted by the light source 11 can interact with the medium 6 in the interaction region 4 of the component 1. Additionally, at least a portion of the electromagnetic radiation 15 may impinge on the photodetector 2 of the component 1 .

[0121] The light source 11 comprises a radiation outcoupling side 12. The component 1 can be in direct contact with the light source 11. For example, the component 1 is in direct contact with the radiation outcoupling side 12 of the light source 11. It is also possible, that the component 1 is attached to the light source 11 via an adhesive layer 21. The adhesive layer 21 can be a connection layer for bonding, gluing, sintering and / or soldering the component 1 and the light source 11 together for forming the assembly 10. That the component 1 is in direct contact with the light source 11 can mean that the assembly 10 formed by the component 1 and the light source 11 is a single device .

[0122] For example, the light source 11 is configured to emit parallel or at least approximately parallel electromagnetic radiation 15. This can mean that the electromagnetic radiation 15 impinges on the component 1 or enters the interaction region 4 with only a small range of different angles of incidence .2024PF00913 November 21, 2025

[0123] P2024, 1015 WO N 22

[0124] The light source 11 can be or can comprise a laser 14. Shown here, the light source 11 is or comprises a vertical cavity surface emitting laser, VCSEL . The component 1 is in contact with the radiation outcoupling side 12 of the laser 14. The laser 14 and / or the component 1, thus, for instance, the assembly 10, can be arranged in a package or form a package, e . g. a TO package . A size, e . g. a lateral expansion of the assembly 10 shown here can be between and including 1 mm to 20 mm, in particular between and including 5 mm to 10 mm.

[0125] The component 1 and / or the light source 11 can comprise electrical contacts 20.

[0126] For example, during operation of the assembly 10 a portion of the electromagnetic radiation 15 emitted by the light source 11 can pass through the wavelength-selective element 3 of the component 1, interact with the medium 6, e . g. the gas 6 within the interaction region 4 and / or impinge on the photodetector 2 assigned to the interaction region 4. The assembly 10 can be a gas sensor .

[0127] The laser 14, in particular the VCSEL, can have an aperture with a diameter of at least 1 pm, for example of at least 2 pm. It is possible that the aperture of the laser 14 is at least approximately 2 pm. The diameter of the aperture of the laser 14 can correspond or at least approximately correspond to a lateral extension of the component 1 or of a single pixel of the component 1. Thereby, a single pixel of the component 1 can be understood as a region of the component 1 comprising only one interaction region 4. This can mean that a lateral extension of the interaction region 4 or of the further interaction region 5 is at least approximately 2 pm or, for example, at least 1 pm or at least 2 pm.2024PF00913 November 21, 2025

[0128] P2024, 1015 WO N - 23 -

[0129] It is possible, not shown, that the light source 11 comprises a plurality of lasers 14, for example a plurality of VCSELs . In this case, for example, the light source 11 can be a pixelated light source 11. The plurality of VCSELs can form a VCSEL array, e . g. of size n x m. A number of single pixels of the component 1, e . g. a number of interaction regions 4, 5 can correspond to a number of VCSELs in the VCSEL array. In other words, each VCSEL can be uniquely assigned to one interaction region 4, 5.

[0130] It is possible that the VCSELs and / or the single pixels of the component 1 are formed contiguous, respectively. Each single pixel of the component 1 can comprise a photodetector 2, shown here, or multiple photodetectors 2, as shown in Figure 3. For instance, the photodetectors 2 can also be referred to as pixels of a pixelated photodetector . In this case, the component 1 can comprise a pixelated photodetector, wherein each photodetector 2 forms a pixel of the pixelated photodetector . The size of the VCSEL array and / or the number of interaction regions 4, 5 is not limited. However, for assemblies 10 comprising large VCSEL arrays and a corresponding number of interaction regions 4, 5 the yield may decrease .

[0131] For example, in this exemplary embodiment, as the light source 11 can comprise a plurality of distinct lasers 14, the spectral linewidth of the light source 11 can be easily adjusted by implementing lasers 14 with suitable laser linewidths .

[0132] Figure 5 shows an assembly 10, for instance a gas sensor, according to another exemplary embodiment . The component 12024PF00913 November 21, 2025

[0133] P2024, 1015 WO N 24

[0134] shown here can correspond to the component 1 shown in Figure 1. However, instead of the component 1 of Figure 1 also the components 1 shown in Figures 2 and 3 may be applied.

[0135] The light source 11 comprises an edge emitting laser 14. The laser 14 can be arranged on a carrier 22, for instance on a submount comprising or consisting of AIN. The carrier 22 comprises a main extension plane .

[0136] The edge emitting laser 14 can be arranged within a housing 23. For instance, the housing 23 can laterally surround the laser 14 and / or the carrier . It is possible, that the housing 23 laterally completely surrounds the laser 14 and / or the carrier . The housing 23 may comprise or be formed of a ceramic material, e . g. of a multilayer ceramic, shown here .

[0137] A prism 25 may be arranged on the carrier 22 at a distance from the laser 14. Preferable, the prism 25 is arranged at the side of the laser 14 on which the laser 14 emits electromagnetic radiation 15. The prism 25 can be configured to deflect or redirect the electromagnetic radiation 15 emitted by the laser 14. Alternatively or in addition to the prism 25, any optical component suitable for directing the electromagnetic radiation 15 in a desired direction may be used. For example, the prism 25 directs the electromagnetic radiation 15 towards a cover 24 of the light source 11.

[0138] The cover 24 can be arranged on the side of the laser 14 facing away from the carrier 22. The cover 24 can at least partially be transparent or translucent for the electromagnetic radiation 15 emitted by the laser 14. For instance, the cover 24 comprises glass . For example, the cover 24 is a glass lid with a metallization. The2024PF00913 November 21, 2025

[0139] P2024, 1015 WO N - 25 -

[0140] metallization of the cover 24 can comprise AuSn or consist of AuSn.

[0141] The component 1 can be arranged on the side of the cover 24 facing away from the carrier 22, the housing 23, the prism 25 and / or the laser 14. For instance, the component 1 can be easily combined with laser packages . This way, for example, a gas sensor can be realized in a space saving and / or surfacemounting technology-suitable manner .

[0142] Due to a deflection of the electromagnetic radiation 15 at the prism 25 arranged downstream of the laser 14, a width of the light beam, e . g. a cross-section, can be expanded. This can mean that the electromagnetic radiation 15 impinges on the component 1 with different angles of incidence .

[0143] This way, in contrast to the exemplary embodiment shown in Figure 4, in the exemplary embodiment shown in Figure 5 one laser 14 can be configured to illuminate multiple interaction regions 4, 5 of the component 1. For instance, a diameter of the electromagnetic radiation 15 at an interface of the cover 24 and the component 1 can be at least 1 mm, for instance at least 3 mm, at least 5 mm or at least 10 mm. It is possible that the diameter of the electromagnetic radiation at the interface of the cover 24 and the component 1 is at most 50 mm, at most 20 mm or at most 10 mm. Deviations of phi = 0° of the electromagnetic radiation 15 can be compensated using known or predetermined angles of incidence .

[0144] Exemplarily, in combination with Figure 5, also a method for operating an assembly 10 is described. During operation of the assembly 10, the light source 11, for instance a laser 14 or a plurality of lasers 14 emit electromagnetic radiation2024PF00913 November 21, 2025

[0145] P2024, 1015 WO N - 26 -

[0146] 15, also referred to as light beam. The laser emission can be a relatively broad in terms of wavelength. The emitted electromagnetic radiation can extend at least approximately in parallel .

[0147] A transmission selection takes place via the wavelength-selective elements 3, for instance Fabry-Perot-cavities .

[0148] Thereby, the resonant wavelengths of the Fabry-Perot-cavities are different from each other in pairs . A transmission of each wavelength-selective element 3 is smaller with respect to the wavelength than the laser emission. For instance, the wavelength-selective elements 3 are matched to characteristic absorption ranges or absorption bands of the materials wo be detected .

[0149] Electromagnetic radiation with a wavelength corresponding to the resonant wavelength of the respective Fabry-Perot-cavity circulates in the interaction regions 4, 5, in particular in the optical cavities 7 formed between the first reflector 8 and the second reflector 9 of the wavelength-selective element 3. Due to the multiple throughputs of the electromagnetic radiation 15 in the interaction region, an interaction of the electromagnetic radiation 15 with the medium 6 is maximized or at least enhanced.

[0150] The electromagnetic radiation 15 impinging on the photodetector / s 2 is a function of the transmission function of the respective wavelength-selective element 3, the respective optical cavity 7 or of the respective interaction region 4, 5 and the concentration of the material, e . g. a gas component, to be detected within the medium 6.2024PF00913 November 21, 2025

[0151] P2024, 1015 WO N - 27 -

[0152] The same method or corresponding methods for operating an assembly 10 can be used for the assemblies 10 shown in Figures 4 and 6 or for assemblies 10 comprising the components 1 described in combination with Figures 1 to 3 .

[0153] Figure 6 shows an assembly 10, for instance a gas sensor, according to another exemplary embodiment . In the assembly 10 according to this exemplary embodiment, the light source 11 comprises a VCSEL .

[0154] The assembly 10 comprises an optical element 13. The optical element 13 is configured to direct the electromagnetic radiation emitted by the light source 11 to the component 1. Shown here, the component 1 and the light source 11 can be arranged on the same side of the optical component 13. For instance, shown here, the optical component comprises two reflective surfaces 26. This way, the component 1 can be easily combined with a VCSEL .

[0155] A size or lateral extension of the assembly 10 shown in Figure 6 can be between and including 5 mm and 100 mm, for example between and including 10 mm and 50 mm.

[0156] This patent application claims priority of German patent application 102025106653.1, the disclosure content of which is hereby incorporated by reference .

[0157] The invention described herein is not limited by the description given with reference to the embodiments . Rather, the invention encompasses any novel feature and any combination of features, including in particular any combination of features in the claims, even if this feature2024PF00913 November 21, 2025

[0158] P2024, 1015 WO N - 28 -

[0159] or this combination is not itself explicitly indicated in the claims or embodiments .2024PF00913 November 21, 2025

[0160] P2024, 1015 WO N

[0161] - 29 -

[0162] References

[0163] 1 component

[0164] 2 photodetector

[0165] 3 wavelength-selective element 4 interaction region

[0166] 5 further interaction region 6 medium

[0167] 7 optical cavity

[0168] 8 first reflector

[0169] 9 second reflector

[0170] 10 ass e mb 1 y

[0171] 11 light source

[0172] 12 radiation outcoupling side 13 optical element

[0173] 14 laser

[0174] 15 electromagnetic radiation 16 substrate

[0175] 17 layer

[0176] 18 spacer

[0177] 19 intermediate layer

[0178] 20 electrical contact

[0179] 21 adhesive layer

[0180] 22 carrier

[0181] 23 housing

[0182] 24 cover

[0183] 25 prism

[0184] 26 reflective surface

Claims

2024PF00913 November 21 , 2025P2024 , 1015 WO N - 30 -Claims1 . A component ( 1 ) , comprising- a photodetector ( 2 ) ,- a wavelength-selective element ( 3 ) , and- an interaction region ( 4 ) , wherein- the interaction region ( 4 ) is arranged within the wavelength-selective element ( 3 ) ,- the photodetector ( 2 ) is arranged adj acent to the wavelength-selective element ( 3 ) , and- the interaction region ( 4 ) is configured to receive a medium ( 6 ) .2 . The component ( 1 ) according to the previous claim, wherein at least three photodetectors ( 2 ) are assigned to the interaction region ( 4 ) .3 . The component ( 1 ) according to one of the previous claims , wherein the wavelength-selective element ( 3 ) forms an optical cavity ( 7 ) with a predetermined resonant wavelength, and wherein the interaction region ( 4 ) is formed by the optical cavity ( 7 ) .4 . The component ( 1 ) according to one of the previous claims , wherein the wavelength-selective element ( 3 ) comprises a first reflector ( 8 ) and a second reflector ( 9 ) arranged on opposing sides of the interaction region ( 4 ) .5 . The component ( 1 ) according to claim 4 , wherein the first and / or second reflector ( 9 ) comprises a dielectric mirror .2024PF00913 November 21 , 2025P2024 , 1015 WO N - 31 -6 . The component ( 1 ) according to one of the previous claims , wherein the photodetector ( 2 ) comprises silicon or InGaAs / InP .7 . The component ( 1 ) according to one of the previous claims , wherein the component ( 1 ) comprises a plurality of photodetectors ( 2 ) , wherein the plurality of photodetectors ( 2 ) is configured to detect electromagnetic radiation passing through the wavelength-selective element ( 3 ) .8 . The component ( 1 ) according to one of the previous claims , wherein the component ( 1 ) comprises at least one further interaction region ( 5 ) , wherein the further interaction region ( 5 ) is laterally spaced apart from the interaction region ( 4 ) , and wherein at least one photodetector ( 2 ) is uniquely assigned to each interaction region ( 4 , 5 ) .9 . The component ( 1 ) according to the previous claim, wherein the interaction region ( 4 ) and the at least one further interaction region ( 5 ) are each assigned at least three photodetectors ( 2 ) .10 . The component ( 1 ) according to one of the claims 8 to 9 , wherein a resonant wavelength of the further interaction region ( 5 ) di f fers from a resonant wavelength of the interaction region ( 4 ) .11 . The component ( 1 ) according to one of the previous claims , wherein the interaction region ( 4 ) comprises a plurality of optical cavities ( 7 ) which are arranged spaced apart from each other .2024PF00913 November 21 , 2025P2024 , 1015 WO N - 32 -12 . The component ( 1 ) according to the previous claim, wherein at least two optical cavities ( 7 ) are stacked along a vertical direction, wherein the vertical direction extends at least approximately perpendicular to a main extension plane of the component ( 1 ) .13 . An assembly ( 10 ) , comprising a component ( 1 ) according to one of the previous claims , and a light source ( 11 ) , wherein the light source ( 11 ) is configured to emit electromagnetic radiation towards the component ( 1 ) , such that , during operation of the assembly ( 10 ) , at least a portion of the electromagnetic radiation emitted by the light source ( 11 ) interacts with the medium ( 6 ) in the interaction region ( 4 ) of the component ( 1 ) and impinges on the photodetector ( 2 ) .14 . The assembly ( 10 ) according to the previous claim, wherein the light source ( 11 ) is configured to emit parallel electromagnetic radiation .15 . The assembly ( 10 ) according to one of the claims 13 to 14 , wherein the light source ( 11 ) comprises a radiation outcoupling side ( 12 ) and the component ( 1 ) is in direct contact with the radiation outcoupling side ( 12 ) of the light source ( 11 ) .16 . The assembly ( 10 ) according to one of the claims 13 to 14 , further comprising an optical element , wherein an optical element ( 13 ) is configured to direct the electromagnetic radiation emitted by the light source ( 11 ) to the component ( 1 ) •17 . The assembly ( 10 ) according to one of the claims 13 to 16 , wherein the light source ( 11 ) comprises a laser ( 14 ) .2024PF00913 November 21, 2025P2024, 1015 WO N - 33 -18. The assembly ( 10) according to one of the claims 13 to 17, wherein the assembly ( 10) is a gas sensor .

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