Detection unit and detection module
By separating the detector components from the laser radiation source and optimizing the interference radiation redirection using optical elements, the crosstalk problem between detectors was solved, achieving a high signal-to-noise ratio and low power consumption for multi-point sensing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 에이엠에스오스람아게
- Filing Date
- 2023-10-20
- Publication Date
- 2026-05-22
AI Technical Summary
Existing detectors struggle to maximize the detection signal without compromising the integrity of the VCSEL signal, and the crosstalk between multiple detectors is difficult to distinguish, limiting their integration in multi-point sensing applications.
By employing separate detector components and laser radiation sources, combined with housing components and optical element design, the properties of external objects are determined through self-mixing interferometry. Optical elements are used to optimize the redirection of interferometric radiation and the detection signal, reducing crosstalk and improving the signal-to-noise ratio.
It achieves improved detection signal quality, reduced crosstalk, lower power consumption, and optimized footprint without compromising the integrity of the laser radiation source signal, making it suitable for multi-point sensing applications.
Smart Images
Figure CN122074104A_ABST
Abstract
Description
[0001] Detection units and detection modules are specified, wherein the detection module comprises at least two detection units. The detection units and modules are suitable for determining, for example, at least one attribute of an external object, such as its distance, velocity, or eye movement. In particular, the detection module is qualified as a power readout module.
[0002] For example, there are detectors for VCSELs (Vertical-Cavity Surface-Emitting Lasers) that utilize integrated photodiodes employing self-mixing interference (SMI). The problem with these detectors is that the detection signal cannot be maximized without compromising the integrity of the VCSEL signal. This makes it difficult to integrate these detectors into applications requiring multi-point sensing implemented with multiple detectors, as the detection signals, potentially affected by crosstalk between the multiple detectors, are quite difficult to distinguish.
[0003] One objective is specifically to specify a detection unit having an improved detection signal. This objective is achieved, in particular, by the detection unit according to the independent claim.
[0004] Another objective is to specify a detection module with an improved detection signal. This objective is achieved, in particular, by the detection module according to the independent claim.
[0005] Other embodiments and developments of the detection unit or detection module are the subject of the dependent claims.
[0006] According to at least one embodiment of the detection unit, the detection unit is designed to determine at least one attribute of an external object. The attribute may be distance, velocity of the external object, or eye movement, wherein the term "object" also includes a living organism or part of a living organism. For example, the external object is an eye, whose position, gaze direction, gaze trajectory, gaze velocity, corneal displacement, and / or orientation will be tracked.
[0007] According to at least one embodiment, the detection unit includes a laser radiation source. Specifically, the laser radiation source emits electromagnetic laser radiation during operation. For example, the laser radiation source includes an optical resonant cavity. The active region of the laser radiation source may be arranged inside the optical resonant cavity. The electromagnetic laser radiation may have a peak wavelength in the visible to infrared spectral range, where the peak wavelength represents the maximum value of the spectral distribution of the electromagnetic laser radiation.
[0008] According to at least one embodiment, the detection unit includes a detector component provided for detecting interference radiation. The detector component may be arranged adjacent to a laser radiation source. The detector component may have a lateral distance from the laser radiation source. Furthermore, the detector component may have a vertical distance from the laser radiation source. While the lateral distance may be determined along a horizontal plane, the vertical distance may be determined along a vertical direction inclined (e.g., perpendicular) to the horizontal plane.
[0009] Specifically, the detector component is a separate component and is not integrated into the laser radiation source. The advantage of separating the detector component from the laser radiation source is that the radiation to be detected by the detector component can be affected without compromising the integrity of the laser radiation source's radiation or signal.
[0010] According to at least one embodiment, a detection unit is provided for self-mixing interferometry. Typically, self-mixing interferometry (SMI) involves detecting interference radiation generated by the interference of laser radiation from a laser radiation source and redirected laser radiation from an external object. For example, the amplitude, phase, and / or frequency of the emitted laser radiation changes due to self-mixing interference. Furthermore, the changed amplitude, phase, and / or frequency of the interference radiation can be used to determine at least one property of the external object. Due to the coherence length of the laser radiation source, the operating range of the SMI detection unit can be up to at least five meters.
[0011] According to at least one embodiment, the detection unit includes a housing component. The housing component may laterally surround the laser radiation source and the detector component. In the context of this application, "lateral" may refer to a transverse direction arranged in a horizontal plane. The laser radiation source and the detector component may be arranged within a cavity of the housing component.
[0012] According to at least one embodiment, the detection unit includes an optical element. Preferably, the optical element is partially transmissive to the radiation emitted and detected by the detection unit. Suitable materials for the optical element are, for example, glass and / or plastic.
[0013] According to at least one embodiment, the optical element covers the laser radiation source and detector components. The optical element may enclose the upper part of the cavity in which the housing component in which the laser radiation source and detector components are arranged.
[0014] According to at least one embodiment, an optical element is provided for redirecting (meaning, for example, reflection and / or refraction) a portion of the interference radiation generated in the optical resonant cavity by the interference of laser radiation from a laser radiation source and redirected laser radiation from an external object to a detector component.
[0015] According to at least one embodiment, the optical element influences a portion of the interference radiation on the detector component in a manner more significant than in the absence of an optical element. Therefore, the detection signal at the detector component can be improved by using the optical element.
[0016] According to at least one embodiment of a detection unit for determining at least one attribute of an external object, the detection unit is provided for a self-mixing interferometry method and includes: - A laser radiation source, provided for emitting laser radiation and including an optical resonant cavity. - Detector components, arranged adjacent to the laser radiation source and provided for detecting interference radiation. - Housing components, which laterally surround the laser radiation source and detector components, and - Optical elements, covering the laser radiation source and detector components, and provided for redirecting a portion of the interference radiation generated in the optical resonant cavity by the interference of laser radiation from the laser radiation source and redirected laser radiation from an external object to the detector components.
[0017] The optical element influences a portion of the interference radiation on the detector component in a manner more significant than in the absence of an optical element.
[0018] According to at least one embodiment or configuration, the detection unit includes a carrier component, at least one of a laser radiation source and a detector component mounted on the carrier component. A housing component may be connected to the carrier component.
[0019] According to at least one embodiment or configuration, the optical element includes at least one planar surface, and the at least one planar surface has a surface normal having a different orientation from the main radiation direction of the laser radiation source. For example, the at least one planar surface extends at an angle to the main extension plane of the detection unit. The main extension plane may be a horizontal plane. Furthermore, the main radiation direction may extend at an angle, for example, perpendicular to the main extension plane. In the context of this application, the main radiation direction may define the direction in which the intensity distribution of electromagnetic laser radiation has its maximum value.
[0020] According to at least one embodiment or configuration, the optical element has a planar or plate-like shape and is tilted relative to the main extending plane of the detection unit. Specifically, in this embodiment or configuration, the optical element does not have optical structures such as gratings and / or variations in refractive index. By tilting the optical element, the radiation projected onto the detector component by the optical element, as well as the height and footprint of the detection unit, can be optimized. Optimizing the projected radiation includes, for example, reducing the divergence of the projected radiation and / or changing the main radiation direction of the projected radiation relative to the main radiation direction of the laser radiation source.
[0021] According to at least one embodiment or configuration, the optical element having a planar shape is tilted at an acute tilt angle different from 45°. Specifically, this acute tilt angle is less than 45°. In this embodiment or configuration, the laser radiation source and detector components can be mounted on the surface of the carrier component. Furthermore, the laser radiation source and detector components may only have a lateral distance from each other and can be easily assembled.
[0022] According to at least one embodiment or configuration, the planar optical element is tilted at a 45° angle. In this embodiment or configuration, the optical element can be a beam splitter. Furthermore, while one of the laser source and detector components can be mounted on the surface of the carrier component, the other can be mounted on the sidewall of the housing component. In this embodiment or configuration, the laser source and detector components can have both lateral and vertical distances from each other. Even with the more complex assembly in this embodiment or configuration, the detection unit offers high SNR (signal-to-noise ratio), good immunity to external light sources, and a small footprint.
[0023] According to at least one embodiment or configuration, the optical element comprising at least one planar surface is a waveguide. A laser radiation source and a detection component can be arranged inside the waveguide. Advantageously, this embodiment or configuration minimizes the height of the detection unit. Furthermore, the waveguide can be implemented at the wafer level, simplifying the manufacturing process of the detection unit or detection module.
[0024] According to at least one embodiment or configuration, the optical element includes a curved surface. This curved surface can be approximated by a plurality of regions with different inclinations. Therefore, as mentioned above, the radiation projected onto the detector component can be optimized by the height and footprint of the optical element and the detection unit. In particular, the radiation projected onto the detector component can be focused by the optical element including the curved surface. In this embodiment or configuration, the optical element can have a curved shape resembling a portion of a spherical surface or a portion of an ellipsoidal surface. Alternatively, the optical element can be a waveguide as mentioned above but with a curved surface instead of a planar surface.
[0025] According to at least one embodiment or configuration, the optical element is a diffractive optical element. The optical element may include, for example, a volumetric phase hologram. In this embodiment or configuration, the optical element may have a planar or plate-like shape and may be horizontally oriented such that the optical element is not tilted relative to the main extension plane of the detection unit or detection module. Advantageously, this results in an even lower unit or module height compared to a tilted optical element.
[0026] According to at least one implementation or configuration, the laser radiation source is a single laser diode. For example, the laser diode is a single VCSEL emitter.
[0027] According to at least one embodiment or configuration, the laser radiation source comprises an array of laser diodes, such as an array of VCSELs. For example, the laser diodes may operate sequentially. Time multiplexing can be applied to drive a single laser diode at a time. The detection signal read out at the detector element originates from a single laser diode each time. This embodiment or configuration allows for units or modules constructed from more than one unit to have reduced power consumption and a smaller footprint in applications, because one detector element is sufficient for multiple laser diodes.
[0028] Suitable materials for laser diodes include semiconductor materials based on arsenide, phosphide, or nitride compound semiconductors.
[0029] According to at least one embodiment or configuration, the detector component is a photodiode. Suitable materials for the detector component are, for example, semiconductor materials such as silicon or materials based on arsenide, phosphide, or nitride compound semiconductors.
[0030] According to at least one embodiment or configuration, the housing component includes a cover element disposed on the side of the optical element opposite to the detector component, and the cover element covers the detector component. The cover element may be provided to block external interference radiation.
[0031] According to at least one embodiment or configuration, the entire housing component may have an optical blocking function. For example, the housing component may include an optical blocking material at least on its outer surface. The housing component may be, for example, a molded body comprising resin or silicone. Furthermore, the optical blocking material, such as carbon particles, may be dispersed in the molded body.
[0032] According to at least one embodiment or configuration, the housing component has a rectangular shape in the plan view of the detection unit.
[0033] According to at least one embodiment or configuration, the detection unit includes at least one control element, and at least one of a laser radiation source and a detector component is arranged on the at least one control element. During operation, the components arranged on the control element are driven by the control element. The control element is, for example, an ASIC (Application-Specific Integrated Circuit).
[0034] Detection units of the type described above can be used in a detection module, which can consist of multiple such detection units. Therefore, all the features described in conjunction with the detection unit also apply to the detection module, and vice versa.
[0035] A detection module according to at least one embodiment is provided for determining at least one property of an external object by means of self-mixing interferometry or interferometry, as mentioned in the incorporation of detection units. For example, the detection module includes at least two detection units of the types mentioned above. Including more than one detection unit qualifies the detection module as a power readout module, which can be used for multi-point sensing, such as for eye-tracking applications, odometers, distance and speed mapping.
[0036] All detection units in the detection module can have the same design or architecture. Furthermore, the detection units can be arranged in a regular pattern. For example, the detection units can be arranged in a grid of rows and columns.
[0037] According to at least one embodiment or configuration, the housing components of adjacent detection units are in contact with each other. For example, at least a portion of the housing components of the detection units are formed as a single unit.
[0038] According to at least one embodiment or configuration, housing components of adjacent detection units form an optical barrier between the detection units. Advantageously, crosstalk and optical coupling between adjacent detection units can be reduced. As mentioned above, the housing components may include an optical blocking material. For example, the housing components may be formed of a black material such as a resin or silicone material comprising carbon particles.
[0039] According to at least one embodiment or configuration, the detection module includes a carrier, on which a laser radiation source and detector components of the detection unit are arranged. Specifically, the carrier is composed of carrier components of the detection unit of the detection module. For example, the carrier components are formed as a single unit. Suitable materials for the carrier components or the carrier are, for example, semiconductor materials such as silicon or ceramic materials such as aluminum nitride.
[0040] The detection units and modules are suitable for AR (Augmented Reality), VR (Virtual Reality), consumer applications, automotive applications, and industrial applications.
[0041] The detection unit and detection module will be further explained with reference to the accompanying drawings described below.
[0042] Figure 1A A schematic perspective view of an exemplary implementation of the detection module is shown, and Figure 1B It shows Figure 1A The diagram shows a schematic cross-sectional view of the detection unit of the detection module along line D1.
[0043] Figure 2A A schematic plan view of another exemplary embodiment of the detection module is shown, and Figure 2B It shows Figure 2A The diagram shows a schematic cross-sectional view of the detection unit of the detection module along line AA'.
[0044] Figures 3 to 6 A schematic cross-sectional view illustrating other exemplary embodiments of the detection module is shown, and
[0045] Figure 7 A schematic cross-sectional view of another exemplary embodiment of the detection unit is shown.
[0046] In the accompanying drawings, elements with the same, equivalent, or equivalent functions may be denoted using the same reference numerals. The drawings are schematic illustrations and therefore not necessarily drawn to scale. For purposes of better illustration, relatively small elements, and in particular layer thicknesses, may be shown exaggerated.
[0047] Combination Figure 1A and Figure 1B The first exemplary implementation of the SMI detection module 100 is described. Figure 1B A schematic cross-sectional view of the detection unit 10 of the detection module 100 along line D1 is shown.
[0048] The detection module 100 includes a plurality of detection units 10, wherein the number of detection units 10 is not limited to four as shown. All detection units 10 have the same design. Furthermore, the detection units 10 are arranged in a regular, grid-like pattern of rows and columns.
[0049] Each detection unit 10 includes a laser radiation source 1 and a detector component 2, the detector component 2 being arranged adjacent to the corresponding laser radiation source 1. The detector components 2 are separate components and are not integrated into the laser radiation source 1. In each case, the advantage of separating the detector component 2 from the laser radiation source 1 is that the radiation or signal to be detected by the detector component 2 can be affected without compromising the integrity of the radiation or signal from the laser radiation source 1.
[0050] Furthermore, each detection unit 10 includes a housing component 3 that laterally surrounds the corresponding laser radiation source 1 and detector component 2. For example, "lateral" means a lateral direction including a first lateral direction L1 and a second lateral direction L2, wherein the first lateral direction L1 and the second lateral direction L1 are inclined to each other, for example, perpendicular to each other. The laser radiation source 1 and detector component 2 are arranged in cavities 4 within the corresponding laterally surrounding housing components 3. For example, the housing component 3 or cavity 4 has at least an approximately rectangular shape in the plan view of the detection module 100, wherein the laser radiation source 1 and detector component 2 can be arranged along the diagonal D1 of the rectangular shape in each case. However, the laser radiation source 1 and detector component 2 can be arranged along any lateral direction including the first lateral direction L1 and the second lateral direction L2.
[0051] In each case, housing component 3 may comprise a plastic material such as resin or silicone. Optical blocking materials such as carbon particles may be dispersed in the plastic material, enabling housing component 3 to have optical blocking functionality and function as an optical barrier. Housing component 3 may be formed by a molding process such as injection molding, making housing component 3 a molded body. For example, all housing components 3, or at least several thereof, may be formed integrally.
[0052] Furthermore, each detection unit 10 includes a carrier component 5, with a corresponding laser radiation source 1 and detector component 2 mounted on the carrier component 5, and a corresponding housing component 3 connected to the carrier component 5. In each case, the carrier component 5 closes the lower part of the cavity 4 of the corresponding housing component 3. The carrier 50 of the detection module 100 is composed of the carrier component 5, which can be formed as a single unit. Suitable materials for the carrier component 5 or carrier 50 are, for example, semiconductor materials such as silicon or ceramic materials such as aluminum nitride.
[0053] Furthermore, each detection unit 10 includes an optical element 6, which covers the corresponding laser radiation source 1 and detector component 2. Each optical element 6 has a planar plate shape and may comprise or be composed of a transparent material such as glass and / or plastic. Specifically, the optical element 6 does not have an optical structure such as a grating and / or a variation in refractive index. In each case, the optical element 6 encloses the upper part of the cavity 4 of the corresponding housing component 3.
[0054] Optical elements 6 are integrated in the top side 3A of the respective housing component 3 such that the planar surface 6A of the optical element 6 and the top surface 10A of the detection unit 10 extend obliquely to the main extending plane of the respective detection unit 10 or detection module 100 in each case. For example, the main extending plane is a horizontal plane defined by a first lateral direction L1 and a second lateral direction L2. In particular, each optical element 6 is rotated out of the horizontal plane, for example, by rotation about a diagonal axis D2 of the respective optical element 6, which may extend obliquely to the diagonal line D1. Therefore, the optical element 6 is obliquely inclined relative to the main extending plane of the respective detection unit 10 or detection module 100 in each case. For example, the optical element 6 is obliquely inclined at an acute angle α, which is different from 45° and preferably less than 45°, in each case.
[0055] In each case, the laser radiation source 1 includes a laser diode 9, such as a VCSEL, which can be a single laser diode 9. The laser diode 9 includes an active region 9C disposed within optical resonant cavities 9A and 9B, which emits electromagnetic laser radiation with a peak wavelength, for example, in the visible to infrared spectral range, during operation. The detector component 2 can be a photodiode that is sensitive to the wavelength range of the interference radiation detected during operation.
[0056] During operation, the laser radiation source 1 of each detection unit 10 can emit electromagnetic laser radiation S1 in the main radiation direction R, for example along the vertical direction V, which is perpendicular to the main extension plane of the corresponding detection unit 10 or detection module 100. In a first exemplary embodiment, the planar surface 6A of the optical element 6 each has a surface normal N with a different orientation from the main radiation direction R of the laser radiation source 1.
[0057] Part of laser radiation S1 t The laser radiation S1 is transmitted through optical element 6 and emitted to the top surface 10A, then incident on the external object O. t A portion of S2 is redirected toward the detection unit 10, incident on the optical element 6, and transmitted to the laser radiation source 1. Interference occurs in the optical resonant cavities 9A and 9B of the laser radiation source 1, and the interference radiation is generated by the interference of the laser radiation S1 from the laser radiation source 1 and the redirected laser radiation S2 from the external object O. The detector component 2 receives a portion of the interference radiation S1 redirected by the optical element 6. r Therefore, the detection unit 10 or the detection module 100 operates based on the principle of self-mixing interferometry or self-mixing interferometry (SMI), wherein, for example, the interfering radiation is compared to the original laser radiation S1 or the redirected laser radiation S1. r The altered amplitude, phase, and / or frequency can be used to determine at least one property of the external object O. Due to the coherence length of the laser radiation source 1, the operating range of the SMI detection unit 10 or the SMI detection module 100 can be up to at least 5 meters.
[0058] Optical element 6 affects the portion S1 of the interferometric radiation on detector component 2 in a more significant manner in each case than it would in the absence of optical element 6. r Therefore, the detection signal at detector component 2 can be improved by optical element 6.
[0059] By tilting the optical elements 6, the interference radiation projected onto the detector component 2 by each optical element 6 can be optimized. Optimizing the projected radiation includes, for example, reducing the divergence β of the projected radiation. Furthermore, the vertical extension height h of the specified unit 10 or module 100, determined along the vertical direction V, and the space occupied by the bottom surface 10B of each detection unit 10, or the bottom surface of the module 100 defined by the overall size of the bottom surface 10B, can be optimized. And, the spacing p, which is the lateral distance between the detection units 10, can be reduced.
[0060] Furthermore, the detection unit 10 or the detection module 100 may have any of the features, characteristics, and advantages mentioned in conjunction with other exemplary embodiments.
[0061] Combination Figure 2A and Figure 2B A second exemplary implementation of the SMI detection module 100 is described. Figure 2B A schematic cross-sectional view of the detection unit 10 of the detection module 100 along line AA' is shown.
[0062] In the second exemplary embodiment, each of the optical elements 6 has a planar shape and can be implemented in the same or similar manner as described in conjunction with the first exemplary embodiment, wherein the optical elements 6 are tilted at a tilt angle α of 45°. The optical elements 6 serve as beam splitters, wherein half of the radiation incident on the optical elements 6 is redirected and the other half is transmitted, such that the interference radiation or signal on the detector component 2 is maximized.
[0063] While in the first exemplary embodiment, the laser source 1 and detector component 2 have only a lateral distance from each other in each case, in the second exemplary embodiment, the laser source 1 and detector component 2 have a lateral distance a1 determined along a horizontal plane defined by a first lateral direction L1 and a second lateral direction L2, and a vertical distance a2 determined along a vertical direction V. For example, the laser source 1 is mounted on a horizontally oriented surface of the corresponding carrier component 5, while the detector component 2 is mounted on a vertically oriented sidewall of the corresponding housing component 3. However, it is also possible to mount the detector component 2 on the surface of the corresponding carrier component 5, while mounting the laser source 1 on the sidewall of the corresponding housing component 3. The surface and sidewall of the carrier component 5 can extend perpendicularly to each other in each case. Even though the assembly is more complex in the second exemplary embodiment than in the first exemplary embodiment, the detection module 100 provides a high SNR (signal-to-noise ratio), good immunity to external light sources, and a small footprint.
[0064] Furthermore, the detection unit 10 or the detection module 100 may have any of the features, characteristics, and advantages mentioned in conjunction with other exemplary embodiments.
[0065] Combination Figure 3 This describes a third exemplary embodiment of the SMI detection module 100. In this third exemplary embodiment, the optical element 6 of the detection unit 10 is a waveguide, each waveguide including a tilted planar surface 6A for redirecting (e.g., refracting) a portion of the interference radiation toward the corresponding detection element 2. The tilted planar surface 6A is tilted relative to the main extension plane of the corresponding detection unit 10 or detection module 100. In particular, each waveguide may include two tilted planar surfaces 6A, such that the waveguide has a prismatic cross-sectional shape that tapers gradually in the main radiation direction R. Alternatively, the optical element 6 may each have a combination of Figure 5 The surface described is a curved surface, not a flat surface 6A.
[0066] The laser radiation source 1 and the detection component 2 of each detection unit 10 are arranged side-by-side inside the corresponding waveguide. Advantageously, in the third exemplary embodiment, the height h of the detection unit 10 can be minimized in each case. Furthermore, the waveguide can be implemented at the wafer level, which simplifies the manufacturing process of the detection unit 10 or detection module 100.
[0067] In each case, the housing component 3 of the detection unit 10 may include a cover element 7, which is arranged on the side of the corresponding optical element 6 facing away from the detector component 2 and covers the corresponding detector component 2. The cover element 7 is provided to block external interference radiation and thus improve the SNR. The cover element 7 can be implemented integrally with the corresponding housing component 3. Therefore, the same material can be used for the cover element 7 and the housing component 3.
[0068] Furthermore, the detection unit 10 or the detection module 100 may have any of the features, characteristics, and advantages mentioned in conjunction with other exemplary embodiments.
[0069] Combination Figure 4 This describes a fourth exemplary embodiment of the SMI detection module 100. In this fourth exemplary embodiment, the detector components 2 are arranged, for example, integrated on a control element 8, wherein a single control element 8 may be provided for each detector component 2, or for several or even all detector components 2. During operation, the detector components 2 are driven by the control element 8. The control element 8 is, for example, an ASIC (Application-Specific Integrated Circuit). The laser radiation source 1 may be driven by the same or different control elements.
[0070] Furthermore, the detection unit 10 or the detection module 100 may have any of the features, characteristics, and advantages mentioned in conjunction with other exemplary embodiments.
[0071] Combination Figure 5 A fifth exemplary embodiment of the SMI detection module 100 is described. In this fifth exemplary embodiment, each of the optical elements 6 includes a curved surface 6A. The curved surface 6A can be approximated by a plurality of regions with different inclinations, having the same effect as described in conjunction with the first exemplary embodiment. Furthermore, the radiation projected onto the detector component 2 can be focused by the optical element 6 in each case. Each of the optical elements 6 is similar to a portion of a spherical surface or a portion of an ellipsoidal surface.
[0072] Furthermore, the detection unit 10 or the detection module 100 may have any of the features, characteristics, and advantages mentioned in conjunction with other exemplary embodiments.
[0073] Combination Figure 6This describes a sixth exemplary embodiment of the SMI detection module 100. In this sixth exemplary embodiment, the optical element 6 is a diffractive optical element, which includes, for example, a volumetric phase hologram. The optical element 6 may have a planar shape or a plate shape and may be horizontally oriented without tilting relative to the main extending plane of the detection unit 10 or the detection module 100. Advantageously, this results in an even lower unit or module height compared to units or modules with tilted optical elements.
[0074] Furthermore, the detection unit 10 or the detection module 100 may have any of the features, characteristics, and advantages mentioned in conjunction with other exemplary embodiments.
[0075] Combination Figure 7 Another exemplary embodiment of the SMI detection unit 10 is described, wherein at least two of these units 10 can be assembled to form a detection module. However, the detection unit 10 itself is suitable for multi-point sensing.
[0076] The detection unit 10 has a laser radiation source 1, which includes an array of laser diodes 9, such as an array of VCSELs. The laser radiation source 1 is arranged next to a detector component 2, which can be a single photodiode. Therefore, one detector component 2 is sufficient to detect signals from several laser diodes 9. The laser diodes 9 can operate sequentially. Time multiplexing can be applied to drive a single laser diode 9 at a time. The detection signal read out at the detector component 2 originates from a single laser diode 9 at each time t0, t1, t2, etc., where t0 < t1 < t2. This unit 10 has a small footprint and reduced power consumption during operation.
[0077] Furthermore, the detection unit 10 or the detection module may have any of the features, characteristics, and advantages mentioned in conjunction with other exemplary embodiments.
[0078] As an alternative to or supplement to the features described in conjunction with the accompanying drawings, the exemplary embodiments shown in the drawings may include other features described in the general portion of the specification. Furthermore, even if such combinations are not explicitly described, the features and embodiments in the drawings may be combined with each other.
[0079] This invention is not limited to the exemplary embodiments described herein. Rather, the invention includes any new features and any combination of features, particularly any combination of features in the patent claims and any combination of features in the exemplary embodiments, even if the feature or combination itself is not expressly specified in the patent claims or exemplary embodiments.
[0080] Figure Labels 1. Laser radiation source 2 detector components 3 housing components 3A Top Side 4 chambers 5 carrier components 6 optical elements 6A surface 7 cover components 8 control elements 9 laser diodes 9A and 9B optical resonators 9C Active Area 10 detection units 10A top surface 10B bottom surface 50 carriers 100 detection module α tilt angle β divergence a1 lateral distance a2 vertical distance p spacing t0, t1, t2 time D1 diagonal D2 diagonal axis L1 First Lateral Direction L2 Second Lateral Direction N surface normal O external object R main radiation direction S1 original laser radiation S1 t Transmitted laser radiation S1 r Redirection part of interferometric radiation S2 transmitted, redirected laser radiation V vertical direction
Claims
1. A detection unit (10) for determining at least one attribute of an external object (O), wherein, The detection unit (10) is provided for self-mixing interferometry (SMI) and includes: - A laser radiation source (1), which is provided for emitting laser radiation (S1) and includes an optical resonant cavity (9A, 9B). - Detector component (2), which is arranged adjacent to the laser radiation source (1) and is provided for detecting interference radiation. - Housing component (3), the housing component (3) laterally surrounding the laser radiation source (1) and the detector component (2), and - Optical element (6), which covers the laser radiation source (1) and the detector component (2), and is provided for converting a portion (S1) of the interference radiation generated in the optical resonant cavity (9A, 9B) by the interference of the laser radiation (S1) from the laser radiation source (1) and the redirected laser radiation (S2) from the external object (O). r ) redirected to the detector component (2). The optical element (6) influences the portion (S1) of the interference radiation on the detector component (2) in a manner more significant than when the optical element (6) is not present. r ).
2. The detection unit (10) according to the preceding claim, wherein, The optical element (6) includes at least one planar surface (6A), and the at least one planar surface (6A) has a surface normal (N) that has a different orientation from the main radiation direction (R) of the laser radiation source (1).
3. The detection unit (10) according to any one of the preceding claims, wherein, The optical element (6) has a planar shape and is inclined relative to the main extension plane of the detection unit (10).
4. The detection unit (10) according to the preceding claim, wherein, The optical element (6) is tilted at an acute angle (α) different from 45°, and the laser radiation source (1) and the detector component (2) are mounted on the surface of the carrier component (5), and the housing component (3) is connected to the carrier component (5).
5. The detection unit (10) according to claim 3, wherein, The optical element (6) is a beam splitter and is tilted at a tilt angle (α) of 45°, and one of the laser radiation source (1) and the detector component (2) is mounted on the surface of the carrier component (5) connected to the housing component (3), and the other is mounted on the side wall of the housing component (3).
6. The detection unit (10) according to claim 1, wherein, The optical element (6) includes a curved surface (6A).
7. The detection unit (10) according to claim 1, 2 or the preceding claim, wherein, The optical element (6) is a waveguide.
8. The detection unit (10) according to claim 1, wherein, The optical element (6) is a diffractive optical element.
9. The detection unit (10) according to any one of the preceding claims, wherein, The laser radiation source (1) is a single laser diode (9).
10. The detection unit (10) according to any one of claims 1 to 9, wherein, The laser radiation source (1) includes an array of laser diodes (9) that can be operated sequentially.
11. The detection unit (10) according to any one of the preceding claims, wherein, The housing component (3) includes a cover element (7) which is arranged on the side of the optical element (6) opposite to the detector component (2) and covers the detector component (2).
12. The detection unit (10) according to any one of the preceding claims, the detection unit (10) comprising at least one control element (8), wherein at least one of the laser radiation source (1) and the detector component (2) is arranged on the at least one control element (8).
13. The detection unit (10) according to any one of the preceding claims, wherein, The detector component (2) is a photodiode.
14. A detection module (100) for determining at least one attribute of an external object (O), wherein, The detection module includes at least two detection units (10) according to any one of the preceding claims, wherein the housing components (3) of adjacent detection units (10) are in contact with each other and form an optical barrier between the detection units (10).
15. The detection module (100) according to the preceding claim, the detection module (100) includes a carrier (50), and the laser radiation source (1) and the detector component (2) of the detection unit (10) are arranged on the carrier (50).