Optical arrangement for emitting multiple light beams with different propagation directions and LiDAR sensor

Abstract

Optical arrangement (12) for emitting multiple light beams (31, 32, 33) with different directions of propagation, comprising at least two light sources (14), a lens system (15), and a scanner (22), wherein the at least two light sources (14) are configured to emit light along parallel directions of propagation and are arranged in a focal plane (40) of the lens system (15) such that their emitted light leaves the lens system (15) with different directions of propagation, wherein all light beams (31, 32, 33) meet in a pupil (42) of the lens system (15) after passing through the lens system (15), and the scanner (22) is arranged at a location where all light beams (31, 32, 33) meet and is configured to deflect the light beams (31, 32, 33) controllably in at least one dimension, characterized in thatthat the scanner (22) is a 1D grating scanner or a 1D scanner comprising a holographic optical element or a 2D grating scanner or a 2D scanner comprising a holographic optical element, in which a deflection of the light rays (31, 32, 33) in a first dimension or in two dimensions is achieved by mechanically adjusting a grating or the holographic optical element and a deflection in a first dimension and / or in a second dimension is achieved by changing the wavelength of the light, furthermore the at least two light sources (14) are designed as transceivers (20) which are configured to emit and receive light.

Description

State of the art

[0001] The invention relates to an optical arrangement for emitting multiple light beams with different directions of propagation, comprising at least two light sources. A further aspect of the invention relates to a LiDAR sensor comprising such an optical arrangement.

[0002] Several concepts for LIDAR (Light Detection and Ranging) sensors are known in the prior art. One possibility is the use of so-called "macro scanners." Here, a rotating macro mirror, for example, has a diameter on the order of several centimeters. This allows a light beam with a diameter of this size to be guided across the mirror. A large beam diameter offers particular advantages in terms of eye safety, since a pupil diameter of 7 mm assumed in the standards (IEC 60825-1) can only capture a fraction of the beam. Furthermore, a larger beam diameter is more robust against interference such as rain or dust. Another possibility is the use of "micro scanners."This technology utilizes small mirrors with diameters on the order of a few millimeters, manufactured using MEMS (Micro-Electro-Mechanical Systems) technology. These mirrors are mounted to oscillate or rotate on one or two axes to deflect the beam. Advantages include their small size and the absence of macroscopically moving elements. However, small mirror diameters negatively impact eye safety and susceptibility to interference. Furthermore, it is difficult to operate these micromirror-based systems in such a way that the same optical path can be used for both transmission and reception. Depending on its size, the micromirror can severely restrict the receiving aperture, resulting in insufficient photon collection for optimal detector illumination.

[0003] Document DE 10 2017 123 875 A1 describes a transmitting device comprising a radiating device and a scan mirror deflectable about its center point, which is arranged within a housing with a transparent cover element. The cover element is formed, at least in one coupling area, by a cutout of a monocentric hemispherical shell with a center of curvature and is arranged to cover the scan mirror such that the center of curvature and the center of the scan mirror coincide.

[0004] From DE 10 2009 010 019 A1 a method for non-contact measurement of the topography of a spherically aspherically curved air-glass surface of an optical lens or lens combination is known.

[0005] DE 10 2015 111 473 A1 describes a scanning method in which a coherent light beam, in particular a laser beam, is deflected two-dimensionally, wherein the light beam is guided in a first deflection direction by a swiveling mirror element.

[0006] Document US 2018 / 0216932A1 discloses measuring instruments and methods for generating highly precise and accurate gas concentration maps that can be overlaid with three-dimensional topographic images by rapidly scanning one or more modulated laser beams with a spatially coded transmitter over a scene to create images.

[0007] From US2017 / 0090031 A1, a system for spatial detection is known in which light from a light source is deflected using optical gratings as spatially dispersive elements. By using two gratings, deflection in two dimensions can be achieved.

[0008] LiDAR systems measure the distance to an object, for example, by directly measuring the time of flight of the emitted light pulse. A laser source emits a light pulse, which is deflected onto an object by a suitable unit. The object reflects the light pulse, and the reflected light pulse is measured and analyzed by a detector. Using time-of-flight measurement, the system can determine the travel time of the emitted and received light pulses and, using the speed of light, the distance of the object from the transmitter / detector. Other methods are based on indirect time-of-flight measurement by modulating the light intensity or the light frequency itself. Another approach is the combination of frequency modulation and coherent detection (coherent frequency modulated continuous wave (FMCW)).

[0009] Modern LiDAR systems must cover a large field of view (FoV) at high resolution, meaning with a high number of pixels. Furthermore, high scan rates are desirable. To enable a compact design and ensure high reliability, the use of macroscopic rotating components should be avoided. It is not possible to meet these requirements with a compact LiDAR system using existing systems. Disclosure of the invention

[0010] An optical arrangement for emitting multiple light beams with different directions of propagation is proposed, comprising at least two light sources, a lens system, and a scanner. The at least two light sources are configured to emit light along parallel directions of propagation and are arranged in a focal plane of the lens system such that their emitted light exits the lens system with different directions of propagation. All light beams converge at a pupil of the lens system after passing through it. The scanner is positioned at the point where all light beams converge and is configured to deflect the light beams in a controllable manner in at least one dimension.

[0011] The optical arrangement can, in particular, be part of a LiDAR sensor, in which light rays are emitted within a field of view (FoV) and light reflected from objects is received in the opposite direction.

[0012] The light source is considered to be a device capable of emitting a light ray along a defined direction of propagation. The position of the light source relative to the lens system is defined as the point from which a diverging light ray exits the light source in the direction of the lens system. In idealized geometric ray optics, this is the point from which the diverging light rays originate in the direction of the lens system. In real optics, this is not a mathematical point, but rather a region of finite extent. In idealized geometric ray optics, the light rays from the light source can be considered a divergent beam with a principal ray that is parallel to the direction of propagation.The device, which is considered a light source, has an emitter that generates the light and typically includes one or more optical elements that shape the light beam. The emitter can be, for example, a light-emitting diode (LED) or a laser. Emitters with wavelengths in the range of 1300 nm to 1600 nm and / or 840 nm to 1000 nm are preferably used. Preferably, the emitter is configured to emit monochromatic light.

[0013] The lens system of the optical arrangement can consist of one or more optical elements and, using simplified geometric ray optics, can be considered a converging lens with a focus length F. Preferably, the lens system is designed as a telecentric lens system, wherein, with object-side telecentrity (i.e., on the side where the at least two light sources are arranged), the entrance pupil is located at infinity. On the opposite exit side, the light rays from the at least two light sources converge in a single pupil.

[0014] A telecentric lens system has the advantage that crosstalk, i.e., interference between adjacent channels or light sources, is minimized, and ideally, no vignetting occurs at off-axis points. In the special case of identical numerical apertures of the channels or light sources and a telecentric lens system without beam vignetting, the light rays from the light sources have an almost identical extent at the pupil. The extent of a light ray is also referred to as the ray diameter.

[0015] The light sources can be arbitrarily arranged within the focal plane of the lens system, which lies at distance F on the object side of the lens system. A light source is considered to be arranged within the focal plane not only when it lies exactly within the focal plane, such that the lens system perfectly collimates the light source. The term "within the focal plane" is intended to encompass slight deviations, allowing the light sources to be arranged slightly outside the focal plane, although the light from light sources located slightly outside the focal plane will not be perfectly collimated. Preferably, the arrangement of a light source deviates from the focal plane by less than 5 mm, and particularly preferably by less than 1 mm. Within the focal plane, the light sources can, for example, be arranged along a line. Alternatively, two-dimensional arrangements along a grid are also possible.The distribution of the light sources in spatial space within the focal plane of the lens system results in a different exit angle for each light ray behind the lens system. The corresponding principal rays of the parallel light rays from the different light sources intersect at a common point, which lies in a pupil plane of the lens system.

[0016] Preferably, between 2 and 160 light sources are arranged, more preferably between 2 and 16 light sources, and most preferably between 2 and 4 light sources. For example, three light sources are used. Each of the light sources, when used in a LiDAR sensor, represents an independent channel for a measurement.

[0017] The scanner, which can be a 1D or 2D scanner, is positioned in or near the pupil and deflects all light rays without vignetting or significant spatial displacement during scanning. A 1D scanner deflects the light in one spatial direction only. A 2D scanner deflects the light in two different spatial directions, which might be perpendicular to each other.

[0018] When used in a LiDAR sensor, the scanner is used to sweep or scan a field of view with light beams. Light reflected from objects is directed by the scanner back towards the light sources.

[0019] The scanner can be a mechanical scanner in which light rays strike a mirror that is moved in one dimension (1D scanner) or in two dimensions (2D scanner) according to the desired deflection. The various light rays, which strike the scanner at different angles, are deflected in different directions. During a scan, the angle at which the light beam is deflected is changed continuously or in steps, so that the light beam gradually sweeps across or scans a predefined field of view.

[0020] Preferably, the scanner is a mechanical 2D scanner, wherein the deflection of light rays along two different dimensions is achieved by mechanically adjusting an element, in particular a mirror element. For example, in a mechanical 2D scanner, the light sources are arranged along a line so that they address different angles in a vertical field of view (vFoV) as different channels. In this example, the mechanical scanner can deflect the light rays vertically by an angle β and horizontally by an angle α. A rotation of the scanner by the angle β results in a displacement of the rays reflected by the scanner mirror by an amount ΔvFoV, thus enabling a scan of all channels in the vertical direction.Through parallelization, a large vFoV is covered by multiple beams, with each beam only needing to scan a small angular range ΔvFoV to address the entire vFoV. The horizontal field of view (hFoV) is covered by a scan of angle α.

[0021] In this way, to cover a large field of view (e.g., h x v: 120° x 30°), a scanner can be used that allows large angles in the horizontal direction (+ / - 30° mechanically -> + / - 60° optically) but only provides smaller angles in the vertical direction (30° / n=10° = + / - 2.5° mechanically for n=3). Here, n denotes the number of light sources arranged in a line or the number of channels. Variants are also conceivable in which the hFoV and vFoV are reversed.

[0022] In another variant, the adjacent light rays can also address only adjacent pixels in, for example, the vFoV. The entire vFoV is covered by the scan in the corresponding dimension. This reduces the requirement for the scan speed in, for example, the vertical direction, but the requirement for the absolute maximum angle in the vertical direction remains approximately the same.

[0023] When an axis is completely parallelized via an array of light beams, it is possible to use a 1D scanner, which accordingly only allows a deflection in one dimension.

[0024] The scanner is a 1D or 2D grating scanner in which the deflection of light rays in a first dimension is achieved by mechanically adjusting a grating, and deflection in a second dimension is achieved by changing the wavelength of the light. The grating is preferably a reflection grating where the diffraction efficiency is optimized for the first diffraction order. For this purpose, a blaze grating can be used, for example, where the blaze angle and / or the period are adjusted. The angle at which the first order is reflected depends on the wavelength of the incident light and can therefore be varied by changing the wavelength. When using such a 1D or 2D grating scanner, deflection in the frontal field of view (vFoV) is achieved, for example, via a wavelength scan, and deflection in the horizontal field of view (hFoV) via a mechanical deflection of the grating.

[0025] Instead of a grating, one or more holographic optical elements (HOEs) can be used. The HOEs and center wavelengths of the light sources can be designed / selected such that each HOE is assigned to a specific center wavelength. For this to work, the center wavelengths must be sufficiently far apart, which means that each HOE is only effective for its corresponding center wavelength and a small bandwidth around it. This allows a defined angle to be addressed for each center wavelength, around which scanning can be performed with a wavelength change of small bandwidth. The advantage of using HOEs is that the center output angle can be set independently for each center wavelength, and that multiple HOEs can be written into a single substrate (e.g., certain plastics) of small dimensions.

[0026] However, a reverse arrangement is also conceivable, in which deflection in the horizontal field of view (hFoV) is achieved via a wavelength scan and deflection in the vertical field of view (vFoV) via a mechanical deflection of the grating. Any distortion of the field of view, e.g., due to a dependence of the angles of the diffraction orders on the absolute angle of the horizontal field of view, can be calibrated out.

[0027] The scanner can, for example, also be designed as a 2D grating scanner, in which two dimensions are mechanically addressable and an additional dimension can be addressed by changing the wavelength, for example by a wavelength scan. The dimension of the wavelength scan can be parallel to one of the two mechanically addressable dimensions or run along a different direction.

[0028] The scanner can be implemented as a macroscopic movable element, for example as a rotating mirror, or alternatively as a MEMS (Micro-Electro-Mechanical Systems) element, in which, for example, a bending beam is controlled and the beam angle can be changed. The macroscopic rotating mirror can be designed, for example, as a galvo, a polygon mirror, or a gimbal mirror.

[0029] The grating of a grating scanner can be designed, for example, as a reflection grating, a hologram, an embossed pattern, or even as an active, switchable grating in the form of an LCD (liquid crystal display). The geometry of the grating can be, for example, a blaze grating, a binary grating, a sinusoidal grating, a freeform grating, an aperiodic grating, or a holographic grating such as a volume hologram.

[0030] In one embodiment, the axis(s) of rotation of a mechanical scanner are centered, i.e., located on the optical axis. In other embodiments, the axes of rotation of the mechanical scanner are not centered on the optical axis.

[0031] The more precisely the scanner can be positioned within the pupil, the better the image quality. If the pupil of the lens system is inaccessible, a relay optic can be inserted behind the lens to image the pupil or pupillary plane to a more accessible relay position. The scanner is then positioned at this relay position. The relay optic can, for example, consist of two converging lenses in a 4f configuration, where each lens has an identical focal length f and is positioned 2f apart. The focal length of the relay optic can be different from or identical to the focal length F of the lens system. The relay optic is positioned at a focal length f away from the pupil of the lens system.

[0032] Preferably, the light emitted by the light sources is monochromatic. Each light source can emit light of the same wavelength. Alternatively, the individual light sources can each emit light of different wavelengths.

[0033] Alternatively, it is preferred that the light emitted by the light sources comprises several different wavelengths. The light can include several discrete individual wavelengths or cover one or more continuous wavelength ranges. Here, too, it is possible for different light sources to have an identical spectrum or for different light sources to emit light with different spectra.

[0034] Furthermore, it is possible to use mixed forms in which at least one light source emits monochromatic light and at least one light source emits light with multiple wavelengths.

[0035] Preferably, at least one light source or channel uses multiple wavelengths over a range larger than the wavelength scan bandwidth of a grating scanner. This directs the different wavelengths incident on the grating into different angular ranges even without an active wavelength scan. Coverage of the entire field of view (FoV) is then achieved via mechanical scanning and / or a wavelength scan.

[0036] The light sources are designed as transceivers, which are configured to emit and receive light. Alternatively, receivers can also be arranged in the optical arrangement, which can receive light and convert it into an electrical signal, preferably with a corresponding receiver assigned to each light source.

[0037] Preferably, each light source or transceiver has at least one dedicated emitter, preferably a laser or an LED. Alternatively, a single emitter can be used whose power is distributed among the various transceivers. Furthermore, a single light source or transceiver can have multiple emitters, allowing, for example, the combination of different wavelengths.

[0038] Preferably, the transceivers have coaxial signal paths in both the transmit and receive directions. Alternatively, the signal path for transmitting the light beams and the signal path for receiving light can be biaxial, thereby separating the point of light coupling from the light source or from the transceiver and the point of light reception.

[0039] Preferably, the transceivers are designed as FMCW (frequency modulated continuous wave), dToF (direct time of flight) or iToF (indirect time of flight) transceivers.

[0040] For example, the transceiver for coherent FMCW interferometry is designed in a coaxial configuration. The basic setup preferably corresponds to a Mach-Zehnder interferometer, which decouples a portion of the laser beam as a local oscillator (i.e., as a reference) and causes this portion to interfere with the received light. For the coaxial arrangement, there is a selective element that ensures the transmit and receive paths are optically separated, even though coupling occurs via the same element. This selective element can be implemented, for example, as a circulator in a fiber-based embodiment. However, an embodiment with only one coupler or beam splitters is also possible.

[0041] Alternatively, a transceiver with coherent FMCW interferometry can be designed as a biaxial arrangement, whereby, in contrast to the coaxial arrangement, the transmit and receive paths are completely separated (biaxial arrangement) and no selective element is necessary.

[0042] In another example, the transceiver is configured with a signal path for coaxial dTOF / iTOF. Unlike the FMCW approach, no reference path is required here. The laser beam is sent through a selective element that separates the transmit and receive paths. This can be implemented in various ways.

[0043] In one variant of a signal path for bi-axial dTOF / iTOF, the transmit and receive paths are separated, so that no selective element is required.

[0044] Each signal path can be implemented as a fiber-based solution or as an integrated solution (photonic integrated circuit, PIC). A free-beam setup is also conceivable (using, for example, beam splitters).

[0045] Another aspect of the invention is to provide a LiDAR sensor comprising at least one of the described optical arrangements. The optical arrangement of the LiDAR sensor preferably includes transceivers as light sources and preferably includes additional components for controlling the transceivers and the scanner, as well as for evaluating the received signals. Advantages of the invention

[0046] The optical arrangement according to the invention enables the construction of LiDAR sensors in which the field of view can be divided into different channels, each addressed by its own light source or transceiver. This allows for parallel processing and thus an improvement in scan speed and / or resolution.

[0047] Furthermore, it is possible to use only a 1D scanner, such as a mirror that can only be tilted or rotated in one direction. To address the entire field of view in two dimensions, a multitude of light sources or channels are arranged along a line perpendicular to the mirror's plane of rotation. This allows the use of large 1D MEMS mirrors with a diameter of 1 cm or more, which are not available as 2D scanners.

[0048] When combined with a grating scanner, the proposed optical arrangement allows for simple multiplexing, for example, via wavelength or angle of incidence. Unlike mechanical scanners, grating scanners, in which the wavelength of the light sources is varied, are not limited by a moment of inertia. This allows for an improved scan frequency and enables the scanning of arbitrary point patterns.

[0049] Another advantage is that in embodiments where a "comb" of light rays is spread over, for example, the entire vFoV by using multiple light sources, the angles between the adjacent light rays are small and therefore scanning can be done very quickly.

[0050] Furthermore, the proposed optical arrangement allows for a particularly compact arrangement of the components required for a LiDAR sensor. Brief description of the drawings

[0051] Exemplary embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. They show Fig. 1a a schematic representation of a state-of-the-art LiDAR sensor, Fig. 1b a schematic representation of a LiDAR sensor according to the invention, Fig. 2 a first embodiment of an optical arrangement, Fig. 3 a second embodiment of an optical arrangement, Fig. 4a a first embodiment of a transceiver configuration, Fig. 4b a second embodiment of a transceiver configuration and Fig. 4c a third embodiment of a transceiver configuration.

[0052] Fig. Figure 1a shows a schematic representation of a state-of-the-art LiDAR sensor 10' with a transceiver 20'. The transceiver 20' comprises a transmitter 24' for generating light and a receiver 26' for detecting light. The LiDAR sensor 10' includes a scanner 22' for scanning the two-dimensional field of view (FoV) to generate three-dimensional images. For this purpose, a light beam 30' from the transmitter 24' is deflected by the scanner 22', and the deflected light beams 60' are scanned across an object 28.

[0053] Light reflected from object 28 can pass in the reverse direction from scanner 22' to receiver 26'. Embodiments of the invention

[0054] In the following description of exemplary embodiments of the invention, identical or similar components and elements are designated by the same or similar reference numerals, whereby a repeated description of these components or elements is omitted in individual cases. The figures represent the subject matter of the invention only schematically.

[0055] Fig. Figure 1b shows a schematic representation of a LiDAR sensor 10 according to the invention. The LiDAR sensor 10 comprises in the Fig. In the example shown in Figure 1b, an optical arrangement 12 with three channels is shown, with each channel being assigned a transceiver 20. Each of the transceivers 20 is configured to transmit and receive light and therefore serves as a light source 14, see Figure 1b. Fig. 2 and Fig. 3. Each transceiver 20 emits a light beam 31, 32, 33. Furthermore, the transceivers 20 can contain additional components that perform an analog-to-digital conversion of a received signal. Additionally, the transceivers 20 can be configured to perform signal processing for distance determination. The optical arrangement 12 of the LiDAR sensor 10 further comprises a lens system 15 and a scanner 22 for scanning the two-dimensional field of view (FoV) to generate three-dimensional images. To accelerate the scanning process and / or increase the scan resolution, the field of view of the LiDAR sensor 10 is divided into three partial fields of view 71, 72, 73, with one of the light beams 31, 32, 33 being deflected by the scanner 22 in such a way that it covers the respective partial field of view 71, 72, 73. For this purpose, the light beams 31, 32, 33 of the transceiver 20 are directed via the lens system 15 onto the scanner 22.The three light rays 31, 32, 33 directed onto scanner 22 in the illustrated example are scanned as deflected light rays 61, 62, 63 via an object 28, with each of the three deflected light rays 61, 62, 63 being assigned to one of the partial fields of view 71, 72, 73. Light reflected from object 28 can pass through scanner 22 in the opposite direction towards the transceivers 20 and thus be received by the transceivers 20.

[0056] The received light can be analyzed using a coherent FMCW (frequency modulated continuous wave) method, in which a beat frequency (i.e., a beat frequency) is generated between the transmitted and received reflected signals via a time-varying optical frequency of the laser. Since this beat frequency is dependent on the time of flight, it allows for distance determination. Alternatively, the distance can be determined using the classic dToF (direct time of flight) method, in which a short pulse (in the nanosecond range) is emitted and the time of flight of the reflected light is measured. Indirect ToF (iToF) methods are also possible, both coherent and incoherent. In these methods, the amplitude or phase of the light is modulated (sinusoidally or with a code), so that a time-of-flight difference, and thus a distance, can be determined by correlating (analog or digital) the received and known transmitted signals.

[0057] Fig. Figure 2 shows a first embodiment of an optical arrangement 12 with a lens system 15 and a scanner 22. The example of Fig. The optical arrangement 12 shown in Figure 2 has three channels and thus three light sources 14, which are arranged here along a line in a focal plane 40 of the lens system 15. Further embodiments may have a different number of light sources 14 and a different arrangement of these.

[0058] For the schematic representation of the Fig. 2. Geometric ray optics is used. The lens system 15 is represented here by a converging lens 16, which has a first focus length F. In a real-world implementation, for example, a lens would be used as the lens system 15. The focal plane 40 of the lens system 15 is located on the object side of the lens system 15 at a distance corresponding to the first focus length F. All light sources 14 are arranged in the focal plane 40 and each emits a light ray 31, 32, 33 (in some embodiments, however, it can also be advantageous for the light sources to be located slightly outside the focal plane and thus not perfectly collimated).Within the framework of the geometric ray optics used for the schematic representation, each light ray 31, 32, 33 is depicted as a beam with three rays, where the middle of the rays represents the principal ray 31', 32', 33', which indicates the direction of propagation of the respective light ray 31, 32, 33. All rays of a beam originate from the light source 14. The rays of the respective beams diverge from the respective light source 14, meaning that the beam of each beam has its smallest diameter at the location of the light source 14. The beam diameter increases with increasing distance from the light source 14. The lens system 15 is defined such that the principal rays 31', 32', 33' of the light rays 31, 32, 33 are parallel to an optical axis 80 of the lens system 15 on the object side (telecentric optics).Since the beams of light rays 31, 32, 33 each originate from a light source 14 located in the focal plane 40 of the lens system 15, all rays of the beams of light rays 31, 32, 33 are parallel to each other after passing through the lens system 15. The principal rays 31', 32', 33 of light rays 31, 32, 33 intersect at the center of the pupil 42 of the lens system 15 and each exhibits a different angle of propagation. In the special case of identical numerical aperture of the channels or light sources 14 and a telecentric lens system 15 without beam vignetting, the beams of light rays 31, 32, 33 have an identical extent or beam diameter in the pupil 42.

[0059] The scanner 22 is located on the side of the lens system 15 opposite the light sources 14. The scanner 22 is positioned at the pupil 42 of the lens system 15. Since the scanner 22 is placed exactly in the pupil 42, it can deflect all light rays 31, 32, 33 without vignetting and without any relevant spatial displacement during scanning.

[0060] The scanner 22 can be configured, in particular, as a 2D scanner capable of deflecting the light rays 31, 32, 33 along two different dimensions or directions. The scanner 22 can be designed as a moving mechanical element, such as a mirror. Alternatively or additionally, the scanner 22 can be configured as a grating, whereby deflection along one dimension is achieved by changing the wavelength of the light emitted by the light sources 14.

[0061] Fig. Figure 3 schematically shows a second embodiment of the optical arrangement 12. In contrast to the one relating to the Fig. In the first embodiment described in Figure 2, the scanner 22 is not located at the position of the pupil 42 of the lens system 15, but is situated further away. A relay optic 19 images the pupil 42 onto a relay position 44, which is mechanically more accessible. The scanner 22 is located at this relay position 44. The relay optic 19 is located in the Fig. The example shown in Figure 3 consists of two converging lenses 16 in a 4f configuration, wherein the two converging lenses 16 each have an identical second focus length f and are arranged at a distance from each other equal to twice the second focus length f. The second focus length f of the relay optics 19 can differ from or be identical to the first focus length F of the lens system 15. The relay optics 19 is positioned a distance from the pupil 42 of the lens system 15 equal to the second focus length f.

[0062] Fig. 4a, Fig. 4b and Fig. Figure 4c shows various embodiments of a transceiver configuration, each comprising, by way of example, transceivers 20. Each of the transceivers 20 comprises an exit point, which represents a light source 14, and an entry point 50 for light, wherein the exit point or the light source 14 is arranged in the optical arrangements 12 such that it lies in the focal plane 40 of the lens system 15, compare Fig. 1b. For all variants, the extraction or reception of a signal backscattered from an object 28 can be achieved via a free-space arrangement with an extraction optic, via an optical fiber, or, in the case of photonically integrated systems, via grating or so-called edge couplers. A signal path containing the components required for conditioning the emitted light and processing the received light is shown in the Fig. 4a, Fig. 4b and Fig. 4c each marked with reference 48.

[0063] In the first embodiment of the Fig. 4a The transceivers 20 are each configured as a coaxial arrangement, such that the entry point 50 and the light source 14 or the exit point are each located on a common axis. Furthermore, in the first embodiment, each of the transceivers 20 has its own emitter in the form of a laser 46.

[0064] In the second embodiment of the Fig. In the second embodiment, the transceivers 20 are each configured as a biaxial arrangement, such that the entry point 50 and the light source 14 or the exit point are located on different axes. In this second embodiment as well, each transceiver 20 has its own emitter in the form of a laser 46.

[0065] In the third embodiment of the Fig. 4c are as in the first embodiment of the Fig. 4a The transceivers 20 are each configured as a coaxial arrangement, such that the entry point 50 and the light source 14 or the exit point each lie on a common axis. In contrast to the first embodiment of the Fig. However, 4a provides for a common emitter in the form of a single laser 46 for all transceivers 20.

[0066] The invention is not limited to the embodiments described here and the aspects highlighted therein. Rather, within the scope specified by the claims, a multitude of modifications are possible that fall within the bounds of what is considered skilled in the art.

Claims

[1] Optical arrangement (12) for emitting multiple light beams (31, 32, 33) with different directions of propagation, comprising at least two light sources (14), a lens system (15), and a scanner (22), wherein the at least two light sources (14) are configured to emit light along parallel directions of propagation and are arranged in a focal plane (40) of the lens system (15) such that their emitted light leaves the lens system (15) with different directions of propagation, wherein all light beams (31, 32, 33) meet in a pupil (42) of the lens system (15) after passing through the lens system (15), and the scanner (22) is arranged at a location where all light beams (31, 32, 33) meet and is configured to deflect the light beams (31, 32, 33) controllably in at least one dimension. characterized by, that the scanner (22) is a 1D grating scanner or a 1D scanner comprising a holographic optical element or a 2D grating scanner or a 2D scanner comprising a holographic optical element, in which a deflection of the light rays (31, 32, 33) in a first dimension or in two dimensions is achieved by mechanically adjusting a grating or the holographic optical element and a deflection in a first dimension and / or in a second dimension is achieved by changing the wavelength of the light, furthermore the at least two light sources (14) are designed as transceivers (20) which are configured to emit and receive light. [2] Optical arrangement (12) according to claim 1, characterized bythat the scanner (22) is arranged at the pupil (42) of the lens system (15) or that the pupil (42) of the lens system (15) is imaged to a relay position (44) via a relay optic (19), wherein the scanner (22) is located at this relay position (44). [3] Optical arrangement (12) according to claim 1 or 2, characterized by , that the scanner (22) is a mechanical 1D scanner, wherein the light rays (31, 32, 33) are deflected along one dimension by mechanically adjusting a mirror element, or is a mechanical 2D scanner, wherein the light rays (31, 32, 33) are deflected along two different dimensions by mechanically adjusting a mirror element. [4] Optical arrangement (12) according to any one of claims 1 to 3, characterized by , that the light emitted by the light sources (14) is monochromatic. [5] Optical arrangement (12) according to any one of claims 1 to 3, characterized by, that the light emitted by the light sources (14) each comprises several different wavelengths. [6] Optical arrangement (12) according to claim 1, characterized by , that the transceivers (20) are designed as FMCW (frequency multiplied continuous wave), as dToF (direct time of flight) or iToF (indirect time of flight) transceivers. [7] LiDAR sensor (10) comprising at least one optical arrangement (12) according to any one of claims 1 to 6.

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