Device for emitting a light beam

Abstract

A device (200, 200', 200'', 200''', 300, 400, 500, 500') includes an optical path (O) and a beam profile redistributor (220, 221, 222, 220', 320, 420, 520, 520') arranged in the optical path to receive an input light beam (210, 310, 410, 510). The beam profile redistributor includes two, non-co-planar reflective surfaces (S2, S3) of at least substantially uniform reflectivity for the input light beam, and is configured to convert the received input light beam (110, 210, 302, 410) so that at least one output light beam (130, 230, 312, 330, 430, 530) of the device includes, in a near field (NF) and / or at the beam profile redistributor, a redistributed beam intensity profile compared to at least one further output light beam when the beam profile redistributor is not present, within a given measuring aperture (AP) at a position (zap) along the optical path in the near field (NF), a lower output light power compared to the at least one further output light beam, and, in a far field (FF), at least substantially the same beam intensity profile compared to the at least one further output light beam.

Description

DEVICE FOR EMITTING A LIGHT BEAMTECHNICAL FIELD

[0001] Embodiments of the present invention relate to devices for emitting a light beam, in particular a laser beam in an eye-safe manner, such as a LIDAR device.BACKGROUND

[0002] Many modern devices rely on lasers to implement desired functions. Well-known everyday examples include an optical mouse and a laser pointer using a collimated laser beam. More complex devices are used in the fields of optical analysis and detection. For example, a LIDAR device may be used to detect and / or measure properties of objects by illuminating the objects with a laser, e.g. an infrared laser, and measuring back reflected light with a sensor. LIDAR has found terrestrial, airborne, and mobile applications such as in driver assist systems and autonomous vehicles. This is because automobiles are desired to be equipped with systems capable of reliably sensing and interpreting their surroundings, including identifying obstacles, hazards, objects, and other physical parameters that might impact navigation of the vehicle.

[0003] A laser is one example of a light source that can be used in a LIDAR system. As with any sensing system, in order for a LIDAR-based sensing system to be fully adopted by the automotive industry, the system should provide reliable data enabling detection of distant objects. Thus, operating in maximum illumination power of LIDAR systems is preferred. Currently, however, the maximum illumination power of LIDAR systems is limited by the need to make the LIDAR systems eye-safe. For example, LIDAR systems are required to prevent damage to the human eye which can occur if a projected light emission enters the eye's cornea and lens, causing thermal damage to the retina.

[0004] In particular when operating with a focused or collimated laser beam, such devices are potentially hazardous to (human unaided) eyes (or even the skin). To prevent damage, such (laser-based) devices are classified accordingly by their potential hazard level, and must fulfill respective safety requirements.

[0005] For example, according to standard EN 60825-1 :2007, a maximum-allowed power, or acceptable emission limit (AEL) level is defined. For a 900 nm wavelength Class 1 laser,the AEL is 1 mW when measuring flux through a 7 mm aperture outside the device (14 mm from the point where the laser beam exits the device).

[0006] Expanding the emitted (transmitted) illumination beams) may reduce the flux by increasing the spot size and spreading the beam energy is over a larger area. However, expanding the emitted (transmitted) beam and enlarging the devices transmission aperture, respectively, is not always a viable solution to ensure eye-safety. Other optical elements of the device, such as a scanner in the light path, may benefit from a smaller beam spot size. The size of these optical elements may need to scale with the size of the beam spot. This may impact size and / or cost constraints. For example, a LIDAR device may include a rotating polygon scanner to deflect laser beams towards a FOV. Light emitted towards the edge of the polygon facet during rotation may be partially incident on the edge of the polygon facet for a longer time, depending on the beam spot size. Thus, increasing the laser beam spot size would require increasing the size of the rotating polygon scanner to ensure the same functionality / performance.

[0007] In recently published document WO 2023 / 156982 Al, respective devices for emitting a light beam with a beam profile redistributor arranged in an optical path to receive an input light beam are described. The beam profile redistributor is configured to convert the received input light beam so that at least one output light beam of the device has, in a near field, a redistributed beam intensity profile compared to at least one further output light beam when the beam profile redistributor is not present and / or replaced by at least one mirror. Within a given measuring aperture at a position along the optical path in the near field, the at least one output light beam has a lower output light power compared to the at least one further output light beam. In a far field, the at least one output light beam has at least substantially the same beam intensity profile compared to the at least one further output light beam. Accordingly, a better trade-off between the effective emission area and the receiving efficiency may be achieved. As a result, eye safety may be ensured at high detection sensitivity in an already comparatively simple and / or cost efficient way. As explained below with regard to Fig. 1 to Fig. 3F, the desired redistribution of light rays may in particular be achieved by two pairs of refractive surfaces of the beam profile redistributor. However, there is still room for further improvement, particularly with regard to manufacturing tolerances, the effort required for alignment in the optical path and costs. Moreover, at least some of the device explained herein allow for a better trade-off between an effective emission area and a receiving efficiency.

[0008] For these and other reasons there is a need for the present invention.SUMMARY

[0009] At least the above-mentioned issues are addressed by the subject matter of the appended claims.

[0010] In one aspect, a device includes an optical path and a beam profile redistributor arranged in the optical path to receive an input light beam. The beam profile redistributor is arranged in the optical path to receive an input light beam and configured to convert the received input light beam so that at least one output light beam of the device includes, in a near field and / or at the beam profile redistributor, a redistributed beam intensity profile compared to at least one further output light beam when the beam profile redistributor is not present and / or is replaced by a beam expander which is configured to expand the received input light beam as the beam profile redistributor; within a given measuring aperture at a position along the optical path in the near field, a lower (typically a lower maximum) output light power compared to the at least one further output light beam; and in a far field, at least substantially the same beam intensity profile compared to the at least one further output light beam.

[0011] The term Near Field (NF) as used herein denotes a portion of the field of view illuminated by light coming from the laser device, in particular an infrared (IR) laser device at which the accumulated effect of the optical path accommodating the beam profile redistributor results in a redistributed intensity profile. In particular in the eye-safety applications of the LIDAR as described herein, the Near Field is the portion of the FOV at which the illuminated beam profile distribution is required to meet stricter eye-safety requirements. For example, the Near Field (NF) may be defined as the distance from the device aperture and up to Im, 2m, 3m up to 5m or 7m.

[0012] The term Far Field (FF) as used herein denotes the portion of the FOV at which the inevitable divergence of the beam illuminated by the laser device overcomes the accumulated effect of the optical path accommodating the beam profile redistributor. In the eye-safety applications of the LIDAR as described herein, the illuminated beam profile distribution at the Far Field is characterized mainly by its intensity and the suitability of the beam intensity for object detection. For example, the Far Field (FF) may be defined as the distance from the end of the Near Field (for example, Im, 2m, 3m up to 5m or 7m away from the device aperture and up to 15m, 20, m, 25m, 30m.

[0013] In one aspect, a device includes an optical path and a beam profile redistributor arranged in the optical path to receive an input light beam. The beam profile redistributor includes two, non-co-planar reflective surfaces each having an at least substantially uniform reflectivity for the input light beam. The beam profile redistributor is configured to convert the received input light beam so that at least one output light beam of the device includes, in a near field and / or at the beam profile redistributor, a redistributed beam intensity profile compared to at least one further output light beam when the beam profile redistributor is not present (and / or is replaced by a light beam redirecting component at least substantially not changing a light beam divergence). Within a given measuring aperture at a position along the optical path in the near field, the at least one output light beam has a lower output light power (typically a lower maximum output light power) compared to the at least one further output light beam, and in a far field, at least substantially the same beam intensity profile compared to the at least one further output light beam.

[0014] In another aspect, a one-piece beam profile redistributor for converting an input light beam into an output light beam with two partial beams is provided. The beam profile redistributor includes: a light transmitting volume or body, a first transmitting surface for transmitting the input light beam into the light transmitting volume or body as a first internal light beam, a first reflective surface for reflecting an incident first portion of the first internal light beam, thereby forming a second internal light beam, a second reflective surface for reflecting the second internal light beam, and a second transmitting surface for receiving the (reflected) second internal light beam and a second portion of the first internal light beam from the light transmitting volume or body, and for transmitting the received (reflected) second internal light beam and the second portion of the first internal light beam to form the output light beam.

[0015] In another aspect, a one-piece beam profile redistributor for converting an input light beam into an output light beam with two partial beams is provided. The beam profile redistributor includes: a light transmitting volume or body, a first reflective surface for reflecting an incident first portion of the input light beam to form a first partial beam of the two partial beams, a first transmitting surface for transmitting an incident second portion of the input light beam into the light transmitting volume or body as a first internal light beam, a second reflective surface for reflecting the first internal light beam to form a second internallight beam, and a second transmitting surface for receiving and transmitting the second internal light beam to form a second partial beam of the two partial beams.

[0016] In yet another aspect, a one-piece beam profile redistributor for converting an input light beam into an output light beam with four, typically spaced apart partial beams is provided. The beam profile redistributor includes a light transmitting volume or body, a first transmitting surface for transmitting the input light beam into the light transmitting volume or body as an internal light beam, a first reflective surface, a second reflective surface, which is at least substantially parallel to the first reflective surface, a third reflective surface, which is at least substantially orthogonal to the first reflective surface, a fourth reflective surface, which is at least substantially parallel to the third reflective surface, and a second transmitting surface, which is at least substantially parallel to the first transmitting surface, for receiving internal light beams and transmitting the received internal light beams to form the output light beam. The received internal light beams incudes a portion of the internal light beam which is received directly from the first transmitting surface, a portion of the internal light beam reflected at the first reflective surface to the second reflective surface and at the second reflective surface to second transmitting surface, a portion of the internal light beam reflected at the third reflective surface to the fourth reflective surface and at the fourth reflective surface to second transmitting surface, and a portion of the internal light beam split at the first reflective surface and the third reflective surface into two partial internal light beams that are re-combined by reflection of the two partial internal light beams at the second reflective surface and the fourth reflective surface.

[0017] In a further aspect, a LIDAR (Light Detection and Ranging) device includes an optical path including a transmitting part and a receiving part, a light detector arranged in the receiving part of the optical path, a light source arranged in the transmitting part of the optical path, and a beam profile redistributor arranged downstream the light source in the transmitting part of the optical path or even two beam profile redistributors arranged downstream one after the other in the transmitting part of the optical path. The beam profile redistributor(s) are configured to convert an input light beam received from the light source (or the upstream beam profile redistributor) into an output light beam (with redistributed beam intensity profile) including two partial beams. The beam profile redistributor(s) include two, non-co-planar reflective surfaces of at least substantially uniform reflectivity for the input light beam, and may in particular be implemented as one-piece beam profile redistributors as explained herein.The transmitting part of the optical path may also be referred to as emitting part of the optical path.

[0018] The beam profile redistributors explained herein are typically configured to redistributed the beam intensity profile in NF by reflecting either one of two partial input light beams of the input light beam at each of the two reflecting surfaces or each of the two partial input beams of the input light beam once at a corresponding one of the two reflecting surfaces. The reflection of the partial input beam(s) at the respective reflective surface may at least substantially polarization-independent or may depend on the polarization.

[0019] Accordingly, the intensity profile of the output light beam is, compared to the input light beam, redistributed in NF without substantially changing the far-field properties (outside the device).

[0020] The device explained herein may be used for emitting the at least one output light beam through a device aperture and to receive, through the device aperture back-reflected light beam(s), in particular back- scattered light beam(s). Compared to known similar devices, the device explained herein allow for a particularly good trade-off between an effective emission area and a receiving efficiency at comparatively low costs. This is due to reduced effort for manufacturing the beam profile redistributor within desired tolerances and / or due to reduced alignment effort of the beam profile redistributor in the optical path. In particular for the described one-piece beam profile redistributors, both manufacturing effort and alignment effort can be reduced. Accordingly, eye safety may be ensured at high detection sensitivity in a comparatively simple and / or cost efficient way.

[0021] Those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The components in the figures are not necessarily to scale, instead emphasis being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts. In the drawings:

[0023] FIG. 1, 2 are diagrams schematically illustrating devices for emitting light beams according to embodiments;

[0024] FIGs. 3A to 3F illustrate beam intensity profiles of light beams that may be generated using the devices illustrated in FIGs. 1, 2;

[0025] FIG. 3G is a diagram schematically further illustrating the devices illustrated in FIGs. 1, 2.

[0026] FIG. 3H illustrate beam paths and beam intensity profiles that may be generated using the devices illustrated in FIG. 3H.

[0027] FIG. 4 is a diagram schematically illustrating a device according to an embodiment;

[0028] FIG. 5 is a diagram schematically illustrating a device according to an embodiment;

[0029] FIGs. 6A to 6C illustrate beam intensity profiles of light beams that may be generated using the device illustrated in FIG. 5;

[0030] FIG. 7 is a diagram schematically illustrating a device according to an embodiment;

[0031] FIG. 8 is a diagram schematically illustrating a device according to an embodiment;

[0032] FIG. 9 is a diagram schematically illustrating a device according to an embodiment;

[0033] FIG. 10 is a diagram schematically illustrating a device according to an embodiment;

[0034] FIGs. 11 A to 11C are diagrams schematically illustrating a device according to embodiments;

[0035] FIGs. 12A to 12B illustrate beam intensity profiles of light beams that may be generated using the device illustrated in FIGs. 11 A-l 1C;

[0036] FIGs. 13A to 13C are diagrams schematically illustrating a device according to embodiments;

[0037] FIGs. 14A to 14C illustrate beam intensity profiles of light beams that may be generated using the device illustrated in FIGs. 13A-13C;

[0038] FIG. 15A schematically illustrates a device according to an embodiment;

[0039] FIG. 15B illustrates beam intensity profiles of light beams that may be generated using the device illustrated in FIG. 15 A;

[0040] FIGs. 16A to 16C are diagrams schematically illustrating a device according to embodiments;

[0041] FIG. 17A schematically illustrates a device according to an embodiment; and

[0042] FIG. 17B illustrates beam intensity profiles of light beams that may be generated using the device illustrated in FIG. 17 A.

[0043] FIG. 18A is a diagram schematically illustrating a device according to an embodiment;

[0044] FIG. 18B illustrates beam intensity profiles of light beams that may be generated using the device illustrated in FIG. 18 A;

[0045] FIG. 19A is a diagram schematically illustrating a device according to an embodiment;

[0046] FIG. 19B illustrates beam intensity profiles of light beams that may be generated using the device illustrated in FIG. 19 A;

[0047] FIG. 20 is a diagram schematically illustrating a device according to an embodiment;

[0048] FIGs. 21 A, 21B are diagrams schematically illustrating a device according to an embodiment;

[0049] FIG. 21C illustrates an NF beam intensity profile of light beams that may be generated using the device illustrated in FIGs. 21 A, 21B;

[0050] FIGs. 22A, 22B are diagrams schematically illustrating a device according to an embodiment;

[0051] FIG. 22C illustrates beam intensity profiles of light beams that may be generated using the device illustrated in FIGs. 22A, 22B;

[0052] FIG. 23A is a diagram schematically illustrating a device according to an embodiment;

[0053] FIG. 23B is a diagram schematically illustrating a device according to an embodiment;

[0054] FIG. 23C is a diagram schematically illustrates beam profile redistributors that may be arranged in the optical path of the devices illustrated in FIGs. 9A, 9B according to embodiments;

[0055] FIG. 24 illustrates is a diagram schematically illustrating a device according to an embodiment;

[0056] FIGs. 25A, 25B, 25C, 25D, 25E, 25F, 25G are diagrams schematically illustrating a device according to an embodiment; and

[0057] FIG. 26 illustrates beam intensity profiles of light beams that may be generated using the device illustrated in FIGs. 25A - 25G;

[0058] For sake of clarity, the Figures are provided with a respective Cartesian coordinate system x, y, z typically representing a respective device coordinate system.DETAILED DESCRIPTION

[0059] The following detailed description refers to the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the following description to refer to the same or similar parts. While several illustrative embodiments are described herein, modifications, adaptations and other implementations are possible. For example, substitutions, additions or modifications may be made to the components illustrated in the drawings, and the illustrative methods described herein may be modified by substituting, reordering, removing, or adding steps to the disclosed methods. Accordingly, the following detailed description is not limited to the disclosed embodiments and examples. Instead, the proper scope is defined by the appended claims.

[0060] First, to enable a better understanding of the present invention, the beam redistribution with maintained perimeter (bounding box) in near filed, as also described in WO 2023 / 156982 Al published after the priory date of the present application, the entire disclosure of which is incorporated herein by reference, is explained.

[0061] FIGs. 1, 2 are diagrams illustrating an exemplary LIDAR system 100Lthe present disclosure is also referring to. LIDAR system 100Lmounted on a vehicle 11, configured to emit a light beam towards a Field of View (FOV). A magnified view of LIDAR system 100Lin Fig. 1 illustrates that the LIDAR system includes a beam profile redistributor 120, arranged in the optical path O (shown in greater details in Fig. 2 illustrating an optical device 100 for emitting a light beam that may be used as LIDAR device or LIDAR system 100Lor part thereof) to receive at least one input light beam Ij. The at least one output light beam Ioof the device has a redistributed beam intensity profile 16 in the Near Field (NF), compared to at least one further output light beam when the beam profile redistributor is not present or replaced by a beam expander. In a far field (FF), at least substantially the same beam intensity profile 18 is received compared to the at least one further output light beam (when the beam profile redistributor is not present, profile 20).

[0062] The term beam expander as used herein intends to describe an optical device that is configured to receive a collimated light beam, expands the size of the received collimated light beam (in radial direction(s)) without (substantially) redistributing light rays of the light beam and output the expanded light beam. In particular, the beam expander may be configured to (only) expand a beam profile, for example a Gaussian beam profile of the received collimated light beam. The beam expander may be a conventional (multiple-)prism beam expander and / or may include lenses.

[0063] The FOV may be characterized as having a Near Field (NF) portion, starting at the LIDAR system housing, up to a defined distance along the z-axis, and a Far Field (FF) portion, from the end of the NF up to the LIDAR maximum range. In the example shown in FIG. 1, a person 14 is in the Near Field NF of the LIDAR system. The person may be a pedestrian in the vicinity of a vehicle equipped with a LIDAR system. The disclosed systems and methods may be relevant for other object such as animals, or sensitive electronic equipment, such as photodetectors. In the near field of a LIDAR system, where the potential risk for damage is greater, the beam profile is redistributed to a distribution 16 that can meet eye-safety requirements, by the beam profile redistributor 12. The beam profile is the cross section of thebeam power or beam energy in plane X-Y. In the far field of the LIDAR system, the beam profile has substantially the same beam intensity profile 18 compared to a similar system without the beam profile redistributor. The near field beam intensity profile increases the eyesafety of the system, while the far field beam intensity profile does not impact the beam properties required for long range detection.

[0064] In addition to the illustrated optical unit (optical components) and a sensing unit (with a light detector, not shown) for detecting back scattered light received from a typically remote object in the FOV, LIDAR system 100Ltypically further includes: a control unit (not shown) configured to control emitting of IR-laser light beams (toward the object in the FOV to be detected) by LIDAR system 100L, and its optical unit, respectively; and / or a calculating unit for calculating one or more parameters referring to the object and / or to a relationship between LIDAR system 100Land the object, such as a distance between LIDAR system 100Land the object or a relative velocity between LIDAR system 100Land the object. The calculating unit may also be provided by the control unit.

[0065] FIG. 2 shows an exemplary optical device 100 for emitting a light beam 130. Device 100 may be used as (part of) LIDAR system 100Lexplained above with regard to FIG. 1. Device 100 typically has a housing 150 and an optical outlet with device aperture 151 for emitting a light beam 130. Device aperture 151 may also be used for incoming light, in particular, back scattered light received from a typically remote object in the FOV, illuminated with one or more emitted light beams 130 in the FOV (far field FF of the light beam(s) 130), for example in a scanning mode of device 100.

[0066] As illustrated in FIG. 2, beam profile redistributor 120 is arranged mirror- symmetrically in an optical path O for receiving an input light beam 110 and converting the received input light beam 110, typically in a transmitting part of the optical path O.

[0067] The exemplary optical path (central ray or center of rays) O is straight. Depending on the type and / or the particular design of optical device 100, optical path O may also be more complex, in particular folded, e.g. due to a mirror or an optical scanning device arranged between beam profile redistributor 120 and device aperture 151.

[0068] Further, beam profile redistributor 120 is configured to change the order of light rays A-K of a (transmitted) light beam. Illustrated beam redistributor 120 may have flat, typically rectangularly shaped receiving (input) and emitting (exit) surfaces for the input lightbeam 110 and output (emitted) light beam(s) 130, respectively. As illustrated by the dashed cuboid, the receiving and emitting surfaces beam profile redistributor 120 may be oriented parallel to each other and / or perpendicular to the optical path (central ray) O.

[0069] As illustrated by dashed lines 121, 122 and described in WO 2023 / 156982 Al, beam redistributor 120 may consist of two spaced apart right trigonal prism 121, 122. As shown, beam redistributor 120 may be at least substantially mirror-symmetric with respect to one axis (x-axis) at least substantially perpendicular to the optical path (central ray) O and the receiving and emitting surfaces, respectively, and at least substantially mirror-symmetric with respect to a plane at least substantially perpendicular to the optical path (central ray) O. Accordingly, beam redistributor 120 may translate the position of the beams in one axis (x- axis). Therefore, beam profile redistributor 120 may also be referred to as one-axis beam profile redistributor.

[0070] Light rays A-C, I-K of input light beam 110 which is near an edge (boundary) of the input light beam 110 are redirected and redistributed, respectively, to corresponding light rays A-C, I-K of output light beam 130 which are nearer to a center line or central ray (optical axis) O of output light beam 130 while light rays D-H of input light beam 110 which are near center line O of input light beam 110 are redirected and redistributed, respectively, to corresponding light rays D-H of output light beam 130 which are near an edge of output light beam 130.

[0071] Accordingly, light rays A-K are redistributed (by distance from optical axis O) with respect to one axis (x-axis in the exemplary embodiment), perpendicular to optical axis O at the location of beam profile redistributor 120 and one plane in which the optical axis lies (central y-z-plane in the exemplary embodiment), respectively. Thus, if the beam power of input light beam 110 is largest in a cross-sectional center region, such as for an input light beam 110 having a Gaussian beam profile, beam power of output light beam 130 in its cross-sectional center region may be reduced in the near field (NF) at the expense of a peripheral cross- sectional region of output light beam 130 in NF.

[0072] As further illustrated in FIG. 2, redistribution of light rays A-K may be achieved by two pairs of refractive surfaces of beam profile redistributor 120 which arranged one behind the other with respect to the optical axis O.

[0073] More particular, beam profile redistributor 120 provides a first pair of adjacent refractive surfaces { 120b1202} and a second pair of adjacent refractive surfaces { 1203, 1204} arranged between downstream from the first pair of refractive surfaces { 120b1202}.

[0074] The adjacent refractive surfaces 220b2202of the first pair are touching each other at a first angle a, the adjacent refractive surfaces 2203, 2204of the second pair of adjacent refractive surfaces are touching each other at a second angle 0 which is at least substantially equal (a=0) to first angle a.

[0075] Typically, the closer a light ray of the input light beam 110 is to the center line O, the closer the corresponding light ray of the output light beam 130 is to the edge of the output light beam 130 and vice versa.

[0076] Accordingly, the (output) light power of output light beam 130 when measured using an aperture AP, in particular an aperture as defined by a safety standard, for example a respective Class 1 laser standard, may be substantially reduced compared to a device / setup without beam profile redistributor 120, for example by at least about 35% or even 40%. In FIG. 1, aperture AP is illustrated as a series of apertures 16 located in the Near Field between the laser device 100 and the pedestrian 14. In FIG. 2, aperture AP is illustrated within the Near Field. As illustrated, aperture AP for measuring eye-safe beam intensities is located at position zap- at a distance from the laser output smaller than dz, or located at a distance from the laser device housing smaller than dzl.

[0077] The Near Field beam intensity profile redistribution may be achieved without substantially changing the far field properties of light beam 130. The beam intensity profile in FF outer boundary of light beam, eye-safety requirements may be ensured during normal device operation without reducing light power and increasing cross-sectional size of light beam 130.

[0078] This is illustrated in FIGs. 3A to 3F showing simulations of beam intensity profiles of light beams 130 measured in NF at a position zapalong the optical path outside device 100 and in FF with and without redistributor 120. Simulations were obtained Zemax OpticStudio®. Each figure corresponds to a density plot and is provided with a linear intensity / power scale.

[0079] Beam intensity profiles shown in FIGs. 3A-3C correspond to beam intensity profiles (radiant flux / power P in radial planes (bounding box 113 in NF downstream from device aperture 151 in FIG. 2) and 115 perpendicular to axis O) of an output light beam of device 100 without beam profile redistributor. FIG. 3D-3F correspond to beam intensity profiles of output light beam 130 of device 100 with a beam profile redistributor 120.

[0080] The simulated beam intensity profiles shown in FIGs. 3D-3F were produced with reference to redistributor 120 shown in FIG. 2, consisting of two spaced apart right trigonal prism 121, 122 which are at least substantially transparent to infrared input light beam 110. The exemplary prisms 121, 122 are identically shaped, and arranged mirror-symmetric in optical path O with respect to each other and a central radial plane 124 of beam profile redistributor 120, respectively (central x-y plane of beam profile redistributor 120).

[0081] FIGs. 3A, 3D show the intensity profiles in NF. As can be seen, the boundary (114 in Fig. 2 within bounding box 113 for the output light beam) of output light beam 130 obtained for device 100 with (FIG. 3D) / without (Fig. 3A) beam profile redistributor 120 is almost the same. Different thereto, in NF, a substantially Gaussian intensity profile (FIGs. 3 A, 3B) of output light beam obtained for device 100 receiving an incident light beam (110 in FIG. 2) of Gaussian intensity profile without beam profile is converted by beam profile redistributor 120 to a redistributed beam profile (FIGs. 3D, 3E) in NF. The redistributed beam profile (FIGs. 3D, 3E) has a substantially 2-fold rotational symmetry (substantially mirror-symmetric with respect to the x-axis and a central x-z plane, respectively).

[0082] Accordingly, the total light power within the exemplary central measuring aperture AP (with 7 mm in diameter) is substantially reduced, by a factor of between 1.3 - 2 .

[0083] A more detailed analysis reveals that for device 100 with a beam profile redistributor 120 the total light power within any 7 mm measuring aperture AP is reduced by at least 20 - 50%, including in the aperture of maximum light power.

[0084] Different thereto, intensity profiles in FF are substantially the same as can be seen from FIGs. 3C, 3F according to which both outer boundary (116 in FIG. 2) of the output light beam and intensity profile are substantially matching.

[0085] Note that beam intensity P in FIGs. 3C, 3F is plotted as respective function of spatial angles (aperture angles) 0X, 0yin contrast with coordinates x, y. This is more appropriatebecause the light beam is (slightly) divergent in FF typically beginning at least a distance of at least 10 m or even 20 m from the beam profile redistributor 120 and an optical outlet / device aperture 151, respectively.

[0086] The redistributed NF beam intensity profile may be at least substantially maintained up to a distance dz, dzl from the beam profile redistributor 120 and the device aperture 151, respectively, of e.g. up to 1 m, more typically up to 3 m, and even more typically up to 5 m or 7m, in particular when referring to laser scanning and LIDAR devices, respectively.

[0087] Reference will now be made in detail to various embodiments, one or more examples of which are illustrated in the figures. Each example is provided by way of explanation, and is not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the present invention includes such modifications and variations.General

[0088] According to embodiments, a device includes an optical path and a beam profile redistributor arranged in the optical path to receive an input light beam, in particular in a transmitting part (OT) of the optical path (O). The beam profile redistributor is arranged in the optical path to receive an input light beam and configured to convert the received input light beam so that at least one output light beam of the device includes, in a near field and / or at the beam profile redistributor, e.g. downstream from the beam profile redistributor and along the optical path (and in the near field), a redistributed beam intensity profile compared to at least one further output light beam when the beam profile redistributor is not present; within a given measuring aperture at a position along the optical path in the near field, a lower (typically a lower maximum) output light power compared to the at least one further output light beam; and in a far field, at least substantially the same beam intensity profile compared to the at least one further output light beam. The beam profile redistributor has two, non-co-planar reflective surfaces of at least substantially uniform reflectivity (square of the magnitude of the ratio of the reflected electric field to the incident electric field at the surface boundary) and / or same reflectance (ratio of the total reflected power to the total incident power) for the input light beam.

[0089] While the output light beam(s) of the device typically refers to an emitted light beam of the device during normal device operation, the further output light beam(s) is (are) not emitted during normal device operation. Instead, the further output light beam(s) may correspond to a (respective) emitted light beam of the device without the beam profile redistributor (when the beam profile redistributor is removed from the optical path and the device, respectively, or replaced by the beam expander), or another (otherwise identical comparison) device without the beam profile redistributor during a comparison measurement, or even to a respective calculated light beam that may be emitted by the device assuming that the beam profile redistributor is not present or replaced by the beam expander. Accordingly, the further output light beam(s) is (are), in the following, also referred to as virtual output light beam(s) (of the device) and undesired output light beam(s) (of the device), respectively.

[0090] The device explained herein may be used for emitting the at least one output light beam through a device aperture, which is typically different to a measuring aperture as required by a safety standard, and is in the following also referred to as aperture for short, and to receive, through the (device) aperture back-reflected (back- scattered) light beam(s)) light beam(s), and at a light detector of the device such as a photodiode.

[0091] The device explained herein allow for, increasing a receiving efficiency (receiving part of the optical path), which may be defined as a ratio between an effective (light sensitive) area of the light detector illuminated by a back-reflected light beam and an area of the back- reflected light beam at the device aperture, at the same effective area (from eye safety perspective) over which the emission energy of the at least one output light beam is spread (in the following also referred to as effective emission area for short), and / or increasing, at the same receiving efficiency, the effective area over which the emission energy of the at least one output light beam is spread, for example doubling the effective emission area.

[0092] In other words, a better trade-off between the effective emission area and the receiving efficiency at comparatively low cost may be achieved with the devices explained herein.

[0093] Accordingly, eye safety may be ensured at high detection sensitivity in a comparatively simple and / or cost efficient way. For example, it is also possible to dispense with reducing the light beam power for safety reasons at times when people are expected or even detected within the field of view of the device, e.g. a LIDAR of a car.

[0094] Note that the above defined receiving efficiency substantially corresponds to portions of the receive aperture blocked by elements included in the system by design, and not the impact of losses due to quality of the optical surfaces (e.g. coatings). Such losses are minor percentage losses due to back-reflected light in the device. These losses amount to at most, a few percent larger or even only at most 1 percent larger than the corresponding power ratio between a power of the back-reflected light beam(s) received at the light detector and a power of the back-reflected light beam(s) at the device aperture.

[0095] The input light beam may originate from (only) one light source, several light sources or even a plurality of light sources.

[0096] For example, light beams emitted by typically substantially equal light sources may be projected, typically focused onto the beam profile redistributor, more particular onto substantially the same area of the beam profile redistributor. The thereby formed input light beam thus includes partial input light beam entering the beam profile redistributor at (substantially) the same area.

[0097] The beam profile redistributor may be arranged in the optical path to receive the input light beam and configured to convert the received input light beam so that at least one output light beam of the device includes, in near field and in a bounding box for the at least one output light beam along the optical path, a redistributed beam intensity profile compared to at least one further output light beam when the beam profile redistributor is not present or is replaced by a beam expander; within a given measuring aperture at a position along the optical path in the near field, a lower (typically a lower maximum) output light power compared to the at least one further output light beam; and in a far field, at least substantially the same beam intensity profile compared to the at least one further output light beam.

[0098] According to an embodiment, the beam profile redistributor is configured to convert the received input light beam into two partial output beams, which do not overlap in the near field.

[0099] The two partial output beams may adjoin. Accordingly, a (minimum) bounding box of the output light beam may be maintained.

[0100] However, the two partial output beams may also be spaced apart from each other.

[0101] The optical path may be folded and / or includes a transmitting part typically at least extending from the beam profile redistributor at least to the device aperture, and a receiving part typically extending from the device aperture through (typically a part of) the beam profile redistributor to the light detector.

[0102] The transmitting part and the receiving part may at least substantially coincide between the device aperture and the beam profile, except for a light beam direction.

[0103] The light source is typically arranged in the transmitting part of the optical path for emitting the incident light beam, in particular an incident light beam of a defined (e.g. linear, elliptic or circular) polarization.

[0104] Further, the device aperture may be arranged in the transmitting part for transmitting the light beam(s) and in a receiving mitting part for receiving corresponding back- reflected light beam(s) and extending to the light detector.

[0105] Further, the devices as explained herein are, due to the respective beam profile redistributor, typically configured to emit (during normal device operation) an output light beam which has, compared to a further (virtual) output light beam corresponding to the device without the beam profile redistributor, a (cross-sectional or radial) beam intensity profile with the following properties: at least substantially the same or an enlarged boundary, in particular in the near field and / or at the beam profile redistributor, a redistributed beam intensity profile in the near field resulting in a lower output light power within a given measuring aperture (typically outside the device and / or having a lower size than an effective output aperture of the device for the output light beam) at one or even all positions along the optical path in the near field, and at least substantially the same beam intensity profile in the far field.

[0106] Since the near field properties of the output light beams are changed by the beam profile redistributor without affecting the far field properties, eye-safety may be ensured in a comparatively simple and compact way even with a small transmission or emission (output) aperture of the device.

[0107] The output aperture of the device may also be used as input aperture of the device for receiving a back-reflected (back-scattered) light beam. In these embodiments, the common input / output aperture of the device is also referred to as device aperture.

[0108] The given measuring aperture is typically different to the output aperture of the device and the device aperture, respectively, typically outside the device and / or typically defined by the respective safety standard, e.g. EN 60825-1 :2007. Note that the transmission aperture of the device is typically larger than e.g. the 7 mm sized measuring aperture Class 1 laser safety.

[0109] The device typically meets the requirements of the respective safety standard, e.g. a Class 1 laser safety standard.

[0110] Accordingly, the output light power of the output light beam can fulfill eye safety requirements when the device is operated in a normal mode, in which the internal light source is operated at rated power, in particular in the near field outside a housing of the device.

[0111] The given aperture may be chosen in accordance with an applicable eye safety standard for laser devices. As such, both the size of the given aperture as well as its position may depend on the wavelength, the optical device and whether the applicable eye safety standard requires an evaluation with binoculars. In particular, for a wavelength in a range from 400 nm - 1400 nm without binocular evaluation, the given aperture may be required to have a diameter of 7 mm. Since lasers operating in this wavelength range are often used, a 7 mm - sized given aperture is used for the results presented below.

[0112] The given aperture may have an at least substantially elliptical shape, an at least substantially circular shape, an at least substantially rectangular or an at least substantially square shape, in particular a circular shape of about 5 mm to about 15 mm diameter, more typically of about 6 mm to about 9 mm diameter, even more typically of about 7 mm diameter, or a square shape of about 5 mm to about 11 mm base length, more typically of about 5 mm to about 9 mm base length, even more typically of about 7 mm base length.

[0113] The devices explained herein may in particular meet the eye safety condition that a maximum integral light power f I(x,y) = P of a circular given (measuring) aperture of 7 mm diameter in the near field is below a safety threshold A7. This results in a corresponding (minimum) effective emission area Aeff7ensured by the device of the (at least one) light beam in the near field of:A =_ A7P _ e^7max[I(x,y) circ(x,y)7mm]with circ(x,y)7mm= 1 within the circle with 7mm diameter centered at (x,y) = 0 otherwise and max[I(x,y) 0 circ x,y)7mm]— maximum of convolution of I(x,y) and circ(x,y)7mm

[0114] The area of the given aperture is typically in a range from about 9 mm2to about 121 mm2, more typically in a range from about 25 mm2to about 81 mm2, and even more typically in a range from about 35 mm2to about 50 mm2, for example about 38 mm2or about 49 mm2.

[0115] The light source is typically a laser, in particular a vertical-cavity surface-emitting laser.

[0116] Further, the beam profile redistributor is typically arranged downstream from and / or next to the light source.

[0117] That two light beams have substantially the same beam intensity profile intends to describe that the respective normalized intensity profiles of the light beams (intensity profile normalized to a respective peak value, e.g. in %), in a given radial plane (orientated perpendicular to the central ray of the respective beam), substantially match, i.e. differ from each other by less than 10% or even 5 % at least on average and / or within a common bounding box enclosing a given percentage of the beam power in a range from about 90% to about 99%, in particular about 95% of the beam power. The beam power in the given radial plane may differ, for example by a few percent due to losses resulting from the beam profile redistributor. However, these losses may be compensated by increasing the power of an internal light source producing the input light beam accordingly. Thus, the output light beam and the virtual output light beam may also have at least substantially the same absolute beam intensity profile.

[0118] Likewise, that two light beams have substantially the same (radial or cross- sectional) boundary (also referred to as edge herein) intends to describe that a distance between the respective boundaries enclosing the given percentage of the beam power is, in the given(radial / cross-sectional) plane, less than 10% or even 5% of a perimeter of one or both of the boundaries.

[0119] The bounding box may be situated at a position with respect to the optical path where the output light beam has a waist. The bounding box may be a minimum bounding box of the output light beam, i.e. the bounding box with smallest area in the near field. Accordingly, the respective output light power may refer to a respective maximum or peak value within near field (at the measuring aperture).

[0120] According to embodiments, the (at least one) output light beam includes, in the near field and / or at the beam profile redistributor and in the bounding box, at least substantially the same boundary compared to the input light beam and the (at least one) further output light beam.

[0121] In these embodiments, the device may include an optical path and a beam profile redistributor arranged in the optical path to receive an input light beam. The beam profile redistributor is configured to convert the received input light beam so that an output light beam of the device includes, in a near field and / or at the beam profile redistributor, and in a bounding box for the output light beam (along the optical path in NF), at least substantially the same boundary but a redistributed beam intensity profile compared to a further output light beam when the beam profile redistributor is not present. Within a given measuring aperture at a position along the optical path in the near field, an output light power of the output light beam is lower compared to the further output light beam. In a far field, the output light beam and the further output light beam have at least substantially the same beam intensity profile.

[0122] The optical path or paths are typically changed by the beam profile redistributor. In particular, the beam profile redistributor may result in a shift of the optical path(s) or a bending or folding of the optical path(s), typically a 90° bending or folding.

[0123] Further, the beam profile redistributor may result in optical losses of at most 5 % or even at most 3% (with respect to total output light beam power).

[0124] A transmittance of the beam profile redistributor, as defined as fraction of the (incident) electromagnetic power of the input light beam that is transmitted through (and / or along the redistributor) at a wave length of a light wave of the input light beam is preferably atleast about 0.8, more preferably at least about 0.9, even more preferably at least about 0.95 or even at least about 0.97.

[0125] In particular, the beam profile redistributor may at least substantially redistribute the rays of the light beam in the near field with respect to one radial axis (perpendicular to the optical axis).

[0126] If redistributing the rays of the light beam in the near field with respect to two typically orthogonal radial axes is desired, two beam profile redistributors arranged one behind the other in the optical path may be used, for example two (substantially) identical beam profile redistributors arranged one behind the other (with respect to the optical axis) and rotated (relative to each other).

[0127] More particular, the beam profile redistributor may be configured to change an order of light rays in the output light beam compared to the further (virtual) output light beam without substantially changing the light beam boundary and / or without substantially changing a light beam divergence.

[0128] For example, the beam profile redistributor may be configured to change the order of light rays such that a light ray of the input light beams which are near an edge or boundary of the input light beam are redirected to a corresponding light ray of the output light beam which is near a center line or center ray of the output light beam, and / or such that light rays of the input light beam which are near a center line or center ray of the input light beam are redirected to corresponding light rays of the output light beam which are near an edge or boundary of the output light beam.

[0129] Further, the beam profile redistributor is typically arranged in the optical path and configured such the redistributed beam intensity profile is at least substantially maintained up to a distance from the beam profile redistributor and / or an optical outlet of the device of at least 1 m, more typically at least 2 m or 3 m, and even more typically at least 5 m, and / or that the far field begins outside the device, in particular at a distance from the beam profile redistributor and / or the optical outlet of the device of at least 10 m or even 20 m. However, these values may also depend on divergence and / or size of the output light beam.

[0130] In an embodiment, the beam profile redistributor comprises a rotational symmetry. In particular, the beam profile redistributor may have a centroid which is asymmetry point of the beam profile redistributor with respect to a point reflection and a 180' degree rotation, respectively.

[0131] The beam profile redistributor may be arranged in a non-symmetrical way and / or off-set with respect to at least one of the input light beam and the at least one output light beam. In particular, the centroid of the beam profile redistributor may at least be arranged off-set to (the central ray of) the input light beam.

[0132] Preferably, the beam profile redistributor may be arranged in the optical path such that a first reflective surface of the two reflective surfaces is configured to only reflect a first portion of the input light beam, preferably about 50% of the input light beam, e.g. a left or right half of the input light beam.

[0133] Further, the beam profile redistributor is typically arranged in at least one of: a transmitting part of the optical path for emitting the at least one output light beam (or at least one light beam derived from the at least one output light beam), and in some cases may also be arranged in a receiving part of the optical path configured to transmit a portion of at least one back-scattered light beam received from the far field (after illuminating an object in FF with the at least one output light beam).

[0134] Moreover, in a projection onto a radial plane perpendicular to a beam propagation direction of the input light beam, a size of at least one of the two reflective surfaces, in particular an area a size of at least one of the two reflective surfaces may only be about 0.5 times a beam width of the input light beam, or at least about 0.5 times the beam width of the input light beam.

[0135] Preferably, the beam profile redistributor has only two reflective surfaces.

[0136] Typically, each of the two reflective surfaces is at least substantially planar.

[0137] Further, the two, non-co-planar reflective surfaces are typically at least substantially parallel and / or spaced apart from each other.

[0138] The respective reflectivity of the two reflective surfaces may varies by at most by 5%, preferably by at most by 2% at and / or along the respective reflective surfaces.

[0139] Further, at least a respective averaged reflectivity of the two reflective surfaces may at least substantially match.

[0140] According to an embodiment, at least one of, preferably each of the two reflective surfaces is angled with respect to (an axial direction of) the input light beam, preferably by an angle of at least about 25° and / or at most about 45°, more preferably by an angle in a range from about 32° to about 45°, for example by an angle of about 41°, of about 43° or about 45°. Accordingly, the desired converting of the input light beam into two partial output beams is facilitated.

[0141] According to an embodiment, the reflectivity of each of the two reflective surfaces is at least substantially polarization-independent.

[0142] In this embodiment, the reflectivity of each of the two reflective surfaces is preferably at least about 0.98, more typically 0.99 at a wave length of a light wave of the input light beam.

[0143] Further, the reflectivity of the two reflective surfaces may at least substantially match.

[0144] The reflectivity of the two reflective surfaces may be obtained by total internal reflection (TIR) or by a (IR-reflecting) mirror coating, for example a coating with a metal, in particular an Au-coating.

[0145] In embodiments, in which TIR is used for providing the reflectivity, the at least substantially transmitting main body preferably has an index of refraction in a range from about 1.4 to about 1.9. Further, in these embodiments, the two non-co-planar reflective surfaces are angled with respect to the respective incident input light beam at an angle below the critical angle, which, depending on the index of refraction of the at least substantially transmitting main body, may be in a range between about 32° to about 45°, e.g. about 41°.

[0146] The two reflective surfaces may even be provided by two respective separate mirrors.

[0147] However, while using two separate mirrors results in a simple beam profile redistributor and particularly low losses, (long-term stable) alignment of the mirrors in the optical path may be more elaborate, in particular for a LIDAR in automotive applications due to vibrations and accelerations during operation.

[0148] Therefore, an implementation as one-piece beam profile redistributor and a rigid body providing the two reflective surfaces, respectively, is typically more appropriate for these applications.

[0149] According to another embodiment, the reflectivity of each of the two reflective surfaces is polarization-dependent.

[0150] Preferably each of the two reflective surfaces is configured to at least substantially reflect light waves of a first (linear) polarization and is at least substantially non- reflective and / or transparent for light waves of a second (linear) polarization different to the first (linear) polarization.

[0151] Preferably the reflectivity of the two reflective surfaces is at least about 0.98, more preferably at least about 0.99 at the first polarization and a wave length of a light wave of the input light beam.

[0152] Further, the reflectivity of the two reflective surfaces is preferably at most about 0.02, more preferably at most about 0.01 at the second polarization and for the wave length of the light wave of the input light beam.

[0153] According to an embodiment, the beam profile redistributor has at least one of, preferably both of a first (at least substantially) transmitting surface arranged in the optical path for receiving at least a portion of the input light beam, and a second (at least substantially) transmitting surface arranged in the optical path for emitting at least a portion of the at least one output light beam.

[0154] Preferably a (directional, typically polarization-independent) transmittance of the first transmitting surface at a wave length of a light wave of the input light beam (in particular at least at the peak wave length) is at least about 0.98, more preferably at least about 0.99.

[0155] Likewise, a (directional, typically polarization-independent) transmittance of the second transmitting surface at the wave length of a light wave of the input light beam is preferably at least about 0.98, more preferably at least about 0.99.

[0156] The first transmitting surface typically forms a receiving surface for at least a part of input light beam and a partial input (light) beam of the input light beam, respectively.

[0157] The second transmitting surface typically forms an emitting surface for at least a part of the (at least one) output light beam and a partial output (light) beam of the (at least one) output light beam, respectively.

[0158] In the following, the first transmitting surface and the second transmitting surface are also referred to as receiving surface and emitting surface of the beam profile redistributor.

[0159] Typically, the first transmitting surface and the second transmitting surface are outer surfaces of (a substantially transparent body of) the beam profile redistributor.

[0160] However, the first transmitting surface and / or the second transmitting surface may also be virtual surfaces.

[0161] The two reflective surfaces and two transmitting surfaces are arranged at and / or around a light transmitting volume of the beam profile redistributor.

[0162] Typically, the beam profile redistributor may only have two (optically effective) reflective surfaces two (optically effective) transmitting surfaces.

[0163] The transmitting surfaces and the reflective surfaces are preferably arranged in an alternating order (with respect to each other).

[0164] In particular, the first reflective surface may be arranged adjacent, adjoining and / or between the two transmitting surfaces.

[0165] Likewise, the second reflective surface may be arranged adjacent, adjoining and / or between the two transmitting surfaces.

[0166] Further, an angle between the first transmitting surface and the first reflective surface may be about 45°, and / or an angle between the second transmitting surface and the first reflective surface may be about 135°.

[0167] The two transmitting surfaces are typically angled with respect to the input light beam, preferably at an angle of about 90° (are substantially perpendicular to the input light beam.

[0168] Further, the second transmitting surface may be arranged in the optical path for emitting at least one of a first portion of the at least one output light beam and a second portion of the at least one output light beam.

[0169] In one embodiment, the first reflective surface is configured to reflect the transmitted first portion of the input light beam towards a second reflective surface of the two reflective surface.

[0170] In this embodiment, the input light beam and the at least one output light beam are typically substantially parallel.

[0171] An area of the first transmitting surface is typically larger than a beam area of the input light beam and / or at least substantially corresponds to an area of the second transmitting surface.

[0172] Further, a length of the beam profile redistributor in an axial direction of the input light beam is at least a width of the beam profile redistributor in a radial direction of the input light beam divided by square root of two.

[0173] Preferably, the width of the beam profile redistributor being less than 7 cm, less than 5 cm or even less than 3 cm.

[0174] In another embodiment, a second reflective surface of the two reflective surfaces is configured to reflect a second portion of the input light beam, after being transmitted through the first transmitting surface, towards the second transmitting surface.

[0175] In this embodiment, the beam profile redistributor is typically configured to fold the optical path.

[0176] Accordingly, the input light beam and the at least one output light beam are angled with respect to each other, preferably by an angle of about 90°.

[0177] According to an embodiment, the two transmitting surfaces and the first reflective surface are coplanar.

[0178] In this embodiment, an area of the first transmitting surface may be smaller than a beam area of the input light beam, and / or the two transmitting surfaces may be angled with respect to the input light beam, preferably by an angle in a range from 33° to about 45°.

[0179] In others embodiments, none of the transmitting surfaces is coplanar with the reflective surfaces.

[0180] In these embodiments, at least one of, typically both of the first transmitting surfaces and the second transmitting surfaces is angled with respect to the input light beam preferably at an angle of about 90°.

[0181] An angle between the first transmitting surface and the first reflective surface may be about 135°. Likewise, an angle between the second transmitting surface and the first reflective surface may about 135°.

[0182] The two transmitting surfaces are typically at least substantially parallel and / or angled with respect to at least one of the two reflective surfaces.

[0183] Further, the first transmitting surface or even both transmitting surfaces may have an anti -reflective coating.

[0184] Preferably, both the first and second reflective surfaces are at least substantially parallel to each other and / or at least substantially flat (plane) and the first and second transmitting surfaces are at least substantially parallel to each other and / or at least substantially flat. The beam profile redistributor may not have any (substantially) curved surfaces.

[0185] The light transmitting volume may be shaped as a convex polyhedron and / or be formed or be provided at least in part by an (at least substantially) transmitting main body of the beam profile redistributor.

[0186] The transmitting main body may have an index of refraction in a range from about 1.4 to about 1.6.

[0187] The transmitting main body may be made of a glass such as BK7.

[0188] Preferably, at least one of the convex polyhedron and the main body is a prism (typically both in optical and geometrical sense), in particular a hexagonal prism, a rectangular cuboid or a rhombic prism.

[0189] This allows for providing one-piece beam profile redistributors with the desired optical properties that are comparatively easy to manufacture, comparatively robust, compact, and can comparatively easily be adjusted in the optical path.

[0190] The first transmitting surface may be arranged in the optical path for transmitting at least one of the first portion of the input light beam and a second portion of the input light beam.

[0191] The first portion of the input light beam and the second portion of the input light beam may also be considered as (first and second) partial input light beams.

[0192] According to embodiments, the two reflective surfaces and the two transmitting surfaces are outer surfaces of the beam profile redistributor.

[0193] In another embodiment, the two reflective surfaces are inner surfaces of the beam profile redistributor, and the two transmitting surfaces are outer surfaces of the beam profile redistributor.

[0194] In this embodiment, the beam profile redistributor may include (typically consist of) a main prism providing the two transmitting surfaces and two side prisms each of which is arranged at the main prism. The interfaces between the side prisms and the main prism are inner surfaces that may provide the reflective surfaces.

[0195] The two side prisms may be glued with the main prism, more particular glued onto side surfaces of the main prism. Typically, the side surfaces of the main prism have at least substantially the same shape as the base of the side prism(s).

[0196] The side prisms may be at substantially shaped identical and / or have at least substantially the same refractive index, in particular at substantially the same refractive index as the main prism.

[0197] Preferably, the two side prisms and the main prism form a cuboid.

[0198] The device may include a further beam profile redistributor arranged in the optical path downstream the beam profile redistributor, and configured to redistribute, in near field and / or at the further beam profile redistributor, the beam profile with respect to a different axis compared to the beam profile redistributor.

[0199] Accordingly, a particularly high detection accuracy and / or reliability while ensuring eye safety in NF can be achieved.

[0200] Alternatively or in addition, device may include an aperture arranged in the optical path, a light detector typically including or being provided by a photodiode arranged in the optical path, preferably in the receiving part of the optical path, a light source arranged in the optical path, preferably in the transmitting part of the optical path, in particular, a lasersuch as an edge-emitting laser or even an array of lasers, a collimator arranged in the optical path, and / or a mirror arranged in the optical path.

[0201] Typically, the device is configured to emit an at least substantially collimated light beam formed by the at least one output light beam or from the at least one output light beam.

[0202] The devices as explained herein are typically optical devices and / or devices for emitting a light beam, in particular a respective device for emitting a light beam and receiving a back-reflected light beam, more particular a back- scattered light beam.

[0203] The device may in particular be a LIDAR device, a LIDAR system (or a part thereof), an optical scanning device and / or include a scanner arranged in the optical path to receive and deflect the output light beam, after optionally being collimated and / or being redirected towards the scanner, with an at least substantially maintained redistributed beam intensity profile (in the near field).

[0204] In one embodiment, the LIDAR device includes an optical path having a transmitting part and a receiving part, a light detector arranged in the receiving part of the optical path, a light source arranged in the transmitting part of the optical path, and a beam profile redistributor arranged downstream the light source in the transmitting part of the optical path and including a polarizing prism.

[0205] The beam profile redistributor is typically arranged in the transmitting part for receiving an input light beam from the light source, converting the received input light beam into at least one output light beam and for generating at least one output light beam, respectively.

[0206] The (LIDAR) device may include a single light source, several light sources or a plurality of light sources emitting a respective light beam that may be collimated by a collimator (arranged in the optical path upstream from the beam profile redistributor) on to the first pair of adjacent refractive surfaces for forming the input light beam may.Alternatively or in addition, the devices explained herein may include a (further) collimator for collimating an intermediate light beam emitted from the beam profile redistributor. Thecollimator(s) may be arranged next to or even at the beam profile redistributor. Further, the collimator(s) may collimate the respective light beam(s) with respect to one or two-axis.

[0207] Further, the LIDAR device may include an optical scanning device and / or a scanner arranged downstream in the optical path to receive and deflect the (at least one) output light beam.

[0208] The following examples are described using specific language which should not be construed as limiting the scope of the appending claims. The drawings may not be scaled and are for illustrative purposes only. For clarity, the same elements or manufacturing steps have been designated by the same references in the different drawings if not stated otherwise.

[0209] A laser is one example of a light source that can be used in a LIDAR system. As with any sensing system, in order for a LIDAR-based sensing system to be fully adopted by the automotive industry, the system should provide reliable data enabling detection of distant objects. Thus, operating in maximum illumination power of LIDAR systems is preferred. Currently, however, the maximum illumination power of LIDAR systems is limited by the need to make the LIDAR systems eye-safe. For example, LIDAR systems are required to prevent damage to the human eye which can occur if a projected light emission enters the eye’s cornea and lens, causing thermal damage to the retina.) In particular, operating with a focused or collimated laser beam may be potentially hazardous to human unaided eyes or even the skin.

[0210] Laser beams are divergent, the laser flux decreases with distance from the emitter along the beam transmission direction. As such, the potential hazard is higher closer to the laser source - in the Near Field (NF) of the laser, and decreases with distance of a target from the laser device. Furthermore, the emitted beam has a non-uniform intensity profile in the Near Field (NF). For example, the laser beam cross section or ‘spot’ may have a gaussian distribution, with the highest intensity at the center of the beam, decreasing towards the periphery of the beam.

[0211] To prevent damage, laser-based devices are classified accordingly by their potential hazard level, and must fulfill respective safety requirements.

[0212] For example, according to standard EN 60825-1 :2007, a maximum-allowed power, or acceptable emission limit (AEL) level is defined. For a 900 nm wavelength Class 1 laser,the AEL is 1 mW when measuring flux through a 7 mm aperture outside the device (14 mm from the point where the laser beam exits the device).

[0213] As shown in FIG. 3G, device 100 may further include a collimator 105 arranged in optical path O to convert a divergent light beam 102 emitted from a light source 101, such as a semiconductor laser, in particular an edge-emitting (semiconductor) laser, or a verticalcavity surface-emitting laser (VCSEL), to a typically substantially collimated input beam 110 to beam profile redistributor 120.

[0214] Further, collimator 105 may be used to redirect light beam 102 to beam profile redistributor 120 if desired as indicated by (alternative) light source 101’ in FIG. 3G.

[0215] Furthermore, it is also possible to use the (single) beam profile redistributor 120 for an array of light sources 101, 101’, e.g. lasers, instead of a single light source 101, 101’.

[0216] For this purpose, the one-axis beam profile redistributor 120 may be arranged within a collimator, i.e. within the empty space between two collimation lenses. This allows for reducing costs and / or complexity of assembly.

[0217] In particular, light beams 102 from light sources 101, 101’ of an array of light sources 101, 101’, for example up to 4, up to 8, up to 16, up to 32 or even more light sources 101, 101’ arranged in a plane, on a curve or even on a line as illustrated by the dashed-dotted line in FIG. 3H, may be redistributed in parallel by a one beam profile redistributor 120 (or any other beam profile redistributor explained herein) in NF without substantially changing the beam intensity profiles in FF.

[0218] More particular, and as shown in FIG. 3H, when using an (linear) array of light sources 101, 101’, the intensity profile of beams 130 of redistributed corresponding incident light beams 110 with slight angular deviations may substantially overlap in NF (resulting in similar, in some instances overlapping intensity profiles as illustrated in FIGs. 3A, 3D), and form separate beams 130 in FF, each of which may have an intensity profile as shown in Figs. 3C, 3F.

[0219] In its lower part, FIG. 3H shows exemplary center rays of output light beams 130 (with exaggerated divergence for illustrative purposes). As shown in the upper part of FIG. 3H, the resulting intensity profile PNFin NF (at CNF), for example up to (at) a distance of about 1m from the device aperture (151 in FIG. 2) for a device without a beam profile redistributor, may qualitatively correspond to an intensity profile resulting from a single light source or a combination of intensity profiles resulting from multiple overlapping beams, while the resulting intensity profile PFF in FF (at CNF), for example at distances of at least several meters shows separated spots (at 9 m in FIG. 3H) each of which may have an intensity profile as shown in Figs. 3C, 3F.

[0220] FIG. 4 shows a device 100’ for emitting a light beam 130. Device 100 is similar to device 100 explained above with respect to FIGs. 2, 3, but further includes a collimator 105 arranged in optical path O to convert a divergent light beam 102 emitted from a light source 101, such as a semiconductor laser, in particular an edge-emitting (semiconductor) laser, or a vertical-cavity surface-emitting laser (VCSEL), to a typically substantially collimated input beam 110 to beam profile redistributor 120.

[0221] Further, collimator 105 may be used to redirect light beam 102 to beam profile redistributor 120 if desired as indicated by (alternative) light source 101’ in FIG. 4.

[0222] Furthermore, it is also possible to use the (single) one-axis beam profile redistributor 120 for an array of light sources 101, 101’, e.g. lasers, instead of a single light source 101, 101’.

[0223] For this purpose, the one-axis beam profile redistributor 120 may be arranged within a collimator, i.e. within the empty space between two collimation lenses. This allows for reducing costs and / or complexity of assembly.

[0224] In particular, light beams 102 from light sources 101, 101’ of an array of light sources 101, 101’, for example up to 4, up to 8, up to 16, up to 32 or even more light sources 101, 101’ arranged in a plane, on a curve or even on a line as illustrated by the dashed-dotted line in FIG. 4, may be redistributed in parallel by one one-axis beam profile redistributor 120 (or one two-axis beam profile redistributor explained below with respect to FIGs. 5 to 8) in NF without substantially changing the beam intensity profiles in FF.

[0225] More particular, when using an array of light sources 101, 101’, the intensity profile of beams 130 of redistributed corresponding incident light beams 110 with slight angular deviations may substantially overlap in NF (resulting in similar, in some instancesslightly smeared profiles compared to FIGs. 3D, 3E), and form separate beams 130 in FF, each of which may have an intensity profile as shown in Figs. 3C, 3F.

[0226] As further illustrated in Fig. 4, each of refractive surfaces 120b1202may form an acute angle a / 2 with the optical axis O, and each of refractive surfaces 1203, 1202may form an acute angle 0 / 2 (typically matching a / 2).

[0227] FIG. 5 shows a further device 200 for emitting a light beam 230. Beam profile redistributor 220 is configured to redistribute the light rays A-K of collimated light beam 210 exiting the collimator 205 to an output light beam 230 in the near field with respect to two radial axes (x-axis and y-axis).

[0228] This is illustrated in Fig. 6A-C showing resulting beam intensity profiles of light beam 230 in NF (FIG. 6A) at two 7 mm measuring apertures AP in NF (FIG. 6B), i.e. a , central aperture and the aperture of maximum total light power. FIG. 6C shows the beam intensity profile in FF.

[0229] Due to the two-axis redistribution of the incident light beam, an NF beam intensity profile with substantially 4-fold rotational symmetric is formed, while the FF properties remain substantially unchanged by beam profile redistributor 220 (data not shown).

[0230] Furthermore, an even lower total light power in the 7 mm aperture may be achieved compared to the single axis redistribution illustrated in FIG. 3.

[0231] The simulation results shown in FIG. 6A-C were obtained with reference to the use of two pairs of right trigonal prism, each pair consists, as described with regard to FIG. 2, of two spaced apart right trigonal prism 121, 122 which are at least substantially transparent to infrared input light beam 110. The exemplary prisms 121, 122 are identically shaped, and arranged mirror-symmetric in optical path O with respect to each other and a central radial plane 124 of beam profile redistributor 120, respectively. The two pairs of prisms are rotated with respect to each other by 90° around optical axis O. Beam profile redistributor 220 may also be referred to as two-axis beam profile redistributor.

[0232] Two-axis beam profile redistributors may also be realized using a single pyramidal prism. In this embodiment, collimation in the two axes is additionally performed, e.g. using collimating lenses as e.g. explained below with regard to FIG. 8.

[0233] In other embodiments, two-axis beam profile redistributors is implemented using a meta surface of a diffractive / refractive optical elements, conical prisms, more particular axicons, instead of the trigonal prisms.

[0234] FIG. 7 partially shows a device 200’, comprising a two-axis beam profile redistributor 220 implemented as a double-axicon system with a collimator (collimating lens) 205 and two axicons 221, 222, (e.g., two AX1220-B axicons of Thorlabs, Inc.), facing each other with their substantially conical surfaces.

[0235] Accordingly, the parallel input light beam 210 is shaped by axicon 221 to a substantially ring-shaped, divergent intermediate light beam with redistributed light rays that is reshaped into a substantially parallel output light beam 230 by axicon 222.

[0236] In embodiments, referring to axicon using beam profile redistributors, each pair of adjacent refractive surfaces {220 2202} and {2203, 2204} are provided by one respective surface. Further, the refractive surfaces {220b2202} as well as the refractive surfaces {2203, 2204} may adjoin each other only in (illustrated) cross-section(s) which include the optical axis O.

[0237] FIG. 8 shows another device 400 for emitting an output light beam 430. In the exemplary embodiment, device 400 is implemented as a scanning device, for example a LIDAR device.

[0238] Accordingly, a scanner 445 is arranged in the optical path O to receive and deflect output light beam 430 received from beam profile redistributor 420 with an at least substantially maintained redistributed beam intensity profile (in NF).

[0239] Scanner 445 may e.g. be implemented as a mirror scanner 445, in particular as an electro optical scanner with an exemplary scanning mirror 445A or as a rotating polygon scanner 445B. Using a rotating polygon scanner 445B can ensure increased eye safety without increasing the cross-sectional size of the laser beam(s) as incident on the polygon facets. As such, the size of the rotating polygon scanner may be more compact. Without beam profile redistributor 420 the cross-sectional size of the laser beam(s) would have to be increased, causing partial signals that can occur when the laser beam is incident on an edge between the polygon facets. This may be mitigated by increasing the size of the rotating polygon scanner, which negatively impacts other system constraints such as overall size, form-factor, and cost.

[0240] In other embodiments, scanner 445 may be implemented as a mechanical mirror, a combination of single axis mechanical rotating mirrors, a biaxial mechanical rotating mirror, a MEMs mirror, a rotating prism, or any other scanner to deflect light across a Field of View. In particular, single or two axes mechanical or electro-mechanical mirrors may be used in embodiments in which the beam perimeter is expanded in NF by the beam profile redistributor, as explained below with reference to Figure 11 A and the following figures.

[0241] The device 400 may comprise a first collimator 405 typically implemented as a collimating lens 405 to collimate the emitted laser beam in a first axis, and a second collimator 425 typically implemented as collimating lens 425 to collimate the emitted laser beam in a second axis perpendicular to the first axis. The beam profile redistributor 420 may be positioned between the first and second collimators 405, 425. Beam profile redistributor 430 may redistribute the beam 402 in a manner similar to FIG. 3D-F in the first axis, which is collimated in the first axis, when the beam reaches beam profile redistributor 420. The beam 402 is then collimated in the second axis by the second collimator 425. The first and second collimators 405, 425 may act as a fast axis collimator 405 and a slow axis collimator 405, respectively.

[0242] Further, output light beam 430 may be (further) collimated using a collimator arranged in optical path O and / or redirected towards a scanning unit (scanner) 445.

[0243] Further, in order to redistribute the beam 402 in a manner similar to FIG. 6A, i.e. inverting the beam profile in the X and Y axes as illustrated in FIG. 6A, and additional beam redistribution element (not shown) may be included after the second collimation lens 445.

[0244] Alternatively, the beam profile redistributor 420 may be positioned after both collimators 405, 425, i.e. after the beam 402 is collimated in both axes. Alternatively, the beam may be collimated in both axes by a single collimation lens, and the beam profile redistributor 420 may be positioned after the single collimation lens.

[0245] Beam profile redistributor 420 may include trigonal prisms 421, 422 as explained above with reference to FIG. 2 (one-axis redistributor) or two pairs thereof as explained with reference to FIGs. 5 to 7 (two axes redistributor). Optionally, beam profile redistributor 420 may be located after (downstream from) a (first) collimator 405 for converting a divergent light beam 402 emitted from light source 402 to an intermediate light beam 410. Further, asecond collimator 425 may be arranged downstream the second prism 422, at the second prism 422 and / or between the second prism 422 and scanner 445.

[0246] For example, beam profile redistributor 420 may include conical prisms instead of the trigonal prisms 421, in particular axicons as explained with reference to FIG. 7.

[0247] Alternatively, the beam profile redistributor components may be integrated with the collimating components, or other optical elements for adjusting the beam size.

[0248] Beam redistribution, as described above and illustrated in FIGs. 3D and 6A, assumes that the beams are (at least substantially) parallel when received by the receiving surface of the beam redistributor in the relevant axis. As such, to redistribute the beam profile as illustrated in FIG. 6A, the beams are to be (at least substantially) collimated in both axes (X and Y), whereas to redistribute the beam profile as illustrated in FIG. 3D, the beams are to be (at least substantially) collimated in the axes in which it is to be inverted (e.g. X or Y axis).

[0249] Positioning the beam profile redistributor after collimation in both axes enables use of a beam profile redistributor that may invert the beam profile in both axes, as illustrated in FIG. 3D, with a single beam redistribution component. The single beam redistribution component may be a pyramidal shaped optical element.

[0250] Additionally, the configuration outlined has the advantage of a compact system with a small form factor, in which the beam profile redistributor may be configured to redistribute the incident beam with respect to two typically orthogonal radial axes with a single component, positioned after a single collimating lens. In alternative solutions, including multiple collimating lenses, multiple beam profile redistributors may be used, thereby increasing the complexity and size of the device.

[0251] FIG. 9 shows a further device 500 for emitting an output light beam 530. Device 500 is similar to devices 100 to 400 explained above with respect to FIGs. 2 to 8.

[0252] In the exemplary embodiment, device 500 uses, similar to device 400, a beam profile redistributor 420 which is, in optical path O, arranged between two collimators 505, 525.

[0253] FIG. 9 illustrates that output light beam 530 may have a waist 535 in NF and that the total output light power may be lower than a threshold safety value when measured at anyposition zapof measuring aperture AP along the optical path O in NF, in particular at waist position zap’.

[0254] Accordingly, eye-safety may be ensured at any distance outside device 500.

[0255] FIG. 10 shows yet a further device 600 for emitting an output light beam 630.Device 600 is similar to devices 100’, 400 explained above with respect to FIGs. 4, 8 and also has a corresponding collimator 605.

[0256] However, beam profile redistributor 620 arranged in optical path O is implemented differently, namely as a single right hexagonal prism 621 resulting in similar beam characteristics as shown in FIGs. 3D-F.

[0257] Similar to beam profile redistributor 120, 420, beam profile redistributor 620 also includes two pairs of adjacent refractive surfaces which are provided by right hexagonal prism 621, i.e. a first pair of adjacent refractive surfaces 620b6202and a second pair of adjacent refractive surfaces 6203, 6204. In the exemplary embodiment, each of the rectangular refractive surfaces 620, - 6204forms an acute angle a / 2 (0<a / 2<7i / 2) with the optical axis O.

[0258] Refractive surfaces 620b6202and 6203, 6204may be provided by prism(s).

[0259] A single component such as single right hexagonal prism 621, compared to using a trigonal prism pair, has the advantages of reducing the number of surfaces crossed along the optical path O, reducing optical losses, and ease of assembly and alignment of optical surfaces.

[0260] Embodiments are described above mainly with reference to a single light source. The invention is not limited thereto and can be used for redistributing light generated by an array of light source. In one embodiment, multiple light sources are used. The beam profile redistributor may comprise e.g., multiple trigonal prism pairs, each pair as described with reference to FIG. 2, 4, 5. Alternatively, the beam profile redistributor may comprise pyramidal prism pairs. Each of the multiple light sources may be associated with a corresponding trigonal prism pair.

[0261] Embodiments are described with reference to a LIDAR system. The invention is not limited thereto and can be used for other devices emitting light generated by a light source, such as rangefinders (e.g. for military applications), free-space optical communication, etc.,which require longer range performance, but are also required to comply with eye-safety standards.

[0262] FIGs. 11 A to 11C shows another device 1000 for emitting an output light beam 1030. Device 1000 is typically similar to the devices 100 to 600 explained above, and may also be implemented as or form a part of a scanning device, in particular a LIDAR device. However, the beam profile redistributor 1020 of device 1000, which is arranged downstream in the transmitting part OTof the optical path O, is not only configured to redistribute the light rays of an input light beam 1010 but also to expand the perimeter of the light beam in NF, as illustrated in FIG. 11 A also showing simulated light rays.

[0263] In the exemplary embodiment, input light beam 1010 is a collimated light beam that originates from a light source 1001 and is collimated by a (first, fast axis) collimator 1005.

[0264] Further, the (collimated) input light beam 1010 is received by a Wollaston prism 1021 of beam profile redistributor 1020 illustrated in more detail in FIGs. 1 IB, 11C.

[0265] Light source 1001 may be a single light source of coherent light or represent several or even a plurality of coherent light sources emitting light with at least substantially same wavelength characteristics (peak wave length, bandwidth), in particular a 1 -dimensional (linear) array of lasers which are substantially focused on a spot (by a not shown optics).

[0266] As the input light beam 1010 is not linearly polarized, but typically elliptically or more typically circularly polarized, a polarization shaping device (PSD) such as a quarter wave plate may be arranged in the optical path O between the primary (actual) light source(s) and beam profile redistributor 1020, in particular upstream collimator 1005.

[0267] Due to using a suitable orientated Wollaston prism 1021, i.e. two attached prisms of a birefringent material, typically a uniaxial material such as calcite, input light beam 1010 is split into two diverging intermediate (partial) light beams 1012 of different (orthogonal) polarization (ordinary beam and an extraordinary beam), as indicated by the dashed and dashed-dotted double-headed arrows in FIG. 11C.

[0268] In the exemplary embodiment, the crystals of the two attached prisms 1027, 1028 of Wollaston prism 1021 have respective optic axes Ocwhich are angled with respect to each other and the optical axis O, OT(at a position of the polarizing prisms 1027, 1028). In thefollowing, the optic axis of a crystals of a polarizing prism (representing the respective direction in which a ray of transmitted light does not experience birefringence and double refraction, respectively) are also referred to as crystal optical axis of the prism and optic axis of the prism for short.

[0269] More particular, the optic axis Ocof prism 1027 forms an angle of 45° with the optic axis Ocof prism 1028, and the optic axes Ocof both prisms 1027, 1028 are orthogonal to the optical axis O as indicated by the corresponding (optic axis) vectors (1,1,0) and (0,1,0) which do not have a z-component.

[0270] Prior leaving and beam profile redistributor 1020, divergent intermediate light beam(s) 1012 are to be (substantially) collimated. In the exemplary embodiment, this is achieved using a (second, slow axis) collimator 1025, for example collimating lens(es) 1025 and, optionally, an additional prism 1057 with a central hole. The collimation is used for ensuring that the optical redistribution does not effect the far-field angular distribution of the system.

[0271] Accordingly, the outer boundary (beam perimeter) of output light beam 1030 is widened compared to input light beam 1010, for example by a factor of about 1.5 to about 3, more typically by factor of about 2.0 to about 2.3.

[0272] Beam profile redistributor 1020 can convert the received input light beam 1010 into an output light beam 1030 having, in NF, a redistributed beam intensity profile and a redistributed beam polarization profile (see the two white arrows FIG. 12A left and right of the polarized partial beams) compared to a further output light beam when the beam profile redistributor 1020 is replaced by a beam expander 1055 whose beam widening properties at least substantially corresponds to the beam widening (scaling) properties of beam profile redistributor 1020.

[0273] Different thereto, in FF, output light beam 1030 has at least substantially the same beam intensity profile shown in FIG. 12B compared to the further output light beam when the beam profile redistributor 1020 is replaced by beam expander 1055. The beam intensity profile in FF for the further output light beam is at this scale not distinguishable from FIG. 12B and therefore not shown.

[0274] In Fig. 11 A, beam expander 1055 is represented by two dashed-dotted lenses of appropriate focal lengths to achieve the same beam widening / expansion as beam profile redistributor 1020. FIG. 12B only shows the beam intensity profile in FF for output light beam 1030.

[0275] Furthermore, a closer examination of the simulation results shown in FIG. 12A for output light beam 1030 shows that, for a given exemplary measuring aperture AP of 7 mm diameter, a significantly lower (maximum) output light power (in the shown plane at distance in beam direction (z) from additional prism 1057 of 20 cm) is achieved in NF compared to the further output light beam (with the beam expander 1055).

[0276] In the exemplary embodiment, a reduction of the maximum of the output light powers of output light beam 1030 at the apertures AP in NF is reduced to about 12% compared to the maximum output light power of the further output light beam at the 7 mm apertures AP in NF!

[0277] Further, it turns out that achievable reduction of the maximum output light power of output light beam at the 7 mm apertures AP in NF compared to the further output light beam is higher compared to the devices 100 to 600 explained above, even when the beam widening is taken into account.

[0278] This is made possible by the additional polarization-dependent redistribution of the light beam.

[0279] For example, the corresponding reduction of the maximum output light power for the simulations shown in FIGs 3 A, 3D amount to about 32%.

[0280] Accordingly, an even better trade-off between effective emission area and receiving efficiency and, thus, an even higher LIDAR detection accuracy and / or reliability while ensuring eye safety in NF can be achieved by using a beam profile redistributor with polarizing prism(s).

[0281] FIGs. 13A to 13C illustrate a further (LIDAR) device 2000. Device 2000 is typically similar to device 1000 explained above with respect to FIGs. 11A-12C. However, instead of a Wollaston prism, to spaced apart polarizing prisms 2027, 2028 are arranged in the transmitting part OTof the optical path O. Further, beam profile redistributor 2020 of device2000 does typically not have an additional (non-polarizing) prism with a central hole downstream the polarizing prisms 2027, 2028.

[0282] In the exemplary embodiment, polarizing prisms 2027, 2028 are arranged such that the optic axis Oc of prisms 2027, 2078 form an angle of 45° with the x-axis (as well as the y-axis) and are perpendicular to the optical axis O, as shown in FIGs. 13B, 13C.

[0283] While FIG. 13 A shows simulated light rays, FIG. 13B only shows a few representative light rays to illustrate the redistribution in the central cross-section.

[0284] As illustrated in FIG. 13B, the two polarizing prisms 2027, 2028 are typically at least substantially centered with respect to each other and the optical axis O.

[0285] Further, the two polarizing prisms 2027, 2028 are typically at least substantially equally shaped, for example substantially triangularly shaped in cross-section(s) parallel to optical axis O, but arranged at least substantially mirror symmetric with respect to the optical axis O and a (radial) plane perpendicular to the optical axis O.

[0286] In other words, the two polarizing prisms 2027, 2028 typically have respective base surfaces 2O27o, 2O28owhich are (at least substantially) parallel to each, facing away from each other and are (at least substantially) perpendicular to the optical axis O.

[0287] As shown in FIG. 13C, base surfaces 2O27o, 2O28oare typically rectangular or square in shape.

[0288] However, it is, in other embodiments referring to beam profile redistributors with two polarizing axicons, also possible for base surfaces 2O27o, 2O28oto be circular (or elliptical) in shape.

[0289] Furthermore, the two polarizing prisms 2027, 2028 typically have, at least in the central cross-section, respective (central) tips pointing at each other which are formed by pairs of adjoining refractive surfaces {2027b20272} and {2028b20282}, respectively.

[0290] Due to using polarizing prisms 2027, 2028 with pairs of adjoining refractive surfaces {2027b20272} and {2028b20282} forming tips pointing to each other, a particularly advantageous beam redistribution can be achieved too.

[0291] As shown in FIG. 13C, the beam profile redistributor 2020 can redirect a light ray A of the input light beam 2010, which is nearer an edge (outer boundary) of input light beam 2010 then a further light ray B of the input light beam, to a corresponding pair of light rays (light ray pair) A’, A” of different (orthogonal) polarization of the output light beam 2030 which is closer to optical axis O than a redirected pair of light rays B’, B” of different (orthogonal) polarization of output light beam 2030 which corresponds to further light ray B. That a first pair of light rays is closer to an (optical) axis than a second pair of light rays intends to describe that the rays of the first pair run closer to the axis at least as an averaged ray or central ray.

[0292] FIGs. 14A to 14C illustrate beam intensity profiles of light beams that may be generated using device 2000. FIG. 14A shows a representative NF intensity profile of the output light beam 2030 with four partial light beams of different polarization as indicated by the white arrows according to a simulation. FIG. 14C shows the intensity profile of the output light beam in FF. This profile is similar to the intensity profile of a further output light beam of a simulated comparison device with a beam expander instead of beam profile redistributor 2020.

[0293] FIG. 14B shows a convolution of the intensity profile of FIG. 14A over a 7 mm measuring apertures AP. The corresponding reduction of the maximum output light power for the simulations shown in FIGs 14A, 14B compared to the comparison device amount to about 15%.

[0294] FIG. 15A illustrates a device 2000’ which corresponds to device 2000 except for the orientation of the optic axes Ocof the polarizing prisms. A resulting representative intensity profile of the output light beam is shown in FIG. 15B. The corresponding reduction of the maximum output light power for the simulations shown in FIG 15B amount to about 12% (compared to 15% for the original design). Changing the orientation of the optical axes allows fine-tuning the light power for the optical design.

[0295] FIGs. 16A to 16C illustrate yet a further (LIDAR) device 3000. Device 3000 is typically similar to device 2000 explained above with respect to FIGs. 13 A-14C. However, the further downstream polarizing prism (2028) of device 2000 is replaced by a non-polarizing (regular) prism 3029 in the beam profile redistributor 3020 of device 3000. This also allowsdesired redistribution of light rays with respect to power and polarization profile in NF without any substantial impact on the far field properties.

[0296] In the exemplary embodiment, prism 3029 is also mirror symmetric with respect to the optical axis but has, in cross-sections parallel to the optical axis O, differently orientated refractive surfaces, namely two (parallel) outer refractive surfaces 2029la, 20292a, and two (parallel) inner refractive surfaces 2029lb, 20292bwhich are arranged at different angles 02, 0i with respect to optical axis O. Typically, a second angle 02between each of inner refractive surfaces 2029lb, 20292band optical axis O is larger than a first angle 0i between each of outer refractive surfaces 2029la, 20292a(02> 0i).

[0297] Further, 0! may in a range from about 30° to about 40° , and 02may in a range from about 33° to about 43°.

[0298] FIG. 17A illustrates a further (LIDAR) device 4000. Device 4000 is typically similar to device 1000 explained above with respect to FIGs. 11A-12B. However, beam profile redistributor 4020 of device 4000 has two differently sized Wollaston prisms 4041, 4021 arranged after each other in the transmitting part OTof the optical path O.

[0299] In the exemplary embodiment, the Wollaston prisms 4041, 4021 are orientated such that the corresponding crystal optical axes of Wollaston prisms 4041, 4021 are parallel to each other, as indicated by the vectors (0,1,0) and (1,0,0) of the corresponding first polarizing prisms 4027, 4027A and second polarizing prisms 4028, 4028A.

[0300] FIG. 17B shows a representative beam intensity profiles of the output light beam 4030 in NF. The corresponding reduction of the maximum output light power for the simulations shown in FIG 17B amount to about 22%.

[0301] According to an embodiment of an optical device, in particular a scanning optical device and / or a LIDAR device, the optical device includes an optical path, and a beam profile redistributor arranged in the optical path, in particular in a transmitting part of the optical path. The beam profile redistributor includes a (first) polarizing prism (1027, 2027, 3027, 4027 in FIGs. 11 A-C, 13A-C, 16A-C, 17A) for receiving a collimated input light beam, in particular a prism of a birefringent material, typically a uniaxial material such as calcite or quartz. Downstream this prism a further (second) polarizing prism with a typically differently orientated crystal optical axis may be arranged in the optical path. Further, the polarizing prismand the further polarizing prism may be separated from each other or be provided by a Wollaston prism.

[0302] This allows for reliably lowering the output light power of an output light beam of the device when measured using a measuring aperture (flux through the aperture) at a or even any position along the optical path in the near field without substantially changing the beam intensity profile of the output light beam in the far field in a comparatively simple and compact manner.

[0303] This also applies to an embodiment of an optical device, in particular a scanning optical device and / or a LIDAR device, in which the optical device includes an optical path, and a beam profile redistributor arranged in the optical path. The beam profile redistributor includes (provides), in a cross-section parallel to the optical path, a first pair of refractive surfaces ({ 120b1202}, {220b2202},{420b4202}, {620b6202}, {2027b20272} in FIGs. 2, 7, 8, 10, 13B) which are adj acent to each other (typically directly adj acent / adj oining) at a first (internal) angle (a), and a second pair of refractive surfaces ({ 1203, 1204}, {2203, 2204}, {4203, 4204}, {6203, 6204}, {2028b20282} in FIGs. 2, 7, 8, 10, 13B) which are adjacent to each other (typically directly adjacent / adjoining) at a second (internal) angle (0) which typically at least substantially matches the first angle (a). The cross-section may be a central cross-section and / or include the optical path (at least at and / or in the beam profile redistributor).

[0304] FIG. 18A shows a device 200a for emitting a light beam 230. Device 200a is typically similar to device 100 explained above with respect to FIGs. 2, 3, 4, and also includes a collimator 205 arranged in optical path O to convert a divergent light beam 202 emitted from a light source 201, such as a semiconductor laser, in particular an edge-emitting (semiconductor) laser, or a vertical-cavity surface-emitting laser (VCSEL), to a typically substantially collimated input beam 210 to beam profile redistributor 220. Light source 201 and collimator 205 form a light source LS for collimated light. Alternatively, device 200a may have a plurality of light sources, as explained with respect to FIGs 3G, 3H, in particular a respective array of typically identical light sources.

[0305] However, the desired power redistribution in NF is achieved differently. In the exemplary embodiment, beam profile redistributor 220 has a first transmitting surface Si for transmitting the input light beam 210 into the light transmitting volume Vt, e.g. a light transmitting (substantially transparent, low light-absorbing) body 220A, as a first internal lightbeam A’, a first reflective surface S2for reflecting a first portion of the first internal light beam A’ as a second internal light beam A”, a second reflective surface S3for reflecting the second internal light beam A”, and a second transmitting surface S4for receiving the reflected second internal light beam A’” and a second portion B’ of the first internal light beam A’ (which was not reflected by the first reflective surface S2) from the light transmitting volume Vtand body 220A, respectively, and for transmitting the received reflected second internal light beam A’ ’ ’ and the second portion B’ of the first internal light beam to form the output light beam 230 having two partial output beams 230 A (A””), 23 OB (B”).

[0306] Compared to the input light beam 210, which has an exemplary Gaussian intensity profile and circular boundary 210S and may be considered to consist of two partial input light beams A, B, the partial output beams 230A (A””), 230B (B”) of output light beam 230 are interchanged (“inverted”).

[0307] Accordingly, beam profile redistributor 220 redistributes the beam intensity profile in NF with respect to the x-axis so that the total light power at any (in particular 7 mm sized) measuring aperture AP in NF, and thus the maximum total light power at (in particular 7 mm sized) measuring apertures AP in NF, is significantly reduced, but without substantially changing the beam intensity profiles in FF as shown in FIG. 18B (simulation results for NF) and FIG. 18C (simulation results for FF).

[0308] The partial input light beams and partial input light beams are also referred to as partial input beams and partial input beams, respectively, for short.

[0309] By reflecting (only) partial input beam B of the two partial input beams A, B of input light beam 210 once at each of the two reflecting surfaces S2, S3(twice in total), the exemplary beam profile redistributor 220 is configured to change the order of the two partial output beams 230 A, 230B compared to the two partial input beams A, B (received at the first transmitting surface Si), after being transmitted through the first transmitting surface Si, and, thus, to redistribute the beam intensity profile in near field (shift the partial input beams A, B with respect to each other in x-direction) without substantially changing the far field properties.

[0310] Beam profile redistributor 200a is configured to change the order of light rays in NF such that light rays of input light beam 210 which are near an edge or boundary 210S of the input light beam 210 are redirected to a corresponding light ray of the output light beam230 which is near a center line of the output light beam (at x=0 in the upper one of the two partial figures of FIG. 18B).

[0311] As shown in Fig. 18 A, beam profile redistributor 220, which is implemented as a rhombic prism, is arranged asymmetrically with respect to the input light beam 210. In particular, the symmetry point c of the beam profile redistributor (with respect to a point reflection and a 180° degree rotation, respectively) is off-set to input light beam 210. Further, the input light beam 210 is typically off-set to a center of at least one of, preferably both of the two transmitting surfaces Si, S3, in particular off-set to a center of transmitting surfaces Si for receiving input light beam 210

[0312] In the exemplary embodiment, the transmitting surfaces Si, S3are parallel to each other, equally sized and orientated perpendicular to the (axial) direction of input light beam 210 and the optical path O, OT, respectively.

[0313] Further, the reflecting surfaces S2, S4are parallel to each other, equally shaped, equally sized and angled with respect to the (axial) direction of input light beam by fl=45°.

[0314] Accordingly, partial output beams 230A, 230B are parallel to input light beam 210 and the output beam 230, and shifted in radial direction (x-direction) with respect to input light beam 210, respectively.

[0315] However, the angle fl may also be lower, e.g. about 43°. This also allows for outputting two parallel partial output beams 230 A, 230B.

[0316] Beam profile redistributor 220 may be arranged such in the optical path that illuminating of corners and / or edges of beam profile redistributor 220, in particular the edge and the comers between the surfaces S3and S4is avoided (to prevent generating of undesired stray light and an increase in transmission losses, respectively). This is facilitated by using an angle fl of less than 45°, e.g. about 43°.

[0317] In one embodiment, the second internal light beam A’ ’ is reflected at least close to the center of the second reflecting surfaces S4.

[0318] Alternatively or in addition, reflections from the edges / corners of the first reflective surface S3may be avoided by adding a light absorbing material in the edge / comer regions to prevent stray light in the system.

[0319] As indicated by the dotted rectangle S’4in Fig. 18A, alternatively or in addition, the reflecting surfaces S2, S’4may be angled with respect to each other and / or with respect to the (axial) direction of the input light beam 210 by an angle which deviates from 90° (as indicated by the angle y for S2). This also results in outputting two parallel partial output beams 230 A, 23 OB. However, the optical alignment is typically facilitated if the transmitting surfaces Si, S4are parallel to each other.

[0320] Moreover, an area of the first and second transmitting surface SbS3is typically larger than a beam area of the input light beam 210.

[0321] The spacing dxof the partial output beams 230 A, 230B depends on the geometry of beam profile redistributor 220.

[0322] Further, a length L of the beam profile redistributor 220 in the axial direction of the input light beam 210 is at least a width W of the beam profile redistributor 220, in a radial direction of the input light beam 210 divided by square root of two (for 9=45°).

[0323] The results shown in FIGs. 18B, 18C were obtained for a beam profile redistributor 220 with L = VF / 2, and assuming a Gaussian intensity profile of input beam 210. This results in adjoining partial output beams 230A, 230B.

[0324] When W > L * 2, the partial output beams 230A, 230B are separated by a nonzero distance (in NF).

[0325] Downstream beam profile redistributor 220 of Fig. 18 A, other optical components may be arranged in optical path O, for example a polygon to maintain the perimeter of the beam.

[0326] The width W of the beam profile redistributor 220 is typically less than 7 cm, preferably less than 5 cm or even less than 3 cm.

[0327] The length L of the beam profile redistributor 220 is typically about the beam width of input light beam times 2 (for 0=45°) or larger to facilitate alignment, typically not much larger, however, in order to keep absorption losses low (as low as possible), e.g. 10% to 50% larger.

[0328] The length L of the beam profile redistributor 220 is typically also less than 7 cm, preferably less than 5 cm or even less than 3 cm.

[0329] Beam profile redistributor 220 is typically implemented as a one-piece optical element, in particular as a rhombic (glass) prism with metal coated reflective Si, S3, e.g. an Au- coating or another coating substantially reflecting light at wavelength(s) of the input beam 210, in particular at IR wavelength(s) of the input beam 210, preferably at least at a peak wavelength of the input beam 210.

[0330] At least one of the two transmitting surfaces Si, S4may be coated with an anti- reflective coating for this / these wavelength(s).

[0331] In the exemplary embodiment, none of the transmitting surfaces Si, S4and the reflective surfaces S2, S3are provided by a rhombic (base) face of prism 220.

[0332] As shown in Fig. 18A, the transmitting surfaces SbS4may be arranged at least substantially orthogonal to the received input light beam 210.

[0333] Further, collimator 205 may be used to redirect light beam 202 to beam profile redistributor 220 if desired as indicated by (alternative) light source 201’ in FIG. 18 A.

[0334] Furthermore, it is also possible to use the (single) one-axis beam profile redistributor 220 for an array of light sources 201, 201’, e.g. lasers, instead of a single light source 201 (or 201’).

[0335] In particular, light beams 202 from light sources 201, 201’ of an array of light sources 201, 201’, for example up to 4, up to 8, up to 16, up to 32 or even more light sources 201, 201’ arranged in a plane, on a curve or even on a line as illustrated by the dashed-dotted line in FIG. 4A, may be redistributed in parallel by one one-axis beam profile redistributor 220 in NF without substantially changing the beam intensity profiles in FF.

[0336] More particular, when using an array of light sources 201, 201’, the intensity profile of beams 230 of redistributed corresponding incident light beams 210 with slight angular deviations may substantially overlap in NF (resulting in similar, in some instances slightly smeared profiles compared to FIGs. 3D, 3E), and form separate beams 230 in FF, eachof which may have an intensity profile as shown in the lower one of the two partial figures of Fig. 18B.

[0337] FIG. 19A shows a device 200’ for emitting a light beam 230. Device 200’ is typically similar to device 200 explained above with respect to FIG. 18A and also includes a beam profile redistributor 220’ that may even correspond to beam profile redistributor 220 of device 200.

[0338] However, while beam profile redistributor 220 in Fig. 18A is arranged such in the optical path O that the complete input light beam 210 is incident to the first transmitting surfaces Si, beam profile redistributor 220’ in Fig. 19A is arranged such in the optical path O that only a first portion A of input light beam 210 is received at first transmitting surfaces Si, internally reflected by the two non-coplanar reflective surfaces S2, S3, and emitted through the second transmitting surface S4. In this embodiment, second portion B of input light beam 210 is (substantially) not changed by beam profile redistributor 220’. In other words, beam profile redistributor 220’ is arranged asymmetrically with respect to the input light beam 210 and the output light beam 230. As shown in FIG. 19A, the symmetry point c of the beam profile redistributor 200’ (with respect to a point reflection and a 180° degree rotation, respectively) is off-set to the input light beam 210 the output light beam 230 and its the partial output beams 230A, 230B, respectively.

[0339] In particular, the beam profile redistributor 220’ may be arranged such in the optical path O of optical device 200’ that the first reflective surface S2, of the two reflective surfaces is configured to only reflect about 50% of the input light beam 210, e.g. a right half of input light beam 210 in the exemplary embodiment.

[0340] Using beam profile redistributor 220’ also results in a desired NF power distribution (beam intensity profile) without substantially changing the desired FF properties (see FIG. 19B).

[0341] However, the partial output beams 230 A, 230B emitted by beam profile redistributor 220’ are spaced apart from each other for geometrical reasons.

[0342] As shown in FIG. 19A, beam profile redistributor 220’ may be arranged such in the optical path that input light beam 210 is split into to substantially equally sized partial input beams A, B. Accordingly, substantially equally sized partial output beams 230A, 230B are formed.

[0343] As only the first portion A of input light beam 210 is changed, the width W of beam profile redistributor 220’ may be smaller compared to beam profile redistributor 220, by the width of the first portion A, e.g. half of the beam width of input light beam 210.

[0344] Likewise, the length L of the beam profile redistributor 220’ may also be smaller compared to beam profile redistributor 220, and is typically about the width of the second (bypassing) portion B times 2 (for 9=45°) or larger, in particular somewhat larger (10% to 50%) to facilitate arranging of beam profile redistributor 220’ in the optical path.

[0345] By reflecting only partial input beam A of the two partial input beams A, B of input light beam 210 at each of the two reflecting surfaces S2, S3, the exemplary beam profile redistributor 220’ does not change the order of the two partial output beams 230A, 230B compared to the two partial input beams A, B.

[0346] FIG. 20 shows another device 200 a” for emitting an output light beam 200. In the exemplary embodiment, device 200” is implemented as a scanning device, in particular a LIDAR device.

[0347] Accordingly, a scanner 245 is arranged in the optical path O to receive and deflect output light beam 230’ received from beam profile redistributor 220”, after being redirected towards scanner 245 using two exemplary mirrors M2, M3 with an at least substantially maintained redistributed beam intensity profile (in NF), and emit the resulting deflected output light beam 240.

[0348] Scanner 245 may e.g. be implemented as a mirror scanner 245, in particular as an electro optical scanner with an exemplary scanning mirror or as a rotating polygon scanner. Using a rotating polygon scanner can ensure increased eye safety without increasing the cross- sectional size of the laser beam(s) as incident on the polygon facets. As such, the size of the rotating polygon scanner may be more compact. Without beam profile redistributor 220” the cross-sectional size of the laser beam(s) would have to be increased, causing partial signals thatcan occur when the laser beam is incident on an edge between the polygon facets. This may be mitigated by increasing the size of the rotating polygon scanner, which negatively impacts other system constraints such as overall size, form-factor, and cost.

[0349] In other embodiments, scanner 245 may be implemented as a mechanical mirror, a combination of single axis mechanical rotating mirrors, a biaxial mechanical rotating mirror, a MEMs mirror, a rotating prism, or any other scanner to deflect light across a Field of View.

[0350] The device 200a” may comprise a first collimator 205’ typically implemented as a collimating lens to collimate the laser beam 202’ emitted from laser 201’ in a first axis, and a second collimator 225’ typically implemented as collimating lens to collimate the emitted laser beam 202’ in a second axis perpendicular to the first axis.

[0351] The first and second collimators 205’, 225’ may act as a fast axis collimator 205’ and a slow axis collimator 205”, respectively.

[0352] Further, an aperture AP’ may be provided in transmitting part OTof the optical path O, in particular between the collimators 205’, 225’ to radially delimit the light beam.

[0353] The beam profile redistributor 220” may be positioned between the first and second collimators 205’, 225, or, as illustrated in Fig. 20, downstream the collimators 205’, 225, after a mirror Ml in the exemplary embodiment.

[0354] Alternatively, the beam may be collimated in both axes by a single collimation lens, and the beam profile redistributor 220” may be positioned after the single collimation lens.

[0355] Beam profile redistributor 220” is typically a one-piece, one-axis beam profile redistributor.

[0356] Beam profile redistributor 220” may correspond to beam profile redistributor 220 explained above with regard to FIG. 18 A.

[0357] Alternatively, a similar device may be provided with a beam profile redistributor 220” that corresponds to beam profile redistributor 220’ explained above with regard to FIG. 19 A.

[0358] In a receiving part ORof the optical path O, OT, OR, a light detector PD such as a photodiode may be arranged for detecting a back-scattered light beam RL received from the far field.

[0359] The described beam redistribution typically assumes an at least substantially parallel input light beam when received by the beam redistributor in the relevant axis. As such, to redistribute the beam profile as illustrated in FIG. 20, the beams are to be (at least substantially) collimated in the axes in which it is to be inverted.

[0360] FIGs. 21 A, 21B shows a further device 200a’ ’ ’ for emitting an output light beam 230. Device 200’” is similar to devices 200a to 200a” explained above with respect to FIGs. 18Ato 20. Further, FIGs. 21A, 21B may also represent a part of a scanning device, in particular a LIDAR device as explained above with respect to Figs. 8, 20.

[0361] Each of the two beam profile redistributor 221, 222 in FIGs. 21 A, 21B is a one- axis beam profile redistributor, preferably a one-piece, one-axis beam profile redistributor as explained above with regard to Fig. 18A to Fig. 20, such as a respective rhombic prism.

[0362] In the exemplary embodiment, beam profile redistributor 221 is arranged in the optical path to redistribute an incident / input light beam with respect to the x-axis, and beam profile redistributor 222 is arranged in the optical path to redistribute an incident / input light beam (received from beam profile redistributor 221) with respect to the y-axis. This is also reflected in the colored light rays in FIGs. 21 A, 21B obtained in a simulation.

[0363] Beam profile redistributors 221, 222 may even be identical but rotated by 90° about the z-axis (and shifted in x-direction in the exemplary embodiment).

[0364] As a result, four partial output light beams are formed. Accordingly, the total light power at any (in particular 7 mm sized) measuring aperture AP in NF may further be reduced as shown in FIG. 21C.

[0365] FIGs. 22 A and 22B show a further device 300 for emitting an output light beam 330. Device 300 is similar to devices 200a to 200a” explained above with respect to FIGs. 18A to 20, and also has, similar to device 200a”, two (fast and slow axis) collimators 305, 325 downstream a light source 301, and an aperture AP’ between the collimators 305, 325. Further, FIGs. 22A, 22B may also represent a part of a scanning device, in particular a LIDAR device.

[0366] However, in the transmitting part OT of optical path O of device 300, a beam profile redistributor 320 is arranged which not only redistributes the power of an input lightbeam 310, but also redirect the light of input light beam 310 by 90° (90° bending or folding of the optical path).

[0367] As can also be seen from the colored light rays, which were obtained by a simulation, the order the two partial beams A, B of input light beam 310 is, different to using beam profile redistributor 200-200”’, not changed by beam profile redistributor 320.

[0368] In the exemplary embodiment, the desired power redistribution is achieved by reflecting each partial beam A, B at one of the reflective surfaces S2, S3of beam profile redistributor 320 (instead of reflecting one of the two partial beams A, B twice at the reflective surfaces).

[0369] The resulting beam intensity profile is shown in FIG. 22C.

[0370] FIG. 23A shows a further device 400a for emitting an output light beam 430.Device 400 is typically similar to devices 200a - 300 explained above with respect to FIGs. 18A to 22B and also has a beam profile redistributor 420 arranged in the optical path O. Beam profile redistributor 420 may also be implemented as a one-piece beam profile redistributor.

[0371] In the exemplary embodiment, beam profile redistributor 420, which is also shown in FIG. 23B in a perspective view, is implemented as a hexagonal prism (main body) 420A with two coplanar, (metal) coated side surfaces providing reflective surfaces S2, S3.

[0372] The first reflective surface S2is arranged opposite the second reflective surface S3, and adjoins two side surfaces of hexagonal prism 420A at an (inner) angle (9) of 135°. These side surfaces form a first transmitting surface Si and a second transmitting surface S4of beam profile redistributor 420.

[0373] Beam profile redistributor 420 is arranged in the optical path O to redistribute the beam intensity profile of an input light beam 410 in NF, and to output the output light beam 430 at 90° with respect to input light beam 410 (resulting in 90° bending or folding of the optical path).

[0374] This is achieved by reflecting each of two partial input beams A, B of the input light beam 410 once at one of the two reflecting surfaces S2;S3which are arranged at an angle of 45° with respect to the input light beam 410 and its axial direction, respectively.

[0375] The resulting beam intensity profiles in NF and FF are similar to those shown in FIG. 18B.

[0376] The width W and depth T of the beam profile redistributor 420 (and 520) may be about the beam width of the input light beam 410, or somewhat larger. The length L of the beam profile redistributor 420 (and 520) may be the width W times the square root of two ( L = 2 * W).

[0377] FIG. 23C shows yet a further device 500a for emitting an output light beam 530. Device 500a is typically similar to device 400a.

[0378] However, and as also shown in FIG. 23B, beam profile redistributor 520 of device 500a consists of a hexagonal prism 520A forming a main prism for redistributing the input light beam 510, and two side prisms 520B, 520C. Each of the two triangular, identically shaped side prisms 520B, 520C is arranged at one of the two reflective surfaces S2, S3.

[0379] Alternatively, the base sides of the side prisms 520B, 520C provide the reflective surfaces S2, S3.

[0380] In the exemplary embodiment, beam profile redistributor 520 is formed as a cube. This may facilitate handling and alignment of the beam profile redistributor 520 in the optical path O.

[0381] According to an embodiment, the reflectivity of each of the two reflective surfaces S2, S3is polarization-dependent.

[0382] Typically, the reflectivity (of each of the two reflective surfaces S2, S3is at least about 0.9, more preferably at least about 0.98, even more preferably at least about 0.99, for example about one (100%) for a defined first polarization Pband / or a matching polarization state of the input light beam 510.

[0383] Further, the two reflective surfaces S2, S3are (substantially) non-refl ective and transparent for light waves of the second linear polarization P2, which is different to the first polarization Pbfor example orthogonal to the first polarization P

[0384] In particular, the two reflective surfaces S2, S3may acts as a beam splitter BS, i.e. an optical element that is reflective / acts as a mirror for light of first linear polarization P3and transparent for light of second linear polarization P2.

[0385] Accordingly, beam profile redistributor 520 is a (one-piece) polarizationdependent beam profile redistributor.

[0386] In the exemplary embodiment, it is assumed that light source LS produces a linearly polarized light beam 510 of the first polarization Pi as indicated by the bracket (100%, 0%) in FIG. 23 C.

[0387] In the Fig. 23C, brackets (Pi%, P2%) represent the percentage of orthogonal first and second polarizations PbP2of transverse waves of the light beams. However, this is not to be understood as limiting. The light beam 510 may have any other defined polarization such as circular and elliptical polarization.

[0388] In the exemplary embodiment, light source LS for collimated light may include a polarization shaping device (not shown) such as a quarter wave plate additionally arranged in the optical path O downstream a light emitter 501 for emitting circularly polarized light, e.g. a respective laser. Accordingly, the circularly polarized light beam of the light emitter 501 in converted into a linearly polarized light 510. Further, a collimator is typically part of light source LS for collimated light.

[0389] As the two reflective surfaces S S3are coplanar and angled with respect to input light beam 510 by 45°, the first transmitting surface Si is orthogonal to the input light beam 510, and the second transmitting surface S4is parallel to the input light beam 510, input light beam 510 (with its two partial input beams A, B) is converted by beam profile redistributor 520 into two parallel partial output beams 530A, 530B which have the same polarization (100%, 0%), but are perpendicular to input light beam 510.

[0390] Accordingly, the transmitting part OTof the optical path O is folded by beam profile redistributor 520.

[0391] As shown in the Fig. 23C, beam profile redistributor 520 may also be arranged in a receiving part OR of optical path O.

[0392] In this embodiment, each of the two shown partial back-scattered (back- reflected) light beams RLA, RLB, which may be received from far field FF (at the far field side of beam profile redistributor 520) and have an exemplary circular polarization (100%, 100%), is converted into two respective partial light beams of different polarizations, (0%, 100%) and (100%, 0%) in the exemplary embodiment.

[0393] For sake of clarity, only the partial light beams RLA’, RLB’ of polarization (0%, 100%) which are emitted towards a light detector PD arranged in the receiving part OR of optical path O without being deflected, are shown in FIG. 23C.

[0394] In the exemplary embodiment, 50% of the received back- scattered partial light beams RLA, RLB (light of the second polarization P2) passes beam profile redistributor 520 undeflected and reaches light detector PD as partial light beams RLA’, RLB’. Thus, only 50% back- scattered light of the first polarization P| of back- scattered light RLA, RLB received at beam profile redistributor 520 does not reach the detector PD, at least not directly.

[0395] As indicated by partial light beam RLC, light detector PD may additionally receive back-reflected (back-scattered) light of both polarizations (100%, 100%) that do not pass through the beam profile redistributor 520.

[0396] As for device 200”, light detector PD of device 500 may be a SiPM (Silicon photomultipliers) which is a solid-state single-photon-sensitive device built from an array of avalanche photodiodes (APD) or a single photon avalanche diodes (SPAD), serving as detection elements on a common silicon substrate. The PD may be any one of or a combination of an APD, SiPM, PIN diode, or any other photodetector.

[0397] Note that the illustrated detector PD is typically not to scale. In particular, the actual light detection area of the detector PD may be (much) smaller due to a typically provided imaging optics, which is arranged in the receiving part ORto focus the partial light beams RLA, RLB, RLC onto the detector PD. This also applies to FIGs. 20, 24.

[0398] FIGs. 24 shows a further (LIDAR) device 500a’. Device 500a’ is typically similar to devices 200a’, 500a explained above with respect to FIGs. 20, 23C. Device 500’ also has a first collimator 505’ to collimate the light beam 502’ emitted from light source 501’ in a first axis, and a second collimator 525’ to collimate the emitted light beam 502’ in a second axis perpendicular to the first axis. Further, a scanner 545 is arranged in the optical path O to receive and deflect output light beam 530’ received from a beam profile redistributor 520’, after being redirected towards scanner 545 by a (polarization independent) mirror M2, and to emit the resulting deflected output light beam 540.

[0399] However, in the exemplary embodiment, the light beam 502 is linearly polarized (has a first polarization Px of 100%).

[0400] Further, a (polarization independent) mirror Ml is arranged between the collimators 505’, 552’ in the transmitting part OTof optical path O of device 500’.

[0401] In the exemplary embodiment, the beam profile redistributor 520’ arranged in folded optical path O is a one-piece, polarization-dependent beam profile redistributor as explained above with respect to FIGs. 23B, 23 C.

[0402] Accordingly, a portion of the back- scattered light beam RL received from object(s) or subjects(s) illuminated with output light beam 540 can reach the detector PD via the beam profile redistributor 520’, i.e. as received light portion of the second polarization P2in the exemplary embodiment (0, 100%).

[0403] FIG. 25A shows yet a further device 200b for emitting an output light beam 230. Device 200b is typically similar to devices 200a’” explained above with respect to FIG. 21A and also has a beam profile redistributor 220X arranged in the optical path O. Beam profile redistributor 220X is typically implemented as a one-piece beam profile redistributor.

[0404] As also shown in FIGs. 25B-25G, exemplary beam profile redistributor 220X may be also implemented as rhombic prism with a light transmitting volume Vtand body 220A, respectively.

[0405] However, the beam profile redistributor 220X ia arranged differently in the optical path O, OTto be configured to redistribute the beam intensity profile in the near field NF with respect to two orthogonal (radial) axes (xy) as illustrated in Fig. 26 for a Gaussian input light beam 210. As can be seen by the numerically determined power distribution in NF, the four adjoining parts 210a, 201b, 210c, 21 Od of input light beam 210 may be mapped to four spaced apart partial output light beams 230a, 230b, 230c, 230d. Also, in this embodiment, a substantial reduction of the maximum of the output light powers of output light beam 230 at exemplary 7 mm - sized apertures AP in NF can be achieved compared to a similar device without beam profile redistributor 220X.

[0406] In the exemplary embodiment, the two axes redistribution is achieved by four internal surfaces S2, S3, S5, S6of beam profile redistributor 220X acting as reflective surfaces.

[0407] Two of the four reflective surfaces S2, S3, S5, S6, namely reflective surfaces S5, S6corresponding to the base faces S5, S6of prism 220X.

[0408] Further, the first transmitting surface Si for receiving the input light beam 210 and the second transmitting surface S4for emitting the at least one output light beam 230, 230a, 230b, 230c, 23 Od are arranged at an acute angle with respect to the (parallel) light beams 210, 230 and the optical axis, respectively, in particular an angle of about 45°.

[0409] As shown in Figs. 25B, 25D, 25H, a portion X4of the internal light beam is transmitted through the first and second transmitting surface Si, S4without being any internal reflection. Accordingly, partial output beam 230d at least substantially corresponds to (at most slightly shifted) partial input beam 210d.

[0410] As shown in Figs. 25B, 25C, 25E, a further portion Xaof the internal light beam, after being received / transmitted through Sbis split at the first reflective surface S5and the third reflective surface S5into two parallel partial internal light beams that are recombined by reflection of the two partial internal light beams at the second reflective surface S3and the fourth reflective surface S6(as also indicated by the arrows in Fig. 25E). Accordingly, partial output beam 230a at least substantially corresponds to partial input beam 210a shifted with respect to both the y-axis and the x-axis.

[0411] As shown in Figs. 25B, 25C, 25F, a portion Xb of the internal light beam, after being received / transmitted through Sbis reflected twice (at the base faces), i.e. at the third reflective surface S5to the fourth reflective surface S6and, thereafter, at the fourth reflective surface S6to second transmitting surface S4. Accordingly, partial output beam 230b at least substantially corresponds to partial input beam 210a shifted with respect to the x-axis only.

[0412] Further, and as shown in Figs. 25B, 25C, 25G, a portion Xcof the internal light beam, after being received / transmitted through Sbis also reflected twice (as side faces), i.e. at the first reflective surface S2to the second reflective surface S3and, thereafter, at the second reflective surface S3to second transmitting surface S4. Accordingly, partial output beam 230c at least substantially corresponds to partial input beam 210c shifted with respect to the x-axis only.

[0413] In the result, the order (arrangement in the radial x-y plane) of partial output light beams 230a, 230b 230c, 230d in NF is changed compared to the partial input beams 210a, 210b 210c, 210d (changed to 230a, 230b 230d, 230c).

[0414] The spacings between partial output light beams 230a, 230b, 230c, 230d in NF depend on and, thus, may be tuned by the geometry of beam profile redistributor 220X. This can e.g. be seen from figures 25D to 25G according to which the shifts of partial output beam 230a, 230b, 230c with respect to (non-shifted) partial output beam 230a (in xy-directions, and with respect to each other) typically depend on at least one of, more typically two or even all of: a first distance between the parallel first and second reflective surfaces S2, S3(first pair of parallel side faces of prism 220X), a second distance between the parallel first and second transmitting surfaces SbS4(second pair of parallel side faces of prism 220X), and a third distance between the third and fourth reflective surfaces S5, S6(between top and bottom faces, high of right rhombic prism 220X). Increasing the first, second and / or the third distancetypically results in increasing the spacing between the partial output light beams 230a, 230b 230c, 230d in xy-directions. This may also depend on the incident angle of input beam 210.

[0415] In particular, a size of the equally shaped (rectangular) first and second reflective surfaces S2, S3may differ from a size of the equally shaped (rectangular) first and second transmitting surfaces S2, S3(elongated rhombic prism).

[0416] Typically, a rhombic prism with equally sized and shaped side faces or an extended (elongated) rhombic prism (with two pairs of differently sized side faces) is used as beam profile redistributor.

[0417] According to an embodiment of an optical device, in particular a scanning optical device and / or a LIDAR device, the optical device includes an optical path, and a beam profile redistributor arranged in the optical path, in particular in a transmitting part of the optical path. The beam profile redistributor includes two non-co-planar reflective surfaces of typically at least substantially uniform reflectivity for an input light beam including two, typically adjoining partial input light beams. The beam profile redistributor is configured to redistributed the beam intensity profile by reflecting either one of the two partial input beams of the input light beam once at each of the two reflecting surfaces(twice) or each of the two partial input beams of the input light beam once at a respective one of the two reflecting surfaces. The reflection of the partial input beam(s) at the respective reflective surface may at least substantially polarization-independent or may depend on the polarization.

[0418] Accordingly, a output light beam of the device includes, in a near field and / or at the beam profile redistributor, a redistributed beam intensity profile compared to a further output light beam (e.g. virtual output light beam) when the beam profile redistributor is not present, within a given measuring aperture at a position along the optical path in the near field, a lower output light power compared to the further output light beam, and in a far field, at least substantially the same beam intensity profile compared to the further output light beam.

[0419] This allows for reliably lowering the output light power of an output light beam of the device when measured using a measuring aperture (flux through the aperture) at a or even any position along the optical path in the near field without substantially changing the beam intensity profile of the output light beam in the far field in a comparatively simple and compact manner.

[0420] This also applies to an embodiment of an optical device, in particular a scanning optical device and / or a LIDAR device, in which the optical device includes an optical path, and a beam profile redistributor arranged in the optical path.

[0421] The beam profile redistributor may be a one-axis or a two-axis beam profile redistributor, in particular a respective single-piece beam profile redistributor.

[0422] Preferably, the beam profile redistributor is configured to at least one of: redistribute the beam intensity profile in NF with respect to at least one (radial) axis, for example with respect to two (radial) axes, flip at least one portion of the received input light beam in NF with respect to the at least one axis, and split the received input light beam into at least to at least two, typically spaced apart partial output light beams in NF.

[0423] Although various exemplary embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that various changes and modifications can be made which will achieve some of the advantages of the invention without departing from the spirit and scope of the invention. It will be obvious to those reasonably skilled in the art that other components performing the same functions may be suitably substituted. It should be mentioned that features explained with reference to a specific figure may be combined with features of other figures, even in those cases in which this has not explicitly been mentioned. Such modifications to the inventive concept are intended to be covered by the appended claims.

[0424] As used herein, the terms “having”, “containing”, “including”, “comprising” and the like are open ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features. The articles “a”, “an” and “the” are intended to include the plural as well as the singular, unless the context clearly indicates otherwise. Further, terms such as “first”, “second”, and the like, are also used to describe various elements, regions, sections, etc. and are also not intended to be limiting. Like terms refer to like elements throughout the description.

[0425] With the above range of variations and applications in mind, it should be understood that the present invention is not limited by the foregoing description, nor is it limited by the accompanying drawings. Instead, the present invention is limited only by the following claims and their legal equivalents.Terms and DefinitionsOptical System

[0426] Disclosed embodiments may involve an optical system. As used herein, the terms “optical system” or “optical device” include any system or device that is used for the generation, detection and / or manipulation of light. By way of example only, an optical system may include one or more optical components for generating, detecting and / or manipulating light. For example, light sources, lenses, mirrors, prisms, beam splitters, collimators, polarizing optics, optical modulators, optical switches, optical amplifiers, optical detectors, optical sensors, fiber optics, semiconductor optic components, while each not necessarily required, may each be part of an optical system. In addition to the one or more optical components, an optical system may also include other non-optical components such as electrical components, mechanical components, chemical reaction components, and semiconductor components. The non-optical components may cooperate with optical components of the optical system. For example, the optical system may include at least one processor for analyzing detected light.LIDAR System

[0427] Consistent with the present disclosure, the optical system may include a LIDAR system or may be included as a portion of a LIDAR system. As used herein, the terms “LIDAR system” or “LIDAR device” include any system or device which can determine values of parameters indicative of a distance between a pair of tangible objects based on reflected light. In one embodiment, the LIDAR system may determine a distance between a pair of tangible objects based on reflections of light emitted by the LIDAR system. As used herein, the term “determine distances” includes generating outputs which are indicative of distances between pairs of tangible objects. The determined distances may represent physical dimensions between a pair of tangible objects. By way of example only, the determined distances may include a line of flight distance between the LIDAR system and another tangible object in a field of view of the LIDAR system. In another embodiment, the LIDAR system may determine the relative velocity between a pair of tangible objects based on reflections of light emitted by the LIDAR system. Examples of outputs indicative of the distance between a pair of tangible objects include: a number of standard length units between the tangible objects (e.g. number of meters, number of inches, number of kilometers, number of millimeters), a number of arbitrary length units (e.g. number of LIDAR system lengths), a ratio between the distance to another length (e.g. a ratio to a length of an object detected in a field of view of the LIDAR system), an amount of time (e.g. given as standard unit, arbitrary units or ratio, for example, the time it takes lightto travel between the tangible objects), one or more locations (e.g. specified using an agreed coordinate system, specified in relation to a known location), and more.Time of Flight

[0428] The LIDAR system may determine the distance between a pair of tangible objects based on reflected light. In one example, the LIDAR system processes detection results of a sensor which creates temporal information indicative of a period of time between the emission of a light signal and the time of its detection by the sensor. The period of time may be referred to as a “time of flight” of the light signal. In one example, the light signal may be a short pulse, whose rise and / or fall time may be detected in reception. Using known information about the speed of light in the relevant medium (usually air), the information regarding the time of flight of the light signal can be processed to provide the distance the light signal travelled between emission and detection. In another embodiment, the LIDAR system may determine the distance based on frequency phase-shift (or multiple frequency phase-shift). Specifically, the LIDAR system may process information indicative of one or more modulation phase shifts (e.g., by solving some simultaneous equations to give a final measure) of the light signal. For example, the emitted optical signal may be modulated with one or more constant frequencies. The at least one phase shift of the modulation between the emitted signal and the detected reflection may be indicative of the distance the light travelled between emission and detection. The modulation may be applied to a continuous wave light signal, to a quasi-continuous wave light signal, or to another type of emitted light signal. It is noted that additional information may be used by the LIDAR system for determining the distance, e.g., location information (e.g., relative positions) between the projection location, the detection location of the signal (especially if distanced from one another), and more.Detecting an object

[0429] In some embodiments, the LIDAR system may be used for detecting a plurality of objects in an environment of the LIDAR system. The term “detecting an object in an environment of the LIDAR system” includes generating information which is indicative of an object that reflected light toward a detector associated with the LIDAR system. If more than one object is detected by the LIDAR system, the generated information pertaining to different objects may be interconnected, for example a car is driving on a road, a bird is sitting on a tree, a man touches a bicycle, a van moves towards a building. The dimensions of the environment in which the LIDAR system detects objects may vary with respect to implementation. For example, the LIDAR system may be used for detecting a plurality of objects in an environmentof a vehicle on which the LIDAR system is installed, up to a horizontal distance of 100m (or 200m, 300m, etc.), and up to a vertical distance of 10m (or 25m, 50m, etc.). In another example, the LIDAR system may be used for detecting a plurality of objects in an environment of a vehicle or within a predefined horizontal range (e.g., 25°, 50°, 100°, 180°, etc.), and up to a predefined vertical elevation (e.g., ±10°, ±20°, +40°-20°, ±90° or 0°-90°).

[0430] As used herein, the term “detecting an object” may refer to determining an existence of the object (e.g., an object may exist in a certain direction with respect to the LIDAR system and / or to another reference location, or an object may exist in a certain spatial volume). Additionally, or alternatively, the term “detecting an object” may refer to determining a distance between the object and another location (e.g. a location of the LIDAR system, a location on earth, or a location of another object). Additionally or alternatively, the term “detecting an object” may refer to identifying the object (e.g. classifying a type of object such as car, plant, tree, road; recognizing a specific object (e.g., the Washington Monument); determining a license plate number; determining a composition of an object (e.g., solid, liquid, transparent, semi-transparent); determining a kinematic parameter of an object (e.g., whether it is moving, its velocity, its movement direction, expansion of the object). Additionally, or alternatively, the term “detecting an object” may refer to generating a point cloud map in which every point of one or more points of the point cloud map correspond to a location in the object or a location on a face thereof. In one embodiment, the data resolution associated with the point cloud map representation of the field of view may be associated with 0. l°x0.1° or 0.3°x0.3° of the field of view.Object

[0431] Consistent with the present disclosure, the term “object” includes a finite composition of matter that may reflect light from at least a portion thereof. For example, an object may be at least partially solid (e.g. cars, trees); at least partially liquid (e.g. puddles on the road, rain); at least partly gaseous (e.g. fumes, clouds); made from a multitude of distinct particles (e.g. sand storm, fog, spray); and may be of one or more scales of magnitude, such as ~1 millimeter (mm), ~5mm, ~10mm, ~50mm, -lOOmm, ~500mm, ~1 meter (m), ~5m, ~10m, ~50m, ~100m, and so on. Smaller or larger objects, as well as any size in between those examples, may also be detected. It is noted that for various reasons, the LIDAR system may detect only part of the object. For example, in some cases, light may be reflected from only some sides of the object (e.g., only the side opposing the LIDAR system will be detected); in other cases, light may be projected on only part of the object (e.g. laser beam projected onto aroad or a building); in other cases, the object may be partly blocked by another object between the LIDAR system and the detected object; in other cases, the LIDAR’s sensor may only detect light reflected from a portion of the object, e.g., because ambient light or other interferences interfere with detection of some portions of the object.FOV

[0432] As used herein the term “field of view of the LIDAR system” may include an extent of the observable environment of the LIDAR system in which objects may be detected. It is noted that the field of view (FOV) of the LIDAR system may be affected by various conditions such as but not limited to: an orientation of the LIDAR system (e.g. is the direction of an optical axis of the LIDAR system); a position of the LIDAR system with respect to the environment (e.g. distance above ground and adjacent topography and obstacles); operational parameters of the LIDAR system (e.g. emission power, computational settings, defined angles of operation), etc. The field of view of LIDAR system may be defined, for example, by a solid angle (e.g., defined using (|>, 9 angles, in which (|> and 9 are angles defined in perpendicular planes, e.g. with respect to symmetry axes of the LIDAR system and / or its FOV). In one example, the field of view may also be defined within a certain range (e.g., up to 299 m).

[0433] The term “instantaneous field of view” may include an extent of the observable environment in which objects may be detected by the LIDAR system at any given moment. For example, for a scanning LIDAR system, the instantaneous field of view is narrower than the entire FOV of the LIDAR system, and it can be moved within the FOV of the LIDAR system in order to enable detection in other parts of the FOV of the LIDAR system. The movement of the instantaneous field of view within the FOV of the LIDAR system may be achieved by moving a light deflector of the LIDAR system (or external to the LIDAR system), so as to deflect beams of light to and / or from the LIDAR system in differing directions. In one embodiment, the LIDAR system may be configured to scan scene in the environment in which the LIDAR system is operating. As used herein the term “scene” may include some or all of the objects within the field of view of the LIDAR system, in their relative positions and in their current states, within an operational duration of the LIDAR system. For example, the scene may include ground elements (e.g., earth, roads, grass, sidewalks, road surface marking), sky, man-made objects (e.g., vehicles, buildings, signs), vegetation, people, animals, light projecting elements (e.g. flashlights, sun, other LIDAR systems), and so on.Light Source

[0434] Consistent with disclosed embodiments, the LIDAR system may include at least one projecting unit with a light source configured to project light. As used herein the term “light source” refers to any device configured to emit light. In one embodiment, the light source may be a laser such as a solid-state laser, laser diode, a high-power laser, or an alternative light source such as, a fiber laser and a light emitting diode (LED)-based light source. In addition, the light source as illustrated throughout the figures, may emit light in differing formats, such as light pulses, continuous wave (CW), quasi-CW, and so on. For example, one type of light source that may be used is a semiconductor laser, such as a vertical-cavity surface-emitting laser (VCSEL) or an edge-emitting laser. Another type of light source that may be used is an external cavity diode laser (ECDL). In some examples, the light source may include a laser diode configured to emit light at a wavelength between about 650 nm and 1150 nm. Alternatively, the light source may include a laser diode configured to emit light at a wavelength between about 800 nm and about 1000 nm, between about 850 nm and about 950 nm, or between about 1300 nm and about 1600 nm. Unless indicated otherwise, the term "about" with regards to a numeric value is defined as a variance of up to 5% with respect to the stated value.Sensor

[0435] Consistent with disclosed embodiments, the LIDAR system may include at least one sensing unit with at least one sensor configured to detect reflections from objects in the field of view. The terms “sensor”, “detector”, “sensing unit”, “detection unit”, “collection unit” include any device, element, or system capable of measuring properties (e.g., power, frequency, phase, pulse timing, pulse duration) of electromagnetic waves and to generate an output relating to the measured properties. In some embodiments, the at least one sensor may include a plurality of detectors constructed from a plurality of detecting elements. The at least one sensor may include light sensors of one or more types. It is noted that the at least one sensor may include multiple sensors of the same type which may differ in other characteristics (e.g., sensitivity, size). Other types of sensors may also be used. Combinations of several types of sensors can be used for different reasons, such as improving detection over a span of ranges (especially in close range); improving the dynamic range of the sensor; improving the temporal response of the sensor; and improving detection in varying environmental conditions (e.g. atmospheric temperature, rain, etc.).

[0436] In one embodiment, the at least one sensor includes a SiPM (Silicon photomultipliers) which is a solid-state single-photon-sensitive device built from an array of avalanche photodiode (APD), single photon avalanche diode (SPAD), serving as detection elements on a common silicon substrate. In one example, a typical distance between SPADs may be between about 10pm and about 50pm, wherein each SPAD may have a recovery time of between about 20ns and about 100ns. Similar photomultipliers from other, non-silicon materials may also be used. Although a SiPM device works in digital / switching mode, the SiPM is an analog device because all the microcells may be read in parallel, making it possible to generate signals within a dynamic range from a single photon to hundreds and thousands of photons detected by the different SPADs. It is noted that outputs from different types of sensors (e.g., SPAD, APD, SiPM, PIN diode, Photodetector) may be combined together to a single output which may be processed by a processor of the LIDAR system.Various aspects and embodiments of the present invention are defined by the following numbered clauses:1. A device comprising:- an optical path; and- a beam profile redistributor arranged in the optical path to receive an input light beam and comprising two, non-co-planar reflective surfaces of at least substantially uniform reflectivity for the input light beam, the beam profile redistributor being configured to convert the received input light beam so that at least one output light beam of the device comprises: o in a near field and / or at the beam profile redistributor, a redistributed beam intensity profile compared to at least one further output light beam when the beam profile redistributor is not present; o within a given measuring aperture at a position along the optical path in the near field, a lower output light power compared to the at least one further output light beam when the beam profile redistributor is not present; and o in a far field, at least substantially the same beam intensity profile compared to the at least one further output light beam when the beam profile redistributor is not present.The device of clause 1, wherein the two non-co-planar reflective surfaces are at least substantially parallel, and / or wherein the two non-co-planar reflective surfaces are spaced apart from each other, and / or wherein each of the two non-co-planar reflective surfaces is at least substantially planar, and / or wherein each of the two non-co-planar reflective surfaces are angled with respect to the input light beam, preferably by an angle of at most about 45°. The device of clause 1 or 2, wherein a transmittance of the beam profile redistributor at a wave length of a light wave of the input light beam is at least about 0.8, more preferably at least about 0.9, even more preferably at least about 0.95, and / or wherein the respective reflectivity of the two reflective surfaces varies by at most by 5%, preferably by at most by 2% at and / or along the respective reflective surfaces, and / or wherein at least a respective averaged reflectivity of the two reflective surfaces at least substantially matches. The device of any of clauses 1 to 3, wherein the beam profile redistributor is arranged in at least one of: a transmitting part of the optical path for emitting the at least one output light beam or at least one light beam derived from the at least one output light beam, and a receiving part of the optical path configured to transmit a portion of at least one back- scattered light beam received from the far field. The device of any of clauses 1 to 4, wherein the reflectivity of the two reflective surfaces is polarization-dependent, preferably each of the two reflective surfaces being configured to at least substantially reflect light waves of a first linear polarization and / or being at least substantially non-refl ective and / or transparent for light waves of a second linear polarization different to the first linear polarization, preferably the reflectivity of the two reflective surfaces being at least about 0.98, more preferably at least about 0.99 at the first polarization and a wave length of a light wave of the input light beam, preferably the reflectivity of the two reflective surfaces being at most about 0.02, more preferably at most about 0.01 at the second polarization and for the wave length of the light wave of the input light beam. The device of any of clauses 1 to 4, wherein the reflectivity of the two reflective surfaces is at least substantially polarization-independent, preferably the reflectivity of the tworeflective surfaces at least substantially matching and / or being at least about 0.98, more typically 0.99 at a wave length of a light wave of the input light beam, and / or wherein the reflectivity is obtained by total internal reflection or by a mirror coating. The device of any of the preceding clauses, wherein the beam profile redistributor is configured to convert the received input light beam into two partial output light beams, which do not overlap in the near field, and / or wherein the beam profile redistributor is configured to redistribute the beam intensity profile by reflecting either one of the two partial input beams once at each of the two reflecting surfaces or each of the two partial input beams of the input light beam once at a respective one of the two reflecting surfaces. The device of any of the preceding clauses, wherein, in a projection onto a radial plane perpendicular to a beam propagation direction of the input light beam, an area of at least one of the two reflective surfaces is at least about 0.5 times a beam width of the input light beam, e.g. about 0.5 times the beam width of the input light beam. The device of any of the preceding clauses, wherein a first reflective surface of the two reflective surfaces is configured to only reflect a first portion of the input light beam. The device of any of the preceding clauses, wherein the beam profile redistributor is a one-piece beam profile redistributor, and / or wherein the beam profile redistributor is implemented as a rigid body, and / or wherein the beam profile redistributor is the beam profile redistributor according to any of clauses 29 to 34, and / or wherein the beam profile redistributor comprises at least one of, preferably both of o a first transmitting surface arranged in the optical path for receiving at least a portion of the input light beam, preferably a transmittance of the first transmitting surface at a wave length of a light wave of the input light beam being at least about 0.98, more preferably at least about 0.99, and o a second transmitting surface arranged in the optical path for emitting at least a portion of the at least one output light beam, preferably a transmittance of the second transmitting surface at a wave length of a light wave of the input light beam being at least about 0.98, more preferably at least about 0.99,the transmitting surfaces and the reflective surfaces preferably being arranged in an alternating order. The device of clauses 9 and 10, wherein, in a projection onto a radial plane perpendicular to a beam propagation direction of the input light beam, a size of the first transmitting surface is at least 1.5 times a beam width of the input light beam, and / or wherein none of the transmitting surfaces and reflective surfaces are coplanar, and / or wherein the first reflective surface is arranged adjacent and / or between the two transmitting surfaces, and / or wherein the second reflective surface is arranged adjacent and / or between the two transmitting surfaces, and / or wherein an angle between the first transmitting surface and the first reflective surface is about 45°, and / or wherein an angle between the second transmitting surface and the first reflective surface is about 135°. The device of any of the clauses 10 to 11, wherein the two transmitting surfaces are angled with respect to the input light beam, preferably at an angle of about 90°, and / or wherein the second transmitting surface is arranged in the optical path for emitting at least one of a first portion of the at least one output light beam and a second portion of the at least one output light beam. The device of clause 12, wherein the two transmitting surfaces are angled with respect to the input light beam by an angle of about 90°. The device of clause 9 and any of the clauses 10 to 13, wherein the first reflective surface is configured to reflect the transmitted first portion of the input light beam towards a second reflective surface of the two reflective surfaces. The device of any of the clauses 10 to 14, wherein a size of the first transmitting surface is larger than a beam size of the input light beam and / or at least substantially corresponds to a size of the second transmitting surface, and / or wherein a length of the beam profile redistributor in an axial direction of the input light beam is at least a width of the beam profile redistributor in a radial direction of the input light beam divided by square root of two, and / or wherein the input light beam and the at least one output light beam are substantially parallel, preferably the width of the beam profile redistributor being less than 7 cm, less than 5 cm or even less than 3 cm.The device of clauses 9 and 10, wherein a second reflective surface of the two reflective surfaces is configured to reflect a second portion of the input light beam, after being transmitted through the first transmitting surface, towards the second transmitting surface, and / or wherein the beam profile redistributor is configured to fold the optical path, and / or wherein the input light beam and the at least one output light beam are angled with respect to each other, preferably by an angle of about 90°, and / or wherein the first reflective surface is arranged adjacent and / or between the two transmitting surfaces. The device of clause 16, wherein the two transmitting surfaces and the first reflective surface are coplanar, and / or wherein a size of the first transmitting surface is smaller than a beam size of the input light beam, and / or wherein the two transmitting surfaces are angled with respect to the input light beam, preferably at an angle of about 45°. The device of clause 16, wherein none of the transmitting surfaces and reflective surfaces are coplanar, wherein at least one of, typically both of the first transmitting surfaces and the second transmitting surfaces is angled with respect to the input light beam, preferably at an angle of about 90°, and / or wherein an angle between the first transmitting surface and the first reflective surface is about 135°, and / or wherein an angle between the second transmitting surface and the first reflective surface is about 135°. The device of any of clauses 10 to 18, wherein the first and second transmitting surfaces are at least substantially flat, and / or wherein the first and second transmitting surfaces are at least substantially parallel, and / or wherein the two transmitting surfaces are at least substantially parallel to one another and / or angled with respect to at least one of the two reflective surfaces , and / or wherein the two transmitting surfaces comprises an anti- reflective coating, and / or wherein the two reflective surfaces and the two transmitting surfaces are arranged at and / or around a light transmitting volume of the beam profile redistributor. The device of clause 19, wherein the light transmitting volume comprises a 180° degree rotational symmetry and / or is shaped as a convex polyhedron and / or formed by an at least substantially transmitting main body of the beam profile redistributor.The device of clause 20, wherein the at least one of: the convex polyhedron and the main body is a prism, in particular a hexagonal prism, a rectangular cuboid or a rhombic prism. The device of any of the clauses 10 to 21, wherein the first transmitting surface is arranged in the optical path for transmitting at least one of the first portion of the input light beam and a second portion of the input light beam. The device of clause 9 and any of the clauses 10 to 22, wherein the two reflective surfaces and the two transmitting surfaces are outer surfaces of the beam profile redistributor. The device of any of the clauses 10 to 23, wherein the two reflective surfaces are inner surfaces of the beam profile redistributor, and wherein the two transmitting surfaces are outer surfaces of the beam profile redistributor. The device of clause 24, wherein the beam profile redistributor comprises a main prism providing the two transmitting surfaces and two side prisms each of which being arranged at the main prism for providing the two reflective surfaces at the respective interface between the main prism the two side prisms, preferably the two side prisms and the main prism forming a cuboid, the two side prisms being glued with the main prism, being at substantially shaped identical and / or comprising at least substantially the same refractive index, for example at substantially the same refractive index as the main prism. The device of any of the preceding clauses, wherein the device comprises at least one of:- a further beam profile redistributor arranged in the optical path downstream the beam profile redistributor, and configured to redistribute, in near field and / or at the further beam profile redistributor, the beam profile with respect to a different axis compared to the beam profile redistributor;- an aperture arranged in the optical path;- a light detector arranged in the optical path, preferably in the receiving part of the optical path, the light detector typically comprising a photodiode; a light source arranged in the optical path, preferably in the transmitting part of the optical path, in particular, a laser such as an edge-emitting laser or even an array of lasers; anda collimator arranged in the optical path, a mirror arranged in the optical path, and / or wherein the device is configured to emit an at least substantially collimated light beam formed by the at least one output light beam or from the at least one output light beam. The device of any of the preceding clauses, wherein the given measuring aperture is defined by a safety standard, in particular a Class 1 laser standard, wherein the device meets the safety standard, wherein the given measuring aperture comprises an at least substantially circular or elliptical shape or an at least substantially square / rectangular shape, in particular a circular shape of about 5 mm to about 15 mm diameter, more typically of about 6 mm to about 9 mm diameter, even more typically of about 7 mm diameter, or a square shape of about 5 mm to about 11 mm base length, more typically of about 5 mm to about 9 mm base length, even more typically of about 7 mm base length, and / or wherein an area of the given measuring aperture is in a range from about 9 mm2to about 121 mm2, more typically in a range from about 25 mm2to about 81 mm2, and even more typically in a range from about 35 mm2to about 50 mm2, for example about 38 mm2or about 49 mm2, wherein the beam profile redistributor is arranged in the optical path and configured such the redistributed beam intensity profile is at least substantially maintained up to a distance from the beam profile redistributor and / or an optical outlet of the device of at least 1 m, more typically at least 3 m, and even more typically at least 5 m, and / or that the far field begins outside the device, in particular at a distance from the beam profile redistributor and / or the optical outlet of the device of at least 10 m or even 20 m. The device of any of the preceding clauses, wherein the device is a scanning device, in particular a respective LIDAR device or a component thereof, the device typically comprising a scanner arranged in the optical path to receive the at least one output light beam, in particular a rotating polygon scanner, after optionally being collimated and / orbeing redirected towards the scanner, with an at least substantially maintained redistributed beam intensity profile. A one-piece beam profile redistributor for converting an input light beam into an output light beam comprising two partial output light beams, the beam profile redistributor comprising:- a light transmitting volume or body;- a first transmitting surface for transmitting the input light beam into the light transmitting volume or body as a first internal light beam;- a first reflective surface for reflecting an incident first portion of the first internal light beam into a second internal light beam;- a second reflective surface for reflecting the second internal light beam; and- a second transmitting surface for receiving the reflected second internal light beam and a second portion of the first internal light beam from the light transmitting volume or body, and for transmitting the received reflected second internal light beam and the second portion of the first internal light beam to form the output light beam. The one-piece beam profile redistributor of clause 29, wherein the beam profile redistributor is configured to at least one of- change the order of the two partial output light beams compared to two partial input beams of the input light beam; and- redistribute the beam intensity profile, by reflecting one of the two partial input beams of the input light beam once at each of the two reflecting surfaces. A one-piece beam profile redistributor for converting an input light beam into an output light beam comprising two partial output light beams, the beam profile redistributor comprising: a light transmitting volume or body;- a first reflective surface for reflecting an incident first portion of the input light beam to form a first partial beam of the two partial output light beams;- a first transmitting surface for transmitting an incident second portion of the input light beam into the light transmitting volume or body as a first internal light beam;- a second reflective surface for reflecting the first internal light beam to form a second internal light beam; and- a second transmitting surface for receiving and transmitting the second internal light beam to form a second partial beam of the two partial output light beams. The one-piece beam profile redistributor of clause 31, wherein each of the two transmitting surfaces is coplanar with the first reflective surface or forms an angle of about 135° with the first reflective surface. The one-piece beam profile redistributor of clause 31 or 32, wherein the beam profile redistributor is configured to redistribute the beam intensity profile by reflecting each of two partial input beams of the input light beam once at a respective one of the two reflecting surfaces. The one-piece beam profile redistributor of any of clauses 29 to 33, wherein the first and second reflective surfaces are at least substantially parallel and / or at least substantially flat, wherein the first and second transmitting surfaces are at least substantially parallel, at least substantially flat and / or angled with respect to the first and second reflective surfaces, and / or wherein the light transmitting volume or body is shaped as a convex polyhedron and / or comprises a 180° degree rotational symmetry. A device comprising:- an optical path; and- a beam profile redistributor arranged in the optical path to receive an input light beam, and configured to convert the received input light beam so that at least one output light beam of the device comprises:o in a near field and / or at the beam profile redistributor, a redistributed beam intensity profile compared to at least one further output light beam when the beam profile redistributor is not present and / or is replaced by a beam expander configured to expand the received input light beam as the beam profile redistributor; o within a given measuring aperture at a position along the optical path in the near field, a lower output light power compared to the at least one further output light beam when the beam profile redistributor is not present and / or is replaced by the beam expander; and o in a far field, at least substantially the same beam intensity profile compared to the at least one further output light beam when the beam profile redistributor is not present and / or is replaced by the beam expander.The device of clause 35, wherein the beam profile redistributor is arranged in a transmitting part of the optical path, wherein the device is a scanning device, in particular a respective LIDAR device or a component thereof, the device typically comprising a scanner arranged in the optical path, in particular in the transmitting part of the optical path to receive the at least one output light beam after optionally being collimated and / or being redirected towards the scanner, with an typically at least substantially maintained redistributed beam intensity profile.The device of any of the clauses 35 and 36, wherein the device comprises at least one of- a light detector arranged in the optical path, in particular in the receiving part of the optical path; and- a light source arranged in the optical path, in particular in the transmitting part of the optical path; and / or wherein the device is configured to emit an at least substantially collimated light beam formed by the at least one output light beam or from the at least one output light beam.The device of any of the clauses 35 to 37, wherein the beam profile redistributor comprises at least one of: a polarizing prism, a regular prism, in particular a respective trigonal prism, an axicon, and a lens, in particular an aspherical lens. A LIDAR device compri sing :- an optical path comprising a transmitting part and a receiving part;- a light detector arranged in the receiving part of the optical path;- a light source arranged in the transmitting part of the optical path; and- a beam profile redistributor arranged downstream the light source in the transmitting part of the optical path and comprising a polarizing prism. The LIDAR device of clause 39, wherein the beam profile redistributor is arranged in the transmitting part for generating at least one output light beam, receiving an input light beam from the light source, and / or for converting the received input light beam into the at least one output light beam. The LIDAR device of clause 40, wherein the beam profile redistributor configured to convert the received input light beam so that the at least one output light beam of the LIDAR device comprises: o in a near field and / or at the beam profile redistributor, a redistributed beam intensity profile compared to at least one further output light beam when the beam profile redistributor is replaced by a beam expander whose beam widening at least substantially corresponds to a beam widening of the beam profile redistributor; o within a given measuring aperture at a position along the optical path in the near field, a lower output light power compared to the at least one further output light beam when the beam profile redistributor is replaced by the beam expander; and o in a far field, at least substantially the same beam intensity profile compared to the at least one further output light beam when the beam profile redistributor is replaced by the beam expander.The device of any of the clauses 35 to 41, wherein the device comprises at least one of:- an aperture arranged in the optical path; and- a collimator arranged in the optical path, in particular in the transmitting part of the optical path. The device of clause 42, wherein the transmitting part of the optical path extends at least from the beam profile redistributor at least to the aperture or even from the light source at least to the aperture, wherein the receiving part extends from the aperture towards the light detector, and / or the wherein the optical path is folded. The device of any of the clauses 39 to 41 and 42, wherein the light detector comprises a photodiode, and / or wherein the light source comprises a laser such as an edge-emitting laser or even an array of lasers. The device of any of the clauses 35 to 44, wherein, in the near field, the at least one output light beam comprises a different polarization profile than the at least one further output light beam. The device of any of the clauses 35 to 45, wherein the beam profile redistributor comprises two polarizing prisms arranged in the optical path, in particular in the transmitting part of the optical path. The device of clause 46, wherein the two polarizing prisms are at least substantially centered with respect to each other and / or with respect to the optical axis, are at least substantially equally shaped, are arranged at least substantially mirror symmetric with respect to the optical axis and / or a plane at least substantially perpendicular to the optical axis, comprise a respective base surface which are parallel to each other and / or are facing away from each other, and / or wherein, the optic axes of the two polarizing prisms are parallel to each other. The device of any of clauses 38 to 47, wherein the respective polarizing prism comprises a birefringent material, typically a uniaxial material such as calcite, and / or wherein the respective polarizing prism comprises a crystal comprising optic axis which is angledwith respect to the optical axis at a position of the respective polarizing prism at the position of the respective polarizing prism. The device of any of clauses 38 to 48, wherein the beam profile redistributor comprises a Wollaston prism arranged in the optical path, in particular in the transmitting part of the optical path. The device of any of clauses 38 to 48, wherein the beam profile redistributor comprises two Wollaston prisms arranged in the optical path, in particular in the transmitting part of the optical path. The device of clause 50, wherein the two Wollaston prisms are arranged one after the other in the optical path, next to each other and / or with parallel corresponding optic axes of a crystal of the two Wollaston prisms. The device of any of clauses 38 or 44, wherein the beam profile redistributor comprises a regular prism arranged downstream the polarizing prism in the optical path, the regular prism and the polarizing prism typically being arranged coaxially, the regular prism typically comprising differently orientated refractive surfaces. The device of any of clauses 38 to 52, wherein the at least one output light beam comprises, in the near field and in a bounding box for the at least one output light beam at least substantially the same boundary compared to the at least one further output light beam. The device of any of clauses 38 to 54, wherein the device and / or an output light power of the at least one output light beam fulfills an eye safety requirement when the device is operated in a normal mode, in which the light source is operated at rated power, in particular in the near field outside a housing of the device and / or after the at least one output light beam left the aperture. The device of any of clauses 38 to 54, wherein the beam profile redistributor is arranged in the optical path and configured such that the far field begins outside the device, inparticular at a distance from the beam profile redistributor and / or the optical outlet of the device of at least 10 m or even 20 m. The device of any of clauses 38 to 55, wherein the given measuring aperture is defined by a safety standard, in particular a Class 1 laser standard, wherein the device meets the safety standard, wherein the given measuring aperture comprises an at least substantially circular or elliptical shape or an at least substantially square / rectangular shape, in particular a circular shape of about 5 mm to about 15 mm diameter, more typically of about 6 mm to about 9 mm diameter, even more typically of about 7 mm diameter, or a square shape of about 5 mm to about 11 mm base length, more typically of about 5 mm to about 9 mm base length, even more typically of about 7 mm base length, and / or wherein an area of the given measuring aperture is in a range from about 9 mm2to about 121 mm2, more typically in a range from about 25 mm2to about 81 mm2, and even more typically in a range from about 35 mm2to about 50 mm2, for example about 38 mm2or about 49 mm2. The device of any of clauses 38 to 56, wherein the beam profile redistributor comprises, in a cross-section parallel to the optical path pairs of refractive surfaces, each pair comprising two refractive surfaces which are adjacent to each other. The device of any of clauses 38 to 57, wherein the beam profile redistributor is configured to change an order of light rays in the at least one output light beam compared to the at least one further output light beam, when the beam profile redistributor is not present and / or is replaced by the beam expander. The device of clause 58, wherein the beam profile redistributor is configured to change the order of light rays such that a light ray of the input light beam, which is nearer an edge of the input light beam than a further light ray of the input light beam is redirected to a corresponding light ray or a corresponding light ray pair with different polarization of the at least one output light beam which is nearer a center line of the at least one output light beam and / or the optical axis compared to a redirected further light ray or light ray pair with different polarization of the at least one output light beam which corresponds to the further light ray.List of reference signs a angular span of light beam a, p angle between adjacent refractive surfaces dz, dzl, Axapdistance x,y,z Cartesian coordinatesA..K light raysAP (virtual) aperture (opening)FF far fieldMl, M2, M3 mirrorNF near fieldO optical axis / central rayP beam powerPD (light) detector101, 101’, 201, 301, 401, 501 light source / laser105, 205, 325, 405, 445, 505, 525 collimator110, 210, 302, 410, 510 input light beam / first light beam / light beam to be converted111, 113, 115, 211, 411 (minimum) bounding box of output light beam114, 116, 512, 514, 516 outer boundary of light beam120, 220, 320, 420, 520 beam profile redistributor124 (radial / symmetry) plane130, 230, 330, 430, 530 output light beam / second light beam / converted light beam210S, 310S light beam boundary240, 540 deflected output light beam / scanning light beam150 device housing151 device (emitting / transmitting) aperture / optical outlet200, 200’, 200”, 300, 400, 500, 500’ (optical) device for emitting a collimated lightbeam / laser emitter (VCEL) / LIDAR (system)220, 221, 222, 220’, 320, 420, 520, 520’ beam profile redistributor

Claims

WHAT IS CLAIMED IS / CLAIMS:

1. A device (100L, 100, 100’, 200, 200’, 200”, 200’”, 200a, 200a’, 200a”, 200a’”, 200b, 300, 400, 400a, 500, 500a, 500a’, 600, 1000, 2000, 2000’, 3000, 4000) comprising:- an optical path (O, OT, OR); and- a beam profile redistributor (120, 220, 220X, 221, 222, 220’, 320, 420, 520, 520’, 620, 1020, 2020, 3020, 4020) arranged in the optical path (O) to receive an input light beam (110, 210, 302, 410, 510, 610, 1010, 2010, 3010, 4010), and configured to convert the received input light beam so that at least one output light beam (130, 230, 312, 330, 430, 530, 630, 1030, 2030, 3030, 4030) of the device comprises: o in a near field (NF) and / or at the beam profile redistributor (120, 220, 320, 420, 520, 620, 1020, 2020, 3020, 4020), a redistributed beam intensity profile compared to at least one further output light beam when the beam profile redistributor (120, 220, 320, 420, 520, 620, 1020, 2020, 3020, 4020) is not present and / or is replaced by a beam expander (1055) configured to expand the received input light beam (110, 210, 302, 410) as the beam profile redistributor (120, 220, 320, 420, 520, 620, 1020, 2020, 3020, 4020); o within a given measuring aperture (AP) at a position (zap) along the optical path in the near field (NF), a lower output light power compared to the at least one further output light beam when the beam profile redistributor (120, 220, 320, 420, 520, 620, 1020, 2020, 3020, 4020) is not present and / or is replaced by the beam expander (1055); and o in a far field (FF), at least substantially the same beam intensity profile compared to the at least one further output light beam (110, 210, 302, 410, 610) when the beam profile redistributor (120, 220, 320, 420, 520, 620, 1020, 2020, 3020, 4020) is not present and / or is replaced by the beam expander (1055).

2. The device (200a, 200a’, 200a”, 200a’”, 200b, 300, 400a, 500a, 500a’) of claim 1, wherein the beam profile redistributor (220, 220X, 221, 222, 220’, 320, 420, 520, 520’) comprises two, non-co-planar reflective surfaces (S2, S3) of at least substantially uniform reflectivity for the input light beam (210, 310, 410, 510), and wherein the beam profileredistributor (220, 220X, 320, 420, 520) is configured to convert the received input light beam so that the at least one output light beam (230, 330, 430, 530) of the device comprises: o in the near field (NF) and / or at the beam profile redistributor, a redistributed beam intensity profile compared to at least one further output light beam when the beam profile redistributor is not present; o within the given measuring aperture (AP), a lower output light power compared to the at least one further output light beam when the beam profile redistributor is not present; and o in the far field (FF), at least substantially the same beam intensity profile compared to the at least one further output light beam when the beam profile redistributor is not present.

3. The device (200a, 200a’, 200a”, 200a’”, 200b, 300, 400a, 500a, 500a’) of claim 2, wherein the two non-co-planar reflective surfaces (S2, S3) are at least substantially parallel, and / or wherein the two non-co-planar reflective surfaces (S2, S3) are spaced apart from each other, and / or wherein each of the two non-co-planar reflective surfaces (S2, S3) is at least substantially planar, and / or wherein each of the two non-co-planar reflective surfaces (S2, S3) are angled with respect to the input light beam (210, 310, 410, 510), preferably by an angle of at most about 45°.

4. The device (200a, 200a’, 200a”, 200a’”, 200b, 300, 400a, 500a, 500a’) of claim 2 or 3, wherein a transmittance of the beam profile redistributor (220, 221, 222, 220’, 320, 420, 520, 520’) at a wave length of a light wave of the input light beam (210, 310, 410) is at least about 0.8, more preferably at least about 0.9, even more preferably at least about 0.95, and / or wherein the respective reflectivity of the two reflective surfaces (S2, S3) varies by at most by 5%, preferably by at most by 2% at and / or along the respective reflective surfaces (S2, S3), and / or wherein at least a respective averaged reflectivity of the two reflective surfaces (S2, S3) at least substantially matches.

5. The device (100L, 100, 100’, 200, 200’, 200”, 200’”, 200a, 200a’, 200a”, 200a’”, 200b, 300, 400, 400a, 500, 500a, 500a’, 600, 1000, 2000, 2000’, 3000, 4000) of any of claims 1 to 4, wherein the beam profile redistributor (220, 221, 222, 220’, 320, 420,520, 520’) is a one-axis or a two-axis beam profile redistributor and / or is configured to at least one of redistribute the beam intensity profile in NF with respect to at least one axis, flip at least one portion of the received input light beam in NF with respect to at least one axis, split the received input light beam into at least to at least two, typically spaced apart partial output light beams in NF, and change the order of at least two partial output light beams (230 A, 23 OB) compared to at least two partial input beams (A, B) of the input light beam, and / or wherein the beam profile redistributor (220, 221, 222, 220’, 320, 420, 520, 520’) is arranged in at least one of a transmitting part (OT) of the optical path (O, OT, OR) for emitting the at least one output light beam (230, 330, 430, 530) or at least one light beam derived from the at least one output light beam, and a receiving part (OR) of the optical path (O, OT, OR) configured to transmit a portion of at least one back-scattered light beam (RLB, RLA) received from the far field (FF).

6. The device (500a, 500a’) of any of claims 2 to 5, wherein the reflectivity of the two reflective surfaces (S2, S3) is polarization-dependent, preferably each of the two reflective surfaces (S2, S3) being configured to at least substantially reflect light waves of a first linear polarization and / or being at least substantially non-reflective and / or transparent for light waves of a second linear polarization different to the first linear polarization, preferably the reflectivity of the two reflective surfaces (S2, S3) being at least about 0.98, more preferably at least about 0.99 at the first polarization and a wave length of a light wave of the input light beam (510, 510’), preferably the reflectivity of the two reflective surfaces (S2, S3) being at most about 0.02, more preferably at most about 0.01 at the second polarization and for the wave length of the light wave of the input light beam (510, 510’).

7. The device (200a, 200a’, 200a”, 200a”’, 200b, 300, 400a) of any of claims 2 to 5, wherein the reflectivity of the two reflective surfaces (S2, S3) is at least substantially polarization-independent, preferably the reflectivity of the two reflective surfaces (S2, S3) at least substantially matching and / or being at least about 0.98, more typically 0.99 at a wave length of a light wave of the input light beam (210, 310, 410), and / or wherein the reflectivity is obtained by total internal reflection or by a mirror coating.

8. The device (200a, 200a’, 200a”, 200a’”, 200b, 300, 400a, 500a, 500a’) of any of the claims 1 to 7, wherein the beam profile redistributor (220, 221, 222, 220’, 320, 420, 520,520’) is configured to convert the received input light beam (210, 310, 410, 510) into at least two partial output light beams (230 A, 230B, 230a, 230b, 230c, 23 Od), which are spaced apart from each other and / or do at not overlap in the near field (NF), and / or wherein the beam profile redistributor (220, 221, 222, 220’, 320, 420, 520, 520’) is configured to redistribute the beam intensity profile by reflecting either one of the two partial input beams once at each of the two reflecting surfaces or each of the two partial input beams of the input light beam once at a respective one of the two reflecting surfaces.

9. The device (200a, 200a’, 200a”, 200a’”, 200b, 300, 400a, 500a, 500a’) of any of the claims 2 to 8, wherein, in a projection onto a radial plane perpendicular to a beam propagation direction of the input light beam (210, 310, 410, 510), an area of at least one of the two reflective surfaces (S2, S3) is at least about 0.5 times a beam width of the input light beam (210, 310, 410, 510), e.g. about 0.5 times the beam width of the input light beam (210, 310, 410, 510).

10. The device (200a, 200a’, 200a”, 200a’”, 200b, 300, 400a, 500a, 500a’) of any of the claims 3 to 9, wherein a first reflective surface (S2) of the two reflective surfaces (S2, S3) is configured to only reflect a first portion (A, A’) of the input light beam (210, 310, 410, 510).

11. The device (200a, 200a’, 200a”, 200a’”, 200b, 300, 400a, 500a, 500a’) of any of the claims 3 to 10, wherein the beam profile redistributor (220, 221, 222, 220’, 320, 420, 520, 520’) is a one-piece beam profile redistributor (220, 221, 222, 220’, 320, 420, 520, 520’), and / or wherein the beam profile redistributor (220, 221, 222, 220’, 320, 420, 520, 520’) is implemented as a rigid body, and / or wherein the beam profile redistributor (220, 221, 222, 220’, 320, 420, 520, 520’) is the beam profile redistributor according to any of claims 31 to 37, and / or wherein the beam profile redistributor (220, 221, 222, 220’, 320, 420, 520, 520’) comprises at least one of, preferably both of o a first transmitting surface (Si) arranged in the optical path (O, OT, OR) for receiving at least a portion of the input light beam (210, 310, 410, 510), preferably a transmittance of the first transmitting surface (Si) at a wave length of a light wave of the input light beam (210, 310, 410) being at least about 0.98, more preferably at least about 0.99, ando a second transmitting surface (S4) arranged in the optical path (O, OT, OR) for emitting at least a portion of the at least one output light beam (230, 330, 430, 530), preferably a transmittance of the second transmitting surface (S4) at a wave length of a light wave of the input light beam (210, 310, 410) being at least about 0.98, more preferably at least about 0.99, the transmitting surfaces (SbS4) and the reflective surfaces (S2, S3) preferably being arranged in an alternating order.

12. The device (200a, 200a’, 200a”, 200a’”) of claims 10 and 11, wherein, in a projection onto a radial plane perpendicular to a beam propagation direction of the input light beam (210, 310, 410, 510), a size of the first transmitting surface (Si) is at least 1.5 times a beam width of the input light beam (210, 310, 410, 510), and / or wherein none of the transmitting surfaces and reflective surfaces are coplanar, and / or wherein the first reflective surface (S2) is arranged adjacent and / or between the two transmitting surfaces (Si, S4), and / or wherein the second reflective surface (S3) is arranged adjacent and / or between the two transmitting surfaces (SbS4), and / or wherein an angle (0) between the first transmitting surface (Si) and the first reflective surface (S2) is about 45°, and / or wherein an angle between the second transmitting surface (S4) and the first reflective surface (S2) is about 135°.

13. The device (200a, 200a’, 200a”, 200a’”, 200b, 300, 400a, 500a, 500a’) of any of the claims 11 and 12, wherein the two transmitting surfaces (SbS4) are angled with respect to the input light beam (210, 310, 410, 510), preferably at an angle of about 90° or about 45°, and / or wherein the second transmitting surface (S4) is arranged in the optical path (O, OT, OR) for emitting at least one of a first portion (A’”) of the at least one output light beam (230, 330) and a second portion (B’) of the at least one output light beam (230, 330).

14. The device (200a, 200a’, 200a”, 200a”’) of claim 13, wherein the two transmitting surfaces (SbS4) are angled with respect to the input light beam (210, 310) by an angle of about 90°.

15. The device (200a, 200a’, 200a”, 200a”’) of claim 10 and any of the claims 11 to 14, wherein the first reflective surface (S2) is configured to reflect the transmitted firstportion (A’) of the input light beam towards a second reflective surface (S3) of the two reflective surfaces (S2, S3).

16. The device (200s, 200s’, 200s”, 200s’”) of any of the claims 11 to 15, wherein a size of the first transmitting surface (Si) is larger than a beam size of the input light beam (210) and / or at least substantially corresponds to a size of the second transmitting surface (S4), and / or wherein a length (L) of the beam profile redistributor (220, 220’) in an axial direction of the input light beam (210) is at least a width (W) of the beam profile redistributor (220, 220’) in a radial direction of the input light beam (210) divided by square root of two, and / or wherein the input light beam and the at least one output light beam are substantially parallel, preferably the width (W) of the beam profile redistributor (220, 220’) being less than 7 cm, less than 5 cm or even less than 3 cm.

17. The device (300, 400a, 500a, 500a’) of claims 10 and 11, wherein a second reflective surface (S3) of the two reflective surfaces (S2, S3) is configured to reflect a second portion (B, B’) of the input light beam, after being transmitted through the first transmitting surface (Si), towards the second transmitting surface (S4), and / or wherein the beam profile redistributor (320, 420, 520, 520’) is configured to fold or shift the optical path, and / or wherein the input light beam and the at least one output light beam are angled with respect to each other, preferably by an angle of about 90°, and / or wherein the first reflective surface (S2) is arranged adjacent and / or between the two transmitting surfaces (Si, S4).

18. The device (300, 500a, 500a’) of claim 17, wherein the two transmitting surfaces (SbS4) and the first reflective surface (S2) are coplanar, and / or wherein a size of the first transmitting surface (Si) is smaller than a beam size of the input light beam, and / or wherein the two transmitting surfaces (SbS4) are angled with respect to the input light beam (210, 310), preferably at an angle of about 45°.

19. The device (400a, 500a, 500a’) of claim 17, wherein none of the transmitting surfaces and reflective surfaces are coplanar, wherein at least one of, typically both of the first transmitting surfaces (Si) and the second transmitting surfaces (S3) is angled with respect to the input light beam (410, 510), preferably at an angle of about 90°, and / or wherein an angle (9) between the first transmitting surface (Si) and the first reflective surface (S2) isabout 135°, and / or wherein an angle (9) between the second transmitting surface (S4) and the first reflective surface (S2) is about 135°.

20. The device (200a, 200a’, 200a”, 200a’”, 300, 400a, 500a, 500a’) of any of claims 11 to 19, wherein the first and second transmitting surfaces (S2, S3) are at least substantially flat, and / or wherein the first and second transmitting surfaces (S2, S3) are at least substantially parallel, and / or wherein the two transmitting surfaces (Si, S4) are at least substantially parallel to one another and / or angled with respect to at least one of the two reflective surfaces (S2, S3) , and / or wherein the two transmitting surfaces (SbS4) comprises an anti -reflective coating, and / or wherein the two reflective surfaces (S2, S3) and the two transmitting surfaces (SbS4) are arranged at and / or around a light transmitting volume (Vt) of the beam profile redistributor (220, 220’, 320, 420, 520).

21. The device (200a, 200a’, 200a”, 200a”’, 300, 400a, 500a, 500a’) of claim 20, wherein the light transmitting volume (Vt) comprises a 180° degree rotational symmetry and / or is shaped as a convex polyhedron and / or formed by an at least substantially transmitting main body (220A, 320A, 420A, 520A) of the beam profile redistributor (220, 220’, 320, 420, 520).

22. The device (200a, 200a’, 200a”, 200a”’, 300, 400a, 500a, 500a’) of claim 21, wherein the at least one of: the convex polyhedron and the main body is a prism, in particular a hexagonal prism, a rhombic prism or an extended and / or elongated rhombic prism, preferably none of the transmitting surfaces (SbS4) and the reflective surfaces (S2, S3) are provided at a rhombic side of the respective prism, the first transmitting surface (Si), when provided by the hexagonal prism, the rhombic prism or the extended and / or elongated rhombic prism, typically being arranged at least substantially orthogonal to the received input light beam, otherwise the first transmitting surface (Si) and the received input light beam typically forming an acute angle, in particular an angle of about 45°.

23. The device (200a, 200a’, 200a”, 200a’”, 300, 400a, 500a, 500a’) of any of the claims 12 to 22, wherein the first transmitting surface (Si) is arranged in the optical path for transmitting at least one of the first portion (A, A’) of the input light beam (210, 310, 410, 510) and a second portion (B, B’) of the input light beam (210, 310, 410, 510).

24. The device (200a, 200a’, 200a”, 200a’”, 300, 400a) of claim 10 and any of the claims 11 to 23, wherein the two reflective surfaces (S2, S3) and the two transmitting surfaces (Si, S4) are outer surfaces of the beam profile redistributor (220, 220’, 320, 420).

25. The device (500s, 500s’) of any of the claims 11 to 24, wherein the two reflective surfaces (S2, S3) are inner surfaces of the beam profile redistributor (520), and wherein the two transmitting surfaces (SbS4) are outer surfaces of the beam profile redistributor (220, 220’, 320, 420).

26. The device (500a, 500a’) of claim 25, wherein the beam profile redistributor (520) comprises a main prism (520A) providing the two transmitting surfaces (SbS4) and two side prisms (520B, 520C) each of which being arranged at the main prism (520A) for providing the two reflective surfaces (S2, S3) at the respective interface between the main prism (520A) the two side prisms (520B, 520C), preferably the two side prisms (520B, 520C) and the main prism (520A) forming a cuboid, the two side prisms (520B, 520C) being glued with the main prism (520A), being at substantially shaped identical and / or comprising at least substantially the same refractive index, for example at substantially the same refractive index as the main prism (520A).

27. The device (200b) of any of claims 2 - 5 and 6, wherein the beam profile redistributor (220X) is configured to redistribute beam intensity profile in the near field with respect to two typically orthogonal axes, and / or wherein the beam profile redistributor (220X) comprises and / or is provided by a rhombic prism or an extended and / or elongated rhombic prism, in particular by six surfaces (SbS2, S3, S4, S5, S6) of the respective prism, more particular by four reflective surfaces (S2, S3, S5, S6) formed by and / or at inner surfaces of the respective prism, two of the four reflective surfaces (S2, S3, S5, S6) corresponding to base faces (S5, S6) of the respective prism, a first transmitting surface (Si) for receiving the input light beam (210) at an acute angle, and a second transmitting surface (S4) for emitting the at least one output light beam (230, 230a, 230b, 230c, 230d).

28. The device of any of the preceding claims, wherein the device comprises at least one of:- a further beam profile redistributor (220, 221, 222, 220’, 320, 420, 520, 520’) arranged in the optical path (O) downstream the beam profile redistributor (220, 221, 222, 220’, 320, 420, 520, 520’), and configured to redistribute, in near field(NF) and / or at the further beam profile redistributor, the beam profile with respect to a different axis compared to the beam profile redistributor (220, 221, 222, 220’, 320, 420, 520, 520’);- a light detector (PD) arranged in the optical path (O), preferably in the receiving part (OR) of the optical path (O, OT, OR), the light detector (PD) typically comprising a photodiode;- an aperture (151, SA, PA) arranged in the optical path (O), preferably the transmitting part (OT) of the optical path (O) extending at least from the beam profile redistributor (120, 220, 320, 420, 520, 620, 1020, 2020, 3020, 4020) at least to the aperture (151, SA) or even from the light source at least to the aperture (151, SA), the receiving part (OR) preferably extending from the aperture (151, SA) towards the light detector (PD), and / or the wherein the optical path (O) is folded;- a light source (LS, 201, 201’, 301, 401, 501, 501’) arranged in the optical path (O), preferably in the transmitting part (OT) of the optical path (O, OT, OR), in particular, a laser such as an edge-emitting laser or even an array of lasers; and- a collimator (205, 205’, 225, 325, 505, 525) arranged in the optical path (O),- a mirror (Ml, M2) arranged in the optical path (O), and / or wherein the device is configured to emit an at least substantially collimated light beam (230, 240, 330, 430, 530, 540) formed by the at least one output light beam or from the at least one output light beam.

29. The device of any of the preceding claims, wherein the given measuring aperture (AP) is defined by a safety standard, in particular a Class 1 laser standard, wherein the device meets the safety standard, wherein the given measuring aperture (AP) comprises an at least substantially circular or elliptical shape or an at least substantially square / rectangular shape, in particular a circular shape of about 5 mm to about 15 mm diameter, more typically of about 6 mm to about 9 mm diameter, even more typically of about 7 mm diameter, or a square shape of about 5 mm to about 11 mm base length, more typically of about 5 mm to about 9 mm base length, even more typically of about 7 mm base length, and / or wherein an area of the given measuring aperture (AP) is in a range from about 9 mm2to about 121 mm2, more typically in a range from about 25 mm2to about 81 mm2, and even more typically in a range from about 35 mm2to about 50 mm2,for example about 38 mm2or about 49 mm2, wherein the beam profile redistributor (220, 320, 420, 520) is arranged in the optical path (O) and configured such the redistributed beam intensity profile is at least substantially maintained up to a distance (dz, dzl) from the beam profile redistributor (120, 220, 320, 420) and / or an optical outlet of the device of at least 1 m, more typically at least 3 m, and even more typically at least 5 m, and / or that the far field (FF) begins outside the device, in particular at a distance from the beam profile redistributor (120, 220, 320, 420) and / or the optical outlet of the device of at least 10 m or even 20 m.

30. The device of any of the preceding claims, wherein the device is a scanning device, in particular a respective LIDAR device or a component thereof, the device typically comprising a scanner arranged in the optical path (O) to receive the at least one output light beam (230’, 430), in particular a rotating polygon scanner (245, 545), after optionally being collimated and / or being redirected towards the scanner, with an at least substantially maintained redistributed beam intensity profile.

31. A one-piece beam profile redistributor (220a, 220a’, 200a”, 200a’”, 221, 222) for converting an input light beam (210) into an output light beam (230) comprising two partial output light beams (230A, 230B), the beam profile redistributor comprising:- a light transmitting volume (Vt) or body (220A);- a first transmitting surface (Si) for transmitting the input light beam into the light transmitting volume (Vt) or body (220 A) as a first internal light beam (A’, B’);- a first reflective surface (S2) for reflecting an incident first portion (A’) of the first internal light beam (A’, B’) into a second internal light beam (A”);- a second reflective surface (S3) for reflecting the second internal light beam (A”); and- a second transmitting surface (S4) for receiving the reflected second internal light beam (A’”) and a second portion (B’) of the first internal light beam (A’, B’) from the light transmitting volume (Vt) or body (220A), and for transmitting the received reflected second internal light beam (A’”) and the second portion (B’) of the first internal light beam (A’, B’) to form the output light beam (230, A””, B”).

32. The one-piece beam profile redistributor (220a, 220a’, 200a”, 200a’”, 221, 222) of claim 31, wherein the beam profile redistributor (220, 221, 222, 220’) is configured to at least one of- change the order of the two partial output light beams (230 A, 230B) compared to two partial input beams (A, B) of the input light beam; and- redistribute the beam intensity profile, by reflecting one of the two partial input beams of the input light beam once at each of the two reflecting surfaces.

33. A one-piece beam profile redistributor (320, 420, 520) for converting an input light beam (310, 410, 510) into an output light beam (330, 430, 530) comprising two partial output light beams (330A, 330B, 430A, 430B, 530A, 530B), the beam profile redistributor comprising:- a light transmitting volume (Vt) or body (320A, 420A, 520A);- a first reflective surface (S2) for reflecting an incident first portion (A) of the input light beam (310, 410, 510) to form a first partial beam (330A, 430A, 530A) of the two partial output light beams (330 A, 330B);- a first transmitting surface (Si) for transmitting an incident second portion (B) of the input light beam into the light transmitting volume (Vt) or body (220A) as a first internal light beam (B’);- a second reflective surface (S3) for reflecting the first internal light beam (B’) to form a second internal light beam (B”); and- a second transmitting surface (S4) for receiving and transmitting the second internal light beam (B”) to form a second partial beam (330B, 430B, 530B) of the two partial output light beams.

34. The one-piece beam profile redistributor (320, 420, 520, 520’) of claim 33, wherein each of the two transmitting surfaces (SbS4) is coplanar with the first reflective surface (S2) or forms an angle of about 135° with the first reflective surface (S2).

35. The one-piece beam profile redistributor (320, 420, 520, 520’) of claim 33 or 34, wherein the beam profile redistributor (320, 420, 520, 520’) is configured to redistribute the beam intensity profile by reflecting each of two partial input beams of the input light beam once at a respective one of the two reflecting surfaces.

36. The one-piece beam profile redistributor (220a, 220a’, 200a”, 200a’”, 221, 222, 320, 420, 520, 520’) of any of claims 31 to 35, wherein the first and second reflective surfaces (S2, S3) are at least substantially parallel and / or at least substantially flat, wherein the first and second transmitting surfaces (S2, S3) are at least substantially parallel, at least substantially flat and / or angled with respect to the first and second reflective surfaces (S2, S3), and / or wherein the light transmitting volume or body is shaped as a convex polyhedron and / or comprises a 180° degree rotational symmetry.

37. A one-piece beam profile redistributor (220X) for converting an input light beam (210, 210a, 210b, 210c, 210d) into an output light beam (230) comprising four partial output light beams (230a, 230b, 230c, 230d), the beam profile redistributor comprising:- a light transmitting volume (Vt) or body (220A);- a first transmitting surface (Si) for transmitting the input light beam into the light transmitting volume (Vt) or body (220A) as an internal light beam (Xa, Xb, Xc, Xd);- a first reflective surface (S2);- a second reflective surface (S3), which is at least substantially parallel to the first reflective surface (S2);- a third reflective surface (S5), which is at least substantially orthogonal to the first reflective surface (S2);- a fourth reflective surface (S6), which is at least substantially parallel to the third reflective surface (S5); and- a second transmitting surface (S4), which is at least substantially parallel to the first transmitting surface (Si), for receiving internal light beams and transmitting the received internal light beams to form the output light beam (230), wherein the received internal light beams comprise:a portion (Xd) of the internal light beam received directly from the first transmitting surface (Si), a portion (Xc) of the internal light beam reflected at the first reflective surface (S2) to the second reflective surface (S3) and at the second reflective surface (S3) to second transmitting surface (S4), a portion (Xb) of the internal light beam reflected at the third reflective surface (S5) to the fourth reflective surface (S6) and at the fourth reflective surface (S6) to second transmitting surface (S4), and a portion (Xa) of the internal light beam split at the first reflective surface (S5) and the third reflective surface (S5) into two partial internal light beams that are recombined by reflection of the two partial internal light beams at the second reflective surface (S3) and the fourth reflective surface (S6), in a near field (NF) downstream the beam profile redistributor and / or at the beam profile redistributor, the four partial output light beams (230a, 230b, 230c, 23 Od) typically being spaced apart from each other, the light transmitting volume or body typically being a rhombic prism or an extended and / or elongated rhombic prism.

38. The device (100L, 100, 200, 200’, 400, 500, 600) of any of the claims 1 and 28, wherein the beam profile redistributor (120, 220, 320, 420, 520, 620, 1020, 2020, 3020, 4020) comprises at least one of: a polarizing prism (1027, 1028, 2027, 2028, 3027, 4027, 4027A, 4028, 4028A), a regular prism (121, 122, 421, 422, 3029), in particular a respective trigonal prism, an axicon (221, 222), and a lens, in particular an aspherical lens.

39. A LIDAR device (200a”, 1000, 2000, 2000’, 3000, 4000) comprising:- an optical path (O) comprising a transmitting part (OT) and a receiving part (OR);- a light detector (PD) arranged in the receiving part (OR) of the optical path (O), the light detector (PD) typically comprising a photodiode;- a light source (LS, 1001, 2001, 3001, 4001) arranged in the transmitting part (OT) of the optical path (O) ), in particular a laser such as an edge-emitting laser or even an array of lasers; and- a beam profile redistributor (1020, 2020, 3020, 4020) arranged downstream the light source (LS, 1001, 2001, 3001, 4001) in the transmitting part (OT) of the optical path (O), the beam profile redistributor comprising at least one of: a one-piece beam profile redistributor of any of the claims 31 to 37, and a polarizing prism (1027, 1028, 2027, 2028, 3027, 4027, 4027A, 4028, 4028 A).

40. The LIDAR device (1000, 2000, 2000’, 3000, 4000) of claim 39, wherein the beam profile redistributor (1020, 2020, 3020, 4020) is arranged in the transmitting part (OT) for generating at least one output light beam (130, 230, 312, 330, 430, 530, 630), receiving an input light beam (1010, 2010) from the light source (LS, 1001, 2001, 3001, 4001 ), and / or for converting the received input light beam (1010, 2010) into the at least one output light beam (1030, 2030).

41. The LIDAR device (200a”, 1000, 2000, 2000’, 3000, 4000) of claim 40, wherein the beam profile redistributor (1020, 2020, 3020, 4020) configured to convert the received input light beam (1010, 2010) so that the at least one output light beam (1030, 2030) of the LIDAR device comprises: o in a near field (NF) and / or at the beam profile redistributor (1020, 2020, 3020, 4020), a redistributed beam intensity profile compared to at least one further output light beam when the beam profile redistributor (1020, 2020, 3020, 4020) is replaced by a beam expander (1055) whose beam widening at least substantially corresponds to a beam widening of the beam profile redistributor (1020, 2020, 3020, 4020); o within a given measuring aperture (AP) at a position (zap) along the optical path in the near field (NF), a lower output light power compared to the at least one further output light beam when the beam profile redistributor (1020, 2020, 3020, 4020) is replaced by the beam expander (1055); and o in a far field (FF), at least substantially the same beam intensity profile compared to the at least one further output light beam when the beam profileredistributor (1020, 2020, 3020, 4020) is replaced by the beam expander (1055).

42. The device (1000, 2000, 2000’, 4000) of any of the claims 39 to 41, wherein, in the near field, the at least one output light beam (110, 210, 302, 410, 610, 1010, 2010) comprises a different polarization profile than the at least one further output light beam.

43. The device (1000, 2000, 2000’, 4000) of any of the claims 39 to 42, wherein the beam profile redistributor (1020, 2020, 4020) comprises two polarizing prisms (1027, 1028, 2027, 2028, 4027, 4027A, 4028, 4028 A) arranged in the optical path (O, O r), in particular in the transmitting part (OT) of the optical path (O).

44. The device (1000, 2000, 2000’, 4000) of claim 43, wherein the two polarizing prisms (1027, 1028, 2027, 2028, 4027, 4027A, 4028, 4028A) are at least substantially centered with respect to each other and / or with respect to the optical axis (O), are at least substantially equally shaped, are arranged at least substantially mirror symmetric with respect to the optical axis (O) and / or a plane (124) at least substantially perpendicular to the optical axis (O), comprise a respective base surface (2O27o, 2O28o) which are parallel to each other and / or are facing away from each other, and / or wherein, the optic axes (Oc) of the two polarizing prisms are parallel to each other.

45. The device (1000, 2000, 2000’, 3000, 4000) of any of claims 38 to 44, wherein the respective polarizing prism (1027, 1028, 2027, 2028, 3027, 4027, 4027A, 4028, 4028A) comprises a birefringent material, typically a uniaxial material such as calcite, and / or wherein the respective polarizing prism (1027, 1028, 2027, 2028, 3027, 4027, 4027A, 4028, 4028A) comprises a crystal comprising optic axis (Oc) which is angled with respect to the optical axis (O, OT) at a position of the respective polarizing prism (1027, 1028, 2027, 2028, 3027, 4027, 4027A, 4028, 4028A, in particular at least substantially perpendicular to the optical axis (O, OT) at the position of the respective polarizing prism (1027, 1028, 2027, 2028, 3027, 4027, 4027A, 4028, 4028A.

46. The device (1000, 4000) of any of the claims 38 to 45, wherein the beam profile redistributor (1020, 4020) comprises a Wollaston prism (1021, 4021, 4021A) arrangedin the optical path (O, OT), in particular in the transmitting part (OT) of the optical path (O).

47. The device (4000) of any claim 46, wherein the beam profile redistributor (4020) comprises two Wollaston prisms (4021, 4021A) arranged in the optical path (O, OT), in particular in the transmitting part (OT) of the optical path (O).

48. The device (4000) of claim 47, wherein the two Wollaston prisms (4021, 4021A) are arranged one after the other in the optical path (O, OT), next to each other and / or with parallel corresponding optic axes (Oc) of a crystal of the two Wollaston prisms (4021, 4021A).

49. The device (3000) of any of claims 38 to 48, wherein the beam profile redistributor (3020) comprises a regular prism (3029) arranged downstream the polarizing prism (3027) in the optical path (O, OT), the regular prism (3029) and the polarizing prism (3027) typically being arranged coaxially, the regular prism (3029) typically comprising differently orientated refractive surfaces (2029b20292).

50. The device (100L, 100, 200, 200’, 400, 500, 600, 1000, 2000, 2000’, 3000, 4000) of any of the preceding claims, wherein the at least one output light beam (130, 230, 312, 330, 430, 530, 630) comprises, in the near field (NF) and in a bounding box (111, 113, 511, 513) for the at least one output light beam (130, 230, 312, 330, 430, 530, 630) at least substantially the same boundary (114, 512, 514, 1014) compared to the at least one further output light beam.

51. The device (100L, 100, 100’, 200, 200’, 200”, 200’”, 200a, 200a’, 200a”, 200a’”, 200b, 300, 400, 400a, 500, 500a, 500a’, 600, 1000, 2000, 2000’, 3000, 4000) of any of the preceding claims, wherein the device and / or an output light power of the at least one output light beam (130, 230, 312, 330, 430, 530, 630) fulfills an eye safety requirement when the device is operated in a normal mode, in which the light source is operated at rated power, in particular in the near field (NF) outside a housing (150, 250) of the deviceand / or after the at least one output light beam (130, 230, 312, 330, 430, 530, 630) left the aperture.

52. The device (100L, 100, 100’, 200, 200’, 200”, 200’”, 200a, 200a’, 200a”, 200a’”, 200b, 300, 400, 400a, 500, 500a, 500a’, 600, 1000, 2000, 2000’, 3000, 4000) of any of the preceding claims, wherein the beam profile redistributor (120, 220, 320, 420) is arranged in the optical path (O) and configured such that the far field (FF) begins outside the device, in particular at a distance from the beam profile redistributor (120, 220, 320, 420) and / or the optical outlet of the device of at least 10 m or even 20 m.

53. The device (100L, 100, 200, 200’, 400, 500, 600, 1000, 2000, 2000’, 3000, 4000) of any of the claims 1, and 28-52, wherein the beam profile redistributor comprises, in a crosssection parallel to the optical path (O) pairs of refractive surfaces ({{ 120b1202}, { 1203, 1204}}, {{220b2202}, {2203, 2204}}, {{420b4202}, {4203, 4204}}, {{620b6202}, {6203, 6204}},{{2027b20272}, {2028b20282}, {2029lb, 20292b}}), each pair comprising two refractive surfaces ({ 120b1202}, { 1203, 1204}, {220b2202}, {2203, 2204}, {420b4202}, {4203, 4204}, {620b6202}, {6203, 6204}, {2027b20272}, {2028b20282}) which are adjacent to each other.

54. The device (100L, 100, 200, 200’, 400, 500, 600, 900, 1000, 2000, 2000’, 3000, 4000) of any of the claims 1, and 28-53, wherein the beam profile redistributor (120, 220, 420, 920, 1020, 2020, 3020, 4020) is configured to change an order of light rays (A-K) in the at least one output light beam (130, 230, 312, 330, 430, 530, 630) compared to the at least one further output light beam, when the beam profile redistributor (120, 220, 420) is not present and / or is replaced by the beam expander (1055).

55. The device (1000, 2000, 2000’, 3000, 4000) of claim 54, wherein the beam profile redistributor (1020, 2020, 3020, 4020) is configured to change the order of light rays (A- K) such that a light ray (A) of the input light beam, which is nearer an edge of the input light beam than a further light ray (B) of the input light beam is redirected to a corresponding light ray (A) or a corresponding light ray pair (A’, A”) with different polarization of the at least one output light beam (130, 230, 312, 330, 430, 2030, 3030) which is nearer a center line of the at least one output light beam (130, 230, 312, 330, 430, 2030, 3030) and / or the optical axis (O) compared to a redirected further light ray(B) or light ray pair (B’, B”) with different polarization of the at least one output light beam (130, 230, 312, 330, 430, 2030, 3030) which corresponds to the further light ray (B).

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