The present invention is directed to an active optical sensor system comprising a light source, which is configured to generate light at a light emitting surface, and an optical detector, which is sensitive for the light.

Active optical sensor systems, such as lidar systems, can be mounted on motor vehicles to implement a wide range of functions of advanced driver assistance systems, ADAS, or other electronic vehicle guidance systems for autonomous or partially autonomous driving. These functions include, for example, distance measurements, distance control algorithms, lane-keeping assistance, object tracking functions, trajectory planning and so on.

A particular challenge in active optical sensor systems is the thermal management, for example of the light source. Since the light source may be implemented based on a semiconductor, for example as a light emitting diode or a laser diode, the junction temperature of the semiconductor must be limited to an acceptable maximum temperature. For automotive applications, the functionality of the active optical sensor system must be ensured at relatively high ambient temperatures, for example up to 85 °C. Therefore, it is important to dissipate the heat generated by the light source in order to keep the junction temperature, or in general the temperature of the light source, low enough. The thermal management of the active optical sensor system does therefore effectively limit the achievable optical output power of the active optical sensor system, since in general for increasing optical output power, also the electrical input power and the generated heat are increased. The optical output power, however, effectively limits the maximum detection range of the active optical sensor system. In consequence, an improvement in the thermal management of the active optical sensor system increases the maximum optical output power achievable by the active optical sensor system and therefore its maximum detection distance.

It is an objective of the present invention to provide an active optical sensor system with an improved thermal management to achieve an increased possible optical output power and/or an increased maximum detection distance of the active optical sensor system.

This objective is achieved by the subject matter of the independent claims. Further implementations and preferred embodiments are subject matter of the dependent claims. The invention is based on the idea to place a light permeable heat dissipation component in the optical emission path of the sensor system, which is in heat-conducting contact with a light emitting surface of the light source of the active optical sensor system.

According to an aspect of the invention, an active optical sensor system is provided. The sensor system comprises a light source, which is configured to generate light at a lightemitting surface of the light source. The sensor system comprises an optical detector, which is sensitive for the light of the light source. The sensor system comprises a first heat dissipation component with a first surface, which is in heat-conducting contact with the light-emitting surface of the light source. The first heat dissipation component is arranged in an optical emission path of the sensor system. The first heat dissipation component comprises a material or consists of the material, which is permeable to the light of the light source.

Here and in the following, “light” may be understood such that it comprises electromagnetic waves in the visible range, in the infrared range and/or in the ultraviolet range. Accordingly, the expression “optical” may be understood to be related to light according to this meaning.

By definition, an active optical sensor system comprises a light source for emitting light or light pulses, respectively. For example, the light source may be implemented as a light emitting diode or a laser, in particular as an infrared laser. Furthermore, an active optical sensor system comprises, by definition, at least one optical detector to detect reflected parts of the emitted light. In particular, the active optical sensor system, for example the at least one optical detector, is configured to generate one or more sensor signals based on the detected fractions of the light and process and/or output the sensor signals. For lidar systems, the light source contains one or more lasers, in particular semiconductor lasers, for example laser diodes.

A known design of lidar systems are so-called laser scanners, in which a laser beam is deflected by means of a light deflection arrangement so that different deflection angles of the laser beam may be realized. The light deflection arrangement may, for example, contain one or more rotatably mounted mirrors. Alternatively, the light deflection arrangement may include a mirror element with a tiltable and/or pivotable surface. The mirror element may, for example, be configured as a micro-electro-mechanical system, MEMS. In the environment, the emitted laser beams can be partially reflected, and the reflected portions may in turn hit the laser scanner, in particular the light deflection arrangement, which may direct them to a detector unit of the laser scanner comprising the at least one optical detector. In particular, each optical detector of the detector unit generates an associated detector signal based on the portions detected by the respective optical detector. Based on the spatial arrangement of the respective optical detector, together with the current position of the light deflection arrangement, in particular its rotational position or its tilting and/or pivoting position, it is thus possible conclude the direction of incidence of the detected reflected components of light. A processing unit or an evaluation unit of the laser scanner may, for example, perform a time-of-flight measurement to determine a radial distance of the reflecting object. Alternatively or additionally, a method, according to which a phase difference between the emitted and detected light is evaluated, may be used to determine the distance.

Other designs of lidar systems are flash lidar systems. These are non-scanning systems, which do not require said light deflection arrangement. Therein, the laser light generated by the light source is diffused by an optical element to irradiate over a wide angle in a single flash.

The light source is configured to generate the light according to an emission wavelength spectrum. The emission wavelength spectrum may for example be essentially given by a single wavelength in case the light source is implemented as a laser light source. In this case, the emission wavelength spectrum may be given by a peak at the respective single wavelength with a certain peak width. That the optical detector is sensitive for the light may be understood such that the optical detector is sensitive for light of the emission wavelength spectrum or a part of the emission wavelength spectrum. Analogously, the material is permeable for light according to the emission wavelength spectrum or a part of the emission wavelength spectrum.

The material being permeable to the light may be understood such that at least a part of the light generated by the light-emitting surface may pass through the material or the heat dissipation component, respectively. In particular, the material may be considered transparent for the light according to the emission wavelength spectrum, which means for example that on a macroscopic scale, Snell's law of refraction is fulfilled. Obviously, however, the permeability of the material for the light does not mean that the transmission coefficient for the light is necessarily equal to 100 %. Rather, the transmission coefficient depends on the emission wavelength spectrum and the exact choice of the material composition as well as the thickness of the material in the optical emission path and, if applicable, on further details of the heat dissipation component, for example whether it contains an anti-reflective coating et cetera.

The transmission coefficient may for example be understood as an inverse ratio of a light intensity of light entering the material or the first heat dissipation component, respectively, to the intensity of the light leaving the material or the first heat dissipation component, respectively, on an opposite side.

For the emission wavelength spectrum, the transmission coefficient of the material or of the first heat dissipation component may for example be 50 % or larger, for example 80 % or larger, in particular 85 % or larger, preferably 90 % or larger.

Such transmission coefficients may achieved, for example for infrared light, by materials such as sapphire, in particular a synthetic sapphire, AI2O3, calcium fluoride, CaF ₂ , or magnesium fluoride, MgF ₂ .

For establishing the heat-conducting contact between the first surface of the first heat dissipation component and the light-emitting surface of the light source, the first surface and the light-emitting surface may be in direct mechanical contact with each other. For example, the first heat dissipation component and the light source may be pressed together with a force generated by a mechanical clamping arrangement. However, in other implementations, a thermal paste or an adhesive or glue may be used to fasten the first heat dissipation component to the light source. The glue or paste are then, in particular, permeable for the light of the light source as well or, in other words, transparent for the light of the light source. For example, adhesive materials as commonly used for assembling fiber-optic devices, which may for example be based on epoxy resins, may be used as an adhesive for connecting the heat dissipation component to the light source. The first surface of the heat dissipation component and the light-emitting surface of the light source may for example be planar or approximately planar. Irregularities or surface structures may also be levelled out by the thermal paste or adhesive or an additional light-permeable filling material in respective embodiments.

In the active optical sensor system according to the invention, the light generated by the light source at the light-emitting surface passes through the first heat dissipation component at least partially and is emitted into an environment of the active optical sensor system. The emitted light may be partially reflected by an object in the environment and reflected portions of the light may again enter the active optical sensor system and reach the optical detector. Depending on the detected light and the sensor or detector signal generated based on the detected light, the distance of the reflecting object may be determined, for example by means of a time-of-flight measurement or by a phase modulation technique for indirect time-of-flight measurement et cetera.

Since the first heat dissipation component is in heat-conducting contact with the lightemitting surface, it transports heat generated by the light source away from the light source and consequently reduces the temperature of the light source, for example a junction temperature of the light source in case of a semiconductor based light source, compared to an arrangement without the first heat dissipation component. Depending on the actual design of the active optical sensor system, for example its housing, the heat may be transported away from the light source to another heat dissipation component or housing or heat sink of the active optical sensor system, which is not arranged in the optical emission path. Consequently, since these further components do not have to be permeable to the light, conventional materials and techniques for heat dissipation may be used, for example metallic structures or using a metallic portion of the housing as a heat sink et cetera.

Since the material of the first heat dissipation component is permeable to the light, the first heat dissipation component does not significantly attenuate the light of the light source or attenuates the light generated by the light source only to an acceptable degree. On the other hand, since the first heat dissipation component reduces the temperature of the light source, the electrical power for driving the light source may be increased without increasing the temperature of the light source. Consequently, the achievable optical output power of the active optical sensor system is increased, which also increases the achievable maximum detection distance of the active optical sensor system. On the other hand, leaving the optical output power unchanged, the invention allows for a reduced temperature of the light source, which increases the lifetime of the light source.

Preferably, the active optical sensor system is a lidar system, wherein the light source is a laser light source, in particular a laser diode. The lidar system may be a laser scanner lidar system or a flash lidar system, for example.

Preferably, the light generated by the light source is infrared light or, in other words, the emission wavelength spectrum lies in an infrared spectral range. For example, the emission wavelength spectrum, in particular the laser wavelength in case of a laser light source, lies within the range [800 nm, 3000 nm]. In case of a laser light source, for example typical emission wavelengths such as 905 nm or 1550 nm may be used.

The optical detector may for example comprise a photo diode, in particular an avalanche photo diode, APD. It is noted that, apart from the light source and the optical detector, in some implementations, the active optical sensor system may also comprise one or more further light sources and/or one or more further optical detectors.

In addition, in some implementations, one or more optical components such as lenses, collimators, diffusors et cetera, may be arranged in the optical emission path of the active optical sensor system. The first heat dissipation component is then for example arranged between the optical components and the light source. Analogously, one or more optical components, such as lenses, collimators, et cetera, may also be arranged in an optical detection path of the active optical sensor system. Depending on the implementation of the active optical sensor system, in particular in case the active optical sensor system is designed as a laser scanner lidar system, it may comprise a light-deflection arrangement, for example one or more mirrors for deflecting the light into different directions to be emitted in the environment and/or for deflecting the reflected portions of the light towards the optical detector.

The thermal conductivity of light-permeable materials may be lower than for typical metallic materials like aluminum or copper. However, it has been found that the achievable thermal conductivities of light-permeable materials may already improve the thermal management significantly. For example, the thermal conductivity of the material may be in the range [20 Wm ¹ K' ¹ , 60 Wm ¹ K' ¹ ] or in the range [30 Wm ¹ K' ¹ , 50 Wm ¹ K' ¹ ] at normal conditions, in particular at a temperature of 20 °C.

In particular, a combination of a thermal conductivity in said ranges with a transmission coefficient of 80 % or more allows for a beneficial tradeoff between light attenuation due to the first heat dissipation component and improved thermal management, or in other words, temperature of the light source.

In preferred embodiments, the material comprises or consists of sapphire, in particular synthetic sapphire. The empirical chemical formula for sapphire is AI2O3. However, obviously impurities or traces of other chemical elements may be present. Preferably, the material comprises or consists of a single synthetic sapphire crystal or, in other words, is a monocrystal.

By using sapphire for the material, said ranges for the optical transmission coefficient and the thermal conductivity may be achieved, in particular for infrared light. By adapting the thickness of the material and/or equipping the first heat dissipation component with an anti-reflective coating and/or tuning the laser wavelength, optical transmission coefficients of significantly more than 80 %, in particular more than 90 % or even of 98 % are achievable. Furthermore, synthetic sapphire is an established material for various applications including for example the use as a substrate for semiconductor devices. Its hardness and ability to be formed in nearly arbitrary shapes make it also well suitable as a cover material for optical displays et cetera. These properties are also beneficial in the context of the invention.

According to several implementations, the active optical sensor system comprises a second heat dissipation component, which is in heat-conducting contact with a second surface of the first heat dissipation component, wherein the second surface is different from the first surface, for example perpendicular or approximately perpendicular to the first surface.

The second heat dissipation component is arranged outside of the optical emission path and/or may define a boundary of the optical emission path. The second heat dissipation component is therefore not necessarily permeable to the light and, in general, is not permeable or transparent to the light. For example, the second heat dissipation component may comprise or consist of a metal. The second surface and a corresponding contact region at the second heat dissipation component may for example be approximately planar.

Regarding the heat-conducting contact between the second heat dissipation component and the second surface of the first heat dissipation component, in general the explanations above regarding the first surface of the first heat dissipation component and the light-emitting surface may be applied analogously. However, since the second heat dissipation component is not arranged in the optical emission path also non-transparent adhesives or pastes may be used.

The second heat dissipation component may form a housing part of a housing of the active optical sensor system. The heat generated by the light source is therefore in part dissipated via the first heat dissipation component to the second heat dissipation component and may then be distributed to parts of the active optical sensor system where it does not harm the performance of the active optical sensor system or it may be dissipated to the environment of the active optical sensor system.

In some implementations, the second heat dissipation component may comprise or may be connected to specific heat dissipation structures, such as cooling ribs, increasing the surface to the environment of the second heat dissipation component to improve the efficiency of the heat transport away from the second heat dissipation component.

In some implementations, the active optical sensor system comprises a further second heat dissipation component, which is in heat-conducting contact with a further second surface of the first heat dissipation component. The second surface and the further second surface of the first heat dissipation component may for example be parallel or approximately parallel to each other and/or arranged on opposite sides of the first heat dissipation component.

Also the further second heat dissipation component may form a further housing part of the housing of the active optical sensor system. The first heat dissipation component may then for example be clamped between the second heat dissipation component and the further heat dissipation component to fix the position of the first heat dissipation component. For example, using an adhesive to fasten the first heat dissipation component to the second and further second heat dissipation component may not be necessary.

In some implementations, the sensor system comprises a third heat dissipation component, which is in heat-conducting contact with a bottom surface of the light source, wherein the bottom surface of the light source lies opposite to the light-emitting surface. The third heat dissipation component may for example be a bottom part of the housing or part of a carrier for the light source. For example, the third heat dissipation component may comprise or consist of a metal.

In such implementations, the thermal management and the overall heat dissipation rate away from the light source may be further improved since the heat generated by the light source is transported away from the light source on the light-emitting surface via the first heat dissipation component and on the opposite bottom surface of the light source via the third heat dissipation component.

For example, the light source may be implemented as a semiconductor chip or based on a semiconductor chip and the light-emitting surface and the bottom surface may correspond to opposite surfaces of the semiconductor chip.

For example, the light source may be implemented as a vertical-cavity surface-emitting laser, VCSEL.

According to several implementations, the active optical sensor system is designed as a flash lidar system.

In contrast to a laser scanner lidar system, in a flash lidar system, the light source illuminates the whole field of view of the active optical sensor system with a single laser pulse, which is diverged or diffused by a corresponding optics in the light emission path. This has for example the advantage that a movable component for a light deflection arrangement as in a laser scanner lidar system is not necessary. On the other hand, since the optical output power is limited and distributed over the whole field of view for a single laser pulse, also denoted as flash, the maximum detection range for a flash lidar system is potentially lower than for a laser scanner lidar system. Therefore, flash lidar systems are particularly useful for near-range applications. On the other hand, since the temperature of the light source may be reduced by means of the invention, it may be particularly useful for flash lidar systems, where an increased maximum detection distance is desirable.

According to several implementations, in particular implementations, where the active optical sensor system is designed as a flash lidar system, a third surface of the first heat dissipation component, which lies opposite to the first surface, is designed to diffuse a light beam of the light generated at the light-emitting surface and passing through the first heat dissipation component.

In other words, the first heat dissipation component is also designed as a light diffusing element. It may act as a diffractive beam shaper. Consequently, dedicated additional components for this purpose, such as diffusing lenses, micro-lens arrays or diffractive optical elements, may not be required. This reduces the complexity of the active optical sensor system, reducing the effort for manufacturing and increasing the robustness of the system. This may be particularly beneficial in case sapphire is used for the material of the first heat dissipation component, since sapphire also has very good optical properties.

In particular, the outer shape of the third surface or a structure of the third surface may be adapted such as to achieve the diffusion. For example, a convex outer surface may lead to a diffusion or the third surface of the first heat dissipation component may be microstructured accordingly.

According to further implementations, the active optical sensor system is designed as a laser scanner lidar system.

In several implementations, in particular implementations, where the active optical sensor system is implemented as a laser scanner lidar system, the third surface of the first heat dissipation component, which lies opposite to the first surface, is designed to collimate light generated at the light-emitting surface and passing through the first heat dissipation component.

In other words, the first heat dissipation component is also designed as a light collimating element. Consequently, dedicated additional components for this purpose, such as collimating lenses may not be required. This reduces the complexity of the active optical sensor system, reducing the effort for manufacturing and increasing the robustness of the system. This may be particularly beneficial in case sapphire is used for the material of the first heat dissipation component, since sapphire also has very good optical properties.

In particular, the outer shape of the third surface or a structure of the third surface may be adapted such as to achieve the collimation. For example, a concave outer surface may lead to a collimation or the third surface of the first heat dissipation component may be microstructured accordingly.

According to several implementations, in particular implementations, where the active optical sensor system is designed as a laser scanner lidar system, the sensor system comprises a light deflection arrangement and the first heat dissipation component is arranged between the light source and the light deflection arrangement.

The light deflection arrangement may be arranged and configured to deflect the light generated by the light source after passing through the first heat dissipation component into different directions in the environment of the active optical sensor system. Optionally, the deflection arrangement may also deflect reflected portions of the emitted light towards the optical detector. In particular, the light deflection arrangement comprises one or more movable or rotatable mirrors.

According to several implementations, the sensor system comprises an adhesive material arranged between the first surface and the light emission surface and fastens the first heat dissipation component to the light source.

The adhesive is, in particular, transparent or permeable for light of the light emission spectrum. Using the adhesive for fastening the first heat dissipation component to the light source has for example the advantage that no additional components have to be used to establish the heat-conducting connection, which simplifies the manufacturing process.

According to several implementations, the sensor system comprises a clamping arrangement, which exerts a force on the first heat dissipation component pressing the first surface to the emission surface.

In such implementations, an adhesive may for example not be necessary between the first surface and the light-emitting surface. Therefore, any optical effect or light attenuation of such an adhesive on the generated light entering the first heat dissipation component may be avoided. The active optical sensor system may for example be used in a vehicle, in particular a motor vehicle, for example an electronic vehicle guidance system of a vehicle.

Consequently, according to a further aspect of the invention, an electronic vehicle guidance system for a vehicle is provided, the electronic vehicle guidance system comprising an active optical sensor system according to the invention. The electronic vehicle guidance system comprises at least one computing unit, which is configured to generate one or more control signals for an actuator of the vehicle depending on the detector signal generated by the optical detector depending on the reflective portions of the emitted light.

The one or more control signals may for example be provided to the actuators and the actuators may affect or carry out a longitudinal and/or lateral control of the vehicle automatically or in part automatically. The actuators may in some implementations also be part of the electronic vehicle guidance system.

A computing unit may in particular be understood as a data processing device, which comprises processing circuitry. The computing unit can therefore in particular process data to perform computing operations. This may also include operations to perform indexed accesses to a data structure, for example a look-up table, LUT.

In particular, the computing unit may include one or more computers, one or more microcontrollers, and/or one or more integrated circuits, for example, one or more application-specific integrated circuits, ASIC, one or more field-programmable gate arrays, FPGA, and/or one or more systems on a chip, SoC. The computing unit may also include one or more processors, for example one or more microprocessors, one or more central processing units, CPU, one or more graphics processing units, GPU, and/or one or more signal processors, in particular one or more digital signal processors, DSP. The computing unit may also include a physical or a virtual cluster of computers or other of said units.

In various embodiments, the computing unit includes one or more hardware and/or software interfaces and/or one or more memory units. A memory unit may be implemented as a volatile data memory, for example a dynamic random access memory, DRAM, or a static random access memory, SRAM, or as a nonvolatile data memory, for example a read-only memory, ROM, a programmable read-only memory, PROM, an erasable programmable read-only memory, EPROM, an electrically erasable programmable read-only memory, EEPROM, a flash memory or flash EEPROM, a ferroelectric random access memory, FRAM, a magnetoresistive random access memory, MRAM, or a phase-change random access memory, PCRAM.

An electronic vehicle guidance system may be understood as an electronic system, configured to guide a vehicle in a fully automated or a fully autonomous manner and, in particular, without a manual intervention or control by a driver or user of the vehicle being necessary. The vehicle carries out all required functions, such as steering maneuvers, deceleration maneuvers and/or acceleration maneuvers as well as monitoring and recording the road traffic and corresponding reactions automatically. In particular, the electronic vehicle guidance system may implement a fully automatic or fully autonomous driving mode according to level 5 of the SAE J3016 classification. An electronic vehicle guidance system may also be implemented as an advanced driver assistance system, ADAS, assisting a driver for partially automatic or partially autonomous driving. In particular, the electronic vehicle guidance system may implement a partly automatic or partly autonomous driving mode according to levels 1 to 4 of the SAE J3016 classification. Here and in the following, SAE J3016 refers to the respective standard dated June 2018.

Guiding the vehicle at least in part automatically may therefore comprise guiding the vehicle according to a fully automatic or fully autonomous driving mode according to level 5 of the SAE J3016 classification. Guiding the vehicle at least in part automatically may also comprise guiding the vehicle according to a partly automatic or partly autonomous driving mode according to levels 1 to 4 of the SAE J3016 classification.

According to a further aspect of the invention, a vehicle, in particular a motor vehicle, is provided. The vehicle comprises an active optical sensor system according to the invention, for example an electronic vehicle guidance system according to the invention.

Further features of the invention are apparent from the claims, the figures and the figure description. The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of figures and/or shown in the figures may be comprised by the invention not only in the respective combination stated, but also in other combinations. In particular, embodiments and combinations of features, which do not have all the features of an originally formulated claim, may also be comprised by the invention. Moreover, embodiments and combinations of features which go beyond or deviate from the combinations of features set forth in the recitations of the claims may be comprised by the invention.

In the following, the invention will be explained in detail with reference to specific exemplary implementations and respective schematic drawings. In the drawings, identical or functionally identical elements may be denoted by the same reference signs. The description of identical or functionally identical elements is not necessarily repeated with respect to different figures.

In the figures:

Fig. 1 shows schematically a motor vehicle with an exemplary implementation of an active optical sensor system according to the invention;

Fig. 2 shows schematically a cross-section view of a further exemplary implementation of an active optical sensor system according to the invention;

Fig. 3 shows a part of a cross-section view of a further exemplary implementation of an active optical sensor system according to the invention;

Fig. 4 shows a part of a cross-section view of a further exemplary implementation of an active optical sensor system according to the invention; and

Fig. 5 shows a part of a cross-section view of a further exemplary implementation of an active optical sensor system according to the invention.

Fig. 1 shows schematically a motor vehicle 10 with an exemplary implementation of an active optical sensor system 1 according to the invention. The active optical sensor system 1 may for example be part of an electronic vehicle guidance system, which also comprises a computing unit 2 of the vehicle 10.

The active optical sensor system 1 comprises a light source 5 and an optical detector 7 (see for example Figs. 2 to 5), which is sensitive for light 17 emitted by the light source 5 at a light-emitting surface 16 (see for example Fig. 3). The active optical sensor system 1 further comprises a first heat dissipation component 6, which comprises or consists of a material, which is permeable to the light, for example synthetic sapphire. The first heat dissipation component 6 is arranged in an optical emission path of the optical sensor system 1 such that light 17 generated by the light source 5 passes through the first heat dissipation component 6 at least partially before it is emitted into an environment of the active optical sensor system 1 and consequently in an environment of the vehicle 10. Reflected portions 18 (see for example Figs. 2, 4 and 5) of the emitted light 17 are detectable by the optical detector 7, which may generate a detector signal depending on the detected portions and provide the detector signal to the computing unit 2.

A first surface 15 (see for example Fig. 3) is in heat-conducting contact with the lightemitting surface 16. Therefore, heat generated by the light source 5 may be transported away from the light source 5 via the light-permeable or, in other words transparent, heat dissipation component 6.

For example, the active optical sensor system 1 may comprise a heat sink component 3, which may for example be part of a housing of the active optical sensor system 1 . The heat sink component 3 may be made of a metal and may optionally have heat dissipating structures 21 , such as cooling ribs or the like, to dissipate the heat to surrounding air or other components of the active optical sensor system 1 or the vehicle 10.

Fig. 2 shows a further exemplary implementation of an active optical sensor system 1 according to the invention, which may for example be used in the electronic vehicle guidance system or the vehicle 10 of Fig. 1 .

In the example of Fig. 2, the active optical sensor system 1 is designed as a lidar system, in particular a laser scanner lidar system. The light source 5 is designed as a laser diode, in particular a VCSEL. The first heat dissipation component 6 may for example consist of a synthetic sapphire, which may for example have approximately the shape of a cuboid. The heat dissipation component 6 may be fastened to the light-emitting surface 16 at a first surface 15 of the first heat dissipation component 6 by means of an adhesive 13, as shown schematically in Fig. 3. Alternatively, the first heat dissipation component 6 may be fixed mechanically to the light source 5, for example by means of a corresponding clamping arrangement (not shown).

For example, the active optical sensor system 1 may comprise a housing, wherein Fig. 2 shows exemplarily four housing components 3a, 3b, 3c, 3d. The housing components 3a, 3b, 3c, 3d may be implemented as separate portions or may also be implemented in one piece. A first housing component 3a may serve as a bottom heat sink for the light source 5. In particular, the light source 5 may be arranged on the first housing component 3a at a bottom surface 19 of the light source 5, as shown in Fig. 3. Conventional thermal adhesives may be used to achieve the heat-conducting contact between the light source 5 and the first housing component 3a. In the example of Fig. 2, a circuit board 4 holds the light source 5 as well as the optical detector 7. For example, an opening in the circuit board 4 may be provided to establish the contact between the first housing component 3a and the light source 5.

A second housing component 3b, which may extend essentially perpendicular to the first housing component 3a may also serve as a heat sink. To this end, a lateral side surface of the first heat dissipation component 6 may be in heat-conducting contact with the second housing component 3b. Furthermore, a third housing component 3c may be arranged between the light source 5 and the optical detector 7, for example to reduce optical crosstalk. The third housing component 3c may also serve as a heat sink and may also be connected to a further lateral side surface of the heat dissipation components 6.

The housing components 3a, 3b, 3c may for example be made of metal or comprise any metal to improve the transport of the heat away from the light source 5. In Fig. 2, arrows with solid lines indicate schematically the flow of heat away from the light source 5 into the first housing component 3a as well as from the light source 5 via the heat dissipation component 6 into the housing components 3b, 3c. As shown schematically in Fig. 3, the second and/or third housing component 3b, 3c may be fastened to the heat dissipation component 6 by means of further adhesives 14.

Furthermore, the active optical sensor system 1 may comprise one or more optical components for beam forming or guiding the light into the environment or from the environment towards the optical detector. For example, a light collimator 8 may be arranged on a side of the heat dissipation component 6 opposite to the light source 5 and may be followed by a focusing lens 9. In this way, a focused laser beam may be generated from the emitted light 17 and may be directed to a rotating mirror 12, which deflects the light 17 into different directions in the environment of the active optical sensor system 1 . The reflected portions 18 of the emitted light 17 may be guided by the same rotating mirror 12 or a further mirror or a further deflection device towards the optical detector 7. Therein, further optical components 11 , in particular lenses, may be arranged in the optical receiving path.

Fig. 4 shows a further exemplary implementation of an active optical sensor system 1 according to the invention. The implementation of Fig. 4 is based on the implementation of Fig. 2 wherein, however, the light collimator 8 is an integrated part of the heat dissipation component 6. In particular, the surface of the heat dissipation component 6 facing away from the light source 5 may be shaped to achieve the beam collimation, for example may be of concave shape.

Not only is the complexity of the system 1 reduced in this way, but also the size of the heat dissipation component 6 is potentially increased, which further improves the heat dissipation rate.

Fig. 5 shows a further exemplary implementation of an active optical sensor system 1 according to the invention. The active optical sensor system 1 according to Fig. 5 is for example implemented as a flash lidar system. Therefore, the rotating mirrors 12 are not necessary in this case. Furthermore, the active optical sensor system 1 comprises a light diffusion element 20 instead of the beam collimator 8. The light diffusion element 20 may be integrated in one piece with the heat dissipation component 6 as described analogously for the beam collimator 8 in the embodiment of Fig. 4. Alternatively, the light diffusion element 20 may be implemented separately from the heat dissipation component 6.

As described, in particular with respect to the figures, the invention allows for an improved thermal management of an active optical sensor system, in particular of its light source, by providing a heat dissipation component in the optical emission path, which is permeable for the light generated by the light source. Consequently, the temperature of the light source may be reduced, which leads to a potentially increased optical output power and, consequently, to an increased maximum detection distance of the active optical sensor system.