Light beam scanning module, photoelectric detection device and electronic equipment

Abstract

The application provides a two-dimensional deflection light beam scanning module, which comprises a light source module, an acousto-optic deflection module, an electro-optic deflection module, a deflection angle amplification module and a control circuit arranged along an optical axis. The light source module emits a light beam along the optical axis. The control circuit is connected with the acousto-optic deflection module and the electro-optic deflection module, respectively, for controlling the acousto-optic deflection module to deflect the passing light beam in a preset first deflection angle range to multiple different preset deflection angles along a first direction, and for controlling the electro-optic deflection module to deflect the passing light beam in a preset second deflection angle range to multiple different preset deflection angles along a second direction. The deflection angle amplification module further amplifies the deflection angle of the light beam deflected by the acousto-optic deflection module and the electro-optic deflection module along the first direction and / or the second direction to form a sensing light beam. The application also provides a photoelectric detection device and an electronic equipment comprising the light beam scanning module.

Description

Technical Field

[0001] This application belongs to the field of photoelectric detection, and in particular relates to a beam scanning module, photoelectric detection device and electronic equipment capable of realizing two-dimensional beam deflection. Background Technology

[0002] LiDAR ranging is typically based on the Time-of-Flight (ToF) measurement principle. This involves emitting laser pulses into the measurement scene and measuring the round-trip time of the laser pulses between the LiDAR and the target object to calculate three-dimensional information such as the distance to the target object. Because of its advantages such as long sensing distance, high accuracy, and low power consumption, ToF measurement is widely used in consumer electronics, autonomous driving, unmanned aerial vehicles, AR / VR, and other fields.

[0003] Distance measurement devices using the Time-of-Flight (ToF) principle have a limited field of view coverage due to the single beam of sensing light emitted. To achieve a wider field of view, the direction of the sensing beam needs to be continuously changed during scanning. Currently, a common method to change the emission direction of the sensing beam involves mechanically rotating the beam scanning and receiving modules of the detection device. However, this method often requires multiple discrete components assembled into a mechanical rotating structure, resulting in high complexity in the debugging and assembly of the transmission / reception optical paths. The mechanical rotating structure is also prone to damage and inaccuracy, and its large size affects the appearance of the terminal equipment using it. Another method to change the emission direction of the sensing beam is a hybrid solid-state solution, which mainly uses moving parts to drive optical components and change the transmission and reception optical paths of the sensing beam. Although the hybrid solid-state solution significantly reduces cost and size compared to the mechanical rotation solution, the reliability of the system remains low due to the susceptibility of moving parts to damage, limiting the application scenarios of the detection device. Summary of the Invention

[0004] In view of this, this application provides a beam scanning module, a photoelectric detection device, and related electronic equipment that can improve the problems of the prior art.

[0005] In a first aspect, this application provides a two-dimensional deflection beam scanning module configured to emit a two-dimensionally deflectable sensing beam into a field of view to perform three-dimensional information detection of objects within the field of view based on the time-of-flight principle. The beam scanning module includes components arranged along its own optical axis:

[0006] The light source module is configured to emit a light beam along the optical axis;

[0007] An acousto-optic deflection module includes an acousto-optic interaction medium and a sound wave generator, wherein the sound wave generator is configured to generate a sound wave propagating in a preset direction within the acousto-optic interaction medium to deflect a light beam passing through the acousto-optic interaction medium in a first direction.

[0008] An electro-optic deflection module includes an electro-optic interaction medium and an electrical signal source, wherein the electrical signal source is configured to generate an electric field in the electro-optic interaction medium along a preset direction to deflect a light beam passing through the electro-optic interaction medium along a second direction different from the first direction.

[0009] The deflection angle amplification module is configured to further amplify the deflection angle of the light beam after being deflected by the acousto-optic deflection module and the electro-optic deflection module along the first direction and / or the second direction, so as to form the sensing light beam; and is respectively connected to the acousto-optic deflection module and the electro-optic deflection module.

[0010] The control circuit is configured to control the frequency of the sound waves emitted by the sound wave generator to deflect the light beam passing through the acousto-optic interaction medium along the first direction by a plurality of different preset deflection angles within a preset first deflection angle range, and is configured to control the intensity of the electric field generated by the electrical signal source to deflect the light beam passing through the electro-optic interaction medium along the second direction by a plurality of different preset deflection angles within a preset second deflection angle range; wherein,

[0011] The first direction and the optical axis together define a first plane, and the second direction and the optical axis define a second plane. The deflection angle of the deflected beam along the first direction is defined as the angle between the projection of the deflected beam in the first plane and the optical axis. The deflection angle of the deflected beam along the second direction is defined as the angle between the projection of the deflected beam in the second plane and the optical axis.

[0012] Secondly, this application provides a photoelectric detection device configured to detect the distance of an object located within a preset field of view. The photoelectric detection device includes a receiving module, a processing module, and a beam scanning module as described above. The receiving module is configured to sense light signals from within the field of view and output corresponding light-sensing signals, and the processing module is configured to analyze and process the light-sensing signals to obtain three-dimensional information of the object within the field of view.

[0013] Thirdly, this application provides an electronic device, including an application module and the photoelectric detection device described above. The application module is configured to perform corresponding functions based on the detection results of the photoelectric detection device.

[0014] The beneficial effects of this application are:

[0015] Compared to mechanical rotation schemes and hybrid solid-state schemes for deflecting the sensing beam, this application achieves two-dimensional deflection scanning of the sensing beam within a preset deflection angle range using a purely solid-state acousto-optic deflection module and an electro-optic deflection module. This eliminates the need for component rotation and vibration, resulting in better reliability and a more compact size. Attached Figure Description

[0016] The features and advantages of the present invention will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the functional modules of an electronic device provided in an embodiment of this application;

[0018] Figure 2 for Figure 1 A functional module diagram of an embodiment of the photoelectric detection device described herein;

[0019] Figure 3 for Figure 2 A schematic diagram of the statistical histogram obtained by the processing module described above;

[0020] Figure 4 A timing diagram of the signal during detection by a photoelectric detection device provided in an embodiment of this application;

[0021] Figure 5 for Figure 2 A three-dimensional optical path diagram of an embodiment of the beam scanning module described herein;

[0022] Figure 6 for Figure 5 A top view of the three-dimensional optical path diagram described in the figure;

[0023] Figure 7 This is a schematic diagram of the structure of an acousto-optic deflection module provided in an embodiment of this application;

[0024] Figure 8 This is a schematic diagram of the structure of an electro-optic deflection module provided in an embodiment of this application;

[0025] Figure 9 This is a three-dimensional optical path diagram of a beam scanning module provided in another embodiment of this application;

[0026] Figure 10 This is a schematic diagram of the optical path module of a beam scanning module provided in another embodiment of this application;

[0027] Figure 11 This is a schematic diagram of the structure of a first cylindrical deflecting lens provided in an embodiment of this application;

[0028] Figure 12 This is a schematic diagram of the structure of a second cylindrical deflecting lens provided in an embodiment of this application;

[0029] Figure 13 This is a schematic diagram of the structure of a two-dimensional deflecting superlens provided in an embodiment of this application;

[0030] Figure 14 This is a schematic diagram of the structure of a first one-dimensional deflecting superlens provided in an embodiment of this application;

[0031] Figure 15 This is a schematic diagram of the structure of a second one-dimensional deflecting superlens provided in an embodiment of this application;

[0032] Figure 16 This is a schematic diagram of the structure of an electro-optic interaction medium provided in an embodiment of this application;

[0033] Figure 17 This is a schematic diagram of the structure of an electro-optic deflection module provided in another embodiment of this application;

[0034] Figure 18 This is a schematic diagram of the structure of an optoelectronic detection device provided in an embodiment of this application as an automotive lidar. Detailed Implementation

[0035] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. In the description of this application, it should be understood that the terms "first" and "second" are used for description only and should not be construed as indicating or implying relative importance or implicitly specifying the number or order of the indicated technical features. Thus, technical features defined with "first" and "second" may explicitly or implicitly include one or more of the stated technical features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0036] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integrated connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0037] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, only specific examples of components and settings are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or reference letters may be repeated in different examples; such repetition is for the purpose of simplifying and clearly describing this application and does not in itself indicate a specific relationship between the various embodiments and / or settings discussed. Moreover, the various specific processes and materials described below are merely examples for implementing the technical solutions of this application; however, those skilled in the art should recognize that the technical solutions of this application can also be implemented using other processes and / or other materials not described below.

[0038] Furthermore, the described features and structures can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced even without one or more of the specific details described, or with other structures, components, etc. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring the focus of this application.

[0039] Embodiments of this application provide a two-dimensional deflection beam scanning module configured to emit a two-dimensionally deflectable sensing beam into a field of view to perform three-dimensional information detection of objects within the field of view based on the time-of-flight principle. The beam scanning module includes components arranged along its own optical axis:

[0040] The light source module is configured to emit a light beam along the optical axis;

[0041] An acousto-optic deflection module includes an acousto-optic interaction medium and a sound wave generator, wherein the sound wave generator is configured to generate a sound wave propagating in a preset direction within the acousto-optic interaction medium to deflect a light beam passing through the acousto-optic interaction medium in a first direction.

[0042] An electro-optic deflection module includes an electro-optic interaction medium and an electrical signal source, wherein the electrical signal source is configured to generate an electric field in the electro-optic interaction medium along a preset direction to deflect a light beam passing through the electro-optic interaction medium along a second direction different from the first direction.

[0043] The deflection angle amplification module is configured to further amplify the deflection angle of the light beam after being deflected by the acousto-optic deflection module and the electro-optic deflection module along the first direction and / or the second direction, so as to form the sensing light beam; and is respectively connected to the acousto-optic deflection module and the electro-optic deflection module.

[0044] The control circuit is configured to control the frequency of the sound waves emitted by the sound wave generator to deflect the light beam passing through the acousto-optic interaction medium along the first direction by a plurality of different preset deflection angles within a preset first deflection angle range, and is configured to control the intensity of the electric field generated by the electrical signal source to deflect the light beam passing through the electro-optic interaction medium along the second direction by a plurality of different preset deflection angles within a preset second deflection angle range; wherein,

[0045] The first direction and the optical axis together define a first plane, and the second direction and the optical axis define a second plane. The deflection angle of the deflected beam along the first direction is defined as the angle between the projection of the deflected beam in the first plane and the optical axis. The deflection angle of the deflected beam along the second direction is defined as the angle between the projection of the deflected beam in the second plane and the optical axis.

[0046] In some embodiments, the first direction and the second direction are perpendicular to each other, the first direction is horizontal and the second direction is vertical; or, the first direction is vertical and the second direction is horizontal.

[0047] In some embodiments, the beam scanning module further includes:

[0048] The collimation module is configured to collimate the light beam emitted by the light source module along the optical axis before it enters the acousto-optic deflection module and the electro-optic deflection module.

[0049] In some embodiments, the deflection angle amplification module includes a first deflection angle amplification unit and / or a second deflection angle amplification unit, wherein the first deflection angle amplification unit is configured to amplify the deflection angle of the passing light beam along the first direction, and the second deflection angle amplification unit is configured to amplify the deflection angle of the passing light beam along the second direction.

[0050] In some embodiments, the first deflection angle magnification unit includes a first cylindrical deflection lens, which is configured to deflect the transmitted light beam along the first direction to amplify the deflection angle of the transmitted light beam along the first direction by a predetermined factor. The first cylindrical deflection lens includes an incident surface and an exit surface arranged sequentially along the light beam propagation direction. At least one of the exit surface and the incident surface is an optical surface for deflecting the light beam along the first direction. The optical surface is curved on the cross section of the first cylindrical deflection lens perpendicular to the second direction, and the optical surface is straight on the cross section of the first cylindrical deflection lens perpendicular to the first direction. The second direction is perpendicular to the first direction.

[0051] In some embodiments, the first deflection angle amplification unit includes a first one-dimensional deflection superlens, on which a plurality of optical modulation sections are formed along the first direction. The light beam deflected by the acousto-optic deflection module and the electro-optic deflection module is incident on one of the optical modulation sections. Each optical modulation section is configured to modulate the optical properties of the incident light beam to amplify the deflection angle of the transmitted light beam along the first direction by a preset multiple.

[0052] In some embodiments, the second deflection angle magnification unit includes a second cylindrical deflection lens, which is configured to deflect the transmitted light beam along the second direction to amplify the deflection angle of the transmitted light beam along the second direction by a predetermined factor. The second cylindrical deflection lens includes an incident surface and an exit surface arranged sequentially along the light beam propagation direction. At least one of the exit surface and the incident surface is an optical surface for deflecting the light beam along the second direction. The optical surface is curved on the cross section of the second cylindrical deflection lens perpendicular to the first direction, and the optical surface is straight on the cross section of the second cylindrical deflection lens perpendicular to the second direction. The second direction is perpendicular to the first direction.

[0053] In some embodiments, the second deflection angle amplification unit includes a second one-dimensional deflection superlens, on which a plurality of optical modulation sections are formed along the second direction. The light beam deflected by the acousto-optic deflection module and the electro-optic deflection module is incident on one of the optical modulation sections. Each optical modulation section is configured to modulate the optical properties of the incident light beam to amplify the deflection angle of the light beam emitted by the optical modulation section along the second direction along the first direction.

[0054] In some embodiments, the deflection angle amplification module includes a first deflection angle amplification unit and / or a second deflection angle amplification unit. The first deflection angle amplification unit is configured to amplify the deflection angle of the light beam along the first direction or the second direction, and the second deflection angle amplification unit is configured to amplify the deflection angle of the light beam along both the first direction and the second direction.

[0055] In some embodiments, the first deflection angle magnification unit includes a first cylindrical deflection lens, which is configured to deflect the transmitted light beam along the first direction to amplify the deflection angle of the transmitted light beam along the first direction by a predetermined factor. The first cylindrical deflection lens includes an incident surface and an exit surface arranged sequentially along the light beam propagation direction. At least one of the exit surface and the incident surface is an optical surface for deflecting the light beam along the first direction. The optical surface is curved on the cross section of the first cylindrical deflection lens perpendicular to the second direction, and the optical surface is straight on the cross section of the first cylindrical deflection lens perpendicular to the first direction. The second direction is perpendicular to the first direction.

[0056] In some embodiments, the first deflection angle magnification unit includes a second cylindrical deflection lens, which is configured to deflect the transmitted light beam along the second direction to amplify the deflection angle of the transmitted light beam along the second direction by a predetermined factor. The second cylindrical deflection lens includes an incident surface and an exit surface arranged sequentially along the light beam propagation direction. At least one of the exit surface and the incident surface is an optical surface for deflecting the light beam along the second direction. The optical surface is curved on the cross section of the second cylindrical deflection lens perpendicular to the first direction, and the optical surface is straight on the cross section of the second cylindrical deflection lens perpendicular to the second direction. The second direction is perpendicular to the first direction.

[0057] In some embodiments, the second deflection angle magnification unit includes at least one axisymmetric lens whose shape is symmetrically distributed about the optical axis passing through its optical center, so as to simultaneously magnify the deflection angle of the light beam along the first direction and the second direction.

[0058] In some embodiments, the second deflection angle amplification unit includes a two-dimensional deflection superlens, on which a plurality of optical modulation sections are formed in a two-dimensional array. The light beam deflected by the acousto-optic deflection module and the electro-optic deflection module is incident on one of the optical modulation sections. Each optical modulation section is configured to modulate the optical properties of the incident light beam to simultaneously amplify the deflection angle of the transmitted light beam by a preset multiple along the first direction and the second direction.

[0059] In some embodiments, the arrangement order of the first deflection angle amplification unit and the second deflection angle amplification unit along the optical axis can be interchanged.

[0060] In some embodiments, the electro-optic interaction medium is a cubic phase potassium tantalate niobate crystal, and the beam scanning module further includes a temperature control module configured to maintain the temperature of the electro-optic interaction medium within a preset temperature range.

[0061] In some embodiments, the electro-optic deflection module deflects the second deflection angle range of the light beam toward the cathode of the electrical signal source, and the light beam forms a preset tilt angle between the direction of incidence of the electro-optic deflection module and the horizontal plane.

[0062] In some embodiments, the electro-optic interaction medium is lithium niobate, lithium tantalate, or potassium titanium oxyphosphate. The electro-optic deflection module includes multiple cascaded electro-optic interaction media. The control circuit adjusts the electric field strength formed by the electrical signal source in the corresponding electro-optic interaction medium to control the deflection angle of the passing beam by the corresponding electro-optic interaction medium. After the beam passes through multiple cascaded electro-optic interaction media for multiple deflections, it can obtain a larger range of second deflection angles along the second direction than after passing through a single electro-optic interaction medium.

[0063] In some embodiments, the beam scanning module further includes a beam narrowing module configured to narrow the size of the beam in a cross section perpendicular to the beam propagation direction to a preset size before the beam enters the acousto-optic deflection module or the electro-optic deflection module.

[0064] Embodiments of this application also provide a photoelectric detection device configured to perform three-dimensional information detection on an object located within a preset field of view. The device includes a beam scanning module as described above, a receiving module, and a processing module. The photoelectric detection device further includes a receiving module and a processing module. The receiving module is configured to sense light signals from within the field of view and output corresponding light-sensing signals. The processing module is configured to analyze and process the light-sensing signals to obtain three-dimensional information of the object within the field of view.

[0065] Embodiments of this application also provide an electronic device including the aforementioned photoelectric detection device. The electronic device performs corresponding functions based on the three-dimensional information obtained by the photoelectric detection device. Examples of such electronic devices include: mobile phones, automobiles, robots, access control / monitoring systems, smart locks, unmanned vehicles, and drones. The three-dimensional information includes, for example, proximity information, depth information, distance information, and coordinate information of objects within the field of view. This three-dimensional information can be used, for example, in fields such as 3D modeling, identity recognition, autonomous driving, machine vision, monitoring, drone control, augmented reality (AR) / virtual reality (VR), simultaneous localization and mapping (SLAM), and object proximity detection; this application does not limit its application to these fields.

[0066] The photoelectric detection device, for example, can be a lidar (LiDAR), used to obtain three-dimensional information of objects within the field of view. LiDAR is applied in fields such as autonomous vehicles, autonomous aircraft, 3D printing, VR, AR, and service robots. Taking an autonomous vehicle as an example, a lidar is installed in the vehicle. The lidar scans the surrounding environment by rapidly and repeatedly emitting laser beams to obtain point cloud data reflecting the shape, position, and movement of one or more objects in the environment. Specifically, the lidar emits a laser beam into the surrounding environment and receives the echo beams reflected back by various objects in the environment. By calculating the time delay (i.e., flight time) between the emission time of the laser beam and the return time of the echo beams, the distance / depth information of each object is determined. Simultaneously, the lidar can also determine the angular information describing the spatial orientation of the laser beam's field of view. Combining the distance / depth information of each object with the angular information of the laser beam generates a three-dimensional map including all objects in the scanned surrounding environment. This three-dimensional map can guide the autonomous driving of the vehicle.

[0067] Hereinafter, embodiments of photoelectric detection devices applied to electronic devices will be described in detail with reference to the accompanying drawings.

[0068] Figure 1 This is a schematic diagram of the functional modules of the photoelectric detection device provided in this application embodiment applied to electronic devices. Figure 2 This is a schematic diagram of the functional modules of the photoelectric detection device provided in the embodiments of this application.

[0069] Reference Figure 1 and Figure 2 The electronic device 1 includes a photoelectric detection device 10. The photoelectric detection device 10 can detect an object 2 within its field of view to obtain three-dimensional information about the object 2. The field of view can be defined as the three-dimensional spatial range within which the photoelectric detection device 10 can effectively perform three-dimensional information detection; it can also be referred to as the field of view angle or field of view range of the photoelectric detection device 10. The three-dimensional information includes, but is not limited to, one or more of the following: proximity information of the object 2, depth information of the surface of the object 2, distance information of the object 2, and spatial coordinate information of the object 2.

[0070] The electronic device 1 may include an application module 20, which is configured to perform preset operations or implement corresponding functions based on the detection results of the photoelectric detection device 10. For example, but not limited to: determining whether an object 2 appears within a preset field of view in front of the electronic device 1 based on its proximity information; or controlling the movement of the electronic device 1 to avoid obstacles based on the distance information of the object 2; or realizing 3D modeling, identity recognition, machine vision, etc., based on the depth information of the object 2's surface. That is, the application module 20 may be a collection of hardware required to perform the above operations and implement the above functions, and software required to control and coordinate the operation of the hardware.

[0071] The electronic device 1 may further include a storage medium 30, which can support the storage needs of the electronic device 1 and / or the photoelectric detection device 10 during operation. Figure 1 As shown, in some embodiments, the storage medium 30 may be disposed inside the electronic device 1. For example... Figure 2 As shown, in some embodiments, the storage medium 30 may also be disposed inside the photoelectric detection device 10.

[0072] The electronic device 1 may further include a processor 40, which can support the data processing needs of the electronic device 1 and / or the photoelectric detection device 10 during operation. Figure 1 As shown, in some embodiments, the processor 40 may be located inside the electronic device 1. For example... Figure 2 As shown, in some embodiments, the processor 40 may also be disposed inside the photoelectric detection device 10.

[0073] Optionally, in some embodiments, the photoelectric detection device 10 may be, for example, a dToF measurement device for three-dimensional information sensing based on the direct time of flight (dToF) principle. The dToF measurement device can emit a sensing beam within the field of view and receive the sensing beam reflected back from the object 2 within the field of view. The time difference between the emission time and the reception time of the reflected sensing beam is called the flight time t of the sensing beam. The three-dimensional information of the object 2 can be obtained by calculating half the distance traveled by the sensing beam within the flight time t. Where c is the speed of light.

[0074] In other embodiments, the photoelectric detection device 10 can also be an iToF measurement device that uses the indirect time of flight (iToF) measurement principle to sense three-dimensional information. The iToF measurement device obtains the three-dimensional information of the object 2 by comparing the phase difference between when the sensing beam is emitted and when it is reflected back and received.

[0075] In the embodiments described below, the photoelectric detection device 10 is mainly used as a dToF measurement device for illustration.

[0076] In some embodiments, such as Figure 2 As shown, the photoelectric detection device 10 includes a beam scanning module 12, a receiving module 14, and a processing module 15. The beam scanning module 12 is configured to emit a sensing beam into the field of view to detect the three-dimensional information of an object 2 within the field of view. A portion of the sensing beam is reflected back by the object 2, and the reflected beam echo carries the three-dimensional information of the object 2. A portion of the reflected beam echo can be sensed by the receiving module 14 to obtain the three-dimensional information of the object 2. The receiving module 14 is configured to sense light signals from the field of view and output corresponding photosensitive signals. By analyzing the photosensitive signals, the three-dimensional information of the object 2 within the field of view can be detected. It is understood that the light signals sensed by the receiving module 14 can be photons, including photons from the reflected sensing beam echo from the object 2 within the field of view and photons from ambient light within the field of view. The processing module 15 is configured to analyze and process the light-sensing signal to obtain the moment when the echo of the sensing beam is sensed by the receiving module 14, and to obtain the three-dimensional information of the object 2 based on the time difference between the emission time of the sensing beam and the time when it is reflected back and sensed.

[0077] The processing module 15 can be disposed on the photoelectric detection device 10. It should be understood that, in some other embodiments, all or part of the functional units of the processing module 15 can also be disposed on the electronic device 1.

[0078] In some embodiments, the sensing beam may be, for example, a plurality of laser pulses emitted sequentially. The beam scanning module 12 is configured to emit the laser pulses as sensing beams according to a preset time sequence. Specifically, the beam scanning module 12 emits sensing beam pulses to different areas of the field of view in a time-division manner according to a preset scanning method for distance detection. For each area, multiple sensing beam pulses are emitted according to a corresponding preset time sequence. By completing the emission of multiple sensing beam pulses for one area and analyzing the time distribution of the light signal sensed by the receiving module 14, the distance information of that area can be obtained. This process can be regarded as a partition detection period. By scanning multiple areas one by one, it can be regarded as completing a frame detection of the entire field of view, and the distance information of all partitions in the entire field of view can be obtained, which can be used to construct a point cloud of a frame of the entire field of view. That is, a frame detection of the field of view includes multiple partition detection periods corresponding to partition scanning.

[0079] Optionally, the sensing beam is, for example, visible light, infrared light or near-infrared light, with a wavelength range of, for example, 390 nm-780 nm, 700 nm-1400 nm, 800 nm-1000 nm, 900 nm-1600 nm, etc.

[0080] Please refer to the following: Figure 2 , Figure 3 and Figure 4 , Figure 3 for Figure 2 A schematic diagram of the statistical histogram obtained by the processing module 15 described above. Figure 4 This is a signal timing diagram of the photoelectric detection device 10 provided in one embodiment of this application during detection. In some embodiments, the processing module 15 may include functional units such as a timing unit 152, a statistics unit 154, a time-of-flight acquisition unit 156, and a three-dimensional information acquisition unit 158.

[0081] The timing unit 152 is configured to determine the reception time of the light signal sensed by the receiving module 14. During the detection process, the photoelectric detection device 10 emits multiple sensing beam pulses through the beam scanning module 12. The timing unit 152 starts timing each time the beam scanning module 12 emits a sensing beam pulse to record the reception time of the light signal sensed by the receiving module 14 between the emission of two adjacent sensing beam pulses. During this period, the receiving module 14 outputs a corresponding photosensitive signal for each light signal received. The timing unit 152 determines the sensing time of the light signal based on the photosensitive signal output by the receiving module 14 and counts it in a time bin corresponding to the sensing time, forming a corresponding light signal count. The time bin is the smallest time unit Δt used by the timing unit 152 to record the moment the photosensitive signal is generated. It reflects the accuracy of the timing unit 152 in recording the light signal sensing time; a finer time bin indicates higher accuracy. In some embodiments, the timing unit 152 can, for example, implement the timing function using a Time-to-Digital Converter (TDC) 1522. The TDC1522 can be connected to the corresponding photosensitive pixel 142 on the receiving module 14 and is configured to record the sensing time of the sensed light signal based on the light sensing signal generated by the corresponding photosensitive pixel 142. For example, the TDC1522 is synchronously triggered to start timing each time a sensing beam is emitted, and subsequently stops timing in response to the light sensing signal generated by the corresponding photosensitive pixel 142, and the time period of timing is used as the sensing time of the corresponding light signal that triggered the light sensing signal.

[0082] In some embodiments, the timing unit 152 may include a counting memory 1524, which has counting storage space allocated according to time bins. Each time the TDC 1522 records the sensing time of an optical signal, it increments by one in the counting storage space of the corresponding time bin, that is, the optical signal count in the corresponding time bin increases by one. The optical signal count value of each time bin corresponds to the number of times the optical signal is sensed at the time represented by that time bin during multiple emission periods of the sensing beam.

[0083] The statistical unit 154 is configured to count the cumulative optical signals within each time slot to obtain a statistical histogram reflecting the time distribution of the number of optical signals sensed by the receiving module 14 during the transmission of multiple sensing beam pulses. For example, Figure 3 As shown, the horizontal axis of the statistical histogram represents the timestamp of each corresponding time bin, and the vertical axis represents the cumulative optical signal count value within each corresponding time bin. In some embodiments, the statistical unit 154 may include a histogram circuit 1544 (see...). Figure 2The histogram circuit 1544 is configured to statistically analyze the optical signal counts within each time bin to generate a statistical histogram. It should be understood that the statistical unit 154 performs statistical analysis on the cumulative optical signal counts corresponding to multiple transmissions of sensing beam pulses within a partition detection period. To ensure the counts have mathematical statistical significance, the number of sensing beam pulse transmissions within a partition detection period can be as high as hundreds, thousands, tens of thousands, hundreds of thousands, or even millions.

[0084] During the sensing process, a large number of ambient light photons are also sensed by the receiving module 14, generating corresponding optical signal counts. The probability of these ambient light photons being sensed and leaving a count in each time slot tends to be the same, constituting the noise level in the field of view. In scenes with strong ambient light, the average level of the measured noise level is relatively high; in scenes with weak ambient light, the average level of the measured noise level is relatively low. Based on this, the optical signal count generated by the sensed beam echo reflected from object 2 is superimposed on the noise level, making the optical signal count in the time slot corresponding to the moment the sensed beam echo is sensed significantly higher than the optical signal count in other time slots, thus forming a prominent signal peak. It is understood that the height of the signal peak count value is affected by factors such as the optical power of the sensing beam, the reflectivity of the object 2, and the field of view of the photoelectric detection device 10. The width of the signal peak is affected by factors such as the pulse width of the emitted sensing beam pulse, the photoelectric conversion element of the receiving module 14, and the time jitter of the TDC1522. Therefore, the time-of-flight acquisition unit 156 can obtain the flight time of the related sensing beam pulse reflected back by the object 2 based on the time difference between the timestamp t1 of the time bin corresponding to the peak value of the signal peak and the emission time t0 of the related sensing beam that generated the signal peak. The three-dimensional information acquisition unit 158 ​​can be configured to obtain the three-dimensional information between the object 2 reflecting the sensing beam and the photoelectric detection device 10 based on the flight time of the sensing beam determined by the statistical histogram, such as the distance between the object 2 and the photoelectric detection device 10 in the field of view.

[0085] It should be understood that the beam scanning module 12 and the receiving module 14 are arranged side by side, with the light-emitting surface of the beam scanning module 12 and the light-incident surface of the receiving module 14 both facing the same side of the photoelectric detection device 10. The distance between the beam scanning module 12 and the receiving module 14 can range from, for example, 2 mm to 20 mm. Since the beam scanning module 12 and the receiving module 14 are relatively close, although the emission path of the sensing beam from the beam scanning module 12 to the object 2 and the return path from the object 2 to the receiving module 14 after reflection are not exactly equal, both are much larger than the distance between the beam scanning module 12 and the receiving module 14, and can be considered approximately equal. Therefore, the distance between the object 2 and the photoelectric detection device 10 can be calculated based on the product of half the flight time t of the sensing beam reflected back from the object 2 and the speed of light c.

[0086] In some embodiments, such as Figure 2 As shown, the receiving module 14 may include a photoelectric sensor 140 and a receiving optics 144. The receiving optics 144 is disposed on the light-incident side of the photoelectric sensor 140 and is configured to transmit light signals from the field of view to the photoelectric sensor 140 for sensing. For example, the receiving optics 144 may include a receiving lens (not shown). Optionally, the receiving lens may include one lens or multiple lenses. The photoelectric sensor 140 is configured to sense the light signals transmitted from the field of view via the receiving optics 144 and output a corresponding light-sensing signal.

[0087] In some embodiments, the receiving module 14 may further include peripheral circuitry (not shown) consisting of one or more devices such as signal amplifiers and analog-to-digital converters (ADCs), which may be partially or wholly integrated into the photoelectric sensor 140.

[0088] Optionally, the photoelectric sensor 140 may include a single photosensitive pixel 142 or a photosensitive pixel array consisting of multiple photosensitive pixels 142. The field of view of the photoelectric detection device 10 may include multiple partitions located at different positions. The photosensitive pixels 142 of the photoelectric sensor 140 have corresponding partitions in the field of view. The light signal returned from the partition is propagated to the corresponding photosensitive pixel 142 for sensing via the receiving optics 144. That is, the partition corresponding to the photosensitive pixel 142 can be regarded as the spatial range covered by the field of view formed by the receiving optics 144 of the photosensitive pixel 142. Thus, when the sensing beam emitted by the beam scanning module 12 scans the partition and there is an object 2 on the partition, the sensing beam echo reflected back by the object 2 is propagated to the corresponding photosensitive pixel 142 for sensing via the receiving optics 144. That is, the light signal returned from the partition includes photons of the ambient light from the partition, and when there is an object 2 in the partition, it also includes the sensing beam echo that was projected onto the partition and reflected back by the object 2.

[0089] A single photosensitive pixel 142 may include a single photoelectric conversion device or multiple photoelectric conversion devices. The photoelectric conversion device is configured to sense the received light signal and convert it into a corresponding electrical signal as the photosensitized signal output. Optionally, the photoelectric conversion device may be, for example, a single-photon avalanche diode (SPAD), an avalanche photodiode (APD), a silicon photomultiplier (SiPM) consisting of multiple SPADs connected in parallel, and / or other suitable photoelectric conversion elements.

[0090] Figure 5 for Figure 2 A three-dimensional optical path schematic diagram of an embodiment of the beam scanning module 12 described herein. Figure 6 for Figure 5 This is a top view of the three-dimensional optical path schematic diagram described herein. To facilitate the description of the deflection scanning of the sensing beam emitted by the beam scanning module 12, an orthogonal rectangular coordinate system is established with the direction of the beam emitted along the midpoint deflection angle of the field of view as the Y-axis, the first direction as the X-axis, and the second direction as the Z-axis. Other optical path schematic diagrams in this application are also described using this coordinate system. It should be understood that in embodiments where the first direction is horizontal and the second direction is vertical, the XOY plane represents the horizontal plane, and the YOZ plane represents the vertical plane.

[0091] like Figure 5 and Figure 6As shown, the beam scanning module 12 includes a light source module 122, at least one acousto-optic deflection module 124, and at least one electro-optic deflection module 126 arranged along its own optical axis. The light source module 122 is configured to emit a beam of light. The acousto-optic deflection module 124 is configured to deflect the beam of light along a first direction within a preset first deflection angle range by multiple different preset deflection angles. The electro-optic deflection module 126 is configured to deflect the beam of light along a second direction within a preset second deflection angle range by multiple different preset deflection angles, where the second direction is different from the first direction. The first and second directions refer to the beam deflection directions, which can be understood as the directions in which the trend of change occurs when the emission direction of the beam is altered. The acousto-optic deflection module 124 and the electro-optic deflection module 126 are independent modules separately arranged. The beam of light emitted by the light source module 122 is first deflected along the first direction by the acousto-optic deflection module 124 and then deflected along the second direction by the electro-optic deflection module 126. The first direction and a portion of the optical axis passing through the acousto-optic deflection module 124 together define a first plane I. The deflection angle of the deflected beam along the first direction is defined as the angle between the projection of the deflected beam on the first plane I and the portion of the optical axis after being bent by the acousto-optic deflection module 124. The second direction and a portion of the optical axis passing through the electro-optic deflection module 126 together define a second plane II. The deflection angle of the deflected beam along the second direction is defined as the angle between the projection of the deflected beam on the second plane II and the portion of the optical axis after being bent by the electro-optic deflection module 126.

[0092] Optionally, the first direction is perpendicular to the second direction. For example, in some embodiments, the first direction is horizontal and the second direction is vertical; in other embodiments, the first direction is vertical and the second direction is horizontal.

[0093] The light source module 122 includes one or more light-emitting units (not shown), which are configured to emit light beams. The light-emitting units can be vertical-cavity surface-emitting lasers (VCSELs), edge-emitting lasers (EELs), light-emitting diodes (LEDs), laser diodes (LDs), fiber lasers, etc. The edge-emitting lasers can be Fabry-Perot (FP) lasers, distributed feedback (DFB) lasers, electro-absorption modulated (EML) lasers, etc., and this embodiment does not limit the specific type of laser.

[0094] In some embodiments, the beam scanning module 12 may further include a collimation module 121. The collimation unit 121 is configured to collimate the beam emitted by the light source module 122 along the optical axis direction to improve the collimation of the beam emitted by the light source module 122. Optionally, the collimation module 121 may employ collimating optical devices such as a collimating lens, a superlens, or a cylindrical lens.

[0095] In some embodiments, the beam scanning module 12 may further include a beam-shrinking module 123, which can be used to narrow the cross-sectional size of the beam, that is, the size of the beam in a cross-section perpendicular to the beam propagation direction. The beam-shrinking module 123 may be disposed in the optical path before the beam enters the acousto-optic deflection module 124 or the electro-optic deflection module 126, and is configured to first shrink the beam emitted by the light source module 122 to a preset size before transmitting it to the acousto-optic deflection module 124 or the electro-optic deflection module 126. It should be understood that in some embodiments, the photoelectric detection device 10 is used as the main lidar of an automobile and needs to meet a large maximum detection distance value. Correspondingly, the light source module 122 is required to emit a sensing beam with a high light emission power. The higher the emission power of the light-emitting unit, the larger the divergence angle of the emitted beam. Since the acousto-optic deflection module 124 and the electro-optic deflection module 126 have an effective working area of ​​a certain size for the incident beam, in the scenario where the photoelectric detection device 10 is used as the main lidar of an automobile, the setting of the beam-shrinking module 123 can enable the relatively divergent beam emitted by the light source module 122 with a high light emission power to enter as much as possible from the effective working area of ​​the acousto-optic deflection module 124 and the electro-optic deflection module 126 for the incident beam, thereby improving the utilization rate of the light source.

[0096] It should be understood that in other embodiments, if the size of the beam emitted by the light source module 122 after collimation already meets the requirements of the acousto-optic deflection module 124 and the electro-optic deflection module 126 for the effective working area of ​​the incident beam, then the beam-shrinking module 123 may also be omitted.

[0097] In some embodiments, the beam scanning module 12 may further include a linear polarizer 1221. The linear polarizer 1221 is disposed in the optical path before the beam enters the acousto-optic deflection module 124 and is configured to convert the beam into linearly polarized light with a preset polarization state before entering the acousto-optic deflection module 124. It should be understood that in other embodiments, if other optical elements can convert the beam into linearly polarized light with a preset deflection state before the beam is transmitted to the acousto-optic deflection module 124, the linear polarizer 1221 may be omitted.

[0098] exist Figure 5 and Figure 6 In this embodiment, the beam-shrinking module 123 is disposed between the light source module 122 and the linear polarizer 1221. It should be understood that in other embodiments, the arrangement order of the beam-shrinking module 123 and the linear polarizer 1221 in the optical path can be interchanged, as long as both are disposed in the optical path before the light beam enters the acousto-optic deflection module 124. This application does not impose specific limitations on this.

[0099] like Figure 7 As shown, in some embodiments, the acousto-optic deflection module 124 includes an acousto-optic interaction medium 1241 and a sound wave generator 1242. The acousto-optic interaction medium 1241 has a preset light-incident surface 1244, a light-exit surface 1246, and a sound wave incident surface 1248. The sound wave generator 1242 is disposed on the sound wave incident surface 1248 and configured to generate sound waves propagating in a preset direction within the acousto-optic interaction medium 1241. The light beam emitted by the light source module 122 enters the acousto-optic interaction medium 1241 from the light-incident surface 1244 at a preset incident angle. Under the action of the sound waves, the acousto-optic interaction medium 1241 deflects the propagation direction of the light beam, and the deflected light beam exits from the light-exit surface 1246.

[0100] The incident angle can be defined as the angle between the incident direction of the light beam and the normal direction of the incident surface 1244. In some embodiments, the material of the acousto-optic interaction medium 1241 is tellurium dioxide (TeO2), the incident angle ranges from 2 to 10 degrees, and there is a preset off-axis angle θ between the propagation direction of the sound wave in the tellurium dioxide crystal and the lattice direction [1,1,0] of the tellurium dioxide crystal. α (Not shown in the image).

[0101] In some embodiments, the acoustic wave generator 1242 may be a piezoelectric transducer, which generates ultrasonic waves that propagate into the acousto-optic interaction medium 1241 to deflect the propagation direction of the light beam passing through the acousto-optic interaction medium 1241 at a preset incident angle.

[0102] It should be understood that the propagation of sound waves within the acousto-optic interaction medium 1241 will cause a change in the refractive index inside the acousto-optic interaction medium 1241. By reasonably configuring the parameters, the incident beam can undergo anomalous Bragg diffraction within the acousto-optic interaction medium 1241 under the action of sound waves. The propagation direction of the resulting diffracted beam is deflected relative to the propagation direction of the incident beam. The deflection angle α is related to the frequency f of the sound wave by equation (1):

[0103]

[0104] Where, θ d Let θ be the exit angle of the diffracted beam, and θ represent the propagation direction of the diffracted beam. i Let be the incident angle of the incident beam, represent the propagation direction of the incident beam, λ be the wavelength of the incident beam and the diffracted beam, n represent the refractive index of the acousto-optic interaction medium 1241, and V be the off-axis angle θ. α The relevant function value is denoted as V = V(θ). a The parameters configured above include the wavelength, polarization state, incident angle, and propagation direction of the incident beam, as well as the frequency and propagation direction of the sound wave. Therefore, by changing the frequency of the sound wave applied to the acousto-optic interaction medium 1241, the deflection angle of the beam passing through the medium can be controlled. When the frequency of the sound wave changes by Δf, the deflection angle of the beam changes accordingly, i.e., the scanning angle is...

[0105] It should be noted that the deflection angle α and scanning angle Δα mentioned above refer to the angle inside the acousto-optic interaction medium 1241. In actual applications, the angle outside the acousto-optic interaction medium 1241 is used. According to the law of refraction, the angle outside the acousto-optic interaction medium 1241 needs to be multiplied by the corresponding refractive index factor. Furthermore, since sound wave propagation takes time, when the frequency of the sound wave just begins to change from f1 to f2, the frequency of the sound wave in the acousto-optic interaction medium 1241 only changes from f1 to f2 in the local area immediately adjacent to the sound wave generator 1242, and the deflection angle of the beam changes from α1 to α2. The frequency of the sound wave and the deflection angle of the beam in the rest of the acousto-optic interaction medium 1241 have not yet changed. If the sound wave propagates through the entire area through which the beam passes in the acousto-optic interaction medium 1241, that is, the width of the acousto-optic interaction medium 1241, the time required is called the sound wave transit time. After the transit time, the frequency of the sound wave in the entire acousto-optic interaction medium 1241 changes from f1 to f2, and the deflection angle of the beam completely changes to α2. Therefore, when adjusting the frequency of the sound wave to change the deflection angle of the beam, the deflection time τ required for the beam to complete one deflection can be considered equal to the transit time of the sound wave. The calculation of the deflection time τ satisfies the following relationship (2):

[0106]

[0107] Where W is the aperture of the incident aperture of the light beam on the acousto-optic interaction medium 1241, that is, the width of the light beam incident on the acousto-optic interaction medium 1241, which is usually equal to the width of the acousto-optic interaction medium 1241, and V is the angle θ with respect to the off-axis. α The relevant function value is denoted as V = V(θ). a ).

[0108] In the acousto-optic interaction medium 1241, the wave vectors of the diffracted beam, the incident beam, and the sound wave need to satisfy the momentum matching condition in order to form a stable and coherent diffracted beam within the acousto-optic interaction medium 1241. The incident angle of the beam that produces anomalous Bragg diffraction changes with the frequency of the sound wave. However, in practical applications, the incident angle of the beam in the acousto-optic interaction medium 1241 remains constant. As the frequency of the sound wave changes, the momentum matching condition no longer holds. The further the beam deviates from the momentum matching condition, the greater the decrease in diffraction efficiency. The range of sound wave frequencies that can effectively complete anomalous Bragg diffraction is called the Bragg bandwidth. In some embodiments, the wavelength of the sensing beam is 905 nm, the material of the acousto-optic interaction medium 1241 is tellurium dioxide crystal, and the Bragg bandwidth of the corresponding acousto-optic deflection module 124 is approximately 30 MHz, the scanning angle is approximately 40 milliradians (mrad), or approximately 2.3 degrees, the deflection time τ required to complete one beam deflection is approximately 10 microseconds (μs), the change accuracy of the acoustic wave frequency is approximately 30 kHz, and the corresponding change accuracy of the scanning angle is approximately 0.04 mrad. Achieving acousto-optic deflection within the tellurium dioxide crystal using anomalous Bragg diffraction requires the incident beam to have a right-handed e-ray component. Optionally, if the incident beam is linearly polarized e-ray, the diffracted beam emitted after acousto-optic deflection is linearly polarized o-ray; if the incident beam is right-handed circularly polarized, the diffracted beam emitted after acousto-optic deflection is left-handed circularly polarized. The utilization rate of the outgoing diffracted beam is determined by the ellipticity of the intrinsic mode right-handed e-beam of the incident beam, which in turn is determined by the wavelength of the incident light, the incident angle, and the material properties of the acousto-optic interaction medium 1241.

[0109] like Figure 8 As shown, the electro-optic deflection module 126 includes an electro-optic interaction medium 1260 and an electrical signal source 1262. The electro-optic interaction medium 1260 has a preset incident surface 1261, an exit surface 1263, and an anode surface 1265 and a cathode surface 1266 corresponding to the electrical signal source 1262. The anode surface 1265 is connected to the anode of the electrical signal source 1262, and the cathode surface 1266 is connected to the cathode of the electrical signal source 1262. The electrical signal source 1262 is configured to generate an electric field along a preset direction within the electro-optic interaction medium 1260 through the anode and cathode. The applied electric field forms a refractive index gradient distribution within the electro-optic interaction medium 1260, causing the passing light beam to be deflected according to the refractive index gradient.

[0110] In some embodiments, the electro-optic interaction medium 1260 may be a cubic potassium tantalate niobate crystal (KTa). 1- x Nb xMaterials such as O3 and KTN can achieve electro-optic deflection by generating a secondary electro-optic effect through the application of an electric field. If the polarization direction of the incident beam is parallel to the direction of the applied electric field, the refractive index change of the KTN crystal under the action of the secondary electro-optic effect can be expressed as the relationship (3):

[0111]

[0112] Where n is the refractive index of the KTN crystal without an electric field; S 11 The second-order electro-optic coefficient of the KTN crystal is expressed in polarization form as the second-order coefficient g. 11 This can be represented as relation (4):

[0113]

[0114] Where ε0 and ε r These are the vacuum permittivity and the relative permittivity of the medium, respectively; g 11 It depends only on the crystal composition and the wavelength of the incident light, and is independent of temperature and dielectric constant. The injected charge enters the KTN crystal and is trapped to form a space charge field. Assuming the trapped charge density is N, according to Gauss's law, the electric field distribution inside the KTN crystal can be expressed as equation (5):

[0115]

[0116] Where e is the elementary charge, ε is the dielectric constant, and d is the distance between the anode and cathode of the KTN crystal.

[0117] When the light transmission distance is L, the beam polarization angle caused by the gradient refractive index can be expressed as equation (6):

[0118]

[0119] Substituting equations (3), (4), and (5) into equation (6), we obtain equation (7) for the electro-optic deflection angle:

[0120]

[0121] According to the above relationship (7), if the electro-optic interaction medium 1260 is a KTN crystal, the deflection angle of the light beam passing through the electro-optic interaction medium 1260 is proportional to the magnitude of the voltage formed between the anode surface 1265 and the cathode surface 1266 of the electro-optic interaction medium 1260 by the electric field applied by the electric signal source 1262. Therefore, by controlling the intensity of the electric field generated by the electric signal source 1262, the light beam passing through the electro-optic interaction medium 1260 can be deflected along the second direction by multiple different preset deflection angles within a preset second deflection angle range.

[0122] It should be understood that, because KTN crystals exhibit a strong secondary electro-optic effect near the phase transition temperature between the paraelectric and ferroelectric phases, thus achieving better beam deflection performance, in embodiments where the electro-optic interaction medium 1260 is a KTN crystal, the KTN crystal needs to be maintained near the phase transition temperature. Correspondingly, in some embodiments where the electro-optic interaction medium 1260 is a KIN crystal, the beam scanning module 12 further includes a temperature control module 127, configured to maintain the temperature of the electro-optic interaction medium 1260 within a preset temperature range, such as 20°C to 28°C, 23°C to 36°C, or 26°C to 38°C. The temperature control module 127 may include, for example, a temperature regulating device and a temperature sensor. The temperature regulating device may be, for example, a thermoelectric cooler (TEC) or other components capable of heating and cooling, and the temperature sensor may be, for example, a thermistor or other components capable of sensing temperature.

[0123] like Figure 5 and Figure 6 As shown, in some embodiments, the light source module 122, the acousto-optic deflection module 124, and the electro-optic deflection module 126 are arranged sequentially along the optical axis of the beam scanning module 12. That is, the beam emitted by the light source module 122 is first deflected along a first direction by the acousto-optic deflection module 124, and then deflected along a second direction by the electro-optic deflection module 126. The first direction is perpendicular to the second direction, the first direction is horizontal, and the second direction is vertical. It should be understood that, as mentioned above, optical devices such as the collimation module 121, the beam-shrinking module 123, and / or the linear polarizer 1221 can also be provided between the light source module 122 and the acousto-optic deflection module 124. This application does not limit this.

[0124] See also Figure 8 The light beam is set to be incident on the electro-optic deflection module 126 along the axis of symmetry. The negative sign in the above relationship (7) indicates that the light beam deflected by the electro-optic deflection module 126 will be deflected toward the cathode of the electrical signal source 1262. The electro-optic deflection module 126 is deflected toward the cathode of the electrical signal source 1262 with respect to the second deflection angle range of the light beam, and is not symmetrically arranged with respect to the incident direction of the light beam. Thus, as Figure 5 and Figure 6As shown, in order to ensure that the beam exits parallel to the horizontal plane when it deflects to the middle of the second deflection angle range, the electro-optic deflection module 126 is tilted at a preset angle relative to the horizontal plane. That is, the beam incident direction of the electro-optic deflection module 126 forms a preset tilt angle with the horizontal plane. It should be understood that the portion of the optical axis of the beam scanning module 12 within the electro-optic deflection module 126 bends with the beam deflection, bending from the original beam incident direction of the electro-optic deflection module 126 to the deflection angle in the middle of the second deflection angle range.

[0125] See also Figure 5 and Figure 7 Since the acousto-optic deflection module 124 uses first-order diffracted light as the deflection beam, and the zero-order light does not participate in the deflection scan, the portion of the optical axis of the beam scanning module 12 located within the acousto-optic deflection module 126 also bends with the deflection of the beam, bending from the incident direction of the beam in the acousto-optic deflection module 124 to the deflection angle in the middle of the first deflection angle range. Since the light beam is first deflected along the first direction by the acousto-optic deflection module 124, and then deflected along the second direction by the electro-optic deflection module 126, and the light beam needs to be incident obliquely onto the light-incident surface 1244 of the acousto-optic interaction medium 1241, the light-out surface 1246 of the acousto-optic deflection module 124 and the incident surface 1261 of the electro-optic deflection module 126 are set at an angle to each other, so that the deflection angle direction in the middle of the first deflection angle range of the acousto-optic deflection module 124 is aligned with the middle position of the incident surface 1261 of the electro-optic deflection module 126, thereby realizing the optical path connection between the acousto-optic deflection module 124 and the electro-optic deflection module 126.

[0126] In some embodiments, such as Figure 5 and Figure 6As shown, the acousto-optic deflection module 124 and the electro-optic deflection module 126 are flush, meaning that the acousto-optic deflection module 124, like the electro-optic deflection module 126, is also inclined relative to the horizontal plane. In this case, the direction of the beam deflected by the acousto-optic deflection module 124 onto the electro-optic deflection module 126 is perpendicular to the direction of the electric field formed by the electrical signal source within the electro-optic interaction medium 1260. The first direction of the beam deflected by the acousto-optic deflection module 124 and the optical axis of the beam scanning module 12 jointly define the first plane I. Since the beam deflected by the acousto-optic deflection module 124 is deflected within the first plane I, the deflected beam itself is its projection within the first plane I, and the angle between the deflected beam and the optical axis is the deflection angle of the beam deflected by the acousto-optic deflection module 124 along the first direction. The second plane II, defined by the second direction and the optical axis of the beam scanning module 12, is perpendicular to the first plane I. The axis of symmetry of the electro-optic deflection module 126 along the incident direction of the intermediate beam is the intersection line of the first plane I and the second plane II. The angle between the projection of the beam deflected by the electro-optic deflection module 126 onto the second plane II and the optical axis of the beam scanning module 12 is the deflection angle of the beam deflected by the electro-optic deflection module 126 along the first direction.

[0127] In some other embodiments, such as Figure 9 As shown, the acousto-optic deflection module 124 can also be horizontally arranged, while the electro-optic deflection module 126, for the same reasons as described above, still needs to be inclined relative to the horizontal plane. Therefore, the electro-optic deflection module 126 is also inclined relative to the acousto-optic deflection module 124. In this case, the deflected beam located at the middle deflection angle within the first deflection angle range deflected by the acousto-optic deflection module 124 no longer enters along the axis of symmetry of the electro-optic deflection module 126 penetrating its own incident surface 1261 and exit surface 1263, but instead enters at a preset inclined angle with the axis of symmetry of the electro-optic deflection module 126 penetrating its own incident surface 1261 and exit surface 1263.

[0128] In other embodiments, the second deflection angle range of the beam deflected by the electro-optic deflection module 126 in the vertical direction can also be configured to be non-symmetrically distributed about the horizontal direction. For example, the second deflection angle range can be tilted downwards in the horizontal direction as a whole, with most of the beam deflection angle located below the horizontal direction, to increase the coverage area of ​​the sensing beam on the ground; or, the second deflection angle range can be tilted upwards in the horizontal direction as a whole. This application does not impose specific limitations on this. It should be understood that the angle at which the electro-optic deflection module 126 is tilted relative to the horizontal plane is related to the tilt angle of the second deflection angle range relative to the horizontal direction.

[0129] In some embodiments, such as Figure 10 As shown, the beam scanning module 12 includes a light source module 122, an electro-optic deflection module 126, and an acousto-optic deflection module 124 arranged sequentially along the optical axis. That is, the beam emitted by the light source module 122 is first deflected along a second direction by the electro-optic deflection module 124, and then deflected along a first direction by the acousto-optic deflection module 124. The first direction is perpendicular to the second direction, which is a horizontal direction, and the second direction is a vertical direction. Similar to the aforementioned embodiments, optical devices such as the collimation module 121, the beam-shrinking module 123, and / or the linear polarizer 1221 can also be disposed between the light source module 122 and the electro-optic deflection module 126. This application does not impose any limitations on this. It should be understood that, for the electro-optic deflection module 126 that uses a KIN crystal to achieve electro-optic deflection, the second deflection angle range of the beam deflected along the second direction is biased toward the cathode of the electro-optic deflection module 126, and the setting angle of the electro-optic deflection module 126 and / or the acousto-optic deflection module 124 relative to the horizontal plane is related to the distribution of the sensing beam deflection angle range that the beam scanning module 12 ultimately wants to achieve relative to the horizontal direction.

[0130] like Figure 2 As shown, the beam scanning module 12 further includes a deflection angle amplification module 128. The deflection angle amplification module 128 is configured to further amplify the deflection angle of the beam after it has been deflected by the acousto-optic deflection module 124 and the electro-optic deflection module 126 along the first direction and / or the second direction, so as to form the sensing beam.

[0131] See also Figure 5 , Figure 6 and Figure 9 The deflection angle amplification module 128 includes a first deflection angle amplification unit 1281 and / or a second deflection angle amplification unit 1282. In some embodiments, the first deflection angle amplification unit 1281 is configured to amplify the deflection angle of the transmitted light beam along the first direction or the second direction, and the second deflection angle amplification unit 1282 is configured to amplify the deflection angle of the transmitted light beam simultaneously along both the first direction and the second direction. The first direction is perpendicular to the second direction. For example, the first direction is horizontal, and the second direction is vertical.

[0132] Optionally, in some embodiments, the first deflection angle amplification unit 1281 includes a first cylindrical deflection lens 1283, which is configured to deflect the transmitted light beam along a first direction to amplify the deflection angle of the transmitted light beam along the first direction by a preset factor. For example... Figure 11As shown, the first cylindrical deflecting lens 1283 includes an incident surface 1283a and an exit surface 1283b sequentially arranged along the beam propagation direction. At least one of the exit surface 1283b and the incident surface 1283a is an optical surface for deflecting the beam along the first direction. For example, in some embodiments, the optical surface is the exit surface 1283b, and the optical surface is a curve on the cross section III of the first cylindrical deflecting lens 1283 perpendicular to the second direction; the optical surface is a straight line on the cross section IV of the first cylindrical deflecting lens 1283 perpendicular to the first direction. The second direction is perpendicular to the first direction, the first direction is horizontal, and the second direction is vertical. It should be understood that... Figure 11 In the illustrated embodiment, the optical surface is a concave surface, while in some other embodiments, the optical surface may also be a convex surface.

[0133] Optionally, in some other embodiments, the first deflection angle amplification unit 1281 includes a second cylindrical deflection lens 1284, which is configured to deflect the transmitted light beam along the second direction to amplify the deflection angle of the transmitted light beam along the second direction by a preset factor. For example... Figure 12 As shown, the second cylindrical deflecting lens 1284 includes an incident surface 1284a and an exit surface 1284b sequentially arranged along the beam propagation direction. At least one of the exit surface 1284a and the incident surface 1284b is an optical surface for deflecting the beam along the second direction. For example, in some embodiments, the optical surface is the exit surface 1284b, and the optical surface is a curve on the cross section V of the second cylindrical deflecting lens perpendicular to the first direction; the optical surface is a straight line on the cross section VI of the second cylindrical deflecting lens perpendicular to the second direction. The second direction is perpendicular to the first direction, the first direction is horizontal, and the second direction is vertical. It should be understood that... Figure 12 In the illustrated embodiment, the optical surface is a concave surface, while in some other embodiments, the optical surface may also be a convex surface.

[0134] Optionally, in some embodiments, the second deflection angle magnification unit 1282 includes at least one axisymmetric lens, the shape of which is symmetrically distributed about the optical axis passing through its optical center, so as to simultaneously magnify the transmitted light beam by a predetermined factor along the deflection angles of the first and second directions. For example, the axisymmetric lens can be a convex lens or a concave lens. The second deflection angle magnification unit 1282 can be a lens combination including one or more convex lenses and one or more concave lenses.

[0135] Optionally, in some other embodiments, the second deflection angle amplification unit 1282 includes a two-dimensional deflection superlens 1285, configured to simultaneously amplify the deflection angle of the beam passing through the light beam along both the first and second directions. For example... Figure 13 As shown, the two-dimensional deflecting superlens 1285 has multiple optical modulation units 1285a arranged in a two-dimensional array. The light beam, after being deflected by the acousto-optic deflection module 124 and the electro-optic deflection module 126, is incident on one of the optical modulation units 1285a. Each optical modulation unit 1285a is configured to modulate the optical properties of the transmitted light beam to simultaneously amplify the deflection angle of the transmitted light beam by a preset factor along both the first and second directions. The positions of the multiple optical modulation units 1285a on the two-dimensional deflecting superlens 1285 are correspondingly set according to the different deflection angles of the light beam after being deflected by the acousto-optic deflection module 124 and the electro-optic deflection module 126. The two-dimensional deflecting superlens 1285 includes an incident light side 1285b and an exit light side 1285c arranged opposite to each other. Each light modulation unit 1285a has a corresponding incident light area and an exit light area on the incident light side 1285b and the exit light side 1285c, respectively. After the light beam enters the two-dimensional deflecting superlens 1285 from the incident light area of ​​one light modulation unit 1285a, it is emitted from the corresponding exit light area of ​​the same light modulation unit 1285a at a preset deflection angle. The optical modulation unit 1285a is provided with a large number of subwavelength structural units (not shown in the figure), which are arranged in a structural array on a two-dimensional surface to modulate the optical properties of the transmitted light beam, such as amplitude, phase, wavelength, and polarization state. By designing the shape, size, and arrangement of the structural units, the optical modulation unit 1285a can simultaneously amplify the deflection angle of the transmitted light beam along both the first and second directions by a corresponding preset factor. The amplification factor of the deflection angle of the transmitted light beam along the first direction and the amplification factor of the deflection angle of the transmitted light beam along the second direction can be designed to be the same or different. It should be understood that since the superlens is a planar optical device and relatively thin, the light beam does not suffer from problems such as spherical aberration after passing through the two-dimensional deflection superlens 1285, which is beneficial to improving the scanning accuracy of the sensing beam emitted by the beam scanning module 12.

[0136] In some embodiments, the first deflection angle amplification unit 1281 is configured to amplify the deflection angle of the light beam along the first direction, and the second deflection angle amplification unit 1282 is configured to amplify the deflection angle of the light beam along the second direction. The first direction is perpendicular to the second direction. For example, the first direction is horizontal, and the second direction is vertical.

[0137] Optionally, in some embodiments, the first deflection angle amplification unit 1281 includes, for example, Figure 11The first cylindrical deflecting lens 1283 shown is configured to deflect the light beam passing through along the first direction. The specific structure of the first cylindrical deflecting lens 1283 is as described above and will not be repeated here.

[0138] Optionally, in some embodiments, the first deflection angle amplification unit 1281 includes a first one-dimensional deflection superlens 1286. For example... Figure 14 As shown, a plurality of optical modulation sections 1286a are formed on the first one-dimensional deflecting superlens 1287 arranged along the first direction. The light beam, after being deflected by the acousto-optic deflection module 124 and the electro-optic deflection module 126, is incident on one of the optical modulation sections 1286a. Each optical modulation section 1286a is configured to modulate the optical properties of the transmitted light beam to amplify the deflection angle of the transmitted light beam along the first direction by a preset factor. The positions of the plurality of optical modulation sections 1286a on the first one-dimensional deflecting superlens 1286 are correspondingly set according to different angles of deflection of the light beam by the acousto-optic deflection module 124 along the first direction. It should be understood that the optical modulation sections 1286a extend a preset length along the second direction so that the light beam, after being deflected by the electro-optic deflection module 126 along the second direction, can also be incident on the optical modulation section 1286a corresponding to the deflection angle along the first direction. The first one-dimensional deflecting superlens 1286 includes an incident light side 1286b and an exit light side 1286c arranged opposite to each other. Each light modulation unit 1286a has a corresponding incident light area and an exit light area on the incident light side 1286b and the exit light side 1286c, respectively. After the light beam enters the first one-dimensional deflecting superlens 1286 from the incident light area of ​​one light modulation unit 1286a, it exits from the corresponding exit light area of ​​the same light modulation unit 1286a at a preset deflection angle. The light modulation unit 1286a is provided with a large number of subwavelength structural units (not shown in the figure), which are arranged on a two-dimensional surface to form a structural array to modulate the optical properties of the transmitted light beam, such as amplitude, phase, wavelength, and polarization state. By designing the shape, size, and arrangement of the structural units, the light modulation unit 1286a can expand the deflection angle of the transmitted light beam along the first direction by a corresponding preset multiple. It should be understood that, since the superlens is a planar optical device and relatively thin, the beam passing through the first one-dimensional deflecting superlens 1286 will not cause problems such as spherical aberration, which is beneficial to improving the scanning accuracy of the sensing beam emitted by the beam scanning module 12.

[0139] Optionally, in some embodiments, the second deflection angle amplification unit 1282 includes, for example, Figure 12 The second cylindrical deflecting lens 1284 shown is configured to deflect the light beam passing through along the second direction. The specific structure of the second cylindrical deflecting lens 1284 is as described above and will not be repeated here.

[0140] Optionally, in some embodiments, the second deflection angle amplification unit 1282 includes a second one-dimensional deflection superlens 1288. For example... Figure 15 As shown, a plurality of optical modulation sections 1288a arranged along the second direction are formed on the second one-dimensional deflecting superlens 1288. The light beam, after being deflected by the acousto-optic deflection module 124 and the electro-optic deflection module 126, is incident on one of the optical modulation sections 1288. Each optical modulation section 1288 is configured to modulate the optical properties of the transmitted light beam to amplify the deflection angle of the transmitted light beam along the second direction by a preset factor. The positions of the plurality of optical modulation sections 1288a on the second one-dimensional deflecting superlens 1288 are correspondingly set according to different angles of deflection of the light beam along the second direction by the electro-optic deflection module 126. It should be understood that the optical modulation section 1288 extends a preset length along the first direction so that the light beam, after being deflected along the first direction by the acousto-optic deflection module 124, can also be incident on the optical modulation section 1288a corresponding to the deflection angle along the second direction. The second one-dimensional deflecting superlens 1288 includes an incident light side 1288b and an exit light side 1288c arranged opposite to each other. Each light modulation unit 1288a has a corresponding incident light area and an exit light area on the incident light side 1288b and the exit light side 1288c, respectively. After the light beam enters the second one-dimensional deflecting superlens 1288 from the incident light area of ​​one light modulation unit 1288a, it exits from the corresponding exit light area of ​​the same light modulation unit 1288a at a preset deflection angle. The light modulation unit 1288a is provided with a large number of subwavelength structural units (not shown in the figure), which are arranged on a two-dimensional surface to form a structural array to modulate the optical properties of the transmitted light beam, such as amplitude, phase, wavelength, and polarization state. By designing the shape, size, and arrangement of the structural units, the light modulation unit 1288a can expand the deflection angle of the transmitted light beam along the second direction by a corresponding preset multiple. It should be understood that, since the superlens is a planar optical device and relatively thin, the beam passing through the second one-dimensional deflecting superlens 1288 will not cause problems such as spherical aberration, which is beneficial to improving the scanning accuracy of the sensing beam emitted by the beam scanning module 12.

[0141] It should be understood that, in the above embodiments, the arrangement order of the first deflection angle amplification unit 1281 and the second deflection angle amplification unit 1282 along the optical axis of the beam scanning module can be interchanged.

[0142] In some embodiments, the electro-optic interaction medium 1260 is a material such as lithium niobate (LiNbO3, LN), lithium tantalate (LiTaO3, LT), or potassium titanium oxyphosphate (KTiOPO4, KTP), which can achieve electro-optic deflection by generating a birefringence effect of light through the application of an electric field. Figure 16As shown, the electro-optic interaction medium 1260 can be, for example, a triangular prism shape, having a predetermined incident surface 1261, an exit surface 1263, and a first electrode surface 1267 and a second electrode surface 1268 corresponding to the electrical signal source 1262. The first electrode surface 1267 and the second electrode surface 1268 are the top and bottom surfaces of the triangular prism, which are parallel to each other. The incident surface 1261 and the exit surface 1263 are the side surfaces of the triangular prism, which are perpendicularly connected to the first electrode surface 1267 and the second electrode surface 1268, respectively. The electrodes of the electrical signal source 1262 with opposite polarities are connected to the first electrode surface 1267 and the second electrode surface 1268, respectively, to generate an electric field with varying intensity along a predetermined direction within the electro-optic interaction medium 1260. The light beam enters the electro-optic interaction medium 1260 from the incident surface 1261, is deflected within the electro-optic interaction medium 1260, and then exits from the exit surface 1263. The deflection direction of the light beam is approximately perpendicular to the direction of the electric field formed within the electro-optic interaction medium 1260, and the deflection plane of the light beam is approximately parallel to the first electrode surface 1267 and the second electrode surface 1268. The deflection angle range of the light beam can be symmetrically distributed about the incident direction of the light beam. By switching the polarity of the electric field applied by the electrical signal source, the light beam can be deflected in opposite angle ranges on both sides of the incident direction.

[0143] Please refer to the following: Figure 16 and Figure 17 The electro-optic deflection module 126 includes multiple electro-optic interaction media 1260s, which are cascaded together in a staggered manner with sharp corners. Each electro-optic interaction media 1260 has a corresponding electric field applied via the electrical signal source 1262 through its respective first electrode surface 1267 and second electrode surface 1268. The light beam enters from the incident surface 1261 of the outermost electro-optic interaction media 1260 and passes through multiple electro-optic interaction media 1260s sequentially before emitting from the exit surface 1263 of the last electro-optic interaction media 1260. When the light beam passes through one of the electro-optic interaction media 1260s, it is further deflected based on the deflection angle of the previous electro-optic interaction media 1260. Therefore, after passing through multiple cascaded electro-optic interaction media 1260s, the light beam can obtain a large second deflection angle range. It should be understood that the multiple cascaded electro-optic interaction media 1260s can each have different dimensions; or, two or more of them can have the same size, which is not limited in this application.

[0144] Since the electro-optic interaction medium 1260 that achieves electro-optic deflection based on birefringence requires the incident beam to have a small width in the deflection direction, the beam scanning module 12 also includes a beam shrinking module 123 disposed in the optical path before entering the electro-optic deflection module to reduce the size of the beam along the second direction. The beam shrinking module 123 can be, for example, a cylindrical beam shrinking lens or a beam shrinking lens group including multiple cylindrical beam shrinking lenses.

[0145] Since the electro-optic deflection module 126 can obtain a large second deflection angle range by cascading multiple electro-optic interaction media 1260, correspondingly, the deflection angle amplification module 128 of the beam scanning module 12 can only include a first deflection angle amplification unit 1281 for amplifying the beam deflection angle along the first direction. The first deflection angle amplification unit 1281 can be, for example, as shown below. Figure 11 The first cylindrical deflecting lens 1283 shown, or as... Figure 14 The first one-dimensional deflecting superlens 1286 is shown.

[0146] It should be understood that the number of deflectable angles (also known as the number of resolvable points) that the acousto-optic deflection module 124 and the electro-optic deflection module 126 can achieve within their respective deflection angle ranges are related to the width of the effective action area of ​​the acousto-optic deflection module 126 and the electro-optic deflection module 124 for the incident beam along the deflection direction, as shown in Equation (8):

[0147] N=ΔαW / λ

[0148] Wherein, N represents the number of deflectable angles that the acousto-optic deflection module 124 and the electro-optic deflection module 126 can achieve within their respective deflection angle ranges, Δα represents the deflection angle ranges of the acousto-optic deflection module 124 and the electro-optic deflection module 126, W represents the width of the effective action area of ​​the acousto-optic deflection module 126 and the electro-optic deflection module 124 along the deflection direction, and λ represents the wavelength of the incident beam. Since the size of the effective action area of ​​the electro-optic interaction medium 1260 for the incident beam is limited by the voltage provided by the electrical signal source 1262, the number of deflectable angles that the electro-optic deflection module 126 can achieve within the corresponding second deflection angle range will be less than the number of deflectable angles that the acousto-optic deflection module 124 can achieve within the corresponding first deflection angle range. Therefore, for deflection directions requiring a higher number of deflectable angles, the acousto-optic deflection module 124 is used to achieve beam deflection. For example, for the beam scanning module 12 used in automotive main LiDAR, a large number of deflectable angles are required in the horizontal direction. Therefore, the acousto-optic deflection module 124 is used to realize the deflection of the sensing beam in the horizontal direction, while the electro-optic deflection module 126 is used to realize the deflection of the sensing beam in the vertical direction.

[0149] Specifically, in some embodiments, the beam scanning module 12 includes an acousto-optic deflection module 124 for deflecting the sensing beam horizontally, an electro-optic deflection module 126 for deflecting the sensing beam vertically, and a deflection angle amplification module 128. The acousto-optic deflection module 124 has an effective horizontal area of ​​2.6 mm for the incident beam, achieving a first deflection angle range of +1.5 to -1.5 degrees and 150 possible horizontal deflection angles. The electro-optic deflection module 126 uses a KTN crystal as its electro-optic interaction medium, has an effective vertical area of ​​0.8 mm for the incident beam, achieving a second vertical deflection angle range of +3.2 to -3.2 degrees and 96 possible vertical deflection angles. The beam scanning module 12 may also include a temperature control module 127 (see...). Figure 2 This is to maintain the temperature of the KTN crystal within a preset temperature range. The deflection angle amplification module 128 includes a first deflection angle amplification unit 1281 and a second deflection angle amplification unit 1282. The first deflection angle amplification unit 1281 is configured to amplify the deflection angle of the transmitted light beam along the horizontal direction, and the second deflection angle amplification unit 1282 is configured to amplify the deflection angle of the transmitted light beam simultaneously along both the horizontal and vertical directions. The first deflection angle amplification unit 1281 includes a first cylindrical deflection lens 1283, which deflects the transmitted light beam along the horizontal direction to amplify the horizontal deflection angle of the transmitted light beam by a preset factor, for example, 10 times. It should be understood that the optical surface on the first cylindrical deflection lens 1283 used to deflect the light beam is curved on the cross-section of the first cylindrical lens 1283 perpendicular to the vertical direction, and straight on the cross-section of the first cylindrical deflection lens 1283 perpendicular to the horizontal direction. The second deflection angle magnification unit 1282 includes an axisymmetric lens, which can magnify the transmitted light beam by a preset factor, such as 4 times, at the same time along the horizontal and vertical deflection angles.

[0150] Therefore, the light beam emitted by the light source module 122 is deflected horizontally by a 3-degree range by the acousto-optic deflection module 124, and then the first cylindrical deflection lens 1283 and the axisymmetric lens amplify the horizontal deflection angle by 10 times and 4 times respectively. This results in the sensing light beam emitted by the beam scanning module 12 achieving a horizontal deflection angle range of 120 degrees and 150 deflectable angles. Correspondingly, the light beam emitted by the light source module 122 is deflected vertically by a 6.4-degree range by the electro-optic deflection module 126, and then the axisymmetric lens amplifies the vertical deflection angle by 4 times. This results in the sensing light beam emitted by the beam scanning module 12 achieving a vertical deflection angle range of 25.6 degrees and 96 deflectable angles.

[0151] In another embodiment, the beam scanning module 12 includes an acousto-optic deflection module 124 for deflecting the sensing beam horizontally, an electro-optic deflection module 126 for deflecting the sensing beam vertically, and a deflection angle amplification module 128. The acousto-optic deflection module 124 has an effective area of ​​2.6 mm in width along the horizontal direction for the incident beam, and can achieve a first deflection angle range of +1.5 degrees to -1.5 degrees in the horizontal direction, with 150 possible deflection angles along the horizontal direction. The electro-optic deflection module 126 uses a KTN crystal as its electro-optic interaction medium 1260, and has an effective area of ​​0.9 mm in width along the vertical direction for the incident beam, achieving a second deflection angle range of +0.96 degrees to -0.96 degrees in the vertical direction, with 32 possible deflection angles along the vertical direction. The deflection angle amplification module 128 includes a second deflection angle amplification unit 1282, configured to simultaneously amplify the deflection angle of the passing beam along both the horizontal and vertical directions. The second deflection angle amplification unit 1282 is, for example, a two-dimensional deflection superlens 1285, designed to amplify the deflection angle of the transmitted light beam by a factor of 40 in the horizontal direction and by a factor of 13.3 in the vertical direction. It should be understood that the two-dimensional deflection superlens 1285 has multiple light modulation sections 1285a arranged in two dimensions in both the horizontal and vertical directions. The positions of the multiple light modulation sections 1285a correspond to each deflection angle of the light beam after deflection by the acousto-optic deflection module 124 and the electro-optic deflection module 126. Each light modulation section 1285a is configured to simultaneously amplify the incident light beam by a factor of 40 in the horizontal direction and by a factor of 13.3 in the vertical direction, based on the initial deflection angle.

[0152] Therefore, the light beam emitted by the light source module 122 is deflected horizontally by a 3-degree range by the acousto-optic deflection module 124, and then the deflection angle in the horizontal direction is correspondingly amplified by 40 times by the two-dimensional deflection superlens 1285. This results in the sensing light beam emitted by the beam scanning module 12 achieving a deflection angle range of 120 degrees and 150 deflectable angles in the horizontal direction. Correspondingly, the light beam emitted by the light source module 122 is deflected vertically by a 1.92-degree range by the electro-optic deflection module 126, and then the deflection angle in the vertical direction is amplified by 13.3 times by the two-dimensional deflection superlens 1285. This results in the sensing light beam emitted by the beam scanning module 12 achieving a deflection angle range of 25.5 degrees and 32 deflectable angles in the vertical direction.

[0153] In another embodiment, the beam scanning module 12 includes an acousto-optic deflection module 124 for deflecting the sensing beam horizontally, an electro-optic deflection module 126 for deflecting the sensing beam vertically, and a deflection angle amplification module 128. The acousto-optic deflection module 124 has an effective horizontal area of ​​2.6 mm for the incident beam, achieving a first deflection angle range of +1.5 degrees to -1.5 degrees, and 150 possible horizontal deflection angles. The electro-optic deflection module 126 consists of multiple cascaded LT, LN, or KTP crystals, with an effective vertical area of ​​0.07 mm for the incident beam, achieving a second vertical deflection angle range of +12.8 degrees to -12.8 degrees, and 32 possible vertical deflection angles. The beam scanning module 12 further includes a beam-shrinking module 123, configured to reduce the size of the beam in the vertical direction to accommodate the smaller effective area of ​​the incident beam by the electro-optic deflection module 126. The deflection angle amplification module 128 includes a second deflection angle amplification unit 1282, configured to amplify the deflection angle of the transmitted beam in the horizontal direction. The second deflection angle amplification unit 1282 is, for example, a first one-dimensional deflection superlens 1286, designed to amplify the horizontal deflection angle of the transmitted beam by a factor of 40. It should be understood that the first one-dimensional deflection superlens 1286 has a plurality of light modulation sections 1286a arranged horizontally. The positions of the plurality of light modulation sections 1286a correspond to each horizontal deflection angle of the beam after deflection by the acousto-optic deflection module 124. Each light modulation section 1286a is configured to amplify the incident beam by a factor of 40 in the horizontal direction based on the initial deflection angle.

[0154] Therefore, the light beam emitted by the light source module 122 is deflected horizontally by a 3-degree range by the acousto-optic deflection module 124, and then the first one-dimensional deflection superlens 1286 amplifies the horizontal deflection angle by a factor of 40. This results in the sensing light beam emitted by the beam scanning module 12 achieving a horizontal deflection angle range of 120 degrees and 150 deflectable angles. It should be understood that since the electro-optic deflection module 126, through cascading, already enables the light beam emitted by the light source module 122 to achieve a large vertical deflection range of 25.6 degrees, the deflection angle amplification module 128 does not need to be configured to amplify the vertical deflection angle of the light beam.

[0155] like Figure 2 As shown, the photoelectric detection device 10 further includes a control module 18, which is configured to control the beam scanning module 12 to emit a sensing beam to scan the field of view, and to control the receiving module 14 to sense the beam returning from the field of view in conjunction with the scanning of the sensing beam. In some embodiments, the control module 18 may include functional units such as a light source control unit 182, an acousto-optic deflection control unit 184, an electro-optic deflection control unit 186, and a sensing control unit 188.

[0156] The acousto-optic deflection control unit 184 is configured to control the acousto-optic deflection module 124 to deflect the transmitted light beam along a first direction by a preset deflection angle within a corresponding first deflection angle range. As mentioned above, the acousto-optic deflection control unit 184 can control the deflection angle of the transmitted light beam by the acousto-optic deflection module 124 by adjusting the frequency of the sound waves applied to the acousto-optic interaction medium 1241. The deflection time τ required for the acousto-optic deflection module 124 to change the deflection angle of the light beam once is approximately 10 microseconds. It should be understood that the acousto-optic deflection control unit 184 may include at least the driving circuit of the sound wave generator 1242 to control the frequency of the sound waves applied to the acousto-optic deflection module 124.

[0157] The electro-optic deflection control unit 186 is configured to control the electro-optic deflection module 126 to deflect the transmitted light beam along a second direction by a preset deflection angle within a corresponding second deflection angle range. As mentioned above, the electro-optic deflection control unit 186 can control the deflection angle of the transmitted light beam by the electro-optic deflection module 126 by adjusting the electric field strength applied to the electro-optic interaction medium 1260 by the electrical signal source. Since the adjustment of the applied electric field can be transmitted to the electro-optic interaction medium 1260 at the speed of light, the electro-optic deflection module 126 can change the deflection angle of the transmitted light beam faster than the acousto-optic deflection module 124. Moreover, since electro-optic deflection does not involve light diffraction, the electro-optic deflection module 126 has less light loss than the acousto-optic deflection module 124.

[0158] The light source control unit 182 is configured to control the light source module 122 to emit sensing beam pulses according to a preset time sequence. As mentioned above, in order to make the time-correlated single-photon counting method used in dToF measurement mathematically statistically meaningful, the light source control unit 182 controls the corresponding light source module 122 to emit multiple sensing beam pulses according to a preset time sequence within a partitioned detection period, such as: tens, hundreds, thousands, tens of thousands, or even millions. The emission of one sensing beam pulse corresponds to one sensing period, that is, one partitioned detection period includes multiple sensing periods.

[0159] The sensing control unit 188 is configured to control the associated photosensitive pixels 142 to perform sensing during corresponding sensing periods in response to light signals from the field of view. It should be understood that in some embodiments, the sensing control unit 142 controls a portion of the photosensitive pixels 142 to work in conjunction with the receiving optics 144 to sense light signals from corresponding preset directions. The working associated photosensitive pixels 142 are related to the scanning direction of the current sensing beam pulse. Therefore, when the sensing beam pulse scans different directions within the field of view during different partition detection periods, the sensing control unit 142 also controls different associated photosensitive pixels 142 to perform sensing accordingly.

[0160] During beam scanning, the acousto-optic deflection control unit 184 controls the acousto-optic deflection module 124 to adjust the deflection angle of the sensing beam along the first direction, and the electro-optic deflection control unit 186 controls the electro-optic deflection module 126 to adjust the deflection angle of the sensing beam along the second direction, thereby adjusting the deflection angle of the sensing beam for two-dimensional scanning within the field of view. For each preset deflection angle of the sensing beam within the field of view, the light source control unit 182 controls the light source module 122 to emit sensing beam pulses according to a preset time sequence, and the sensing control unit 188 controls the relevant photosensitive pixels 142 to sense the light signal from the direction corresponding to that beam deflection angle, thereby performing three-dimensional detection in the direction corresponding to that beam deflection angle.

[0161] For each deflection angle of the sensing beam, the beam scanning module 12 needs to emit multiple sensing beam pulses to detect the distance information in the direction illuminated by that beam deflection angle. The number of sensing beam pulses emitted by the beam scanning module 12 along different preset deflection angles can be different. For example, the number of sensing beam pulses emitted along a certain direction can be set according to the maximum distance detection value that the photoelectric detection device 10 needs to meet in the direction illuminated by each preset deflection angle. Within the partitioned detection period related to the preset deflection angle, a sensing time period corresponding to the number of sensing beam pulses is set.

[0162] The duration of the sensing period can be set according to the maximum distance detection value that the detected partition needs to meet, and should be at least greater than the photon flight time corresponding to the maximum distance detection value. Multiple different sensing periods belonging to the same partition detection period can be set to have the same duration.

[0163] In some embodiments, for multiple different sensing time periods, the sensing beam pulses can be emitted at the same time in the corresponding sensing time period, for example, all emitted at the beginning of the sensing time period; while in other embodiments, for multiple different sensing time periods, the sensing beam pulses can also be emitted at different times in each corresponding sensing time period, so as to prevent interference between different photoelectric detection devices 10 or reduce crosstalk between adjacent photosensitive pixels on the receiving module. The multiple different sensing time periods can belong to the same partition detection time period or belong to different partition detection time periods.

[0164] In some embodiments, the sensing time period length can be different when scanning and sensing partitions located at different preset deflection angles within the field of view. For example, the sensing time period length in the partition detection time period is positively correlated with the maximum distance detection value that the corresponding detection area needs to meet. For detection areas with a larger maximum distance detection value, the corresponding sensing time period is longer; for detection areas with a smaller maximum distance detection value, the corresponding sensing time period is shorter.

[0165] In some embodiments, all or part of the functional units in the control module 18 and / or processing module 15 may include firmware embedded in the storage medium 30 or computer software code stored in the storage medium 30, and be executed by one or more corresponding processors 40 to control related components to achieve corresponding functions. The processor 40 may be, for example, but not limited to, an application processor (AP), a central processing unit (CPU), a microcontroller unit (MCU), etc. The storage medium 30 may include, but is not limited to, flash memory, electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), hard disk, etc.

[0166] In some embodiments, the processor 40 and / or storage medium 30 may be disposed within the photoelectric detection device 10, for example, integrated on the same circuit board as the beam scanning module 12 or the receiving module 14. Optionally, in other embodiments, the processor 40 and / or storage medium 30 may also be disposed in other locations of the electronic device 1, such as on the main circuit board of the electronic device 1.

[0167] In some embodiments, some or all of the functional units of the control module 18 and / or processing module 15 may also include hardware, for example, implemented by any one or a combination of the following techniques: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), object-specific drive circuits, etc.

[0168] It is understood that some different functional units of the control module 18 and / or processing module 15 may each include the same hardware. For example, the acoustic-optical deflection control unit 184 and the emission energy adjustment unit 189 may both include the drive circuit of the acoustic wave generator 1242.

[0169] It is understood that the hardware used to implement the functions of the control module 18 and / or processing module 15 can be located within the photoelectric detection device 10. Alternatively, the hardware used to implement the functions of the control module 18 and / or processing module 15 can also be located in other locations on the electronic device 1, such as on the main circuit board of the electronic device 1.

[0170] like Figure 18 As shown, in some embodiments, the photoelectric detection device 10 is, for example, a lidar, and the electronic device 1 is, for example, a car. The lidar can be installed in multiple different locations on the car to detect the distance information of objects within the car's surrounding area and thereby achieve driving control.

[0171] Compared to lidar that uses mechanical rotation and hybrid solid-state methods to achieve sensing beam scanning, the lidar provided in this application uses a pure solid-state acousto-optic deflection module 124 and a secondary deflection module 126 to achieve sensing beam deflection scanning. Since it no longer relies on rotating or vibrating components, it has higher reliability and a more compact structure, is easier to pass strict automotive-grade requirements, and has less impact on the appearance of the car.

[0172] It should be noted that the technical solution to be protected by this application may satisfy only one of the above embodiments or simultaneously satisfy multiple of the above embodiments. In other words, embodiments composed of one or more of the above embodiments also fall within the protection scope of this application.

[0173] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with the said embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0174] It should be understood that various parts of the embodiments of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple functional units can be implemented using software or firmware stored in a storage medium and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0175] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A two-dimensional deflection beam scanning module, characterized in that, Configured to emit a two-dimensionally deflectable sensing beam into a field of view for use by a lidar to perform three-dimensional information detection of objects within the field of view based on the time-of-flight principle, the beam scanning module includes: arranged along its own optical axis. The light source module is configured to emit a light beam along the optical axis; An acousto-optic deflection module includes an acousto-optic interaction medium and a sound wave generator, wherein the sound wave generator is configured to generate a sound wave propagating in a preset direction within the acousto-optic interaction medium to deflect a light beam passing through the acousto-optic interaction medium in a first direction. An electro-optic deflection module includes an electro-optic interaction medium and an electrical signal source, wherein the electrical signal source is configured to generate an electric field in the electro-optic interaction medium along a preset direction to deflect a light beam passing through the electro-optic interaction medium along a second direction different from the first direction. The deflection angle amplification module is configured to further amplify the deflection angle of the light beam after it has been deflected by the acousto-optic deflection module and the electro-optic deflection module along the first direction and / or the second direction, so as to form the sensing light beam. as well as A control circuit is connected to both the acousto-optic deflection module and the electro-optic deflection module. The control circuit is configured to control the frequency of the sound waves emitted by the sound wave generator to deflect the light beam passing through the acousto-optic interaction medium along the first direction by multiple different preset deflection angles within a preset first deflection angle range; and is configured to control the intensity of the electric field generated by the electrical signal source to deflect the light beam passing through the electro-optic interaction medium along the second direction by multiple different preset deflection angles within a preset second deflection angle range. The first direction and the optical axis together define a first plane, and the second direction and the optical axis define a second plane. The deflection angle of the deflected beam along the first direction is defined as the angle between the projection of the deflected beam in the first plane and the optical axis. The deflection angle of the deflected beam along the second direction is defined as the angle between the projection of the deflected beam in the second plane and the optical axis. The light-emitting surface of the acousto-optic deflection module and the incident surface of the electro-optic deflection module are inclined to each other at a preset angle so that the deflection angle direction in the middle of the first deflection angle range of the acousto-optic deflection module is aligned with the middle position of the incident surface of the electro-optic deflection module.

2. The beam scanning module as described in claim 1, characterized in that, The first direction and the second direction are set perpendicular to each other, the first direction is horizontal and the second direction is vertical; or, the first direction is vertical and the second direction is horizontal.

3. The beam scanning module as described in claim 1, characterized in that, The beam scanning module also includes: The collimation module is configured to collimate the light beam emitted by the light source module along the optical axis before it enters the acousto-optic deflection module and the electro-optic deflection module.

4. The beam scanning module as described in claim 1, characterized in that, The deflection angle amplification module includes a first deflection angle amplification unit and / or a second deflection angle amplification unit. The first deflection angle amplification unit is configured to amplify the deflection angle of the passing light beam along the first direction, and the second deflection angle amplification unit is configured to amplify the deflection angle of the passing light beam along the second direction.

5. The beam scanning module as described in claim 4, characterized in that, The first deflection angle magnification unit includes a first cylindrical deflection lens, which is configured to deflect the transmitted light beam along the first direction to amplify the deflection angle of the transmitted light beam along the first direction by a preset factor. The first cylindrical deflection lens includes an incident surface and an exit surface arranged sequentially along the light beam propagation direction. At least one of the exit surface and the incident surface is an optical surface for deflecting the light beam along the first direction. The optical surface is curved on the cross section of the first cylindrical deflection lens perpendicular to the second direction, and the optical surface is straight on the cross section of the first cylindrical deflection lens perpendicular to the first direction. The second direction is perpendicular to the first direction.

6. The beam scanning module as described in claim 4, characterized in that, The first deflection angle amplification unit includes a first one-dimensional deflection superlens. Multiple optical modulation sections are formed on the first one-dimensional deflection superlens and arranged along the first direction. The light beam deflected by the acousto-optic deflection module and the electro-optic deflection module is incident on one of the optical modulation sections. Each optical modulation section is configured to modulate the optical properties of the incident light beam to amplify the deflection angle of the transmitted light beam along the first direction by a preset multiple.

7. The beam scanning module as described in claim 4, characterized in that, The second deflection angle magnification unit includes a second cylindrical deflection lens, which is configured to deflect the transmitted light beam along the second direction to amplify the deflection angle of the transmitted light beam along the second direction by a preset factor. The second cylindrical deflection lens includes an incident surface and an exit surface arranged sequentially along the light beam propagation direction. At least one of the exit surface and the incident surface is an optical surface for deflecting the light beam along the second direction. The optical surface is curved on the cross section of the second cylindrical deflection lens perpendicular to the first direction, and the optical surface is straight on the cross section of the second cylindrical deflection lens perpendicular to the second direction. The second direction is perpendicular to the first direction.

8. The beam scanning module as described in claim 5, characterized in that, The second deflection angle amplification unit includes a second one-dimensional deflection superlens. Multiple optical modulation sections are formed on the second one-dimensional deflection superlens and arranged along the second direction. The light beam deflected by the acousto-optic deflection module and the electro-optic deflection module is incident on one of the optical modulation sections. Each optical modulation section is configured to modulate the optical properties of the incident light beam to amplify the deflection angle of the light beam emitted by the optical modulation section along the second direction along the first direction.

9. The beam scanning module as described in claim 1, characterized in that, The deflection angle amplification module includes a first deflection angle amplification unit and / or a second deflection angle amplification unit. The first deflection angle amplification unit is configured to amplify the deflection angle of the light beam along the first direction or the second direction. The second deflection angle amplification unit is configured to amplify the deflection angle of the light beam along both the first direction and the second direction.

10. The beam scanning module as described in claim 9, characterized in that, The first deflection angle magnification unit includes a first cylindrical deflection lens, which is configured to deflect the transmitted light beam along the first direction to amplify the deflection angle of the transmitted light beam along the first direction by a preset factor. The first cylindrical deflection lens includes an incident surface and an exit surface arranged sequentially along the light beam propagation direction. At least one of the exit surface and the incident surface is an optical surface for deflecting the light beam along the first direction. The optical surface is curved on the cross section of the first cylindrical deflection lens perpendicular to the second direction, and the optical surface is straight on the cross section of the first cylindrical deflection lens perpendicular to the first direction. The second direction is perpendicular to the first direction.

11. The beam scanning module as described in claim 9, characterized in that, The first deflection angle magnification unit includes a second cylindrical deflection lens, which is configured to deflect the transmitted light beam along the second direction to amplify the deflection angle of the transmitted light beam along the second direction by a preset factor. The second cylindrical deflection lens includes an incident surface and an exit surface arranged sequentially along the light beam propagation direction. At least one of the exit surface and the incident surface is an optical surface for deflecting the light beam along the second direction. The optical surface is curved on the cross section of the second cylindrical deflection lens perpendicular to the first direction, and the optical surface is straight on the cross section of the second cylindrical deflection lens perpendicular to the second direction. The second direction is perpendicular to the first direction.

12. The beam scanning module as described in claim 9, characterized in that, The second deflection angle magnification unit includes at least one axisymmetric lens whose shape is symmetrically distributed about the optical axis passing through its optical center, so as to simultaneously magnify the deflection angle of the light beam along the first direction and the second direction.

13. The beam scanning module as described in claim 9, characterized in that, The second deflection angle amplification unit includes a two-dimensional deflection superlens. Multiple optical modulation sections are formed on the two-dimensional deflection superlens in a two-dimensional array. The light beam deflected by the acousto-optic deflection module and the electro-optic deflection module is incident on one of the optical modulation sections. Each optical modulation section is configured to modulate the optical properties of the incident light beam to simultaneously amplify the deflection angle of the transmitted light beam by a preset multiple along the first direction and the second direction.

14. The beam scanning module as described in claim 4 or 9, characterized in that, The arrangement order of the first deflection angle amplification unit and the second deflection angle amplification unit along the optical axis can be interchanged.

15. The beam scanning module as described in claim 1, characterized in that, The electro-optic interaction medium is a cubic phase potassium tantalate niobate crystal, and the beam scanning module also includes a temperature control module configured to maintain the temperature of the electro-optic interaction medium within a preset temperature range.

16. The beam scanning module as described in claim 15, characterized in that, The electro-optic deflection module deflects the second deflection angle range of the light beam toward the cathode of the electrical signal source, and the light beam forms a preset tilt angle between the direction of incidence of the electro-optic deflection module and the horizontal plane.

17. The beam scanning module as described in claim 1, characterized in that, The electro-optic interaction medium is lithium niobate, lithium tantalate, or potassium titanium oxyphosphate. The electro-optic deflection module includes multiple cascaded electro-optic interaction media. The control circuit adjusts the electric field strength formed by the electrical signal source in the corresponding electro-optic interaction medium to control the deflection angle of the passing beam by the corresponding electro-optic interaction medium. After the beam passes through multiple cascaded electro-optic interaction media for multiple deflections, it can obtain a larger range of second deflection angles along the second direction than after passing through a single electro-optic interaction medium.

18. The beam scanning module as described in claim 1, characterized in that, The beam scanning module further includes a beam narrowing module, configured to narrow the size of the beam in a cross section perpendicular to the beam propagation direction to a preset size before the beam enters the acousto-optic deflection module or the electro-optic deflection module.

19. A photoelectric detection device, characterized in that, Including the beam scanning module as described in any one of claims 1-18, the photoelectric detection device further includes a receiving module and a processing module, the receiving module being configured to sense light signals from within the field of view and output corresponding light sensing signals, and the processing module being configured to analyze and process the light sensing signals to perform distance detection within the field of view.

20. An electronic device, characterized in that, Including the photoelectric detection device as described in claim 19, the electronic device further includes an application module configured to perform corresponding functions based on the detection results of the photoelectric detection device.

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