Optical module, laser radar and terminal

Abstract

An optical module, a laser radar and a terminal are applied to the technical field of detection. The optical module comprises N (N is a positive integer) transmitting ports, N receiving ports, a light beam processing module and a beam expanding module. The N transmitting ports are used for transmitting N transmitting light beams, and the N receiving ports are used for receiving return light beams of the N transmitting light beams. And the light beam processing module is used for transmitting the N emission light beams to the beam expanding module, and deflecting and spreading the N return light beams from the beam expanding module to the N receiving ports. The beam expanding module is used for expanding the N emitted light beams. Wherein the N return light beams are return light beams of the N emission light beams, and the N emission light beams passing through the light beam processing module and the N return light beams from the beam expanding module are coaxial light beams. The optical module is small in overall size, and when the optical module is applied to the detection device, the overall size of the detection device can be remarkably reduced under the condition that the detection performance of the detection device is not reduced.

Description

Technical Field

[0001] The present application relates to the field of detection technology, and in particular to optical modules, laser radars and terminals. Background Art

[0002] With the development of information technology and computer vision, detection technology has made rapid progress, and various detection devices have brought great convenience to people's lives and travel. Detection devices can be regarded as the "eyes" of the device to perceive the environment, including visual sensors such as cameras and radar sensors such as millimeter wave radars, laser radars and ultrasonic radars. Among them, laser radar (light detection and ranging, Lidar, or light detection and ranging device) has the advantages of high resolution, good detection performance, and strong concealment. It plays an important role in the process of equipment sensing the environment, especially in the field of intelligent driving. It has been widely used and has helped the further development of intelligent driving technology. Among them, coherent laser radar is a radar that uses frequency modulated signal light as the transmitting signal for target detection, and processes the local oscillation (LO) of the transmitting signal and the return signal of the transmitting signal to obtain relevant information of the target. The laser carrier of the coherent laser radar is often modulated in a certain form so that the frequency changes with time, and its pattern can be a sawtooth, triangle or sine waveform. The laser radar whose frequency of the emitted light beam changes linearly is called frequency modulated continuous wave (FMCW) laser radar, which combines laser linear frequency sweeping ranging technology and scanning imaging technology, has unique speed detection advantages and is widely used in intelligent driving scenarios.

[0003] The laser radar includes a transmitting end and a receiving end, and because it needs to transmit and receive lasers, a variety of optical components need to be set up inside to process the light beam. Especially for FMCW laser radar, coherent components (such as the optical path for transmitting LO, the mixing components of the return signal and LO, etc.) are required to support coherent detection. However, laser radars are often carried on mobile terminals. If the volume of the laser radar is large, it will take up a large space, which may affect the aesthetics of the mobile terminal and the user's riding comfort. In some solutions, the overall volume of the laser radar is increased by reducing the optical path length of the laser radar and using small optical components, but this method often reduces the diameter of the light beam emitted by the laser radar, so that the light spot formed by the emitted light beam is relatively small, resulting in reduced detection performance of the laser radar.

[0004] How to reduce the size of the laser radar without reducing the detection performance of the laser radar is a hot issue that technicians in this field are currently studying. Summary of the invention

[0005] The embodiments of the present application provide an optical module, a laser radar and a terminal, which can reduce the volume of the detection device without reducing the detection performance of the laser radar.

[0006] In a first aspect, an embodiment of the present application provides an optical module including N transmitting ports, N receiving ports, a beam processing module and a beam expansion module, where N is an integer greater than or equal to 0. The N transmitting ports are used to transmit N transmitting beams, and the N receiving ports are used to receive return beams of the N transmitting beams. The beam processing module is used to transmit the N transmitting beams to the beam expansion module, and to deflect and propagate the N return beams from the beam expansion module to the N receiving ports. The beam expansion module is used to expand the N transmitting beams.

[0007] Among them, the N return beams are the return beams of the N emission beams, and the N emission beams passing through the beam processing module and the N return beams from the beam expansion module are coaxial beams.

[0008] The embodiment of the present application proposes an optical module comprising a two-stage optical system, wherein the beam processing module is a first-stage optical system and the beam expansion module is a second-stage optical system. The first-stage optical system is used to achieve the coaxiality of the emission beam and the return beam, and to achieve the deflection of the return beam so that the return beam can be received by the receiving port. The second-stage optical system is used to amplify the emitted light beam (i.e., expand the beam), thereby increasing the diameter of the emitted light beam to meet the requirements of light output collimation and receiving aperture. Furthermore, since the optical path is reversible, the emission beam is expanded by the beam expansion module, and the return beam can be contracted after passing through the beam expansion module in the reverse optical path direction of the emission beam.

[0009] On the one hand, since the diameters of the emitted light beam before passing through the beam expansion module and the return light beam after passing through the beam expansion module are relatively small, the size of the light beam processing module can also be designed to be relatively small, thereby reducing the overall volume of the light beam module. Moreover, when the size of the light beam is relatively small, the process tolerance angle of the optical elements for achieving coaxiality is also relatively high, and the engineering implementation is relatively easy. On the other hand, the aperture of the second-stage optical system is relatively large, which can meet the needs of large-diameter light emission and light collection and ensure detection performance. Moreover, since the first-stage optical system has achieved coaxial transmission and reception, the emitted light beam and the return light beam can share the same set of second-stage optical systems, which can further reduce the overall volume of the optical module. In summary, when the optical module is applied to a detection device, the overall size of the detection device can be significantly reduced, thereby improving the application value of the detection device.

[0010] In combination with the first aspect, in a possible implementation of the first aspect, the N transmitting ports and the N receiving ports may be integrated on the same module. In some schemes, the N transmitting ports and the N receiving ports are implemented by an optical fiber array or a waveguide chip. Exemplarily, the N transmitting ports and the N receiving ports may be arranged on an end face of the waveguide chip.

[0011] Further, the N transmitting ports and the N receiving ports may be arranged along the first direction. Alternatively, when N>1, the N receiving ports may be arranged along the first direction on the end face of the module, and the N transmitting ports and the N receiving ports may be arranged on the same end face or on different end faces.

[0012] Since FMCW needs to mix the LO corresponding to the transmitted light beam and the return light beam, the device integration of the detection device based on FMCW technology can be greatly improved by integrating N transmitting ports and N receiving ports on the same module, and the size of the whole device can be further reduced.

[0013] In combination with the first aspect, in another possible implementation of the first aspect, the N transmitting ports and the N receiving ports may be integrated on different modules. Further, when N>1, the N receiving ports may be arranged along a first direction on an end face of the module. In this case, the N transmitting ports and the N receiving ports may be arranged on the same end face or on different end faces.

[0014] In combination with the first aspect, in another possible implementation of the first aspect, the beam processing module includes a polarization beam splitter PBS and a quarter wave plate (QWP), and the QWP is arranged on the optical path between the PBS and the beam expansion module.

[0015] Among them, N emission light beams are transmitted to the beam expansion module through the PBS and QWP, and N return light beams from the beam expansion module are transmitted to the PBS through the QWP.

[0016] In this way, the transmitted light beam and the returned light beam are separated based on the PBS and the wave plate, the coaxial transmission and reception are achieved, and the beam loss in the coaxial process is significantly reduced.

[0017] Alternatively, the QWP may be replaced by two eighth wave plates, or the QWP may be replaced by one QWP plus one half wave plate (HWP).

[0018] In combination with the first aspect, in another possible implementation of the first aspect, the beam processing module further includes an HWP, and the HWP is arranged on the optical path between the PBS and the N receiving ports. On the one hand, the polarization direction of the N return beams can be adjusted by the HWP, and the polarization direction of the return beam can be made the same as that of the emitted beam in combination with the QWP. In particular, when the transmitting port and the receiving port are implemented by a waveguide chip (or optical fiber array), when the waveguide (or optical fiber) is polarized in a certain polarization direction, the combination of the HWP and the QWP can make the returned beam have the same polarization direction as the emitted beam, and further make the return beam and the waveguide have the same polarization direction, which is beneficial to reduce the loss caused by the transmission of the return beam in the waveguide (or optical fiber) and improve the detection performance. On the other hand, the combination of the HWP and the QWP has an achromatic effect in some scenarios, which can further improve the detection accuracy.

[0019] In combination with the first aspect, in another possible implementation of the first aspect, the PBS is used to transmit a light beam in a first polarization direction and reflect a light beam in a second polarization direction. The first polarization direction is perpendicular to the second polarization direction. Specifically, the PBS can transmit light whose polarization direction is parallel to the polarization direction of the PBS (referred to as P polarized light, i.e., a light beam in the first polarization direction), and reflect (or block) light whose polarization direction is perpendicular to the polarization direction of the PBS (referred to as S polarized light, i.e., a light beam in the second polarization direction).

[0020] The QWP is used to change the polarization direction of the passing light beam. The polarization direction of the return light beam of the N emitted light beams after passing through the QWP is perpendicular to the polarization direction of the N emitted light beams. Exemplarily, the N emitted light beams transmitted by the PBS are P polarized light, which is provided to the object space after passing through the QWP, and the light beams returning from the object space (such as the N return light beams) can be S polarized light after passing through the QWP again, and the S polarized light is reflected after passing through the PBS. In this way, coaxial transmission and reception can be achieved, and the beam loss in the coaxial process can be significantly reduced.

[0021] Alternatively, in this embodiment, the QWP can also be replaced by two eighth wave plates. Alternatively, in this embodiment, the QWP can also be replaced by one QWP plus one HWP.

[0022] In combination with the first aspect, in another possible implementation of the first aspect, the beam processing module further includes a folding mirror, which is used to deflect the beam passing through the PBS and propagate it to the N receiving ports. Further, the HWP can be arranged between the PBS and the folding mirror.

[0023] In combination with the first aspect, in another possible implementation of the first aspect, the optical module further includes a scanning module. The scanning module is movable so as to emit and receive light beams at multiple angles.

[0024] Furthermore, the scanning module is used to scan the N emission light beams passing through the beam expansion module to the object space, and to propagate the return light beams of the N emission light beams from the object space to the beam expansion module.

[0025] In combination with the first aspect, in another possible implementation of the first aspect, N≥2, the N return light beams after passing through the scanning module are arranged along the first direction, and the scanning direction of the scanning module is the second direction. The walk-off angle direction of each of the N return light beams is the second direction, and the second direction is different from the first direction.

[0026] Furthermore, the optical module further includes a spot transfer mechanism, which is used to transfer the walk-off angle direction of each of the N return beams to the arrangement direction of the N return beams. Optionally, the spot transfer mechanism is arranged on the optical path between the scanning module and the N receiving ports. For example, when the beam processing module includes a PBS, the spot device mechanism can be arranged between the beam expansion module and the PBS, or between the PBS and the N receiving ports.

[0027] In the above implementation, N emission beams are irradiated onto the scanner, and after being scanned by the scanner at a certain angle onto the target object in the object space, they can be reflected by the target object in the object space to obtain the corresponding return beam. Since the scanner is continuously scanning, and there is a certain distance between the target object in the object space and the scanner, when the return beam returns and passes through the scanner, the scanner has rotated a certain angle, so that the return beam no longer propagates along the direction of the original N return beams, but has a certain deviation angle, that is, the walkoff angle. It is not difficult to see that the angular direction of the walkoff angle is the same as the scanning direction of the scanning module. Since the N emission beams form a linear array, when scanning, the scanning direction (or fast axis direction) of the scanning module is usually different from the arrangement direction of the N emission beams, while the arrangement direction of the N return beams is the same as the arrangement direction of the N emission beams, so it is easy to obtain that the angular direction of the walkoff angle is different from the arrangement direction of the N emission beams.

[0028] However, the embodiment of the present application adjusts the direction of the walk-off angle to the arrangement direction of the N return light beams through the spot transposition mechanism. Since it is difficult to compensate for the walk-off angle of the N receiving ports in the direction perpendicular to the arrangement direction of the ports, after the direction of the walk-off angle is adjusted to the arrangement direction of the N return light beams, the angle deviation of the N return light beams caused by the walk-off angle can be compensated by displacing them in the arrangement direction of the N receiving ports, which can help reduce the signal loss caused by the walk-off angle and improve the effectiveness of the signal.

[0029] In some cases, if the scanner is in a stationary state, the return beams of the N emitted beams will propagate along the optical path of the ideal return beam, and the walk-off angle is 0°. Therefore, in some cases, the scanner is in an active state, and the offset angle (i.e., the walk-off angle) of the N return beams and the ideal return beam is a first angle (the first angle is greater than 0°). At this time, if the N receiving ports are set on the optical path of the ideal return beam, it will make it difficult for the light spots of the N return beams to accurately enter the receiving port, resulting in light spot loss. Therefore, the receiving port is offset along the arrangement direction of the port to compensate for the offset of the N return beams, so that the light spots of the N return beams can be closer to the effective receiving area of ​​the receiving port, and even coincide with the center of the receiving port. In this way, the N receiving ports can receive the N return beams more accurately, improve the effectiveness of the received echo signal, and improve the detection performance.

[0030] In combination with the first aspect, in another possible implementation of the first aspect, the light spot transposition mechanism includes a step reflector, the step reflector includes N reflective surfaces arranged in steps along the arrangement direction of the N return light beams, and each reflective surface is used to reflect one light beam.

[0031] In combination with the first aspect, in another possible implementation manner of the first aspect, the light spot transposition mechanism includes a first stepped reflector and a second stepped reflector, wherein:

[0032] The first stepped reflector includes N first reflective surfaces arranged in a stepped manner. The first stepped reflector includes N second reflective surfaces arranged in a stepped manner, the N first reflective surfaces are opposite to the N second reflective surfaces one by one, and the second stepped reflector is used to reflect the emitted light of the first group of stepped reflectors again.

[0033] In combination with the first aspect, in another possible implementation of the first aspect, each of the N first reflection surfaces is used to fold one of the N return light beams and propagate it to one of the N second reflection surfaces. Each of the N second reflection surfaces is used to fold one of the N return light beams so that a walk-off angle direction of the one return light beam is along an arrangement direction of the N return light beams.

[0034] In combination with the first aspect, in another possible implementation of the first aspect, the N first reflection surfaces are not parallel to the walk-off angle directions of the N return light beams. Further, the N second emission surfaces are not parallel to the walk-off angle directions of the N return light beams.

[0035] Exemplarily, non-parallel includes perpendicular.

[0036] In combination with the first aspect, in another possible implementation of the first aspect, the angle between the N first reflection surfaces and the bottom surface of the first step reflector is 45°, and the angle between the N second reflection surfaces and the bottom surface of the second step reflector is 45°.

[0037] In combination with the first aspect, in another possible implementation manner of the first aspect, an angle between the N first reflection surfaces and the bottom surface of the first stepped reflector is 45°;

[0038] The included angles between the N second reflecting surfaces and the bottom surface of the first stepped reflecting mirror gradually increase from the step center of the second stepped reflecting mirror along both sides of the step of the second stepped reflecting mirror.

[0039] In combination with the first aspect, in another possible implementation manner of the first aspect, the light spot transposition mechanism is a prism, and the N first reflection surfaces and the N second reflection surfaces are realized by coating a reflection film in the prism.

[0040] In combination with the first aspect, in another possible implementation manner of the first aspect, the first stepped reflector includes a first substrate and N first reflectors, the N first reflectors are attached to the first substrate, and each first reflector includes a first reflective surface;

[0041] The second step reflector includes a second substrate and N second reflectors, the N second reflectors are attached to the second substrate, and each second reflector includes a first reflective surface.

[0042] In combination with the first aspect, in another possible implementation of the first aspect, the beam expansion module includes a first lens group and a second lens group, and the first lens group and the second lens group have a common focal plane.

[0043] In combination with the first aspect, in another possible implementation of the first aspect, the light spot transfer mechanism is disposed between the first lens group and the second lens group.

[0044] In combination with the first aspect, in another possible implementation manner of the first aspect, the first lens group includes N lenses, and each lens of the N lenses is used to pass one return light beam among the N return light beams.

[0045] In combination with the first aspect, in another possible implementation of the first aspect, the optical module further includes a transmitting lens group and a receiving lens group, the transmitting lens group is arranged between the N transmitting ports and the beam expansion module, and the receiving lens group is arranged between the N receiving ports and the beam expansion module;

[0046] N transmitting ports, a transmitting lens group, N receiving ports, a receiving lens group and a beam processing component are packaged as a first optical component, and the beam expansion module is packaged as a second optical component. The first optical component and the second optical component are provided with light-transmitting windows, which are used to pass N transmitting light beams and N returning light beams.

[0047] In combination with the first aspect, in another possible implementation manner of the first aspect, the N transmitting ports and the N receiving ports are waveguide ports of a waveguide chip.

[0048] In combination with the first aspect, in another possible implementation manner of the first aspect, the N emission light beams are FMCW lasers.

[0049] In a second aspect, an embodiment of the present application further provides an optical module, the optical module comprising a beam transceiver module and a light spot transposition mechanism;

[0050] The light beam transceiver module comprises N transmitting ports and N receiving ports, and the N transmitting ports and the N receiving ports are cross-arranged along the end face of the light beam transceiver module, and N is an integer greater than 1.

[0051] The N transmitting ports are used to transmit N transmitting light beams, and the N receiving ports are used to receive N returning light beams, and the N returning light beams are returning light beams of the N transmitting light beams. The spot transposition mechanism is arranged on the optical paths of the N transmitting light beams and the N returning light beams, and the N transmitting light beams after passing through the spot transposition mechanism are used to scan the object space, and the scanning direction is the second direction. The walk-off angle direction of the N returning light beams before passing through the spot transposition mechanism is the second direction, and the N returning light beams are arranged along the first direction, and the second direction is different from the first direction. The spot transposition mechanism is used to fold the walk-off angle direction of each returning light beam in the N returning light beams into the arrangement direction along the N returning light beams, and provide it to the N receiving ports.

[0052] In combination with the second aspect, in a possible implementation manner of the second aspect, the light spot transposition mechanism includes a first step reflector and a second step reflector, wherein:

[0053] The first stepped reflector includes N first reflective surfaces arranged in a stepped manner.

[0054] The first stepped reflector includes N second reflective surfaces arranged in a stepped manner, the N first reflective surfaces are opposite to the N second reflective surfaces one by one, and the second stepped reflector is used to reflect the emergent light of the first group of stepped reflectors again.

[0055] In combination with the second aspect, in another possible implementation of the second aspect, each of the N first reflection surfaces is used to fold one of the N return light beams and propagate it to one of the N second reflection surfaces.

[0056] Each of the N second reflection surfaces is used to fold one of the N return light beams so that the walk-off angle direction of the one return light beam is along the arrangement direction of the N return light beams.

[0057] In combination with the second aspect, in another possible implementation of the second aspect, the angle between the N first reflection surfaces and the bottom surface of the first step reflector is 45°, and the angle between the N second reflection surfaces and the bottom surface of the second step reflector is 45°.

[0058] In combination with the second aspect, in another possible implementation manner of the second aspect, an angle between the N first reflection surfaces and the bottom surface of the first stepped reflector is 45°.

[0059] The included angles between the N second reflection surfaces and the bottom surface of the first stepped reflection mirror gradually increase from the step center of the second stepped reflection mirror along both sides of the step of the second stepped reflection mirror.

[0060] In combination with the second aspect, in another possible implementation manner of the second aspect, the light spot transposition mechanism is a prism, and the N first reflection surfaces and the N second reflection surfaces are realized by coating a reflection film in the prism.

[0061] In combination with the second aspect, in another possible implementation of the second aspect, the first step reflector includes a first substrate and N first reflectors, the N first reflectors are attached to the first substrate, and each first reflector includes a first reflective surface.

[0062] The second step reflector includes a second substrate and N second reflectors, the N second reflectors are attached to the second substrate, and each second reflector includes a first reflective surface.

[0063] In combination with the second aspect, in another possible implementation of the second aspect, the optical module further includes a beam expansion module, and the beam expansion module is used to expand the N emission light beams and shrink the N return light beams.

[0064] In combination with the second aspect, in another possible implementation of the second aspect, the beam expansion module includes a first lens group and a second lens group, the first lens group and the second lens group have a common focal plane, and the first lens group is arranged on an optical path between the spot device structure and the second lens group.

[0065] In combination with the second aspect, in another possible implementation of the second aspect, the beam expansion module includes a first lens group and a second lens group, and the first lens group and the second lens group have a common focal plane. Further, the spot transfer mechanism is arranged on the optical path between the first lens group and the second lens group.

[0066] In combination with the second aspect, in another possible implementation manner of the second aspect, the first lens group includes N lenses, and each lens of the N lenses is used to pass one of the N return light beams.

[0067] In combination with the second aspect, in another possible implementation of the second aspect, the optical module further includes a transmitting lens group and a receiving lens group, the transmitting lens group is arranged between the N transmitting ports and the beam expansion module, and the receiving lens group is arranged between the N receiving ports and the beam expansion module.

[0068] N transmitting ports, a transmitting lens group, N receiving ports, a receiving lens group and a beam processing component are packaged as a first optical component, and the beam expansion module is packaged as a second optical component. The first optical component and the second optical component are provided with light-transmitting windows, which are used to pass N transmitting light beams and N returning light beams.

[0069] In combination with the second aspect, in another possible implementation manner of the second aspect, the N transmitting ports and the N receiving ports are waveguide ports of a waveguide chip.

[0070] In combination with the second aspect, in another possible implementation of the second aspect, the N emission light beams are FMCW lasers.

[0071] In a third aspect, an embodiment of the present application provides a laser radar, which includes the optical module described in any one of the first aspects, or the laser radar includes the optical module described in any one of the second aspects.

[0072] In a possible implementation of the third aspect, the laser radar further includes a light source. For example, the light source is a laser.

[0073] In another possible implementation of the third aspect, the laser radar further includes a detector, which is used to obtain an electrical signal based on the light beam.

[0074] In a fourth aspect, an embodiment of the present application provides a terminal, wherein the terminal includes the optical module of any one of the first aspect, or the terminal includes the optical module of any one of the second aspect, or the terminal includes the laser radar of any one of the third aspect.

[0075] Optionally, the terminal can be an intelligent terminal or means of transportation such as a vehicle, a drone, or a robot. Of course, the terminal can also be replaced by industrial equipment, entertainment and leisure equipment, etc. Intelligent terminals include mobile phones, tablet computers, laptops, smart bracelets, smart watches, or smart glasses. Transportation tools include vehicles, ships, aircraft, or logistics robots. Industrial equipment includes industrial robots and robotic arms. Leisure and entertainment equipment includes virtual reality (VR) equipment, mixed reality (MR) equipment, massage chairs, or 4D cinema cabins. This application does not impose strict restrictions on the devices to which the electrical connector can be applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] The following is a brief introduction to the drawings required for describing the embodiments.

[0077] Figure 1 is a schematic structural diagram of a detection device based on an off-axis architecture provided in an embodiment of the present application;

[0078] Figure 2 is a schematic diagram of the structure of a detection device based on a coaxial architecture provided in an embodiment of the present application;

[0079] Figure 3 is a schematic diagram of an optical module provided in an embodiment of the present application;

[0080] Figure 4A is a schematic diagram of a waveguide chip provided in an embodiment of the present application;

[0081] Figure 4B This is a schematic diagram of an optical path design of a waveguide chip provided in an embodiment of the present application;

[0082] Figure 5 is a schematic diagram of another waveguide chip provided in an embodiment of the present application;

[0083] Figure 6 is a schematic diagram of another waveguide chip provided in an embodiment of the present application;

[0084] Figure 7 is a schematic diagram of another optical module provided in an embodiment of the present application;

[0085] Figure 8 is a schematic diagram of another optical module provided in an embodiment of the present application;

[0086] Fig. 9 is a schematic diagram of two beam expansion modules provided in an embodiment of the present application;

[0087] Fig.10 is a structural schematic diagram of another optical module provided in an embodiment of the present application;

[0088] Fig.11 is a structural schematic diagram of another optical module provided in an embodiment of the present application;

[0089] Fig.12 is a schematic diagram of a walk-off angle provided in an embodiment of the present application;

[0090] Fig.13 is a schematic diagram of another walk-off angle provided in an embodiment of the present application;

[0091] Fig.14 It is a structural schematic diagram of another optical module provided by the present application;

[0092] Fig.15 This is a schematic diagram of the effect of light spot transposition provided by an embodiment of the present application;

[0093] Fig.16A is a schematic structural diagram of a stepped reflector provided in an embodiment of the present application;

[0094] Fig. 16B is a structural schematic diagram of another stepped reflector provided in an embodiment of the present application;

[0095] Fig. 16C is a structural schematic diagram of another stepped reflector provided in an embodiment of the present application;

[0096] Fig.17A It is a structural schematic diagram of another light spot transposition mechanism provided in an embodiment of the present application;

[0097] Fig. 17B It is a structural schematic diagram of another light spot transposition mechanism provided in an embodiment of the present application;

[0098] Fig. 17C It is a structural schematic diagram of another light spot transposition mechanism provided in an embodiment of the present application;

[0099] Fig.18 It is a structural schematic diagram of a transceiver integrated module provided in an embodiment of the present application;

[0100] Fig.19 is a structural schematic diagram of another optical module provided in an embodiment of the present application;

[0101] Fig. 20 is a structural schematic diagram of another optical module provided in an embodiment of the present application;

[0102] Fig.21 is a structural schematic diagram of another optical module provided in an embodiment of the present application;

[0103] Fig. 22 This is a schematic diagram of an emission light path of another optical module provided in an embodiment of the present application;

[0104] Fig.23 is a schematic diagram of the structure of an optical module using an off-axis architecture provided in an embodiment of the present application;

[0105] Fig.24 This is a schematic diagram of the structure of another optical module using an off-axis architecture provided in an embodiment of the present application. DETAILED DESCRIPTION

[0106] In recent years, with the increasing requirements for equipment intelligence and the rapid development of detection technology, detection devices have been widely used in various fields. The detection device here includes a device that detects by emitting a light beam and receiving a light beam returned from the object space, wherein detection can be understood as obtaining relevant information about the target in the object space, and detection includes but is not limited to target detection, distance measurement, speed measurement, angle measurement, target tracking, imaging recognition, and one or more detections. Exemplarily, the detection device can be a laser radar, or a fusion detection device that integrates a laser radar and a camera.

[0107] Among them, the detection method of the detection device may include a coherent detection method. Coherent detection technology refers to a method of extracting relevant information of the target based on a mixed signal of two signals (such as LO and a return light beam). Since the emitted light beam changes after being reflected by the target, coherent detection extracts information about the target through this change. Coherent detection has advantages in sensitivity, target resolution, and anti-interference. In some schemes, by transmitting a frequency modulated continuous wave, the speed of the target can be calculated based on the frequency change of the return light beam and the frequency change of the local oscillator signal of the emitted light beam.

[0108] The following is an illustrative introduction to the architectures of two detection devices.

[0109] See also Figure 1 , Figure 1 1 is a schematic diagram of a detection device based on an off-axis architecture provided in an embodiment of the present application. The detection device 10 includes a transmitter 101 and a detector 102, and optionally also includes a transmitting optical system and a receiving optical system. The transmitter 101 can generate a transmitting light beam, which is transmitted to the object space through the transmitting optical system. The transmitting light beam is reflected by the target in the object space to form a return light beam, and part of it can enter the receiving optical system and be transmitted to the detector 102. Figure 1 In the detector, the emission beam and the return beam have different principal optical axes, that is, the optical principal axis of the emission beam is not colinear with the optical principal axis of the return beam that can be detected by the detector. Therefore, it is difficult to align the field of view corresponding to the emission beam emitted by the transmitter and the field of view corresponding to the beam that can be received by the detector.

[0110] See also Figure 2 , Figure 2 2 is a schematic diagram of a detection device based on a coaxial structure provided in an embodiment of the present application. The detection device 20 includes a transmitter 201, a detector 202 and a coaxial element 203. The transmitter 201 can generate a transmission light beam, which is transmitted to the object space through the transmission optical system and the coaxial element 203. The transmission light beam is reflected by the target in the object space to form a return light beam, and the return light beam also passes through the coaxial optical element to enter the receiving optical system and is transmitted to the detector 202. Figure 2 In the embodiment, the emission light beam and the return light beam have the same principal optical axis, that is, the optical principal axis of the emission light beam is collinear with the optical principal axis of the return light beam that can be detected by the detector.

[0111] Combination Figure 1 , Figure 2 It can be seen that the detection device needs to emit and return light beams, so a variety of optical elements need to be set up inside to process the light beams. With the user's requirements for the aesthetics, comfort and stability of the terminal, the detection device is increasingly moving towards miniaturization and integration. How to reduce the overall size of the detection device is a hot issue that technicians in this field are studying. The embodiment of the present application provides an optical module, a laser radar and a terminal to reduce the volume of the detection device without reducing the detection performance of the detection device. The solution of the present application is introduced below.

[0112] See also Figure 3 , Figure 3 30 is a schematic diagram of an optical module provided in an embodiment of the present application. The optical module 30 comprises a transmitting port 301, a receiving port 302, a beam processing module 303 and a beam expansion module 304. Among them:

[0113] The number of transmitting ports 301 may be one or more. When the number of transmitting ports is one, one transmitting port may emit one transmitting light beam (or referred to as an transmitting light beam of one channel). When the number of transmitting ports is multiple, multiple transmitting ports may respectively emit light beams to form multiple transmitting light beams (or referred to as transmitting light beams of multiple channels). For ease of explanation, the present application takes an optical module including N transmitting ports as an example for explanation, where N is an integer greater than or equal to 1. It is understandable that N transmitting light beams may be emitted through the N transmitting ports. Similarly, the number of receiving ports 302 is also set to N for ease of explanation. The N receiving ports are used to receive return light beams of the N transmitting light beams. Exemplarily, the N receiving ports are used to receive N return light beams, wherein each receiving port is used to receive one return light beam.

[0114] It should be understood that the total number of transmitting ports (or receiving ports) in the optical module 30 may be more than N. For example, if the optical module includes 30 transmitting ports, but there are currently 10 transmitting ports in working state, then 10 (ie, N=10) channels of transmitting light beams may be transmitted through the 10 transmitting ports.

[0115] The light beam processing module 303 is used to process the light beam, and the processing here includes propagation and changes to the characteristics of the light beam during the propagation process. Among them, propagation can include one or more of the propagation processes such as transmission, refraction, or reflection, and the change to the characteristics of the light beam includes one or more of the changes to the light path of the light beam (such as deflection, reflection, etc.), the change of the polarization direction of the light contained in the emission light beam, the change of the wavelength distribution (such as filtering), etc.

[0116] Exemplarily, the beam processing module 303 is used to transmit N emission beams to the beam expansion module 304, and to propagate N return beams from the beam expansion module 304 to the N receiving ports 302. Further, the beam processing module 303 can propagate the N return beams to the N receiving ports along an optical path different from that of the N emission beams (i.e., perform beam folding).

[0117] Combination Figure 3 It can be seen that the N return beams here are the return beams of the N emission beams, and the N emission beams passing through the beam processing module 303 and the N return beams from the beam expansion module 304 are coaxial beams. It should be noted that the coaxial beams here mean that the N emission beams and the N return beams can pass through a common optical element. Moreover, under ideal conditions, the main optical axes of the N emission beams passing through the beam processing module 303 and the N return beams from the beam expansion module 304 should be collinear, but in the actual implementation process, due to process errors, the rotation of the scanning mechanism, and even the movement of the optical module 30, etc., the main optical axes of the two may not be completely collinear, but the N emission beams and the N return beams can pass through the common beam expansion module 304, as well as other optical elements (described below), so the two are coaxial beams.

[0118] The beam expansion module 304 is used to expand the N emission light beams. Figure 1 As shown, taking an emission light beam as an example, before passing through the beam expansion module 304, the diameter of the emission light beam is represented as d1, and after passing through the beam expansion module 304, the diameter of the emission light beam is represented as d2, d2>d1. Furthermore, since the optical path is reversible, the emission light beam is expanded after passing through the beam expansion module 304, and the return light beam can be contracted after passing through the beam expansion module 304 in the reverse optical path direction of the emission light beam.

[0119] Combination Figure 3It can be seen that the present application proposes an optical module comprising a two-stage optical system. The beam processing module 303 is the first-stage optical system, and the beam expansion module 304 is the second-stage optical system. The first-stage optical system is used to achieve the coaxiality of the transmitted light beam and the return light beam, and to achieve the deflection of the return light beam so that the return light beam can be received by the receiving port. The second-stage optical system is used to amplify the emitted light beam (i.e., expand the beam), thereby increasing the diameter of the emitted light beam to meet the requirements of light output collimation and receiving aperture. Furthermore, since the optical path is reversible, the emitted light beam is expanded by the beam expansion module, and the return light beam can be contracted after passing through the beam expansion module in the reverse light path direction of the emitted light beam.

[0120] On the one hand, since the diameters of the emission light beam before passing through the beam expansion module 304 and the return light beam after passing through the beam expansion module 304 are relatively small, the size of the light beam processing module 303 can also be designed to be relatively small, thereby reducing the overall volume of the light beam module. Moreover, when the size of the light beam is relatively small, the process tolerance angle of the optical elements for achieving coaxiality is also relatively high, and the engineering implementation is relatively easy. On the other hand, the aperture of the second-stage optical system is relatively large, which can meet the requirements of large-diameter light emission and light collection, and ensure detection performance. Moreover, since the first-stage optical system has achieved coaxial transmission and reception, the emission light beam and the return light beam can share the same set of second-stage optical systems, which can further reduce the overall volume of the optical module. In summary, when the optical module is applied to a detection device, the overall size of the detection device can be significantly reduced, thereby reducing costs.

[0121] The transmitting port and receiving port in the embodiment of the present application are introduced below.

[0122] In some possible implementations, the emission port can be implemented by multiple waveguides or optical amplifiers. In some schemes, the emission port is implemented by a coupler arranged on a waveguide chip, such as an edge coupler or a grating coupler. In some other schemes, the emission port can be implemented by the light outlet (or light outlet end face) of the optical amplifier. An optical amplifier is a device for amplifying signal light, including but not limited to semiconductor amplifiers or optical fiber amplifiers. Among them, the semiconductor optical amplifier (SOA) uses semiconductor materials as gain media, which can amplify the power of signal light without significantly reducing its optical indicators. Alternatively, the emission port can also include multiple laser emitters, which can generate emission light beams.

[0123] In some possible implementations, the receiving port may be a receiving port of a waveguide, and an exemplary receiving port may be implemented by a coupler disposed on a waveguide chip. Alternatively, the receiving port may be an end face of a plurality of detection elements for receiving light, and the detection element may be a photodiode (PD) capable of detecting light energy, such as InGaAs PD, InP PD, or germanium PD.

[0124] In a possible implementation, N transmitting ports and N receiving ports may be integrated on the same module. In some solutions, the N transmitting ports and N receiving ports are implemented by modules capable of propagating light beams, such as optical fiber arrays or waveguides. In the following, a module integrated with a waveguide (or optical fiber) is described by a waveguide chip, and this name is an exemplary description and is not intended to limit the structure of the module.

[0125] Optionally, the N transmit ports and the N receive ports can be located on the same end face. Figure 4A , Figure 4A Schematic diagram of a waveguide chip provided in an embodiment of the present application, N (taking N=2 as an example) transmitting ports 301 and N receiving ports 302 can be arranged on an end surface of the waveguide chip 40. The arrangement direction of the N receiving ports 302 is along the first direction (i.e. Figure 4A Furthermore, the N transmitting ports and the N receiving ports are arranged along the y direction. Figure 4A As shown, N transmitting ports 301 and N receiving ports 302 are arranged along the y direction. The y direction is a direction used as an example for the convenience of explaining the present solution. The remaining x direction, z direction, etc. can be referred to in Figure 4A The coordinate systems shown are examples and are not intended to limit this solution. Figure 4B , Figure 4B This is a schematic diagram of the optical path design of a waveguide chip provided in an embodiment of the present application. The waveguide chip 40 can receive the light beam of the FMCW laser and divide it into a transmitting (transmitter, Tx) beam and a LO beam. The transmitting beam is emitted after being split and amplified (realized by SOA) inside the waveguide. The transmitting port 301 is realized by the light output port of the SOA. The waveguide chip is also provided with a receiving port. The receiving (Receiver, Rx) beam received by the receiving port can be mixed with LO in a mixer. The mixed signal is used as the input of the detection element (such as PD) in the detector array, and is received by the detector element to process and obtain relevant information of the target in the object space.

[0126] Alternatively, the N transmit ports and the N receive ports may be located on different end faces of the same module. Figure 5 , Figure 53 is a schematic diagram of another waveguide chip provided in an embodiment of the present application, wherein N transmitting ports 301 may be located on the left end surface, and N receiving ports 302 are located on the front end surface of the waveguide chip 40. Wherein, when N>1, the arrangement direction of the N receiving ports 302 is along the x direction.

[0127] In another possible implementation, the N transmitting ports and the N receiving ports may be integrated on different modules. For example, the N transmitting ports and the N receiving ports are located on different waveguide chips. Figure 6 FIG. 1 is a schematic diagram of another optical platform provided in an embodiment of the present application. Figure 6 As shown, N transmitting ports 301 may be located on a first waveguide chip 401, and N receiving ports may be located on a second waveguide chip 402. Further, in the case of N>1, the arrangement direction of the N receiving ports 302 is along the y direction.

[0128] The following introduces Figure 3 The optical module shown is a beam processing module 303. In the above solution, the beam processing module 303 can realize coaxial transmission and reception. In the specific implementation process, the beam processing module 303 can include PBS, circulator, semi-transparent and semi-reflective beam splitter and other optical elements for realizing coaxiality.

[0129] Among them, the semi-transparent and semi-reflective beam splitter can split a beam of light into two beams of light with roughly the same spectral components, for example, within a certain wavelength region, such as a wavelength range of 300nm to 100μm, each wavelength has the same (the same here does not necessarily mean completely the same, and there can be fluctuations within a certain range) transmittance and reflectivity. Generally speaking, neutral beam splitters in which the transmitted light and reflected light each account for 50% are more commonly used, but the present application is also applicable to beam splitters with other transmission ratios (reflection ratios), such as a beam splitter with 40% transmission and 60% reflection. At this time, after the N emitted light beams pass through the semi-transparent and semi-reflective beam splitter, each emitted light beam is partially reflected and partially transmitted, so that there is a loss of energy in the N emitted light beams propagating to the beam expansion module 304. Similarly, the N return light beams from the beam expansion module are also partially emitted and partially transmitted after passing through the semi-transparent and semi-reflective mirrors, so that there is also a certain loss of energy in the N return light beams.

[0130] A circulator is a multi-port device that transmits the incident wave entering any port to the next port in a direction determined by the static bias magnetic field. Its outstanding feature is that it transmits energy in one direction and controls the electromagnetic wave to be transmitted along a certain circular direction. Exemplarily, a circulator has three ports, and the light beam goes from port 1 to port 2, from port 2 to port 3, and from port 3 to port 1. The other paths are blocked, that is, it is impossible to go from port 2 to port 1 (that is, it has high isolation). At this time, N emission light beams can enter from port 1 and exit from port 2. The exiting light beams can continue to propagate to reach the beam expansion module, and N return light beams from the beam expansion module can enter from port 2 and exit from port 3, thereby achieving coaxial transmission and reception and reducing the loss of light beams.

[0131] A polarization beam splitter (PBS) is used to split a beam of light into two linearly polarized lights with orthogonal polarization directions, horizontal polarization and vertical polarization, and separate them into two different propagation directions, usually the two propagation directions are perpendicular to each other. For example, a PBS can split an incident light beam into P polarized light and S polarized light, and the polarization directions of the P polarized light and the S polarized light are perpendicular to each other.

[0132] Since PBS splits light based on the polarization direction of light, coaxial transmission and reception can be achieved by combining PBS with an element that can change the polarization direction of the light beam (such as a wave plate). Consider a possible situation. If the polarization direction of the N emission light beams entering the PBS is the same as the P polarized light, the N emission light beams will pass through the PBS. At this time, by setting an optical element that can change the polarization direction between the PBS and the beam expansion module, the polarization direction of the N return light beams entering the PBS can be adjusted to be the same as the S polarized light, so that the N return light beams are reflected by the PBS. In short, by combining PBS with an element that can change the polarization direction of the light beam, coaxial transmission and reception can be achieved, and the loss of the echo signal can be reduced.

[0133] See also Figure 7 , Figure 7 is a schematic diagram of another optical module provided in an embodiment of the present application, such as Figure 7 In the optical module 30 shown, the beam processing module 303 includes PBS3031 and QWP3032. The light beam entering the PBS from the transmitting port may include a signal with a polarization direction of the first polarization direction. After passing through PBS3031 and QWP3032, it can reach the beam expansion module 304 and be further transmitted to the object space. The light beam from the object space reaches QWP3032 again through the beam expansion module 304. The polarization direction of the light beam after passing through QWP3032 twice is perpendicular to the polarization direction of the light beam passing through PBS3031. Therefore, when passing through PBS, it will be emitted through other optical paths to reach the receiving port 302, and will not propagate in the reverse direction of the original transmitting light beam. In addition, Figure 7 , the transmitting port and receiving port are integrated in different modules.

[0134] Furthermore, the beam processing module 303 may also include more components to further process the beam. Figure 7 As shown, the beam processing module 303 also includes HWP3033, and HWP3033 is arranged on the optical path between PBS3031 and N receiving ports 302. In this way, the beam processing module 303 includes PBS3031, QWP (i.e., 1 / 4 wave plate) 3032 and HWP (i.e., 1 / 2 wave plate) 3033. The N emission beams incident on the PBS are linearly polarized light. After passing through PBS3031 and QWP3032, the N emitted reflected beams are circularly polarized light. The circularly polarized light irradiates the target surface in the object space. The N return beams obtained after reflection from the target pass through QWP3032 again. At this time, the polarization direction of the N return beams is perpendicular to the polarization direction of the N emission beams incident on the PNS. Therefore, the N reflected beams after passing through QWP3032 are reflected by PBS3031, and after passing through the HWP wave plate 3033, the polarization direction of the N return beams is rotated by 90° again, so as to be the same as the polarization direction of the N emission beams incident on the PBS. This is beneficial for combining with polarization-maintaining optical waveguides to further reduce the loss of the return beam, and to improve the effectiveness of the received return beam, thereby improving the detection performance.

[0135] See also Figure 8 , Figure 8 3031 is a schematic diagram of another optical module provided in an embodiment of the present application. The beam processing module includes PBS3031, QWP3032 and a folding mirror 3034. Most of the modules can be seen in Figure 7 The folding mirror 3034 can fold the return light beam emitted from the PBS, so that its propagation direction is changed and it propagates to the receiving port 302. At this time, the transmitting port and the receiving port can be integrated in the same module (such as in the waveguide chip 40). Of course, at this time, the transmitting port and the receiving port may not be integrated in the same module, for example Figure 6 The first waveguide chip 401 and the second waveguide chip 402 shown can be replaced Figure 8 The waveguide chip 40 in the embodiment of the present invention. Optionally, the folding mirror 3034 can be realized by a reflecting mirror, or by coating a prism with a reflecting film.

[0136] It should be understood that Figure 8 A HWP may also be provided in the structure shown, for example, between the PBS 3031 and the folding mirror 3034. Alternatively, in the aforementioned embodiment, the QWP may also be replaced by two eighth wave plates. Alternatively, the QWP may also be replaced by one QWP plus one HWP.

[0137] The following introduces Figure 3 The optical module shown includes a beam expansion module 304. The beam expansion module 304 can be implemented by a telescope beam expansion system. Exemplarily, the beam expansion module includes a front lens group and a rear lens group, and the rear lens group refers to a lens that is closer to the object space on the optical path. Among them, the front lens group and the rear lens group can be implemented by a single lens, respectively, or by a lens group, respectively, or partially by a single lens, and partially by a combined lens. Further, the front lens group and the rear lens group are connected by a focal plane, and the focal plane here can be a real focal plane or a virtual focal plane. Exemplarily, the front lens group and the rear lens group respectively include a front focal plane and a rear focal plane, and the rear focal plane refers to a focal plane that is closer to the object space on the optical path. In some schemes, the front lens group is used to converge the incident light beam onto the rear focal plane of the front lens group, and the rear lens group re-collimates the light beam on the front focal plane of the rear lens group. For example, the focal length of the front lens is f1, the focal length of the rear lens is f2, and the beam expansion ratio of the beam expansion module 304 can be expressed as: N = f2 / f1. In some schemes, the detection device requires the diameter of the output light spot to be d2, and the diameter d1 of the emitted light beam passing through the beam processing module needs to satisfy: d1 = d2 / N.

[0138] See also Fig. 9 , Fig. 9 Schematic diagram of two beam expansion modules provided in the embodiments of the present application. Fig. 9 In part (a), the first lens group 3401 is realized by one lens, and the second lens group 3402 is also realized by one lens. The first lens group 3401 and the second lens group 3402 have a common focal plane 901. Optionally, the common focal plane 901 between the two can be a real focal plane or a virtual focal plane. The focal length of the first lens group 3401 can be smaller than the focal length of the second lens group 3402. Fig. 9 In part (b), the first lens group 3401 is implemented by multiple lenses, and the second lens group 3402 is also implemented by one lens. The focal length of each lens in the first lens group 3401 is smaller than the focal length of the second lens group 3402, and the first lens group 3401 and the second lens group 3402 have a common focal plane 902. Optionally, the common focal plane 902 between the two can be a real focal plane or a virtual focal plane. Fig. 9 It can be seen that the diameter of the emitted light beam can be expanded through the beam expansion system, thereby meeting the needs of large-diameter light emission and light collection and ensuring detection performance.

[0139] Optionally, the N emission light beams incident on the first lens group 3401 may be converging light beams (described below).

[0140] In another possible implementation, the optical module 30 may also include a scanning module. The scanning module is used to scan the N emission light beams that have passed through the beam expansion module to the object space, and to propagate the return light beams of the N emission light beams from the object space to the beam expansion module. The "scanning to the object space" here means that the N emission light beams are propagated to the object space at different angles through movement. Specifically, the scanning method of the scanning module may be one-dimensional or two-dimensional, and the present application does not limit the scanning method, the device for realizing the scanning, etc. For example, the scanning device may realize one-dimensional or two-dimensional scanning by means of a swing mirror, a rotating mirror (Polygon), a micro-electro-mechanical system (MEMS) galvanometer, a metal galvanometer, and the like.

[0141] See also Fig.10 , Fig.10 is a structural schematic diagram of another optical module provided in an embodiment of the present application, such as Fig.10 The optical module 30 shown may include a scanning module (or scanner) 305, which can be moved to form multiple angles, so as to propagate N emission beams to the object space at different angles. Of course, the return beam is also propagated to the beam expansion module through the scanning module.

[0142] Optionally, when N=1, the scanning direction of the scanning module can have multiple possible designs. Fig.10 As shown, the active axis of the scanning module can be perpendicular to the Z axis, such as Fig.10 The active axis 1 shown in the figure, at this time, the scanning direction is perpendicular to the active axis direction, that is, rotating or swinging around the active axis. Alternatively, its active axis can also be parallel to the z-axis, such as Fig.10 The movable axis 2 is shown. It should be noted that when the scanning module performs 2D scanning, the aforementioned scanning direction may be the fast axis direction of the scanning module.

[0143] Optionally, when N>1, since the N emission light beams form multiple channels in the arrangement direction, the scanning direction of the scanning module 305 is usually not parallel to the arrangement direction of the N light beams. Fig.11 , Fig.11 This is a structural diagram of another optical module provided in an embodiment of the present application. Taking N=2 as an example, the emission light beams of the two channels are arranged along the y direction, and the plane of light beam propagation is parallel to the XY plane. At this time, the active axis of the scanning module 305 is usually perpendicular to the z direction, and the scanning module swings or rotates around the z axis. Exemplarily, the scanning direction of the scanning module is perpendicular to the arrangement direction of the N emission light beams. For example, when multiple channels are arranged horizontally (that is, multiple channels are arranged in at least one row), the scanning module needs to be vertically movable so that multiple channels scan the object space in the form of "row scanning".

[0144] In the optical module 30 including the scanning module 305, if the scanning module is inactive (or in a stationary state), the main optical axes of the N return beams after passing through the scanning module 305 are parallel or even collinear with the main optical axes of the N emission beams before passing through the scanning module 305. At this time, the N return beams can be called ideal return beams. When the scanning module works normally, the scanning module has moved at an angle, so that the N return beams no longer propagate along the direction of the ideal return beam (i.e., parallel to the direction of the N emission beams), but have a certain deviation angle, i.e., the walkoff angle. It is not difficult to see that the angular direction of the walkoff angle is the same as the scanning direction of the scanning module. Since the area where the receiving port can receive light (referred to as the effective receiving area) is limited, especially for receiving ports with relatively small pattern spots and relatively small light ports such as optical fibers and waveguides, the walkoff angle of the light beam will seriously affect the loss of the return beam during the receiving process.

[0145] See also Fig.12 , Fig.12 This is a schematic diagram of a walk-off angle provided in an embodiment of the present application. Taking N=1 as an example, the scanning direction of the scanner is the y direction (perpendicular to the z-axis direction and the direction in which the emitted light beam is incident on the scanning module 305). Since the scanner is continuously scanning, there is a walk-off angle γ between the N return light beams and the ideal return light beam. When the scanner is moving, the first angle is greater than 0° and less than 90°, that is, 0°<γ<90°. The existence of the walk-off angle γ causes an offset between the optical paths of the N return light beams and the ideal return light beam (indicated by the dotted line), and the direction of the offset is the y direction. In some schemes, the offset caused by the walk-off angle of the N return light beams can be compensated for by offsetting the position of the receiving port compared to the spot position of the ideal return light beam. Combined with Fig.12 , the spot of the ideal receiving light beam reaching the waveguide chip 40 is represented by region 1101. The position of the receiving port 302 is offset from region 1101, for example, offset by Δy in the y direction, which can compensate for the offset of the N return light beams, so that the spot of the first return light beam can be closer to the effective receiving area of ​​the receiving port 302, and even coincide with the center of the effective receiving area of ​​the receiving port 302. In this way, the receiving port 302 can receive the first return light beam more accurately, improve the effectiveness of the received echo signal, and improve the detection performance.

[0146] In some scenarios, the direction of the walk-off angle is different from the direction of arrangement of the N return beams because the scanning direction is different from the direction of arrangement of the N return beams. Fig.13 is a schematic diagram of another walk-off angle provided in an embodiment of the present application. Fig.13In the embodiment, multiple transmitting ports can emit beams of multiple channels. For example, when N=2 and the scanning direction of the scanner is the z direction, there is a walk-off angle γ between the N return beams and the ideal return beam due to the continuous scanning of the scanner. The walk-off angle γ indicates the offset of the N return beams and the ideal return beam in the z direction. However, the arrangement direction of the N beams is arranged along the y direction, so the direction of the walk-off angle is inconsistent with the arrangement direction of the N beams, and is even perpendicular (i.e., the walk-off direction is the z direction). When the N return beams propagate to the N receiving ports, if the receiving port 302 is set at the spot position where the ideal return beam arrives at the receiving port, the presence of the walk-off angle causes the spot position of the N beams when they arrive at the receiving port 302 to be offset from the spot position of the ideal return beam when it arrives at the receiving port 302, and when the walk-off angle is in the z direction, the two are offset by Δz in the z direction. At this time, the spot of the return beam cannot be accurately received by the receiving port 302, resulting in a large amount of loss of the beam received by the receiving port, which seriously affects the accuracy of detection. Furthermore, the walk-off angle is positively correlated with the detection distance and the scanning speed of the scanning module. It is understandable that when the target in the object space is far from the beam module, the walk-off angle is large, and vice versa.

[0147] In some solutions, the position of the receiving port can be offset in the z direction to compensate for the light spot offset caused by the walk off angle and reduce the signal loss caused by the walk off angle.

[0148] In some cases, when the N receiving ports are arranged along the first direction, the implementation of the N receiving ports may be difficult to support the design offset in other directions (especially the thickness direction), that is, it is difficult to support the offset in the z direction, so it is impossible to compensate for the offset caused by the walk-off angle, resulting in a high loss of the light beam during the receiving process, affecting the detection performance. As a possible implementation, the optical module 30 may also include a spot transposition mechanism, which can adjust the walk-off angle of the N return light beams to the arrangement direction of the N light beams. Fig.14 etc. introduce the optical module including the light spot transposition mechanism.

[0149] See also Fig.14 , Fig.14 30 is a schematic diagram of the structure of another optical module provided by the present application. The optical module 30 may include a light spot transfer mechanism 306, which is used to transfer the walk-off angle direction of each of the N return light beams to the arrangement direction of the N return light beams. Fig.14As shown, before passing through the spot transfer mechanism 306, the existence of the walk-off angle γ causes the N return beams to be offset from the ideal return beam in the z direction. After passing through the spot transfer mechanism 306, the directions of the walk-off angles of the N return beams are converted to the arrangement direction of the N beams. After the direction of the walk-off angle is adjusted to the arrangement direction of the N return beams, the angle offset of the N return beams caused by the walk-off angle can be compensated by displacing them in the arrangement direction of the N receiving ports, which can help reduce the signal loss caused by the walk-off angle and improve the effectiveness of the signal.

[0150] See also Fig.15 , Fig.15 This is a schematic diagram of the effect of spot transposition provided by an embodiment of the present application. The return beams of the multiple channels are arranged along the first axis, and the scanner scans along the second axis. The departure direction of the return beams is consistent with the scanning direction of the scanner. Therefore, the departure direction of the return beams will be inconsistent with the arrangement direction of the multiple channels, and may even be perpendicular to each other. Fig.15 As shown, the solid circle is used to represent the light spot of the return beam, and the dotted circle is used to represent the light spot of the return beam in an ideal situation (or the light spot of the emission beam on the coaxial optical path). The return beam contains 4 channels, which are represented as CH1 to CH4. The arrangement direction of the return beams of the 4 channels is along the y-axis direction, and the walk-off direction is along the z-axis direction, so the walk-off direction is along the z-axis direction. After the light spot is transposed, the arrangement direction of the return beam is still along the y-axis direction, but the light spot of each channel is rotated by a certain angle, so that the walk-off direction of the return beam is also along the y-axis direction, that is, the walk-off direction of the return beam is consistent with the arrangement direction of the multiple channels.

[0151] In some solutions, the receiving port is implemented by waveguide or optical fiber, etc. Taking N receiving ports implemented by N waveguides as an example, the arrangement direction of the N return light beams is consistent with the arrangement direction of the N waveguides. Fig.14 Since the N receiving ports are also arranged along the y-axis, it is easy to offset the N receiving ports along the y-axis during design in the waveguide process, so that the beam loss caused by the walk-off angle can be compensated by misalignment in the arrangement direction of the N receiving ports 302, which is beneficial to reduce the signal loss caused by the walk-off angle and improve the effectiveness of the signal. For related descriptions, please refer to Fig.12 For a description of the offset receiving port 302, refer to the related description of FIG.

[0152] It should be understood that Fig.14 The structure shown can also be implemented in a single-channel case, and the specific circumstances are not described here one by one.

[0153] The light spot transposition mechanism and its effect are mentioned above. The following is an exemplary introduction to the possible implementation of the light spot transposition mechanism. The light spot transposition mechanism 306 may include one or more step reflectors. Among them, the step reflector includes N reflective surfaces arranged in a step. A step design method may be: N reflective surfaces are arranged in sequence along a certain direction and arranged at intervals in another direction to form a step, and each reflective surface is used to reflect one of the N return beams, and can also be used to reflect one of the N emission beams.

[0154] See also Fig.16A , Fig.16A : is a schematic diagram of the structure of a stepped reflector provided in an embodiment of the present application. The first stepped reflector 3061 includes four reflecting surfaces, which are respectively represented as reflecting surface A1B1C1D1, reflecting surface A3B3C3D3, reflecting surface A4B4C4D4, etc. Among them, reflecting surface A1B1C1D1 is used to reflect a returning light beam. Fig.16A It can be seen that the four reflection surfaces are arranged in sequence along the y direction (i.e., the arrangement direction of the light beams), the four first reflection surfaces are arranged at a certain interval along the x direction (i.e., the propagation direction of the N light beams), and the four reflection surfaces are at the same position in the z direction. Taking the optical path of the return light beam as an example, when the walk-off angle of the return light beam is in the z direction, after passing through the step reflector, the walk-off angle direction is rotated 90 degrees, i.e., along the x direction.

[0155] Optional, in Fig.16A In the embodiment, the reflection surface in the step reflector intersects with the beam plane formed by the N returning receiving beams (i.e., the plane formed by the propagation direction and the arrangement direction), and further, the two are neither parallel nor perpendicular. Further, the bottom surface of the reflection surface of the step reflector is 45°, or the reflection surface of the step reflector is 45° to the beam plane of the ideal receiving beam (i.e., the XY plane). At this time, the N reflection surfaces in the step reflector are parallel to each other.

[0156] Optionally, the N reflection surfaces may not be parallel. Exemplarily, the reflection surface in the step reflector intersects with the beam plane formed by the N return receiving beams (i.e., the plane formed by the propagation direction and the arrangement direction), and the angle between the reflection surface and the bottom surface increases from the center of the step to the edge of the step. In other words, the reflection surfaces of the multiple steps are deflected inward relative to the center of the step so that the multiple reflection surfaces are in an inward convergence state. See Fig. 16B , Fig. 16B : is a schematic diagram of the structure of another stepped reflector provided in an embodiment of the present application. Taking N=4 as an example, the reflective surface A1B1C1D1, the reflective surface A2B2C2D2, the reflective surface A3B3C3D3, the reflective surface A4B4C4D4 and the bottom surface in the first stepped reflector 3061, that is, Fig. 16BThe angle between the XY planes increases gradually from the step center to the step edge. In other words, the angle between the reflective surface A1B1C1D1 and the bottom surface is greater than the angle between the reflective surface A2B2C2D2 and the bottom surface, and the angle between the reflective surface A4B4C4D4 and the bottom surface is greater than the angle between the reflective surface A3B3C3D3 and the bottom surface.

[0157] The angles between the multiple optional reflecting surfaces and the bottom surface are all greater than or equal to 45°. In some schemes, the N non-parallel reflecting surfaces can be regarded as four reflecting surfaces that originally had an angle of 45° with the bottom surface, and are rotated along the rotation axis to the center of the step by the following angles α1, α2, α3, and α4. Among them, the rotation axis is an axis that is 45° to the beam plane of the ideal received light beam (i.e., the XY plane). Further optionally, the rotation angle gradually increases from the inside of the step to the outside of the step center. For example, α1, α2, α3 and α4 can be 9°, 3°, 3° and 9°, respectively, and other designs can be used during the specific implementation process. It should be noted that this is for the purpose of understanding the design and implementation of the reflecting surface. Therefore, the description of the state of the reflecting surface by rotation does not mean that the reflecting surface can be rotated during use. Fig. 16B The step reflector shown can change the pointing angles of the multiple light beams passing through, and the four parallel incident light beams will be converged after passing through the step reflector.

[0158] It should be understood that Fig. 16B The design of the N reflective surfaces shown is only an example, and other designs are possible in some embodiments. For example, see Fig. 16C , Fig. 16C This is a schematic diagram of the structure of another step reflector provided in an embodiment of the present application. The N non-parallel reflective surfaces are regarded as four reflective surfaces that originally have an angle of 45° with the bottom surface, and are rotated along the rotation axis to the outside of the step by the following angles α4, α5, α6, and α7. The rotation axis is an axis that is 45° to the beam plane (i.e., the XY plane) of the ideal received light beam. Further, optionally, the rotation angle gradually increases from the inside of the step to the outside of the center of the step. By Fig. 16C The step reflector shown can change the pointing angles of the multiple light beams passing through, and the four parallel incident light beams will be diverged after passing through the step reflector.

[0159] In some possible implementations, the spot transfer mechanism may include a stepped reflector and a folding mirror. In the case where the optical module 30 includes a PBS3031 and a beam expansion module 304, the position of the spot device structure may be located between the beam expansion module 304 and the PBS3031. The front lens group of the beam expansion module (e.g., the first lens group 3041) includes a stepped microlens array (i.e., multiple lenses), wherein the TX port, the reflective surface of the stepped reflector, and the microlens correspond one to one, and further, the TX port, the reflective surface of the stepped reflector, the microlens, and the RX port correspond one to one.

[0160] In some further possible implementations, the light spot transposition mechanism may include a plurality of step reflectors, and the plurality of step reflectors may be arranged relative to each other, thereby rotating the direction of the walk-off angle twice.

[0161] See also Fig.17A , Fig.17A It is a structural schematic diagram of another light spot transposition mechanism provided in an embodiment of the present application. The light spot transposition mechanism 306 includes two groups of stepped reflectors arranged opposite to each other, which are conveniently distinguished as the first stepped reflector 3061 and the second stepped reflector 3062. Each group of stepped reflectors includes multiple reflective surfaces arranged in a stepped manner, and one reflective surface can be used to fold a return light beam. The first stepped reflector 3061 includes four first reflective surfaces, such as the first reflective surface A1B1C1D1, the first reflective surface A3B3C3D3, the first reflective surface A4B4C4D4, etc. The four first reflective surfaces are arranged in sequence along the y-axis direction (i.e., the arrangement direction of the return light beam) and are arranged at a certain interval in the x-direction (i.e., the propagation direction of the return light beam). One first reflective surface is used to fold one return. The second stepped reflector 3062 includes four second reflective surfaces, such as the second reflective surface E1F1G1H1, the second reflective surface E3F3G3H3, the second reflective surface E4F4G4H4, etc. The four second reflection surfaces are arranged in sequence along the x direction (i.e., the propagation direction of the return light beam before passing the first step reflector 3061), and are arranged at a certain interval in the y direction (i.e., the arrangement direction of the return light beam before passing the first step reflector 3061). One second reflection surface is used to fold one return light beam.

[0162] Combination Fig.17A It can be seen that each first reflection surface in the first stepped reflection mirror 3061 is used to fold one of the N return beams and propagate it to one of the N second reflection surfaces, and each of the N second reflection surfaces is used to fold one of the N return beams so that the walk-off angle direction of the N return beams is along the arrangement direction of the N return beams. Fig. 16BAfter passing through the light spot transfer mechanism 306, the walk-off angle direction of the light beam is transferred to the x direction. At this time, the N returning light beams are also arranged along the x direction, and the light beam offset caused by the walk-off angle is also an offset Δx in the x direction.

[0163] In some possible implementations, the spot transfer mechanism 306 is also used to adjust the pointing angles of the N light beams passing through. For example, the spot transfer mechanism 306 is used to adjust the pointing angles of the N transmitted light beams and / or the N received light beams passing through. Fig. 16B or Fig. 16C The stepped reflector shown.

[0164] See also Fig. 17B , Fig. 17B It is a structural schematic diagram of another light spot transposition mechanism provided by an embodiment of the present application, wherein the angle of the first group of 1*4 step reflectors 3601 is 45°, while the angle of the second group of 1*4 step reflectors 3601 is different from the angle of the other reflective surfaces in at least one surface. Exemplarily, the angles of the 1*4 step reflectors are all deflected inward, and the deflection angle increases from the center of the step to the outside. For example, the two outermost reflective surfaces are deflected by 9°, while the inner reflective surface is deflected by 3°, thereby achieving different directions of the light beam.

[0165] In some possible implementations, a stepped reflector, such as Fig.16A , Fig. 16B , Fig. 16C The first step reflector 3061 is shown, and Fig.17A , Fig. 17B The first stepped reflector 3061 and the second stepped reflector 3062 shown include a substrate and N reflectors, wherein the N reflectors are attached to the substrate, and each reflector is used to provide a reflective surface. Exemplarily, the first stepped reflector 3061 includes a first substrate and N first reflectors, wherein the N first reflectors are attached to the first substrate, and each first reflector includes a first reflective surface. The second stepped reflector includes a second substrate and N second reflectors, wherein the N second reflectors are attached to the second substrate, and each second reflector includes a second reflective surface.

[0166] In some possible implementations, the light spot transfer mechanism is a prism, and the N first reflection surfaces and the N second reflection surfaces are realized by coating a reflection film in the prism. Fig. 17C , Fig. 17C 306 is a schematic diagram of the structure of another light spot transfer mechanism provided in an embodiment of the present application. The light spot transfer mechanism 306 is a prism, which includes multiple reflective surfaces realized by coating, such as four first reflective surfaces and four second reflective surfaces. The positional relationship between the reflective surfaces can be seen in Fig.17A Related description.

[0167] In some possible implementations, the position of the light spot transposition mechanism may be designed in a variety of ways. Fig.14 The positions shown are only examples. For example, the spot transfer mechanism can also be set on the optical path of the return light beam after it passes through the PBS, that is, between the PBS and the receiving port. For another example, when the beam expansion module includes a first lens group and a second lens group, the spot transfer mechanism can also be set between the first lens group and the second lens group.

[0168] The following is a description of the components included in the optical module provided in the embodiment of the present application. In some possible implementations, the optical module 30 further includes a transmitting lens group and a receiving lens group. The transmitting lens group is arranged between the N transmitting ports and the beam processing module, and the receiving lens group is arranged between the N receiving ports and the beam processing module. Further, the transmitting lens group and / or the receiving lens group may also be included in the beam processing module.

[0169] Optionally, the emission lens group may include one or more lenses. Exemplarily, when there are multiple emission ports, the emission lens group may be implemented by multiple lenses, each lens corresponding to one emission port. In some embodiments, the emission lens group may be a microlens array. Exemplarily, one lens may correspond to at least one emission port among multiple emission ports. For example, light beams emitted by N emission ports are collimated by one lens.

[0170] Similarly, the transmitting lens group may include one or more lenses. Exemplarily, when there are multiple receiving ports, the receiving lens group may be implemented by multiple lenses, each lens corresponding to one receiving port. In some embodiments, the receiving lens group may be a microlens array. Exemplarily, one lens may correspond to at least one receiving port among multiple receiving ports. For example, light beams emitted by N receiving ports are collimated by one lens.

[0171] The packaging design of the optical module in the embodiment of the present application is exemplarily introduced below. In some possible implementations, the transmitting port, the transmitting lens group, the receiving port, the receiving lens group and the beam processing module are packaged as a first optical component, and the beam expansion module is packaged as a second optical component. The first optical component and the second optical component are provided with a light-through window, and the light-through window is used to pass N transmitting light beams and N returning light beams.

[0172] Optionally, the transmitting lens group, receiving lens group, and beam processing module can be packaged as a transceiver module. Fig.18 , Fig.181 is a schematic diagram of the structure of a transceiver integrated module provided in an embodiment of the present application, and the transceiver integrated module 180 may include a transmitting lens group 307, a receiving lens group 308, a PBS 3031, a QWP 3032, a HWP 3033 and a folding mirror 3034. In this way, the coaxiality and collimation of transmission and reception can be achieved through a combination of an integrated lens and a prism, thereby further reducing the overall volume of the detection device.

[0173] As a possible implementation, the first optical component includes a transmitting port, a receiving port and a transceiver integrated module, wherein the transmitting port and the receiving port can be replaced by a waveguide chip including the transmitting port and the receiving port.

[0174] Alternatively, the transmitting lens group, receiving lens group, beam processing module and beam expansion module can be packaged as a transceiver module. Fig.18 As shown, the transceiver module may optionally include the first lens group 3041 in the beam expansion module 304. As another possible implementation, the first optical component includes a transmitting port, a receiving port and the transceiver module, and the rear group of the beam expansion module is packaged as a second optical component.

[0175] A variety of possible solutions have been mentioned above. Figures 19 to 24 Continuing to explain some possible designs of this solution, it should be understood that the various possible designs and possible implementations shown in this application can be combined.

[0176] See also Fig.19 , Fig.19 is a structural diagram of another optical module provided in an embodiment of the present application. Among them, the transmitting port and the receiving port are arranged on a waveguide (WG) chip, that is, the waveguide port (WGport) includes a transmitting (TX) port and a receiving (RX) port. Fig.19 The transmitting port and receiving port are both set on the right side of the waveguide chip. The beam processing module includes PBS, QWP, HWP and folding mirror, and optionally also includes a transmitting lens group (TX lens) and a receiving lens group (RXlens). The beam expansion module includes two groups of lenses, the front and rear lenses, and the front lens group and the rear lens group are connected by the focal plane P1.

[0177] During transmission, the light beam emitted from the transmitting port passes through the TX lens, PBS, QWP, and beam expansion module to the scanner, and is scanned by the scanner into the object space. The return light beam from the object space passes through the scanner, beam expansion module, QWP, PBS, HWP, folding mirror, and RX lens to the receiving port. The return light beam of the close-range target is reflected and converged at position 1. Since the return light beam of the distant target has a longer flight time in the air, the walk-off angle is larger, so the return light beam of the distant target converges at position 2. Furthermore, the span between position 1 and position 2 corresponds to the size of the mode spot of the waveguide along the walk-off direction.

[0178] In some possible designs, the components in the optical module can be packaged to further improve the integration and stability of the device. Among them, the waveguide chip, TX lens, RX lens, PBS polarization beam splitter component (including PBS components, QWP, HWP), and folding mirror can be packaged as the first optical component, or called the first-level optical system, that is, Fig.19 The IO package (IO package) shown. The front lens group and the rear lens group in the beam expansion system are integrally packaged to form a second optical component, or a second-level optical system. There is a window through which light can pass between the first-level optical system and the second-level optical system (such as by setting a window piece). At this time, since the first-level system contains waveguide chips and small-sized optical components, it is easier to perform tube and shell packaging and achieve a better coefficient of thermal expansion (CTE) matching design, thereby improving integration and stability. The second-level system can be regarded as a beam expansion lens group and is installed as a whole between the first-level optical system, which improves the overall stability of the optical module and can be decoupled from the first-level optical system.

[0179] In the case of a two-stage optical system package, when transmitting, the light enters the second optical system from the first optical system. The second optical system further expands the light beam to meet the design requirements and then emits it from the second optical system of the optical module. When receiving, the light enters from the second optical system, and the beam expansion module is used to expand the received light beam. The return light beam after the beam expansion module is reduced in size passes through the optical window and enters the first optical system. After passing through the PBS component, the folding mirror, and the RX lens in the first optical system, it is coupled into the waveguide chip.

[0180] See also Fig. 20 , Fig. 20 is a schematic diagram of the structure of another optical module provided in an embodiment of the present application. Fig.19The difference is that the port of the waveguide chip includes multiple transmitting ports and multiple receiving ports, and the optical module includes a light spot transposition mechanism. Since the port of the waveguide chip includes multiple transmitting ports and multiple receiving ports, the transmitting beam and the returning beam are both multi-channel beams. Fig. 20 , the multi-channels are arranged along the first axis, and the scanner scans along the second axis. The walk-off direction is consistent with the scanning direction of the scanner, so the walk-off direction is inconsistent with the arrangement direction of the multi-channels. Due to the limitation of the waveguide process, the walk-off direction needs to be transposed to the waveguide arrangement direction, and the spot transposition mechanism can adjust the walk-off direction to be consistent with the arrangement direction of the multi-channels, such as Fig. 20 Optionally, the light spot transfer mechanism is also used to change the directions of the multiple light beams passing through, so that the emission light beams of multiple channels enter the beam expansion system after being converged.

[0181] In a possible optical path design, taking an optical module including 4 transmitting ports and 4 receiving ports as an example, after the 4 transmitting light beams emitted by the 4 transmitting ports emerge from the optical module, the angle between adjacent light beams is 1.2° (that is, the pointing angles are 1.8°, 0.6°, -0.6° and -1.8° respectively). The interval between the four transmitting ports is exemplarily 2.2mm, the focal length of the TX lens is exemplarily 0.5mm, the focal length of the RX lens is exemplarily 2.5mm, and the center distance between two adjacent reflecting surfaces of the step reflector is exemplarily 2.2mm. The front lens group of the beam expansion module is a 1*4 microlens array to achieve beam convergence, and the rear lens group is a collimator to achieve beam expansion and pointing. The focal length of the front lens group is exemplarily 6.8mm, and the focal length of the rear collimator is exemplarily 68mm, thereby achieving a beam expansion ratio of 1:10. In this optical path design, the size of each optical element and the distance between the light beams can be in the millimeter level, which significantly reduces the overall volume of the detection device.

[0182] See also Fig.21 , Fig.21 is a schematic diagram of the structure of another optical module provided in an embodiment of the present application. Fig.18 The difference is that the waveguide port includes multiple transmitting ports and multiple receiving ports, and the optical module includes a light spot transposition mechanism. Fig.19 The difference is that the front lens group (i.e., the lens close to the PBS) in the beam expansion system can include multiple lenses, and the spot transposition mechanism does not need to change the direction of the multiple light beams passing through.

[0183] In some possible implementations, combining Fig.21, the spot transposition mechanism can include a group of step reflectors, and the front group of the beam expansion module is a group of microlens arrays with step settings. Among them, the TX port, the reflection surface in the step reflector, and the microlens in the microlens array correspond one to one, and further, the three correspond one to one to the RX port. A transmission light beam emitted by a TX port is incident on a reflection surface of the step reflector, and enters a lens in the microlens array after reflection. Correspondingly, a return light beam passes through a lens in the microlens array, enters a reflection surface of the step reflector, and is received by an RX port through the PBS, etc.

[0184] In some other possible implementations, the spot transfer mechanism may include two step reflectors, one of which is as follows: Fig. 16B As shown. In a possible optical path design, taking an optical module including 4 transmitting ports and 4 receiving ports as an example, after the 4 transmitting light beams emitted by the 4 transmitting ports exit the optical module, the angle between adjacent light beams is 1.2° (that is, the pointing angles are 1.8°, 0.6°, -0.6° and -1.8° respectively). The interval between the four transmitting ports is exemplarily 2.2mm, the focal length of the TX lens is exemplarily 1mm, the focal length of the RX lens is exemplarily 5mm, and the center distance between two adjacent reflecting surfaces of the step reflector is exemplarily 2.2mm. Among them, in the first group of 1*4 step reflectors in the spot transposition mechanism, the angle between the four surfaces and the bottom surface is 45°, and the angle between the four surfaces and the bottom surface of the second group of 1*4 step reflectors is 45°. At the same time, relative to Fig. 16B The movable axis shown rotates ±3° and ±9°, so that the N emission beams emitted from the beam module can be arranged to form a linear array. In this optical path design, the size of each optical element and the distance between the beams can be in the millimeter level, which significantly reduces the overall volume of the detection device.

[0185] See also Fig. 22 , Fig. 22 FIG. 1 is a schematic diagram of an emission light path of another optical module provided in an embodiment of the present application. Figure 19-21 The difference is that the spot transfer mechanism is located inside the beam expansion module, and the front lens in the beam expansion module is a microlens array, which can include multiple microlenses arranged in steps to focus the passing light beam. The spot transfer mechanism can be used to adjust the walk-off foot of the return light beam, and the rear lens can increase the aperture of the emitted light beam and improve the detection performance.

[0186] The spot transfer mechanism may include one or more step reflectors for realizing the rotation of the walk-off angle. For details, see the aforementioned Fig.16A , Fig. 16B , Fig. 16C , Fig.17A and Fig. 17B Related description.

[0187] The above describes some solutions of the present application by taking the coaxial structure as an example. The following introduces the optical module using the off-axis structure provided in the embodiment of the present application.

[0188] See also Fig.23 , Fig.23 It is a structural schematic diagram of an optical module using an off-axis architecture provided in an embodiment of the present application, wherein the optical module 230 includes a beam transceiver module 2301 and a light spot transfer mechanism 306, wherein the beam transceiver module 2301 includes N transmitting ports 301 and N receiving ports 302, and the N transmitting ports 301 and the N receiving ports 302 are cross-arranged along the end face of the beam transceiver module.

[0189] Among them, the N transmitting ports are used to transmit N transmitting light beams, and the N receiving ports are used to receive N returning light beams, and the N returning light beams are returning light beams of the N transmitting light beams. The spot transfer mechanism 306 is arranged on the optical path of the N transmitting light beams and the N returning light beams, and the N transmitting light beams after passing through the spot transfer mechanism are used to scan the object space, and the scanning direction is the second direction. The walk-off angle direction of the N returning light beams before passing through the spot transfer mechanism is the second direction, and the N returning light beams are arranged along the first direction, and the second direction is different from the first direction.

[0190] The spot transfer mechanism is used to transfer the walk-off angle direction of each of the N return beams to the arrangement direction of the N return beams, and provide them to the N receiving ports. The relevant design of the spot transfer mechanism can be found in the above, for example Fig.16A , Fig. 16B , Fig. 16C , Fig.17A and Fig. 17B Related description.

[0191] In a possible implementation, the optical module 30 further includes a beam expansion module 304, which is used to expand the N emission light beams and shrink the N return light beams. Further, the design of the beam expansion module 2303 can be referred to above.

[0192] For example, Fig.23 The beam expansion module shown may include a first lens group 3041 and a second lens group 3042, and the first lens group 3041 and the second lens group 3042 have a common focal plane 901. The first lens group 3041 may include a plurality of lenses, and the plurality of lenses may be arranged in a stepped manner or in parallel.

[0193] Optional, in Fig.23 In the structure shown, the spot transfer mechanism may include one or more Fig.16AThe step reflector shown is used to turn the walk-off angle direction of each of the N return beams to the arrangement direction of the N return beams. For related descriptions, see Fig.16A and Fig.17A Related description.

[0194] Optional, combined Fig.23 The optical module 30 may also include a scanning module, which is arranged on the optical path of the end of the light spot transfer mechanism away from the emission port. The relevant description can be found in the above, and will not be described one by one here.

[0195] See also Fig.24 , Fig.24 It is a structural schematic diagram of another optical module using an off-axis architecture provided in an embodiment of the present application. Among them, N transmitting ports 301 and N receiving ports 302 are arranged crosswise, that is, the port next to a transmitting port is a receiving port. The N transmitting ports 301 can emit N transmitting light beams, each transmitting light beam passes through a spot transposition mechanism 306 (optionally passing through a beam expansion module) to reach a scanner 305, and the N return light beams from the scanner 305 follow the opposite path of the transmitting light beam and pass through the spot transposition mechanism to reach the N receiving ports.

[0196] After passing through the spot transposition mechanism 306, the walk-off directions of the N return beams are transposed to the arrangement directions of the N return beams, which is beneficial for offsetting the arrangement direction of the receiving port to achieve walk-off compensation, thereby reducing the loss of the return beams and improving the detection performance.

[0197] The embodiment of the present application also provides a laser radar, which includes the aforementioned optical module. Further, the laser radar also includes a light source, such as a laser. Optionally, the frequency of the light beam emitted by the light source can be continuously variable, such as a frequency modulated continuous wave (FMCW) laser.

[0198] Furthermore, the laser radar also includes a detector, which is used to obtain an electrical signal according to the light beam. For example, the detector may include a photodiode (PD) capable of detecting light energy, such as InGaAs PD, InP PD, or germanium PD.

[0199] The embodiment of the present application further provides a terminal, which includes the aforementioned optical module. Alternatively, the terminal includes the aforementioned laser radar.

[0200] Optionally, the terminal can be an intelligent terminal or means of transportation such as a vehicle, a drone, or a robot. Of course, the terminal can also be replaced by industrial equipment, entertainment and leisure equipment, etc. Intelligent terminals include mobile phones, tablet computers, laptops, smart bracelets, smart watches, or smart glasses. Transportation tools include vehicles, ships, aircraft, or logistics robots. Industrial equipment includes industrial robots and robotic arms. Leisure and entertainment equipment includes virtual reality (VR) equipment, mixed reality (MR) equipment, massage chairs, or 4D cinema cabins. This application does not impose strict restrictions on the devices to which the electrical connector can be applied.

[0201] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, a conflicting connection or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0202] In the embodiments of the present application, the words "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0203] The "at least one" mentioned in the embodiments of the present application refers to one or more, and "plurality" refers to two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can be represented by: a, b, c, (a and b), (a and c), (b and c), or (a and b and c), where a, b, c can be single or multiple. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can be represented by: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0204] Furthermore, unless otherwise specified, the ordinal numbers such as "first" and "second" used in the embodiments of the present application are used to distinguish multiple objects, and are not used to limit the order, timing, priority or importance of multiple objects. For example, the first reflecting surface and the second reflecting surface are only for the convenience of describing the reflecting surfaces, and do not indicate the difference in structure, importance, etc. between the first reflecting surface and the second reflecting surface.

Claims

1. An optical module, characterized in that: The optical module includes N transmitting ports, N receiving ports, a beam processing module and a beam expansion module, wherein N is an integer greater than or equal to 1. The N transmitting ports are used to transmit N transmitting light beams; The N receiving ports are used to receive the return light beams of the N transmitted light beams; The beam processing module is used to transmit the N emission beams to the beam expansion module, and to deflect and propagate the N return beams from the beam expansion module to the N receiving ports, wherein the N return beams are return beams of the N emission beams, and the N emission beams passing through the beam processing module and the N return beams from the beam expansion module are coaxial beams; The beam expansion module is used to expand the N emission light beams.

2. The optical module according to claim 1, characterized in that: The beam processing module comprises a polarization beam splitter PBS, a quarter wave plate QWP and a folding mirror, wherein the QWP is arranged on the optical path between the PBS and the beam expansion module, and the folding mirror is arranged on the optical path between the PBS and the N receiving ports, wherein: The N emission light beams are propagated to the beam expansion module through the PBS and the QWP, and the N return light beams from the beam expansion module are propagated to the folding mirror through the QWP and the PBS; The folding mirror is used to deflect the light beam passing through the PBS and propagate it to the N receiving ports.

3. The optical module according to claim 2, characterized in that: The PBS is used to transmit a light beam in a first polarization direction and reflect a light beam in a second polarization direction, wherein the first polarization direction is perpendicular to the second polarization direction; The QWP is used to change the polarization of the passing light beam, and the polarization direction of the returning light beam of the N emitted light beams after passing through the QWP is perpendicular to the polarization direction of the N emitted light beams.

4. The optical module according to any one of claims 1 to 3, characterized in that: The optical module also includes a scanning module, which is used to scan the N emission light beams passing through the beam expansion module to the object space, and propagate the return light beams of the N emission light beams from the object space to the beam expansion module.

5. The optical module according to any one of claims 4, characterized in that: N≥2, the N returning light beams after passing through the scanning module are arranged along the first direction, The scanning direction of the scanning module is a second direction, the walk-off angle direction of each of the N returning light beams is the second direction, and the second direction is different from the first direction; The optical module further comprises a light spot transposition mechanism, which is arranged on an optical path between the scanning module and the N receiving ports. The light spot transfer mechanism is used to transfer the walk-off angle direction of each of the N return light beams to the arrangement direction of the N return light beams.

6. The optical module according to claim 5, characterized in that: The light spot transposition mechanism comprises a first step reflector and a second step reflector, wherein: The first stepped reflector includes N first reflective surfaces arranged in a stepped manner. The first stepped reflector includes N second reflective surfaces arranged in a stepped manner, the N first reflective surfaces are opposite to the N second reflective surfaces one by one, and the second stepped reflector is used to reflect the emergent light of the first group of stepped reflectors again.

7. The optical module according to claim 6, characterized in that: Each of the N first reflection surfaces is used to fold one of the N return light beams and propagate it to one of the N second reflection surfaces. Each of the N second reflection surfaces is used to fold one of the N return light beams so that the walk-off angle direction of the one return light beam is along the arrangement direction of the N return light beams.

8. The optical module according to claim 6 or 7, characterized in that: The included angle between the N first reflection surfaces and the bottom surface of the first stepped reflection mirror is 45°, and the included angle between the N second reflection surfaces and the bottom surface of the second stepped reflection mirror is 45°.

9. The optical module according to claim 6 or 7, characterized in that: The included angle between the N first reflecting surfaces and the bottom surface of the first stepped reflecting mirror is 45°; The included angles between the N second reflecting surfaces and the bottom surface of the first stepped reflecting mirror gradually increase from the step center of the second stepped reflecting mirror along both sides of the step of the second stepped reflecting mirror.

10. The optical module according to any one of claims 6 to 9, characterized in that: The light spot transposition mechanism is a prism, and the N first reflection surfaces and the N second reflection surfaces are realized by coating a reflection film in the prism.

11. The optical module according to any one of claims 6 to 9, characterized in that: The first stepped reflector comprises a first substrate and N first reflectors, wherein the N first reflectors are attached to the first substrate, and each first reflector comprises a first reflective surface; The second stepped reflector includes a second substrate and N second reflectors, the N second reflectors are attached to the second substrate, and each second reflector includes a first reflective surface.

12. The optical module according to any one of claims 6 to 11, characterized in that: The beam expansion module includes a first lens group and a second lens group, and the first lens group and the second lens group have a common focal plane.

13. The optical module according to claim 12, characterized in that: The light spot transfer mechanism is arranged between the first lens group and the second lens group.

14. The optical module according to claim 12 or 13, characterized in that: The first lens group includes N lenses, and each lens of the N lenses is used to pass one of the N return light beams.

15. The optical module according to any one of claims 1 to 14, characterized in that: The optical module further comprises a transmitting lens group and a receiving lens group, wherein the transmitting lens group is arranged between the N transmitting ports and the beam expansion module, and the receiving lens group is arranged between the N receiving ports and the beam expansion module; The N transmitting ports, the transmitting lens group, the N receiving ports, the receiving lens group and the beam processing component are packaged as a first optical component, the beam expansion module is packaged as a second optical component, and the first optical component and the second optical component are provided with light-transmitting windows, which are used to pass the N transmitting light beams and the N returning light beams.

16. The optical module according to any one of claims 1 to 15, characterized in that: The N transmitting ports and the N receiving ports are waveguide ports of a waveguide chip.

17. An optical module, characterized in that: The optical module includes a beam transceiver module and a light spot transposition mechanism; The beam transceiver module comprises N transmitting ports and N receiving ports, and the N transmitting ports and the N receiving ports are cross-arranged along the end face of the beam transceiver module, and N is an integer greater than 1. The N transmitting ports are used to transmit N transmitting light beams; The N receiving ports are used to receive the N return light beams, where the N return light beams are return light beams of the N emission light beams; The light spot transposition mechanism is arranged on the optical paths of the N emission light beams and the N return light beams, The N emission light beams after passing through the light spot transposition mechanism are used to scan the object space, and the scanning direction is the second direction. The walk-off angle direction of the N returning light beams before passing through the light spot transfer mechanism is the second direction, the N returning light beams are arranged along the first direction, and the second direction is different from the first direction, The light spot transfer mechanism is used to transfer the walk-off angle direction of each of the N return light beams to the arrangement direction of the N return light beams, and provide the direction to the N receiving ports.

18. The optical module according to claim 17, characterized in that: The light spot transposition mechanism comprises a first step reflector and a second step reflector, wherein: The first stepped reflector includes N first reflective surfaces arranged in a stepped manner. The first stepped reflector includes N second reflective surfaces arranged in a stepped manner, the N first reflective surfaces are opposite to the N second reflective surfaces one by one, and the second stepped reflector is used to reflect the emergent light of the first group of stepped reflectors again.

19. A laser radar, characterized in that: The laser radar includes the optical module as described in any one of claims 1-16, or includes the optical module as described in claim 17 or 18.

20. A terminal, characterized in that: The terminal includes the optical module as described in any one of claims 1-16, or includes the optical module as described in claim 17 or 18, or includes the laser radar as described in claim 19.

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