WO2024045550A1

WO2024045550A1 - Laser radar transmitting module, transceiver device and laser radar

Info

Publication number: WO2024045550A1
Application number: PCT/CN2023/081256
Authority: WO
Inventors: 潘政清; 向少卿
Original assignee: 上海禾赛科技有限公司
Priority date: 2022-08-29
Filing date: 2023-03-14
Publication date: 2024-03-07
Also published as: CN117665771A

Abstract

A laser radar transmitting module, a transceiver device and a laser radar. The transmitting module comprises: a multi-wavelength light emitting unit, the multi-wavelength light emitting unit being suitable for generating a light beam; a wavelength switching unit, the wavelength switching unit receiving the light beam generated by the multi-wavelength light emitting unit, and the wavelength switching unit controlling, by means of an electrical signal, a plurality of switching elements to switch the wavelength of the output light beam; and a light splitting unit, the light splitting unit being located in an optical path downstream of the wavelength switching unit, and the light splitting unit being used for splitting the received light beam and enabling each obtained beam to further form multi-line detection light. By means of an electrical signal, switching elements (i.e., an optical switch) are controlled to switch the wavelength of the output light beam, thereby effectively reducing the manufacturing process difficulty of the wavelength switching unit, and effectively reducing the control difficulty of achieving high-speed wavelength switching.

Description

LiDAR transmitting module, transceiver device and LiDAR

This application claims priority to the Chinese patent application filed with the China Patent Office on August 29, 2022, with the application number 202211042630.6 and the invention name "Laser Transmitter Module, Transceiver Device and Lidar", the entire content of which is incorporated by reference in in this application.

Technical field

The invention relates to the field of laser detection, and in particular to a laser radar transmitting module, a transceiver device and a laser radar.

Background technique

Lidar is a commonly used ranging sensor with the characteristics of long detection range, high resolution, and low environmental interference. It is widely used in unmanned driving, intelligent robots, drones and other fields. In recent years, autonomous driving technology has developed rapidly, and lidar, as the core sensor for distance sensing, has become indispensable.

Among them, the development of frequency modulated continuous wave (FMCW) lidar requires comprehensive consideration of range, field of view (FOV), frame rate and number of lines. In the traditional frequency modulated continuous wave system, due to the existence of the delay angle, the scanning speed of the fast axis of the scanner is restricted, which affects the improvement of the field of view angle, frame rate, line number and other indicators.

The parameters of existing frequency modulated continuous wave lidar are: 64 lines; ranging capability: reflectivity of 10% less than 200 meters (<200m@10%R); field of view angle of 120°. For time-of-flight (TOF) lidar, the number of lines can generally reach 128 lines, or even 300 lines, and the range measurement capability is 250 meters.

Therefore, the performance parameters of existing frequency modulated continuous wave lidar are lagging behind. Therefore, in order to achieve a higher line number of frequency modulated continuous wave lidar, it is urgent to develop a new architecture and improve various indicators.

Contents of the invention

The problem solved by this invention is how to reduce the manufacturing difficulty and Control the difficulty.

In order to solve the above problems, the present invention provides a laser radar transmitting module, including:

A multi-wavelength light-emitting unit, the multi-wavelength light-emitting unit is suitable for generating a light beam; a wavelength switching unit, the wavelength switching unit receives the light beam generated by the multi-wavelength light-emitting unit, the wavelength switching unit controls a plurality of switching elements through electrical signals Switch the wavelength of the output light beam; a light splitting unit, the light splitting unit is located in the optical path downstream of the wavelength switching unit, the light splitting unit is used to split the received light beam and further form each split beam into multiple Line detection light.

Optionally, the wavelength switching unit controls multiple switching elements according to a preset timing sequence to achieve time-sharing switching of the wavelength of the output light beam.

Optionally, the wavelength switching unit includes: channel elements, the channel elements are suitable for forming the optical path into m channels; m switching elements, the m switching elements correspond to the m channels one by one, and the The switching element controls the opening and closing of the corresponding channel; the control element controls the opening and closing of m switching elements according to a preset time sequence; where m is an integer greater than 1.

Optionally, the light beam of each channel is a light beam of a single wavelength; or, the light beam of each channel includes a set of equally spaced frequency light beams.

Optionally, the channel element includes: one of a wavelength division multiplexing filter and an optical cross-wavelength division multiplexer.

Optionally, the switching element includes: one of a silicon-based optical switch, a thin film lithium niobate electro-optical switch, and a semiconductor optical amplifier.

Optionally, the wavelength switching unit further includes: an energy monitoring element, the energy monitoring element is located between the channel element and the switch element, the energy monitoring element is suitable for monitoring the energy of the light beam of each channel; The control element adjusts the gain of the corresponding switching element according to the energy of the light beam of each channel and the preset value.

Optionally, the control element controls m switching elements so that the same preset time period Only 1 channel is open.

Optionally, the multi-wavelength light-emitting unit includes multiple lasers, and the center wavelengths of different lasers are not equal; or, the multi-wavelength light-emitting unit includes at least one laser and a multi-wavelength generating component.

Optionally, the multi-wavelength generating component includes: an electro-optical modulation element and a semiconductor optical amplifier; or, the multi-wavelength generating component includes: a micro-ring resonant cavity.

Optionally, it also includes: a plurality of emission ports, one line of the detection light is emitted from one of the emission ports; the plurality of emission ports are arranged along the first direction to obtain scanning of the emitted light beam in the first plane; the emission The module also includes: a one-dimensional scanning unit, which is located in the optical path downstream of the emission port. The one-dimensional scanning unit causes the detection light to scan in a second plane, and the second plane is perpendicular to the first plane. flat.

Optionally, it also includes: multiple port groups, each port group including multiple light-emitting ports; multiple light-emitting ports of the same port group are continuously arranged along the first direction, and the light-emitting ports of different port groups are continuously arranged along the first direction. The wavelengths of the detection lights emitted from the plurality of light-emitting ports are in the same order.

Optionally, the light splitting unit includes: a 1×n beam splitter, which is suitable for splitting the received light beam with equal energy, where n is an integer greater than 1; n wavelength separation elements. , each wavelength separation element further forms each beam split by the 1×n beam splitter into multi-line detection light.

Optionally, the wavelength separation element includes: at least one of a wavelength division multiplexing filter, a prism, a grating, and an optical cross-wavelength division multiplexer.

Optionally, the transmitting module is used as a transceiver device for coaxial transceiver, and the splitting unit also includes: n connectors, each connector is located at the 1×n beam splitter and 1 wavelength separation element. , the first end of the connector is connected to the 1×n beam splitter, and the second end is connected to the wavelength separation element.

Optionally, the connector is at least one of a circulator or a polarizing beam splitter.

Optionally, the transmitting module is used as a transceiver device for frequency modulated continuous waves. The transmitting module The block further includes: a first coupling unit located in the optical path between the wavelength switching unit and the light splitting unit, and the first coupling unit splits the light beam output from the wavelength switching unit. Out of this vibration.

Correspondingly, the present invention also provides a laser radar transceiver device, including:

A transmitting module, which is the transmitting module of the present invention; the emitted detection light is reflected in a three-dimensional space to form echo light; and a receiving module, which is suitable for receiving the echo light.

Optionally, the transceiver device is a frequency modulated continuous wave transceiver device, and the transmitting module further includes: a first coupling unit located in the optical path between the wavelength switching unit and the light splitting unit. , the first coupling unit separates the local oscillator light from the light beam output by the wavelength switching unit; the receiving module includes: a 1×n beam splitter, and the 1×n beam splitter of the receiving module is suitable for The local oscillator light separated by the first coupling unit is split into equal energy beams; n receiving units are provided, and the n receiving units correspond to the n split local oscillator lights one-to-one, and each receiving unit corresponds to Connect the third end of 1 connector.

Optionally, the receiving unit includes: a coupler and a balanced detector connected in sequence.

In addition, the present invention also provides a laser radar, including: the transceiver device of the laser radar of the present invention.

Compared with the existing technology, the technical solution of the present invention has the following advantages:

In the technical solution of the present invention, in the laser radar transmitting module, the wavelength switching unit controls multiple switching elements to switch the wavelength of the output light beam through electrical signals. By controlling the switching element (ie, optical switch) with an electrical signal to switch the wavelength of the output light beam, the manufacturing process difficulty of the wavelength switching unit can be effectively reduced, and the control difficulty of achieving high-speed wavelength switching can be effectively reduced.

In an optional solution of the present invention, the wavelength switching unit controls multiple switching elements according to a preset timing sequence to achieve time-sharing switching of the wavelength of the output light beam. Wavelength switching in a time-sharing manner can effectively reduce the difficulty of collecting and calculating lidar detection data.

In the optional solution of the present invention, the detection light is emitted from one emission port; multiple emission ports are arranged along the first direction to obtain scanning of the emitted light beam in the first plane; the emission module also includes: one-dimensional scanning unit, the one-dimensional scanning unit is located in the optical path downstream of the emission port, and the one-dimensional scanning unit causes the detection light to scan in a second plane, and the second plane is perpendicular to the first plane. When the first plane (such as the vertical direction) is scanned using a multi-channel electronic control method, and the second plane (such as the horizontal direction) is scanned using a low-speed one-dimensional scanning unit, the scanning speed of the scanning unit can be effectively reduced, and the scanning speed can be effectively reduced. Alleviate the delay angle problem.

In an optional solution of the present invention, the transmitting module includes multiple port groups, each port group includes multiple light-emitting ports, and the multiple light-emitting ports of the same port group are continuously arranged along the first direction. The detection light emitted by each light-emitting port has a different wavelength, and the wavelength order of the detection light emitted by multiple light-emitting ports in different port groups is the same, so that the wavelengths generated by the multi-wavelength light-emitting unit through multiple wavelength separation elements can be staggered as much as possible. The direction of the field of view corresponding to the beams of the same wavelength can minimize the interference between the beams of the same wavelength.

In an optional solution of the present invention, the channel element of the wavelength switching unit includes: one of a wavelength division multiplexing filter and an optical cross-wavelength division multiplexer; the switching element includes: a silicon-based optical switch, a thin film lithium niobate battery One of optical switches and semiconductor optical amplifiers. Demultiplexing filters, optical cross-wavelength division multiplexers, silicon-based optical switches, thin-film lithium niobate electro-optical switches, and semiconductor optical amplifiers can all be produced on a large-scale chip, and the cost of arraying is very low, so it can effectively reduce Production difficulty and process cost.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of a frequency modulated continuous wave lidar;

Figure 2 is a schematic diagram of the scanning mirror field of view scanning of the laser radar shown in Figure 1;

Figure 3 is a functional block diagram of an embodiment of the laser radar transmitting module of the present invention;

Figure 4 is a functional block diagram of the wavelength switching unit in the embodiment of the laser radar transmitting module shown in Figure 3;

Figure 5 is a timing diagram of the control element in the wavelength switching unit controlling multiple switching elements in the embodiment of the laser radar transmitting module shown in Figure 4;

Figure 6 is a functional block diagram of the light splitting unit in the embodiment of the laser radar transmitting module shown in Figure 3;

Figure 7 is a schematic diagram of the distribution of transmission ports in the embodiment of the lidar transmission module shown in Figure 3;

Figure 8 is a schematic diagram of the distribution of emission ports in an embodiment of the laser radar transmission module of the present invention;

Figure 9 is a schematic diagram of the optical path in which the connector is set as a polarizing beam splitter in another embodiment of the laser radar transmitting module of the present invention;

Figure 10 is a functional block diagram of another embodiment of the laser radar transmitting module of the present invention;

Figure 11 is a functional block diagram of a multi-wavelength light-emitting unit in the embodiment of the laser radar transmitting module shown in Figure 10;

Figure 12 is the frequency distribution of the light beam generated by the multi-wavelength light-emitting unit in the embodiment of the laser radar transmitting module shown in Figure 11;

Figure 13 is a timing diagram of the control element in the wavelength switching unit controlling multiple switching elements in the embodiment of the laser radar transmitting module shown in Figure 10;

FIG. 14 is a schematic diagram corresponding to each wavelength of light in the dotted box in the timing diagram of the embodiment of the laser radar transmitting module shown in FIG. 13 .

Detailed ways

It can be seen from the background technology that in the existing technology, frequency modulated continuous wave lidar has problems that need to be improved in various performance indicators. Now let’s analyze the reasons for the poor performance index of a frequency modulated continuous wave lidar:

Referring to Figure 1, a schematic structural diagram of a frequency modulated continuous wave lidar is shown.

The laser radar includes: a laser 11, a transmitting coupler 12, a connector 13, a collimating unit 14 and a scanning mirror 15 arranged in sequence along the optical path of the detection light; and a receiving coupler 16, 16 and 16 arranged in sequence along the optical path of the local oscillator light. Detector 17 and processing unit 18.

The first end of the connector 13 is connected to the launch coupler 12 , the second end of the connector 13 is connected to the collimation unit 14 , and the third end of the connector 13 is connected to the The receiving coupler 16 is connected. Specifically, the connector 13 may be a circulator, and the connector 13 is connected to the corresponding component through an optical waveguide, such as an optical fiber.

The initial light generated by the laser 11 is divided into detection light and local oscillation light by the emission coupler 12; after the detection light is transmitted through the connector 13, it emerges from the collimation unit 14 and is reflected by the scanning mirror 15. Scanning is realized in three-dimensional space; the echo light formed by the reflection of the detection light in the three-dimensional space is reflected by the scanning mirror 15 and received by the collimation unit 14 , and is transmitted to the receiving coupler 16 through the connector 13 .

After receiving the local oscillator light separated by the transmitting coupler 12 and the echo light transmitted by the connector 13, the receiving coupler 16 mixes the received local oscillator light and the echo light to perform coherent beat frequency, The detector 17 collects the mixed light beam, and the processing unit 18 obtains information such as distance, speed and reflectivity of the target to be measured based on beat frequency signal analysis.

The connector 13 has three ports. The signal input at the first end a will be output from the second end b, and the signal input from the second end b will be output from the third end c; therefore, the detection light will be output from the first end a. Input, second terminal b output, echo light input from the second terminal b, third terminal c output; therefore, the use of the connector 13 can enable the frequency modulated continuous wave laser radar to achieve coaxial transceiver.

In frequency modulated continuous wave lidar, most of them are realized by continuous rotation of the scanning mirror 15 Scan three-dimensional space. In a laser radar with a common transmission and reception path, the scanning mirror 15 not only needs to scan the detection light, but also needs to receive the formed echo light.

Due to the continuous rotation of the scanning mirror 15, the angle of the scanning mirror 15 when receiving the echo beam is already different from the angle of the scanning mirror 15 when the detection beam is emitted, that is, the scanning mirror 15 generates a delay angle. The retardation angle is proportional to the scanning angular velocity. The greater the scanning angular velocity, the greater the retardation angle generated by the scanning mirror 15 at the same time. The delay angle causes the light spot of the echo light at the receiving end face (usually using an optical fiber) to tilt and shift, which in turn leads to a decrease in receiving efficiency.

With reference to Figure 2, a schematic diagram of the scanning of the field of view of the scanning mirror 15 is shown. The fast axis corresponds to the scanning of the horizontal field of view, and the slow axis corresponds to the scanning of the vertical field of view. The figure shows the scanning process of one frame of the slow axis. Figure The number of black dots in can be considered as the number of equivalent lines of the scanning mirror 15 (the number of lines output by the point cloud in the vertical direction). The fast axis of the scanning mirror 15 is usually in a resonant state, the scanning frequency is as high as kHz, and the scanning angular velocity is large. Therefore, the spot of the echo beam at the receiving end face is tilted and shifted greatly.

The solutions to the above delay angle problem mainly include: 1. Give up the mechanical scanning mirror and use an optical phased array to achieve electronically controlled step scanning. The disadvantage is that the current technical level is difficult to overcome the small size and high loss of the phased array optical antenna. Defects; 2. Using multi-mode waveguide for reception, although the reception efficiency is improved, the mutual interference between modes will cause a decrease in signal-to-noise ratio; 3. Separation of transmitting and receiving, appropriately shifting the position of the receiving waveguide, and pre-compensating the delay angle, at the cost of nearly The distance reception efficiency is reduced.

In order to solve the above technical problems, the present invention provides a laser radar transmitting module, including:

The technical solution of the present invention is that in the laser radar transmitting module, the wavelength switching unit controls multiple switching elements to switch the wavelength of the output light beam through electrical signals. By controlling the switching element (ie, optical switch) with an electrical signal to switch the wavelength of the output light beam, the manufacturing process difficulty of the wavelength switching unit can be effectively reduced, and the control difficulty of achieving high-speed wavelength switching can be effectively reduced.

In order to make the above objects, features and advantages of the present invention more obvious and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 3 , a functional block diagram of an embodiment of the laser radar transmitting module of the present invention is shown.

The transmitting module of the laser radar includes: a multi-wavelength light-emitting unit 110, which is suitable for generating a light beam; a wavelength switching unit 120, which receives the light beam generated by the multi-wavelength light-emitting unit 110. , the wavelength switching unit 120 controls multiple switching elements 121 to switch the wavelength of the output light beam through electrical signals; the spectroscopic unit 130 is located in the optical path downstream of the wavelength switching unit 120, and the spectroscopic unit 130 uses The received light beam is split and each split beam is further formed into a multi-line detection light.

By controlling the switching element 121 with an electrical signal to switch the wavelength of the output light beam, the manufacturing process difficulty of the wavelength switching unit 120 can be effectively reduced, and the control difficulty of achieving high-speed wavelength switching can be effectively reduced.

The multi-wavelength light-emitting unit 110 serves as a light source to generate light beams.

In some embodiments of the present invention, the multi-wavelength light-emitting unit 110 includes multiple lasers, and the center wavelengths of different lasers are not equal. In some embodiments, the lidar is a frequency modulated continuous wave lidar, so the laser is a frequency modulated laser, and the frequency modulated laser can, for example, implement linear frequency modulation. Specifically, the multi-wavelength light-emitting unit 110 includes: m independent frequency-modulated lasers, and the center wavelengths of each frequency-modulated laser are λ ₁ , λ ₂ , λ ₃ ...λ _m respectively.

The wavelength switching unit 120 is controlled by electrical signals to implement wavelength scanning.

In some embodiments of the present invention, the wavelength switching unit 120 controls multiple switching elements according to a preset timing sequence to achieve time-sharing switching of the wavelength of the output light beam. Wavelength switching in a time-sharing manner can effectively reduce the difficulty of collecting and calculating lidar detection data.

With reference to FIG. 4 , a functional block diagram of the wavelength switching unit 120 in the transmit module embodiment of the lidar shown in FIG. 3 is shown.

In some embodiments of the present invention, the wavelength switching unit 120 includes: channel element 121, which is suitable for forming the optical path into m channels; m switching elements S ₁ , S ₂ , S ₃ ...S _m , The m switching elements correspond to the m channels one-to-one, and the switching element S _m controls the opening and closing of the corresponding channel; the control element 123 controls the m switching elements according to a preset timing sequence. On and off; where, m is an integer greater than 1.

It should be noted that, as shown in FIG. 4 , the multi-wavelength light-emitting unit 110 has one light output port, and the light beams generated by the multi-wavelength light-emitting unit 110 are output through the light output port. In other embodiments of the present invention, the multi-wavelength light-emitting unit 110 may also have multiple light output ports, and the light beam generated by the multi-wavelength light-emitting unit 110 is output through the multiple light output ports.

Specifically, in some embodiments, the multi-wavelength light-emitting unit has m light output ports, and the m light output ports correspond to the m channels; the light beams generated by the multi-wavelength light-emitting unit are respectively passed through the The light output port is input to the corresponding channel.

In addition, in some embodiments, the multi-wavelength light-emitting unit includes m lasers, and the center wavelengths of different lasers are not equal; the m light-emitting ports of the multi-wavelength light-emitting unit correspond to the m lasers one-to-one; the m light-emitting ports The ports correspond to the m channels one-to-one, so the light beam generated by each laser is input to the corresponding channel through the corresponding light output port.

The channel element 121 is used to form multiple channels.

In some embodiments of the present invention, the light beam of each channel is a light beam of a single wavelength. Specifically, in some embodiments, the multi-wavelength light-emitting unit 110 includes m central wavelengths with different The same frequency modulated laser, therefore, the channel element 121 forms m channels, namely channel 1221, channel 1222, channel 1223,..., channel 122m; each channel transmits a beam of wavelength, that is, channel 1221 transmits a wavelength λ ₁ beam, channel 1222 transmits a beam of wavelength λ ₂ , channel 1223 transmits a beam of wavelength λ ₃ , ..., channel 122m transmits a beam of wavelength λ _m .

In some embodiments of the present invention, when the multi-wavelength light-emitting unit has one light output port, the channel element 121 includes: a demultiplexing filter (DEMUX). The demultiplexing filter can be produced on a large scale on a chip, and the cost of arraying is very low, so it can effectively reduce the manufacturing difficulty and process cost.

In some embodiments of the present invention, when the multi-wavelength light-emitting unit has m light output ports, the channel element 121 includes, for example, an optical fiber array composed of m optical fibers, and each light output port corresponds to each optical fiber in the optical fiber array. , thereby forming m channels.

The switch element is used to control the opening and closing of the corresponding channel.

Specifically, each channel branched from the channel element 121 is provided with one of the switch elements to control its opening and closing. As shown in the embodiment shown in Figure 4, a switching element _S1 is set on channel 1221 to control the transmission of a beam of wavelength _λ1 , a switching element _S2 is set on channel 1222 to control the transmission of a beam of wavelength _λ2 , and a switch is set on channel 1223. The element S ₃ is used to control the transmission of the light beam with the wavelength λ ₃ ,..., the switching element Sm is provided on the channel 122m to control the transmission of the light beam with the wavelength λ _m .

In some embodiments of the present invention, the switching element includes: an optical switch, such as one of a silicon-based optical switch, a thin film lithium niobate electro-optical switch, and a semiconductor optical amplifier (SOA). The gains of the silicon-based optical switches, thin-film lithium niobate electro-optical switches and semiconductor amplifiers are adjustable, and can not only control the opening and closing of the corresponding channels, but also adjust the gain of the corresponding channels. Silicon-based optical switches, thin-film lithium niobate electro-optical switches and semiconductor optical amplifiers can all be mass-produced on chips, and the cost of arraying is very low, so they can effectively reduce manufacturing difficulty and process costs.

In some embodiments of the present invention, the wavelength switching unit 120 further includes: energy monitoring Element 124. The energy monitoring element 124 is located between the channel element and the switching element SOA. The energy monitoring element 124 is suitable for monitoring the energy of the beam of each channel.

The control element 123 is used to control the plurality of switching elements.

The control element 123 has a pre-stored timing sequence for controlling the switching element; the control element 123 sequentially controls the turning on and off of the corresponding switching element according to the above timing sequence. By timing the wavelength switching, it is possible to avoid signals that are prone to interference from being generated at the same time, thereby reducing the possibility of interference between signals, effectively reducing the manufacturing process difficulty of the wavelength switching unit, and reducing the difficulty of controlling wavelength switching.

With reference to FIG. 5 , a timing diagram in which the control element in the wavelength switching unit 120 controls multiple switching elements in the laser radar transmit module embodiment shown in FIG. 4 is shown.

In some embodiments of the present invention, the control element 123 controls m switching elements so that only one channel is turned on within the same preset time period.

Specifically, between time t11 and time t12, the switching element S ₁ is turned on, and other switching elements are turned off, so that only the light beam with wavelength λ ₁ passes through the channel 1221; between time t21 and time t22, all switching elements are turned on. The switching element S ₂ is turned off, and other switching elements are turned off, and only the light beam with wavelength λ ₂ is allowed to pass through the channel 1222; between time t31 and t32, the switching element S ₃ is turned on, and other switching elements are turned off, and only the light beam with wavelength λ 2 is allowed to pass through the channel 1222. The light beam with wavelength λ ₃ passes through channel 1223; ...; between time tm1 and time tm2, the switching element Sm is turned on, and other switching elements are turned off, so that only the light beam with wavelength λ _m passes through channel 122m.

It should be noted that in some embodiments of the present invention, the wavelength switching unit 120 also includes an energy monitoring element 124 that monitors the light beam of each channel. Therefore, the control element 123 is based on the energy of the light beam of each channel and the preset value. , adjust the gain of the corresponding switching element SOA to make the energy of each channel equal.

In some embodiments of the present invention, the transmitting module is used for a frequency modulated continuous wave transceiver device. The frequency modulated continuous wave transceiver device analyzes the distance, speed, reflectivity and other information of the target by analyzing the beat frequency signal, where the beat frequency signal is used for detection. The echo light formed after light is reflected and from The signal obtained after coherent beating of the local oscillator light separated by the detection light. Therefore, as shown in Figure 4, the transmitting module also includes: a first coupling unit 141. The first coupling unit 141 is located in the optical path downstream of the wavelength switching unit 120. The first coupling unit 141 switches from the wavelength to the wavelength switching unit 120. The local oscillator light is separated from the light beam output by the switching unit 120 .

In addition, the channel element 121 divides the optical path into multiple channels, so in order to simplify the device structure, as shown in Figure 4, the transmitting module also includes: a merging unit 142, the merging unit 142 is located in the first coupling unit 141 In the optical path between the wavelength switching unit 120 and the wavelength switching unit 120, multiple channels branched out by the channel element 121 share the same first coupling unit 141 in a time-sharing manner. Specifically, the merging unit 142 may be a multiplexer (MUX).

In addition, in order to improve the luminous intensity, as shown in FIG. 4 , the emission module further includes: an amplification unit 143 located in the optical path between the first coupling unit 141 and the merging unit 142 . Specifically, the amplification unit 143 may be an optical amplifier.

To sum up, as shown in Figure 4, the multi-wavelength light-emitting unit 110 generates multi-wavelength light beams. The wavelengths of the multi-wavelength light beams include: λ ₁ , λ ₂ , λ ₃ ...λ _m ; the multi-wavelength light beams pass through the wavelengths After switching the channel element 121 of the unit 120, the channels formed by the wavelength switching units are respectively transmitted; within a preset time period, the switching element λ _i is turned on, and other switching elements are turned off, so that only the light beam with the wavelength λ _i passes through. The corresponding channel passes; the light beam with wavelength λ _i is transmitted through the combining unit 142 and further amplified by the amplifying unit 143, and is divided into local oscillator light and detection light by the first coupling unit 141.

Therefore, in different time periods, different switching elements are turned on, and the remaining switching elements are turned off, so that only the light beam of the corresponding wavelength passes through the channel; the passing light beam is transmitted through the combining unit 142 and further amplified by the amplification unit 143 , will be divided into local oscillation light and detection light by the first coupling unit 141. That is to say, in different time periods, local oscillation light and detection light of different wavelengths will be formed through the first coupling unit 141.

Continuing to refer to Figure 3, combined with reference to Figure 6, the transmitting module also includes: a spectroscopic unit 130 to form multi-line detection light emitted at a single wavelength, wherein Figure 6 shows the spectroscopic unit in the embodiment of the lidar transmitting module shown in Figure 3 Functional block diagram of 130.

As shown in Figure 6, in some embodiments of the present invention, the light splitting unit 130 includes: a 1×n beam splitter 131, the 1×n beam splitter 131 is suitable for splitting the received light beam with equal energy, where n is an integer greater than 1; there are n wavelength separation elements 132, and each wavelength separation element 132 causes each beam split by the 1×n beam splitter to form multi-line detection light emitted at a single wavelength.

The 1×n beam splitter 131 is used to achieve equal energy beam splitting; each beam split by the 1×n beam splitter 131 passes through one of the wavelength separation elements 132 to form a single wavelength multi-line detection. Light. Specifically, the wavelength separation element 132 includes: at least one of a wavelength division multiplexing filter, a prism, a grating, and an optical cross-wavelength division multiplexer.

In some embodiments of the present invention, the multi-wavelength light-emitting unit 110 includes m frequency-modulated lasers with different central wavelengths. Therefore, the channel element 121 branches out m channels; therefore, the channel element 121 branches out each channel, Each channel is time-switched by the corresponding switching element, and then enters the merging element 142. After being emitted from the merging element 142 and amplified by power, it is divided into n beams by the 1×n beam splitter 131.

As specifically shown in Figure 6, between time t11 and time t12, the light beam with wavelength λ ₁ passing through channel 1221 is split into n sub-beams by the 1×n beam splitter 131 with equal energy. The sub-beams form a line of detection light through the corresponding wavelength separation element 132. Therefore, after the light beam with wavelength λ ₁ of channel 1221 is passed between time t11 and time t12, n lines of detection light with wavelength λ ₁ are emitted. Specifically, The n-line detection light with wavelength λ ₁ is emitted from n wavelength separation elements, each corresponding to a line; between time t21 and time t22, the light beam with wavelength λ ₂ passing through channel 1222 is divided by the 1×n The beamer 131 forms n sub-beams after equal energy splitting. Each sub-beam forms a line of detection light through the corresponding wavelength separation element 132. Therefore, between the t21 time and the t22 time, the beam with the wavelength λ ₂ of the channel 1222 is passed. , there are n lines of detection light with wavelength λ ₂ emitted. Specifically, n lines of detection light with wavelength λ ₂ are emitted from n wavelength separation elements, each corresponding to a line; between time t31 and time t32, it passes through channel 1223 The light beam with a wavelength of λ ₃ is split into n sub-beams by the 1×n beam splitter 131 with equal energy. Each sub-beam forms a line of detection light through the corresponding wavelength separation element 132. Therefore, at time t31 to between time t32 After the beam of wavelength λ ₃ in channel 1223 passes through, n lines of detection light with wavelength λ ₃ are emitted. Specifically, the n lines of detection light with wavelength λ ₃ are emitted from n wavelength separation elements, each corresponding to a line;… ; Between time tm1 and time tm2, the light beam with wavelength λ _m passing through channel 122m is split into n sub-beams by the 1×n beam splitter 131 with equal energy, and each sub-beam passes through the corresponding The wavelength separation element 132 forms a line of detection light, so after the light beam with the wavelength λ _m of the channel 122m is passed between the time tm1 and the time tm2, n lines of detection light with the wavelength λ _m are emitted, specifically the n line has the wavelength λ _m . The detection light is emitted from n wavelength separation elements, each corresponding to a line.

Since the exit angles of light beams of different wavelengths from the wavelength separation element 132 are different, the multi-wavelength light-emitting unit 110 includes m frequency-modulated lasers with different central wavelengths, and the channel element 121 forms the optical path into m single-wavelength channels. , therefore, each channel separates out n-line detection light through the spectroscopic unit 130, so in the cycle process in which the switching elements S ₁ to S _m are turned on once in sequence, a wavelength separation element generates λ ₁ , λ ₂ , λ ₃ ... ...m wavelengths of λ _m and n wavelength separation elements form a total of n×m line detection light.

As shown in Figure 7, in some embodiments of the present invention, the launch module further includes: a plurality of launch ports 151. The exit ports are, for example, the end faces of optical fibers. The light emitted from the wavelength separation element 132 enters the optical fiber for transmission. It can also be It is other types of optical waveguides, such as the end surface of a planar optical waveguide. The detection light in one line is emitted from one of the emission ports 151; multiple emission ports 151 are arranged along the first direction to obtain scanning of the emitted light beam in the first plane. ; The transmitting module also includes: a one-dimensional scanning unit 152. The one-dimensional scanning unit is located in the optical path downstream of the emitted light from the transmitting port 151. The one-dimensional scanning unit 152 causes the detection light to scan in the second plane, so The second plane is perpendicular to the first plane.

When the multi-channel electronically controlled method is used to realize scanning in the first plane (such as the vertical direction), instead of the fast axis high-speed scanning in the existing technology, and the low-speed one-dimensional scanning unit is used to realize scanning in the second plane (such as the horizontal direction), This can effectively reduce the scanning speed of the scanning unit and alleviate the problem of delay angle.

The positions of the emission ports 151 can be arranged as required, and combined with the collimating lens 154 to form line beam scanning in the first plane. Specifically, in the embodiment shown in Figure 7, multiple of the The emission ports 151 are equally spaced in the focal plane of the collimating lens 154 , that is, they are evenly distributed in the focal plane of the collimating lens 154 .

In some embodiments of the present invention, the transmitting module further includes: multiple port groups 153, each of the port groups 153 includes a plurality of the light-emitting ports 151, and one port group 153 corresponds to one wavelength separation element 132; the same The plurality of light-emitting ports 151 of the port group 153 are continuously arranged along the first direction, and the wavelength order of the detection light emitted by the plurality of light-emitting ports 151 of different port groups 153 is the same.

Specifically, as shown in Figure 7, in the port group 153i, the transmitting port 1511, the port 1512, the port 1513,..., the port 151m are arranged in sequence along the first direction, and the wavelengths are λ ₁ , λ ₂ , λ ₃ ,... , λ _m emits from the emission port 1511, port 1512, port 1513, ..., port 151m in sequence.

The multiple transmit ports 151 of different port groups 153 are arranged in the same manner. Specifically, in the embodiment shown in Figure 7, the arrangement of the multiple transmit ports 151 in the port group 153j is the same as the arrangement of the multiple transmit ports 151 in the port group 153i, that is, the transmit port 1511, the port 1512, the port 1513, ..., the ports 151m are also arranged in sequence along the first direction.

Moreover, the wavelength order of the detection light emitted by the plurality of light-emitting ports 151 of different port groups 153 is the same. Specifically, in the embodiment shown in Figure 7, the wavelength distribution of the detection light emitted by the multiple emission ports 151 in the port group 153j is the same as the wavelength distribution of the detection light emitted by the multiple emission ports 151 in the port group 153i. That is, the wavelengths λ ₁ , λ ₂ , λ ₃ ,..., λ _m in the port group 153i also emit from the emission port 1511, the port 1512, the port 1513,..., the port 151m in sequence.

The wavelength order of the detection light emitted by the plurality of light-emitting ports 151 of different port groups 153 is made to be the same, that is, the light-emitting ports 151 that emit detection light of the same wavelength have the largest height difference on the focal plane of the collimating lens 154 and are the same. The fields of view between the detection lights of the same wavelength should be staggered as much as possible to reduce the interference between the detection lights of the same wavelength.

In some embodiments of the present invention, the transmitting module is used as a transceiver device for coaxial transceiver. The light splitting unit 130 further includes: n connectors 133, each connector 133 is located at Between the 1×n beam splitter 131 and one of the wavelength separation elements 132, the first end of the connector 133 is connected to the 1×n beam splitter 131, and the second end is connected to the wavelength separation element. 132 connected. Specifically, the connector 133 is a circulator.

In summary, as shown in Figures 4 and 6, the detection light formed by the first coupling unit 141 is divided into n-line detection lights of equal energy by the 1×n beam splitter 131 of the spectroscopic unit 130. A line is input from the first section of the connector 133 and output from the second end of the connector 133; the detection light output from the second end passes through the wavelength separation element 132 and emerges from a preset emission port. for detection.

It should be noted that, as shown in FIG. 7 , a plurality of the emission ports 151 are equidistantly distributed in the focal plane of the collimating lens 154 . However, this arrangement is only an example. In other embodiments of the present invention, as shown in Figure 8, the distance d1 between adjacent transmitting ports 251 located at the edge is greater than that between adjacent transmitting ports 251 located in the center (the transmitting ports 251 within the dotted box 253 in Figure 8). The spacing d2 between them is combined with the collimating lens 254 to form a line beam scanning with dense center in the vertical direction. Specifically, along the direction from the edge to the center, the spacing between adjacent emission ports 251 gradually decreases, and the density of the emission ports 251 gradually increases to form a line bundle that is gradually denser from the edge to the center.

It should also be noted that the method of arranging multiple lasers in the multi-wavelength light-emitting unit 110 to generate light beams with different center wavelengths is only an example. In other embodiments of the present invention, the multi-wavelength light-emitting unit may also be composed of a single laser and a multi-wavelength generating component.

In addition, in the embodiment shown in FIG. 6 , the connector 133 is a circulator. However, configuring the connector as a circulator is only an example. In other embodiments of the present invention, the connector may also be a polarizing beam splitter. As shown in Figure 9, the connector 533 is a polarizing beam splitter. The first end 533a of the connector 533 is connected to the 1×n beam splitter 531, the second end 533b is connected to the wavelength separation element 532, and the third end 533c is connected to the receiving module of the laser radar. The detection light generated by the 1×n beam splitter 531 enters the connector 533 from the first end 533a. After passing through the connector 533, for example, the TM polarized part exits from the second end 533b (preferably, it passes through a 1/4 wave plate to form circularly polarized light. ), passes through the wavelength separation element 532 and is finally emitted to the environment, and the echo light (passes through the 1/4 wave plate again, and is converted from circularly polarized light TE polarized light) enters the connector 533 through the second end 533b, is reflected and exits from the third end 533c, forming a circulator-like function. Alternatively, the TE polarized part may be emitted from the second end 533b, and the TM polarized part in the echoed light may be partially reflected and emitted from the third end 533c.

Referring to FIG. 10 , a functional block diagram of another embodiment of the laser radar transmitting module of the present invention is shown.

The same points as the previous embodiments will not be described again here. One of the differences from the previous embodiment is that in this embodiment, as shown in FIG. 11 , the multi-wavelength light-emitting unit 310 includes at least one laser 311 and a multi-wavelength generating component 312 to control hardware costs. When the lidar is a frequency modulated continuous wave lidar, the laser 311 is a frequency modulated laser.

Specifically, the center frequency of the laser 311 is f ₁ , and multiple frequencies f ₁ , f ₂ , f ₃ ... _fi (corresponding to multiple wavelengths λ ₁ , λ ₂ , λ ₃ ...λ _i ), the intervals between multiple frequencies are the same as Δf, as shown in Figure 12.

As shown in Figure 11, in some embodiments of the present invention, the multi-wavelength generating component 312 includes: an electro-optical modulation element 312a and a semiconductor optical amplifier 312b. Multiple wavelengths can be generated based on electro-optical modulation effects and four-wave mixing effects.

As shown in Figure 11, the light emitted by the laser 311 with the center frequency f ₁ passes through the electro-optical modulation element 312a and generates at least two frequency values, namely frequency f ₂ and frequency f ₃ , in addition to the original frequency; and then passes through the semiconductor The optical amplifier 312b then produces a greater number of wavelengths, i.e., _fi shown in Figure 11. Moreover, by adjusting the gain of the semiconductor optical amplifier 312b, the energy of the beams of different wavelengths output by the semiconductor optical amplifier 312b is nearly equal.

It should be noted that the method of using the electro-optical modulation element 312a and the semiconductor optical amplifier 312b to constitute the multi-wavelength generating component 312 is only an example. In other embodiments of the present invention, the multi-wavelength generating component may also include: a micro-ring resonant cavity. The four-wave mixing effect in the microring resonator is stronger, more wavelengths can be produced, and the wavelength range is also larger. Moreover, compared with the electro-optical modulation element 312a and the semiconductor optical amplifier 312b forming the multi-wavelength generating component 312, the four-wave mixing effect in the microring resonant cavity can generate more wavelength to form an optical comb. For example, a multi-wavelength light-emitting unit composed of a single laser, an electro-optical modulation element and a semiconductor optical amplifier can produce 16 wavelengths, and a single laser and a micro-ring resonant cavity can produce 64 wavelengths.

In some embodiments of the present invention, when using a single laser and a micro-ring resonant cavity to generate more wavelengths, the channel element 321 in the wavelength switching unit 320 includes an optical cross-wavelength division multiplexer (Inter Lever). Each channel formed by the optical cross-wavelength division multiplexer is comb filtered, and the output is a set of equally spaced frequency beams. Moreover, the optical cross-wavelength division multiplexer can be produced on a large-scale chip basis, and the cost of arraying is very low, so it can effectively reduce the manufacturing difficulty and process cost. Due to the limitation of power consumption, high-power power amplification components such as 143 in Figure 4 cannot actively dissipate heat and can only passively dissipate heat; and power amplification components will cause gain spectrum drift at different temperatures. When the multi-wavelength light-emitting unit 310 forms an optical comb, each channel includes multiple wavelengths after passing through the optical cross-wavelength division multiplexer. After time-sharing switching by the corresponding switching element, the multiple wavelengths of each channel reach the power amplifying element at the same time. In this case, even if there is gain spectrum drift, one of the multiple wavelengths always falls within the gain spectrum range, so temperature control is not required. Specifically, in the transmitting module shown in Figure 10, when each channel transmits a beam including multiple wavelengths, when the ambient temperature changes greatly, the gain of the power amplification element will also change accordingly. However, since each channel The light beam transmitted by the channel includes multiple wavelengths, and there is a high probability that at least one wavelength is still within the gain range of the power amplifier element. In other words, the impact of ambient temperature changes on the light energy of the channel can be reduced.

Continuing to refer to FIG. 10 , in some embodiments of the present invention, the light beam of each channel includes a set of equally spaced frequency light beams. Specifically, in some embodiments, the multi-wavelength light-emitting unit finally generates light beams including N equally spaced frequencies. The number of wavelengths of light beams included in each channel is a divisor of the number of frequencies generated by the multi-wavelength light-emitting unit. That is to say, the number of wavelengths of light beams generated by the multi-wavelength light-emitting unit is the wavelength of the light beams included in each channel. An integer multiple of the quantity. Therefore, the number of channels is set based on the number of wavelengths generated by the multi-wavelength light emitting unit and the number of wavelengths included in the light beam transmitted by each channel.

Specifically, the optical cross-wavelength division multiplexer in the channel element 321 is 1 minute m The optical cross-wavelength division multiplexer is used to form m channels, that is, the light beam generated by the multi-wavelength light-emitting unit includes N wavelengths, λ' ₁ , λ' ₂ , λ' ₃ , λ' ₄ , λ' ₅ ,... , λ' _N , where N is an integer multiple of m, that is, N=km, and k is a positive integer.

As shown in the embodiment shown in FIG. 10 , the optical cross-wavelength division multiplexer in the channel element 321 is a 1-minute-m optical cross-wavelength division multiplexer, that is, the light beam generated by the multi-wavelength light-emitting unit includes N wavelengths. , divided into m groups into m channels, each channel includes k, that is, k = N/m number of wavelengths, and the frequencies corresponding to the k wavelengths are equally spaced. For example, when N is 64 wavelengths, through a 1/4 optical cross-wavelength division multiplexer, 4 channels are generated, each channel including 16 wavelengths.

Therefore, channel 3221 transmits light beams with wavelengths λ' ₁ , λ' _1+m , λ' _1+2m , λ' _1+3m , λ' _1+4m ,..., λ'_1+(k-1)m; Channel 3222 transmits light beams with wavelengths λ' ₂ , λ' _2+m , λ' _2+2m , λ' _2+3m , λ' _2+4m ,..., λ'_2+(k-1)m; channel 3223 Transmits beams with wavelengths λ' ₃ , λ' _3+m , λ' _3+2m , λ' _3+3m , λ' _3+4m ,..., λ'_3+(k-1)m; channel 3224 transmits wavelength λ' ₄ , λ' _4+m , λ' _4+2m , λ' _4+3m , λ' _4+4m ,..., λ' _4+(k-1)m beam;...; channel 322m transmission Beams with wavelengths λ' _m , λ' _2m , λ' _3m , λ' _4m , λ' _5m ,..., λ' _km .

The switching elements provided on each channel are used to control the opening and closing of the corresponding channel. As shown in the embodiment shown in Figure 10, switching elements are provided on the channel 3221 to control the wavelengths λ' ₁ , λ' _1+m , λ' _1+2m , λ' _1+3m , λ' _1+4m ,..., λ ' _1+(k-1)m beam transmission, switch elements are provided on channel 3222 to control wavelengths λ' ₂ , λ' _2+m , λ' _2+2m , λ' _2+3m , λ' _2+4m ,..., λ' _2+(k-1) _m beam transmission, switch elements are set on channel 3223 to control wavelengths λ' ₃ , λ' _3+m , λ' _3+2m , λ' _3+3m , For the transmission of beams of λ' _3+4m ,..., λ' _3+(k-1)m , channel 3224 is provided with switching elements to control the wavelengths λ' ₄ , λ' _4+m , λ' _4+2m , λ ' _4+3m , λ' _4+4m ,..., λ' _4+(k-1)m beam transmission,..., a switching element is provided on the channel 322m to control the wavelength λ' _m , λ' _2m , λ ' _3m , λ' _4m , λ' _5m ,..., λ' _km beam transmission.

Referring to FIG. 13 and FIG. 14 in conjunction, FIG. 13 shows a timing diagram for the control element in the wavelength switching unit to control multiple switching elements in the embodiment of the laser radar transmitting module shown in FIG. 10. FIG. 14 is the timing diagram shown in FIG. 13 The corresponding schematic diagram of each light wavelength in the dotted line box in the timing diagram of the embodiment of the laser radar transmitting module.

In some embodiments of the present invention, the control element controls multiple switching elements so that only one channel is turned on within the same preset time period.

Specifically, between time t11 and time t12, the switching element SOAi1 is turned on, and other switching elements are turned off, so that only the wavelengths are λ' ₁ , λ' _1+m , λ' _1+2m , and λ' _1+3m , λ' _1+4m ,..., λ' _1+(k-1)m light beam passes through channel 3221, that is to say, between time t11 and time t12, the output wavelength of channel 3221 is λ' ₁ , λ' _1+m , λ' _1+2m , λ' _1+3m , λ' _1+4m ,..., λ' ₁₊ _(k-1)m beam (dotted box at1 in Figure 13); at time t21 Between time t22, the switching element SOAi2 is turned on, and other switching elements are turned off, so that only the wavelengths are λ' ₂ , λ' _2+m , λ' _2+2m , λ' _2+3m , and λ' _2+4m ,..., λ' _2+(k-1)m light beam passes through channel 3222, that is to say, between time t21 and time t22, the output wavelength of channel 3222 is λ' ₂ , λ' _2+m , λ' _2+2m , λ' _2+3m , λ' _2+4m ,..., λ' _2+(k-1)m beam (dotted box at2 in Figure 13); between time t31 and time t32, Turn on the switching element SOAi3 and turn off other switching elements, so that only the wavelengths are λ' ₃ , λ' _3+m , λ' _3+2m , λ' _3+3m , λ' _3+4m ,..., λ' A beam of _3+(k-1)m passes through channel 3223. That is to say, between time t31 and time t32, the output wavelength of channel 3223 is λ' ₃ , λ' _3+m , λ' _3+2m , λ' _3+3m , λ' _3+4m ,..., λ' _3+(k-1)m beam (dashed line frame at3 in Figure 13); between time t41 and time t42, turn on the switching element SOAi4 , turn off other switching elements, and only make the wavelengths λ' ₄ , λ' _4+m , λ' _4+2m , λ' _4+3m , λ' _4+4m ,..., λ' _{4+(k-1 )m} beam passes through channel 3224, that is to say, between time t41 and time t42, the output wavelength of channel 3224 is λ' ₄ , λ' _4+m , λ' _4+2m , λ' _4+3m , λ' _4+4m ,..., λ' _4+(k-1)m beam (dashed line frame at4 in Figure 13);...; between tm1 time and tm2 time, the switching element SOAim is turned on and turned off Other switching elements only allow light beams with wavelengths λ' _m , λ' _2m , λ' _3m , λ' _4m , λ' _5m ,..., λ' _km to pass through the channel 322m, that is, from time tm1 to time tm2 Between them, channel 322m outputs beams with wavelengths of λ' _m , λ' _2m , λ' _3m , λ' _4m , λ' _5m ,..., λ' _km (dotted line atm in Figure 13).

It should be noted that in Figure 13, the positions of the dotted frame at1, the dotted frame at2, the dotted frame at3, the dotted frame at4 and the dotted frame atm are staggered to ensure clear display.

When the multi-wavelength light-emitting unit 310 forms an optical comb, the wavelength switching unit 320 cooperates with An optical cross-wavelength division multiplexer is used as the channel element 321. Each channel formed by the optical cross-wavelength division multiplexer is a comb filter, and the output is a set of optical combs of equally spaced frequencies. Therefore, the emitted light of each channel formed by the channel element 321 is a light beam including multiple wavelengths.

It should also be noted that in some embodiments of the present invention, the wavelength separation element may be an optical cross-wavelength division multiplexer. The multi-wavelength light-emitting unit forms an optical comb, and the wavelength separation element is set as an optical cross-wavelength division multiplexer. During a cycle in which the switching element is turned on once in sequence, one wavelength separation element generates m groups of wavelengths (one group corresponds to one line) , n wavelength separation elements form a total of n×m line detection light. At this time, since each line of detection light formed by the wavelength separation element includes multiple wavelengths, the detection light of multiple wavelengths is irradiated at the same position of the object, which can effectively reduce the speckle effect on the rough surface and reduce the jitter of the echo power.

It should be noted that the light beam in the launch module can be transmitted through optical fibers, that is, different units and components are connected through optical fibers. Specifically, the optical fiber may be a single-mode optical fiber or a planar optical waveguide.

Correspondingly, the present invention also provides a laser radar transceiver device.

Referring to FIG. 4 and FIG. 6 , a functional block diagram of an embodiment of the laser radar transceiver device of the present invention is shown.

The laser radar transceiver device includes: a transmitting module, which is the transmitting module of the present invention; the emitted detection light is reflected in a three-dimensional space to form echo light; a receiving module, the receiving module is suitable for receiving the Echo light.

The transmitting module is the transmitting module of the present invention. Therefore, for the specific technical solution of the transmitting module, reference is made to the foregoing embodiment of the transmitting module, and the present invention will not be repeated here.

In some embodiments of the present invention, the transmitting module is used as a transceiver device for coaxial transceiver, The light splitting unit 130 also includes: n connectors 133, each connector 133 is located between the 1×n beam splitter 131 and one of the wavelength separation elements 132, and the first end of the connector 133 It is connected to the 1×n beam splitter 131, and the second end is connected to the wavelength separation element 132. Specifically, the connector 133 is at least one of a circulator or a polarizing beam splitter.

In addition, in some embodiments of the present invention, the transceiver device is a frequency modulated continuous wave transceiver device. Therefore, as shown in Figure 4, the transmitting module also includes: a first coupling unit 141. The first coupling unit 141 is located in the optical path downstream of the wavelength switching unit 120. The first coupling unit 141 switches from the wavelength to the wavelength switching unit 120. The local oscillator light is separated from the light beam output by the switching unit 120 .

The receiving module is used to receive echo signals to achieve detection.

In some embodiments of the present invention, the transceiver device is a coaxial frequency modulated continuous wave transceiver device; and in order to perform equal energy beam splitting through the 1×n beam splitter 131 in the light splitting unit 130; therefore, the receiving module includes: 1 ×n beam splitter 410, the 1×n beam splitter 410 of the receiving module is suitable for splitting the local oscillator light separated by the first coupling unit 141 into equal energy beams; n receiving units 420, the n Each receiving unit 420 corresponds to n split local oscillator lights in a one-to-one manner, and each receiving unit 420 is connected to the third end of one connector 133 . Specifically, the receiving unit 420 includes: a coupler 421 and a balanced detector (BPD) 422 connected in sequence.

After the echo light is received by the wavelength separation element 132, it is input through the second end of the connector 133, and is output from the third end of the connector 133 to the receiving unit 420; the local oscillator light is split into equal energy beams. Finally, it is also input to the receiving unit 420; the local oscillator light and the echo light input to the receiving unit 420 are mixed in the coupler 421, and then detected by the balanced detector 422 to achieve detection.

It should be noted that the light beam in the transceiver device can be transmitted through optical fibers, that is, different units and components are connected through optical fibers. Specifically, the optical fiber may be a single-mode optical fiber or a planar optical waveguide.

In addition, the present invention also provides a laser radar, which includes: a transceiver device, and the transceiver device is the transceiver device of the present invention.

The transceiver device is the transceiver device of the present invention. Therefore, for the specific technical solutions of the transceiver device, reference is made to the foregoing embodiments of the transceiver device, and the present invention will not be repeated here.

In the transmitting module of the transceiver device, the wavelength switching unit controls a plurality of switching elements to switch the wavelength of the output light beam through electrical signals. By controlling the switching element (ie, optical switch) with an electrical signal to switch the wavelength of the output light beam, the manufacturing process difficulty of the wavelength switching unit can be effectively reduced, and the control difficulty of achieving high-speed wavelength switching can be effectively reduced.

Moreover, the channel element of the wavelength switching unit includes: one of a wavelength division multiplexing filter and an optical cross-wavelength division multiplexer; the switching element includes: a silicon-based optical switch, a thin film lithium niobate electro-optical switch, and a semiconductor optical amplifier. one of them. Demultiplexing filters, optical cross-wavelength division multiplexers, silicon-based optical switches, thin-film lithium niobate electro-optical switches, and semiconductor optical amplifiers can all be produced on a large-scale chip, and the cost of arraying is very low, so it can effectively reduce Production difficulty and process cost.

Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

A laser radar transmitting module, characterized by including:

A multi-wavelength light-emitting unit, the multi-wavelength light-emitting unit is adapted to generate a light beam;

A wavelength switching unit, the wavelength switching unit receives the light beam generated by the multi-wavelength light-emitting unit, and the wavelength switching unit controls a plurality of switching elements to switch the wavelength of the output light beam through electrical signals;

The light splitting unit is located in the optical path downstream of the wavelength switching unit. The light splitting unit is used to split the received light beam and further form each split beam into multi-line detection light.
The transmitting module of claim 1, wherein the wavelength switching unit controls a plurality of switching elements according to a preset timing sequence to achieve time-sharing switching of the wavelength of the output light beam.
The transmitting module according to claim 1, wherein the wavelength switching unit includes:

Channel element, the channel element is suitable for forming the optical path into m channels;

m switching elements, the m switching elements are in one-to-one correspondence with the m channels, and the switching elements control the opening and closing of the corresponding channels;

A control element that controls the turning on and off of m switching elements according to a preset sequence;

Among them, m is an integer greater than 1.
The transmitting module of claim 3, wherein the light beam of each channel is a light beam of a single wavelength;

Alternatively, the beam for each channel includes a set of equally spaced frequency beams.
The transmitting module according to claim 3 or 4, characterized in that the channel element includes: one of a demultiplexing filter and an optical cross-wavelength multiplexer.
The transmitting module according to claim 3, characterized in that the switch element includes:

One of silicon-based optical switches, thin film lithium niobate electro-optical switches and semiconductor optical amplifiers.
The transmitting module according to claim 6, wherein the wavelength switching unit further includes:

An energy monitoring element, the energy monitoring element is located between the channel element and the switch element, the energy monitoring element is adapted to monitor the energy of the light beam of each channel;

The control element adjusts the gain of the corresponding switching element according to the energy of the light beam of each channel and the preset value.
The transmitting module of claim 3, wherein the control element controls m switching elements so that only one channel is turned on within the same preset time period.
The transmitting module of claim 1, wherein the multi-wavelength light-emitting unit includes multiple lasers, and the center wavelengths of different lasers are not equal;

Alternatively, the multi-wavelength light-emitting unit includes at least one laser and a multi-wavelength generating component.
The transmitting module according to claim 9, characterized in that the multi-wavelength generating component includes: an electro-optical modulation element and a semiconductor optical amplifier;

Alternatively, the multi-wavelength generating component includes: a micro-ring resonant cavity.
The transmitting module according to claim 1, further comprising: a plurality of transmitting ports, and one line of the detection light is emitted from one of the transmitting ports;

The plurality of emission ports are arranged along the first direction to obtain scanning of the outgoing light beam in the first plane;

The emission module also includes: a one-dimensional scanning unit located in the optical path downstream of the emission port. The one-dimensional scanning unit causes the detection light to scan in a second plane, and the second plane is perpendicular to the Describe the first plane.
The transmitting module according to claim 11, further comprising: a plurality of ports Groups, each of the port groups includes a plurality of the light-emitting ports;

The plurality of light-emitting ports of the same port group are continuously arranged along the first direction, and the wavelength order of the detection light emitted by the plurality of light-emitting ports of different port groups is the same.
The transmitting module according to claim 1, characterized in that the light splitting unit includes:

1×n beam splitter, the 1×n beam splitter is suitable for splitting the received light beam with equal energy, where n is an integer greater than 1;

There are n wavelength separation elements, and each wavelength separation element further forms each beam split by the 1×n beam splitter into multi-line detection light.
The transmitting module according to claim 13, wherein the wavelength separation element includes: at least one of a demultiplexing filter, a prism, a grating and an optical cross-wavelength division multiplexer.
The transmitting module according to claim 13, characterized in that the transmitting module is used as a transceiver device for coaxial transceiver, and the light splitting unit further includes: n connectors, each connector is located at the 1×n branch. Between the beam splitter and one wavelength separation element, the first end of the connector is connected to the 1×n beam splitter, and the second end is connected to the wavelength separation element.
The transmitting module of claim 15, wherein the connector is at least one of a circulator or a polarizing beam splitter.
The transmitting module according to claim 1, characterized in that the transmitting module is used for a frequency modulated continuous wave transceiving device, the transmitting module further includes: a first coupling unit, the first coupling unit is located at the wavelength switching In the optical path between the unit and the light splitting unit, the first coupling unit separates the local oscillator light from the light beam output by the wavelength switching unit.
A laser radar transceiver device, characterized by:

A transmitting module, the transmitting module is as described in any one of claims 1 to 16;

The emitted detection light is reflected in the three-dimensional space to form echo light;

A receiving module, the receiving module is adapted to receive the echoed light.
The transceiver device according to claim 18, wherein the transceiver device is a frequency modulated continuous wave transceiver device, and the transmitting module further includes:

The first coupling unit is located in the optical path between the wavelength switching unit and the spectroscopic unit. The first coupling unit separates the local oscillator light from the light beam output by the wavelength switching unit. ;

The receiving module includes:

1×n beam splitter, the 1×n beam splitter of the receiving module is suitable for splitting the local oscillator light separated by the first coupling unit into equal energy beams;

There are n receiving units, the n receiving units are in one-to-one correspondence with the n split local oscillator lights, and each receiving unit is connected to the third end of a connector.
The transceiver device according to claim 19, wherein the receiving unit includes:

The coupler and balanced detector are connected in sequence.
A lidar, characterized by including:

A transceiver device as claimed in any one of claims 18 to 20.