Optical module and laser radar

Abstract

The application provides a light module and a laser radar. The light module comprises a circuit board and a light emitting sub-module. The light emitting sub-module comprises a laser and an MCU. A bias circuit and a modulation circuit are arranged between the laser and the MCU. The bias circuit comprises a first filtering sub-circuit. The modulation circuit comprises a second filtering sub-circuit. The first filtering sub-circuit and the second filtering sub-circuit filter and process bias current and modulation current respectively, so that electrical noise in line width testing is eliminated, the line width of the laser of the light module is close to the intrinsic line width, and the requirement of applying the light module to the laser radar is met. The light module provided in the embodiment of the application is applied to the laser radar as a light source structure of the laser radar, and the laser radar is applied to automatic driving, so that the distance of a measured object in the automatic driving process is tested by the laser radar. The light module provided in the application is expected to be applied to the field of automatic driving.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical communication, and in particular to an optical module and a laser radar BACKGROUND

[0002] Automatic driving is a new way of travel in the future, and its safety and reliability are the primary conditions for people to choose automatic driving. The stronger the sensing ability of the surrounding environment, the higher the safety and reliability of automatic driving.

[0003] The sensor used for automatic driving sensing includes a laser radar. The laser radar can not only give the distance of an object, but also has little influence on ambient light and can sense static and dynamic objects. Therefore, the laser radar is more applicable in automatic driving than light.

[0004] The laser radar is a mainstream sensor in automatic driving at present. The laser radar senses the distance of an obstacle in front by emitting and receiving a laser pulse and calculating the flight time of the laser pulse. All the sensed surface points of the obstacle form a 3D laser point cloud in the laser radar data. A conventional laser radar can obtain several ten thousand 3D point clouds for analysis and processing within 100ms, and can identify the size and position of the obstacle and the like. SUMMARY

[0005] The present application provides an optical module and a laser radar to apply the optical module to the field of automatic driving.

[0006] In one aspect, the present application provides an optical module, comprising:

[0007] a circuit board;

[0008] a light emission sub-module, electrically connected with the circuit board, for converting an electrical signal into an optical signal;

[0009] The light emission sub-module comprises:

[0010] a laser, disposed on the circuit board, for outputting an optical signal;

[0011] an MCU, disposed on the circuit board, comprising an I2C interface, and the I2C interface is electrically connected with an I2C pin on a golden finger;

[0012] a bias circuit is arranged between the MCU and the laser, and the bias circuit comprises a first filter sub-circuit for filtering a bias current output by the bias circuit;

[0013] a modulation circuit is arranged between the MCU and the laser, and the modulation circuit comprises a second filter sub-circuit for filtering a modulation current output by the modulation circuit.

[0014] In another aspect, the application provides a laser radar, comprising:

[0015] a light source configured to output a light signal;

[0016] a light splitter configured to split the light signal from the light source into probe light and local oscillator light;

[0017] a fiber amplifier configured to amplify the probe light and output the amplified probe light to a measured object;

[0018] a collimating lens configured to collimate the reflected light from the measured object into parallel light;

[0019] a combiner configured to combine the local oscillator light and the parallel light;

[0020] a photodetector configured to convert the light signal from the combiner into an electrical signal;

[0021] a signal processing unit configured to process the electrical signal to obtain the distance of the measured object.

[0022] Beneficial effects: The application provides a light module and a laser radar using the light module. The light module comprises a circuit board and a light-emitting sub-module. The light-emitting sub-module comprises a laser and an MCU. A bias circuit and a modulation circuit are arranged between the laser and the MCU. The bias circuit is configured to output a bias current to provide power supply for the laser to emit a light signal. The modulation circuit is configured to output a modulation current to make the laser output light signals of different wavelengths. The bias circuit comprises a first filter sub-circuit, and the modulation circuit comprises a second filter sub-circuit. The first filter sub-circuit and the second filter sub-circuit are configured to filter the bias current and the modulation current respectively. The first filter sub-circuit and the second filter sub-circuit can eliminate electrical noise in the line width test without affecting the sweep time of the modulation current, so that the line width of the laser of the light module is close to the intrinsic line width, and the use requirement of applying the light module to the laser radar is met. The light module provided in the application is applied to the laser radar as a light source structure of the laser radar, and the laser radar comprising the light module is applied to automatic driving, so that the distance of the measured object in the automatic driving process is tested by the laser radar. The light module provided in the application is expected to be applied to the field of automatic driving. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, other drawings can also be obtained by those skilled in the art without any creative labor on the basis of these drawings.

[0024] Figure 1 a schematic diagram of a connection relationship of an optical communication terminal;

[0025] Figure 2 Fig. 1 is a schematic diagram of an optical network terminal structure;

[0026] Figure 3 Fig. 2 is a schematic diagram of an optical module structure provided by an embodiment of the present application;

[0027] Figure 4 Fig. 3 is a schematic diagram of an optical module exploded structure provided by an embodiment of the present application;

[0028] Figure 5 Fig. 4 is a schematic diagram of an internal structure of an optical module provided by an embodiment of the present application;

[0029] Figure 6 Fig. 5 is a schematic diagram of a connection between an optical module and a host computer provided by an embodiment of the present application;

[0030] Figure 7 Fig. 6 is a schematic diagram of a structure of a laser radar provided by an embodiment of the present application. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0032] One of the core links of fiber-optic communication is the mutual conversion of optical signals and electrical signals. Fiber-optic communication uses optical signals carrying information to be transmitted in information transmission equipment such as optical fibers and optical waveguides, and the passive transmission characteristics of light in optical fibers and optical waveguides can be used to achieve low-cost and low-loss information transmission. However, computer and other information processing equipment use electrical signals. In order to establish information connection between the information transmission equipment such as optical fibers and optical waveguides and the information processing equipment such as computers, it is necessary to realize the mutual conversion of electrical signals and optical signals.

[0033] An optical module realizes the mutual conversion function of optical signals and electrical signals in the field of fiber-optic communication technology, and the mutual conversion of optical signals and electrical signals is the core function of the optical module. The optical module realizes electrical connection with an external host computer through a gold finger on an internal circuit board of the optical module, and the main electrical connections include power supply, I2C signals, data signals, and ground. The electrical connection mode realized by the gold finger has become the mainstream connection mode in the optical module industry, and the definition of pins on the gold finger has formed various industry protocols / specifications.

[0034] Figure 1 Fig. 7 is a schematic diagram of a connection relationship of an optical communication terminal. For example, Figure 1As shown, the connection of the optical communication terminal mainly includes the interconnection between the optical network terminal 100, the optical module 200, the optical fiber 101, and the network cable 103.

[0035] One end of the optical fiber 101 is connected to the remote server, and one end of the network cable 103 is connected to the local information processing device. The connection between the local information processing device and the remote server is completed by the connection between the optical fiber 101 and the network cable 103. The connection between the optical fiber 101 and the network cable 103 is completed by the optical network terminal 100 with the optical module 200.

[0036] The optical port of the optical module 200 is connected to the optical fiber 101, establishing a bidirectional optical signal connection with the optical fiber 101; the electrical port of the optical module 200 is connected to the optical network terminal 100, establishing a bidirectional electrical signal connection with the optical network terminal 100; the optical module internally realizes the mutual conversion between optical signals and electrical signals, thereby realizing the establishment of an information connection between the optical fiber and the optical network terminal; specifically, the optical signal from the optical fiber is converted into an electrical signal by the optical module and then input into the optical network terminal 100, and the electrical signal from the optical network terminal 100 is converted into an optical signal by the optical module and then input into the optical fiber.

[0037] The optical network terminal has an optical module interface 102 for connecting to the optical module 200 and establishing a bidirectional electrical signal connection with the optical module 200; the optical network terminal has a network cable interface 104 for connecting to the network cable 103 and establishing a bidirectional electrical signal connection with the network cable 103; the optical module 200 and the network cable 103 are connected through the optical network terminal 100. Specifically, the optical network terminal transmits signals from the optical module to the network cable and transmits signals from the network cable to the optical module. The optical network terminal acts as a host computer for the optical module to monitor the operation of the optical module.

[0038] At this point, the remote server establishes a two-way signal transmission channel with the local information processing equipment via optical fiber, optical module, optical network terminal and network cable.

[0039] Common information processing equipment includes routers, switches, and computers; optical network terminals are the host computers of optical modules, providing data signals to and receiving data signals from optical modules. Other common host computers for optical modules include optical line terminals.

[0040] Figure 2 This is a schematic diagram of an optical network terminal structure. (Example) Figure 2 As shown, the optical network terminal 100 has a circuit board 105, and a cage 106 is provided on the surface of the circuit board 105; an electrical connector is provided inside the cage 106 for connecting to the electrical port of the optical module such as the gold finger; a heat sink 107 is provided on the cage 106, and the heat sink 107 has fins and other protrusions to increase the heat dissipation area.

[0041] The optical module 200 is inserted into the optical network terminal, specifically, the electrical port of the optical module is inserted into the electrical connector inside the cage 106, and the optical port of the optical module is connected with the optical fiber 101.

[0042] The cage 106 is located on the circuit board, and the electrical connector on the circuit board is wrapped in the cage, so that the electrical connector is arranged inside the cage; the optical module is inserted into the cage, and the optical module is fixed by the cage; the heat generated by the optical module is conducted to the cage 106, and then diffused through the heat sink 107 on the cage.

[0043] Figure 3 A structure schematic diagram of an optical module 200 is provided for the embodiment of the present application, Figure 4 An exploded structure schematic diagram of the optical module 200 is provided for the embodiment of the present application. As shown in Figure 3 and Figure 4 The optical module 200 provided by the embodiment of the present application includes an upper shell 201, a lower shell 202, a circuit board 300, an unlocking handle 203, an optical transmitting sub-module 206 and an optical receiving sub-module 207.

[0044] The upper shell 201 is covered on the lower shell 202 to form a wrapped cavity with two openings; the outer contour of the wrapped cavity generally presents a square body, specifically, the lower shell includes a main plate and two side plates located on both sides of the main plate and arranged perpendicularly to the main plate; the upper shell includes a cover plate, the cover plate is covered on the two side plates of the upper shell to form the wrapped cavity; the upper shell can further include two side walls located on both sides of the cover plate and arranged perpendicularly to the cover plate, the two side walls are combined with the two side plates to realize that the upper shell is covered on the lower shell.

[0045] The two openings can be two end openings (204, 205) in the same direction, or two openings in different directions; one of the openings is an electrical port 204, and the gold fingers of the circuit board extend out of the electrical port 204 and are inserted into the upper host computer such as an optical network unit; the other opening is an optical port 205, which is used for external optical fiber access to connect the optical transmitting sub-module 206 and the optical receiving sub-module 207 inside the optical module; the optoelectronic devices such as the circuit board 300, the optical transmitting sub-module 206 and the optical receiving sub-module 207 are located in the wrapped cavity.

[0046] The assembly mode of the combination of the upper shell and the lower shell facilitates the installation of the devices such as the circuit board 300, the optical transmitting sub-module 206 and the optical receiving sub-module 207 into the shell, and the upper shell and the lower shell form the outermost packaging protective shell of the optical module; the upper shell and the lower shell are generally made of metal material, which is beneficial to realize electromagnetic shielding and heat dissipation; generally, the shell of the optical module is not made into an integrated structure, so that the positioning components, heat dissipation and electromagnetic shielding structure cannot be installed when assembling the devices such as the circuit board, and the production automation is not conducive.

[0047] The unlocking handle 203 is located on the outer wall of the package cavity / lower shell 202, and is used to realize the fixed connection between the optical module and the host computer, or to release the fixed connection between the optical module and the host computer.

[0048] The unlocking handle 203 has a clamping structure matched with the cage of the host computer. The end of the unlocking handle can be pulled to relatively move the unlocking handle on the surface of the outer wall. The optical module is inserted into the cage of the host computer, and the clamping structure of the unlocking handle fixes the optical module in the cage of the host computer. By pulling the unlocking handle, the clamping structure of the unlocking handle moves, and the connection relationship between the clamping structure and the host computer is changed, so as to release the clamping relationship between the optical module and the host computer, and the optical module can be pulled out of the cage of the host computer.

[0049] The optical transmitting sub-module 206 and the optical receiving sub-module 207 are respectively used to realize the transmission of optical signals and the reception of optical signals. The optical transmitting sub-module 206 and the optical receiving sub-module 207 can also be combined together to form an optical transceiver integrated structure. The optical transmitting sub-module 206 includes an optical transmitting chip and a back light detector, and the optical receiving sub-module 207 includes an optical receiving chip.

[0050] The circuit board 300 is located in the package cavity formed by the upper shell 201 and the lower shell 202. The circuit board 300 is provided with circuit traces, electronic elements (such as capacitors, resistors, transistors, MOS tubes), and chips (such as microprocessors MCU, laser driving chips, limiting amplifiers, clock data recovery CDR, power management chips, data processing chips DSP), etc.

[0051] In the embodiment of the application, the transimpedance amplifier is closely related to the optical receiving chip. The transimpedance amplifier can be independently packaged on the circuit board 300. The optical receiving chip and the transimpedance amplifier form an electrical connection with the circuit board 300 through an independent packaging body. The transimpedance amplifier and the optical receiving chip can be packaged together in an independent packaging body, such as a same coaxial tube shell TO or a same square cavity. The independent packaging body can not be used, and the optical receiving chip and the transimpedance amplifier can be arranged on the surface of the circuit board. The optical receiving chip can be independently packaged, and the transimpedance amplifier can be arranged on the circuit board. The receiving signal quality can also meet some relatively low requirements.

[0052] The chip on the circuit board can be a multi-in-one chip. For example, a laser driving chip and an MCU chip can be fused into one chip. A laser driving chip, a limiting amplifier chip, and an MCU can also be fused into one chip. The chip is an integration of circuits, but the functions of each circuit do not disappear because of the integration. Therefore, when the circuit board is provided with three independent chips of an MCU, a laser driving chip, and a limiting amplifier chip, it is equivalent to a scheme in which a single chip with three functions is arranged on the circuit.

[0053] The circuit board 300 connects the electrical devices in the optical module according to the circuit design through the circuit traces to realize the power supply, electrical signal transmission and grounding functions. The circuit board 300 is the carrier of the main electrical devices of the optical module, and the electrical devices not arranged on the circuit board are finally electrically connected with the circuit board. The electrical connector on the circuit board 300 realizes the electrical connection between the optical module and the host computer.

[0054] The circuit board 300 is generally a rigid circuit board. Due to the relatively hard material, the rigid circuit board can also realize the bearing function. For example, the rigid circuit board can stably bear the chip. When the optical transmitting sub-module 206 and the optical receiving sub-module 207 are located on the circuit board, the rigid circuit board can also provide stable bearing. The rigid circuit board can also be inserted into the electrical connector in the cage of the host computer. Specifically, a metal pin / gold finger is formed on the end surface of one side of the rigid circuit board, which is used to connect with the electrical connector. These are not convenient to realize by the flexible circuit board.

[0055] The end surface of the circuit board 300 has a gold finger 301, which is composed of independent pins. The circuit board 300 is inserted into the electrical connector in the cage, and the gold finger establishes electrical connection with the host computer. The host computer and the optical module can adopt the I2C protocol to transmit information through the I2C pin. The host computer can write information to the optical module. Specifically, the host computer can write information to the register of the optical module. The optical module cannot write information to the host computer. When the optical module needs to provide information to the host computer, the optical module writes the information to the preset register in the optical module, and the host computer reads the register. The register of the optical module is generally integrated in the MCU of the optical module, and can also be independently arranged on the circuit board 300 of the optical module.

[0056] The flexible circuit board is also used in part of the optical module as a supplement to the rigid circuit board. The flexible circuit board is generally used in cooperation with the rigid circuit board. For example, the rigid circuit board and the optical transceiver device can be connected by the flexible circuit board.

[0057] The optical transmitting sub-module 206 and the optical receiving sub-module 207 are respectively used to realize the transmission of optical signals and the reception of optical signals. In this embodiment, the optical transmitting sub-module 206 adopts a coaxial TO package and is physically separated from the circuit board, and the electrical connection is realized through the flexible board. The optical receiving sub-module 207 also adopts a coaxial TO package and is physically separated from the circuit board, and the electrical connection is realized through the flexible board. In another common implementation manner, the optical transmitting sub-module 206 and the optical receiving sub-module 207 can be arranged on the surface of the circuit board 300. In addition, the optical transmitting sub-module 206 and the optical receiving sub-module 207 can also be combined together to form an optical transceiver integrated structure.

[0058] Figure 5 A partial structure schematic diagram of an optical module is provided for the embodiment of the present application. As shown in FIG. 6, the optical module includes a circuit board 300, an optical transmitting sub-module 206 and an optical receiving sub-module 207. Figure 5As shown, in the optical module provided in this embodiment, a row of gold fingers 301 is arranged on the surface of one end of the circuit board 300. An MCU 302 is arranged on the circuit board 300. The row of gold fingers 301 is composed of independent gold fingers. The circuit board 300 is inserted into the electrical connector in the cage, and an electrical connection is established between the gold fingers 301 and the host computer. The MCU 302 is electrically connected to the gold fingers 301. The optical receiving sub-module 207 includes an APD, a transimpedance amplifier chip (also known as a transimpedance amplifier, TIA), a limiting amplifier chip (also known as a limiting amplifier, LA), and an MCU 302. The essence of a chip is the integration of circuits. Circuits can be integrated into a chip, and some functions of the chip can also be implemented by circuits on the circuit board. The functions of the chip can be implemented by the chip, by circuits, or by the main chip combined with peripheral circuits. Different functions can also be integrated into the same chip. Changes in the circuit integration form are still within the protection scope of this invention.

[0059] During optical signal reception, the optical receiving sub-module 207 contains an internal optical receiving chip, typically an APD, used to receive optical signals sent by external devices and convert them into electrical signals. The input pin of the transimpedance amplifier chip is connected to the output pin of the optical receiving sub-module 207, converting the electrical signal output by the sub-module into a voltage signal. The high-frequency signal input pin of the limiting amplifier chip is connected to the output pin of the transimpedance amplifier chip, amplifying the first voltage signal output by the transimpedance amplifier chip. The input pin of the clock data recovery chip is connected to the high-frequency signal output pin of the limiting amplifier chip, shaping the voltage signal output by the limiting amplifier chip. The output pin of the clock data recovery chip is connected to the gold finger 301. Through the gold finger 301, the signal received by the optical module can be transmitted to the host computer.

[0060] like Figure 6 As shown, the optical module provided in this application embodiment includes

[0061] A laser, mounted on a circuit board, is used to output optical signals. In this embodiment, the laser is a wavelength-tunable laser.

[0062] The MCU is mounted on the circuit board and includes an I2C interface, which is electrically connected to the I2C pins on the gold fingers.

[0063] A bias circuit is provided between the MCU and the laser. The bias circuit includes a first filter sub-circuit, which is used to filter the bias current output by the bias circuit.

[0064] A modulation circuit is provided between the MCU and the laser. The modulation circuit includes a second filter sub-circuit, which is used to filter the modulation current output by the modulation circuit.

[0065] The MCU is connected with the host computer through the golden finger 301, and the host computer sends an enable signal to the MCU. When the enable signal sent by the host computer is in a low state, the MCU sends an instruction signal to the laser, specifically instructing the laser to turn on. At the same time, the MCU outputs a bias current and a modulation current to the laser. The bias current is output through a bias circuit arranged between the MCU and the laser, and the modulation current is output through a modulation circuit arranged between the MCU and the laser.

[0066] The MCU includes a bias current output port, the laser includes a bias current receiving port, a bias circuit is arranged between the bias current output port and the bias current receiving port, and the bias circuit is used to provide power supply for the laser.

[0067] The MCU includes a modulation current output port, the laser includes a modulation current receiving port, a modulation circuit is arranged between the modulation current output port and the modulation current receiving port, and the modulation circuit is used to control the laser to output optical signals of different wavelengths.

[0068] In this way, the bias current is used to drive the laser to emit light, and the modulation current is used to drive the laser to output optical signals of different wavelengths.

[0069] The laser radar requires the laser to output wavelengths in the range of 1530-1560nm. With the adjustment of the modulation current DBR, the output frequency needs to have a strict linear frequency modulation characteristic. For near-range applications, with the scanning of the output frequency, the line width of the laser needs to be within 2MHz to ensure the scanning accuracy of the radar. However, the output line width of the laser is affected by the internal electrical noise of the optical module, which makes the line width characteristic of the laser worse. Therefore, in the embodiment of the application, a filter circuit is specially built to filter the bias current (Bias current) and the modulation current (DBR current). On the basis of not affecting the DBR sweep time, the electrical noise in the line width test is basically eliminated. At this time, the line width of the laser output by the optical module is close to its intrinsic line width, which meets the use requirements of the laser radar.

[0070] In the embodiment of the application, a first filter sub-circuit is arranged in the bias circuit, and a second filter sub-circuit is arranged in the modulation circuit. The first filter sub-circuit is arranged between the bias current output port and the bias current receiving port and includes a filter capacitor.

[0071] The second filter sub-circuit is arranged between the modulation current output port and the modulation current receiving port and includes a filter capacitor.

[0072] The first filter sub-circuit includes a first filter capacitor, a second filter capacitor and a third filter capacitor, and the first filter capacitor, the second filter capacitor and the third filter capacitor are arranged in parallel.

[0073] The second filter sub-circuit comprises a fourth filter capacitor, a fifth filter capacitor, a sixth filter capacitor, a seventh filter capacitor, an eighth filter capacitor and a ninth filter capacitor, which are arranged in parallel.

[0074] The light module provided in the application comprises a circuit board and a light emitting sub-module, the light emitting sub-module comprises a laser and an MCU, a bias circuit and a modulation circuit are arranged between the laser and the MCU, the bias circuit is used to output a bias current to provide power supply for the laser to emit a light signal, the modulation circuit is used to output a modulation current to make the laser output light signals of different wavelengths, wherein the bias circuit comprises a first filter sub-circuit, the modulation circuit comprises a second filter sub-circuit, the first filter sub-circuit and the second filter sub-circuit are used to filter the bias current and the modulation current respectively, to eliminate electrical noise in line width testing without affecting the sweep time of the modulation current, so that the line width of the laser of the light module is close to the intrinsic line width, and the use requirement of applying the light module to the laser radar is met; the light module provided in the application is applied to the laser radar as a light source structure of the laser radar.

[0075] The application aims to provide a light source structure of a laser radar, the light source structure can be in the form of the light module, a laser emitting device or other light emitting units, therefore, the laser radar structure in the application is not limited to the light module, but can also be other light emitting structures.

[0076] The light module provided in the above embodiment is applied to the laser radar, so that Figure 7 The laser radar comprises:

[0077] A light source is used to output a light signal, and the light source is the light module provided in the above embodiment.

[0078] A light splitter is used to divide the light signal from the light source into probe light and local oscillator light.

[0079] A fiber amplifier is used to amplify the probe light and output the probe light to a measured object.

[0080] A collimating lens is used to collimate the reflected light from the measured object into parallel light.

[0081] A combiner is used to combine the local oscillator light and the parallel light.

[0082] A photodetector is used to convert the light signal from the combiner into an electrical signal.

[0083] A signal processing unit is used to process the electrical signal to obtain the distance of the measured object.

[0084] Based on the above structure of the laser radar, the working principle of the laser radar in the embodiment of the application is as follows:

[0085] The light module provided in the embodiment of the application continuously modulates frequency points as a light source, guarantees high-speed and high-power output light signals, and a light splitter divides the light emitted by the laser into one local oscillator light and one probe light, and the splitting ratio is determined according to the average power of the laser; the probe light is amplified to the required power output by the optical fiber amplifier and then is subjected to two-dimensional spatial scanning, the probe light is reflected by an object, the reflected light enters the detector after collimation and combination with the local oscillator light, and the distance, moving speed and other information of the detected object are determined through the digital signal processing circuit.

[0086] The laser output light source in the light module provided in the application needs to have the following characteristics: fast wavelength or frequency modulation speed, i.e., fast scanning speed; narrow laser linewidth for ensuring scanning resolution; and strict linear frequency modulation.

[0087] The filter circuit is specially built in the light module provided in the embodiment of the application, and the bias current and the modulation current are subjected to filter processing, which basically eliminates the electric noise in the linewidth test without affecting the DBR frequency scanning time, so that the laser linewidth output by the light module is close to the intrinsic linewidth, and the use requirement of the laser radar is met. The filter circuit specifically includes: a first filter sub-circuit is arranged in the bias circuit, and a second filter sub-circuit is arranged in the modulation circuit, the first filter sub-circuit is arranged between the bias current output port and the bias current receiving port, and includes a filter capacitor. The second filter sub-circuit is arranged between the modulation current output port and the modulation current receiving port, and includes a filter capacitor.

[0088] The first filter sub-circuit includes a first filter capacitor, a second filter capacitor and a third filter capacitor, and the first filter capacitor, the second filter capacitor and the third filter capacitor are arranged in parallel.

[0089] The second filter sub-circuit includes a fourth filter capacitor, a fifth filter capacitor, a sixth filter capacitor, a seventh filter capacitor, an eighth filter capacitor and a ninth filter capacitor, and the fourth filter capacitor, the fifth filter capacitor, the sixth filter capacitor, the seventh filter capacitor, the eighth filter capacitor and the ninth filter capacitor are arranged in parallel.

[0090] Based on the laser radar provided in the above embodiment, the application further provides an automatic driving test device, the automatic driving test device in the application includes a laser radar, and the optical module provided in the application is used as a light source of the laser radar, has a continuous modulation frequency point, guarantees a high-speed and high-power output light signal, and then a light splitter in the structure of the laser radar divides the light emitted by the laser into one local oscillation light and one detection light, and the splitting ratio is determined according to the average power of the laser; the detection light is amplified to a required power output by a fiber amplifier and then is subjected to spatial two-dimensional scanning, the detection light is reflected by an object, the reflected light enters a detector after being combined with the local oscillation light, and distance, moving speed and other information of the detected object are determined through a digital signal processing circuit.

[0091] In summary, the application provides an optical module and a laser radar, the optical module includes a circuit board and a light emission sub-module, the light emission sub-module includes a laser and an MCU, a bias circuit and a modulation circuit are arranged between the laser and the MCU, the bias circuit is used to output a bias current to provide a power supply for the light signal emitted by the laser, and the modulation circuit is used to output a modulation current to make the laser output light signals of different wavelengths, wherein the bias circuit includes a first filter sub-circuit, and the modulation circuit includes a second filter sub-circuit, the first filter sub-circuit and the second filter sub-circuit are used to filter the bias current and the modulation current respectively, to eliminate electrical noise in the line width test without affecting the sweep time of the modulation current, so that the line width of the laser of the optical module is close to the intrinsic line width, and the use requirement of applying the optical module to the laser radar is met; the optical module provided in the application is used as a light source structure of the laser radar, and the laser radar including the optical module is applied to automatic driving, so that the distance of the measured object in the automatic driving process is tested by the laser radar. The optical module provided in the application is expected to be applied to the field of automatic driving.

[0092] Finally, it should be noted that: the present embodiment is described in a progressive manner, and different parts can be referred to each other; in addition, the above embodiments are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application.

Claims

1. A lidar, characterized in that, include: A light source for outputting optical signals, the light source comprising: Circuit board; The optical emission sub-module is electrically connected to the circuit board and is used to convert electrical signals into optical signals; The optical emission sub-module includes: A laser, mounted on the circuit board, is used to output optical signals; An MCU, mounted on the circuit board, includes an I2C interface electrically connected to the I2C pins on the gold fingers; the MCU is configured to: receive an enable signal provided by a host computer; when the enable signal is low, the MCU sends an enable command signal to the laser, and simultaneously controls the output bias current and modulation current of the laser. A bias circuit is provided between the MCU and the laser. The bias circuit includes a first filter sub-circuit for filtering the bias current output by the bias circuit. The first filter sub-circuit includes a first filter capacitor, a second filter capacitor, and a third filter capacitor, which are connected in parallel. A modulation circuit is provided between the MCU and the laser. The modulation circuit includes a second filter sub-circuit for filtering the modulation current output by the modulation circuit. The second filter sub-circuit includes a fourth filter capacitor, a fifth filter capacitor, a sixth filter capacitor, a seventh filter capacitor, an eighth filter capacitor, and a ninth filter capacitor, which are connected in parallel. A beam splitter is used to split the optical signal from the light source into probe light and local oscillator light; An optical fiber amplifier is used to amplify the probe light and output it to the object under test. A collimating lens is used to collimate the reflected light from the object under test into parallel light. A combiner is used to combine the local oscillator light and the parallel light. A photodetector is used to convert optical signals from the multiplexer into electrical signals; The signal processing unit is used to process the electrical signal to obtain the distance to the object being measured.

2. The lidar according to claim 1, characterized in that, The MCU includes a bias current output port, the laser includes a bias current receiving port, and a bias circuit is provided between the bias current output port and the bias current receiving port. The bias circuit is used to provide power to the laser. The MCU includes a modulation current output port, the laser includes a modulation current receiving port, and a modulation circuit is provided between the modulation current output port and the modulation current receiving port. The modulation circuit is used to control the laser to output optical signals of different wavelengths.

3. The lidar according to claim 2, characterized in that, The first filter sub-circuit is located between the bias current output port and the bias current receiving port, and includes a filter capacitor.

4. The lidar according to claim 2, characterized in that, The second filter sub-circuit is located at the modulation current output port and the modulation current receiving port, and includes a filter capacitor.

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