Laser emission circuit and lidar

Abstract

The present disclosure provides a laser emission circuit and a laser radar. The laser emission circuit comprises: a laser, the laser comprising a multilayer PN junction; a driving circuit, the driving circuit being connected to a voltage source and one end of the laser, for providing a first voltage to the laser; and a pre-bias circuit, the pre-bias circuit being connected to the other end of the laser, for providing a second voltage to the laser, the second voltage being a negative voltage. The laser emission circuit of the present disclosure can improve the driving capability of the multilayer junction laser, improve the power density and light output efficiency of the laser, and at the same time can reduce the demand and cost of the output voltage of the driving circuit.

Description

Technical Field

[0001] This disclosure generally relates to the field of lidar technology, and more particularly to a laser emitting circuit and lidar. Background Technology

[0002] Lidar (Light Detection and Ranging) is a radar system that uses laser beams to detect the position, velocity, and other characteristics of objects. Due to its advantages such as high resolution, strong resistance to active interference, good detection performance, small size, and light weight, lidar is widely used in fields such as autonomous driving, transportation communication, drones, intelligent robots, and resource exploration.

[0003] To improve the range accuracy of lidar, it is necessary to increase the power density and emission efficiency of the laser. However, this places higher demands on the performance of the laser emitting circuit components, leading to increased costs. Therefore, how to effectively control the cost increase of the emitting circuit while ensuring improved laser emission efficiency is the technical problem that this disclosure aims to solve.

[0004] The content of the background section is merely the technology known to the inventor and does not necessarily represent the prior art in this field. Utility Model Content

[0005] In view of one or more of the problems existing in the prior art, this disclosure provides a laser emitting circuit that can improve the light output efficiency of the laser while effectively controlling the cost of the emitting circuit.

[0006] The laser emitting circuit includes a laser, the laser including a multilayer PN junction; a driving circuit connected to a voltage source and one end of the laser, for providing a first voltage to the laser; and a pre-bias circuit connected to the other end of the laser, for providing a second voltage to the laser, the second voltage being a negative voltage.

[0007] Optionally, the driving circuit includes a switch, the first end of which is connected to the voltage source, and the second end of which is connected to the anode of the laser; the pre-bias circuit is connected to the cathode of the laser.

[0008] Optionally, the switch includes at least one of a metal-oxide-semiconductor field-effect transistor, a gallium nitride switch, or a switching transistor.

[0009] Optionally, the driving circuit further includes a switch driver; the switch driver includes a first input terminal, a second input terminal, and an output terminal; the input voltage of the first input terminal is greater than or equal to the voltage of the voltage source; the second input terminal is connected to ground; and the output terminal is connected to the control terminal of the switch.

[0010] Optionally, the first voltage includes at least two voltage levels; and / or, the second voltage includes at least two voltage levels.

[0011] Optionally, the absolute value of the second voltage is less than the threshold voltage of the laser.

[0012] Optionally, the laser has PN junction layers greater than or equal to 3.

[0013] Optionally, the laser has 8 or more PN junction layers.

[0014] This disclosure also provides a lidar, including the laser emitting circuit described above.

[0015] Optionally, the laser includes a vertical cavity surface laser or an edge-emitting laser.

[0016] Optionally, the lidar further includes a scanner for changing the exit direction of the detection beam emitted by the laser; the scanner includes a rotating mirror or a tilting mirror.

[0017] The laser emitting circuit disclosed herein employs a multilayer junction laser, which can improve the power density and light extraction efficiency of the laser, thereby enhancing the range-finding capability of the lidar. By providing a first voltage to the laser through a driving circuit and a second voltage that is negative through a pre-bias circuit, the driving capability of the multilayer junction laser can be improved. At the same time, it can reduce the requirement for improving the withstand voltage performance of each component in the laser emitting circuit, effectively controlling the cost of the emitting circuit. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the following description of the embodiments will be provided as examples. The drawings described below are merely embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort. The drawings are used to provide a further understanding of this disclosure and constitute a part of the specification. They are used together with the embodiments of this disclosure to explain this disclosure and do not constitute a limitation of this disclosure.

[0019] Figure 1 A schematic diagram of an exemplary laser emitting circuit consistent with some embodiments of this disclosure is shown.

[0020] Figure 2 A schematic diagram of an exemplary laser emitting circuit consistent with some embodiments of this disclosure is shown.

[0021] Figure 3A A partial schematic diagram of an exemplary laser emitting circuit consistent with some embodiments of this disclosure is shown.

[0022] Figure 3B A partial schematic diagram of an exemplary laser emitting circuit consistent with some embodiments of this disclosure is shown.

[0023] Figure 3C A partial schematic diagram of an exemplary laser emitting circuit consistent with some embodiments of this disclosure is shown.

[0024] Figure 3D A partial schematic diagram of an exemplary laser emitting circuit consistent with some embodiments of this disclosure is shown.

[0025] Figure 4 A schematic diagram of an exemplary lidar consistent with some embodiments of this disclosure is shown.

[0026] Figure 5 A schematic diagram of an exemplary lidar consistent with some embodiments of this disclosure is shown. Detailed Implementation

[0027] In the following description, only certain exemplary embodiments are shown. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this disclosure. Therefore, the drawings and description are to be considered exemplary in nature and not restrictive.

[0028] In the description of this disclosure, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "coupling" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or connections that allow for communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0030] The following provides numerous different embodiments or examples for implementing various structures of this disclosure. To simplify this disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit this disclosure. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, this disclosure provides examples of various specific processes and materials, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0031] The following description, in conjunction with the accompanying drawings, illustrates some embodiments of this disclosure. It should be understood that the embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of this disclosure.

[0032] In lidar, increasing the driving voltage supplied to the laser can improve its power density and light extraction efficiency. However, simply increasing the driving voltage may cause other components to be damaged by overvoltage. Therefore, to ensure the normal operation of the driving circuit, the voltage withstand requirements of each component in the driving circuit become higher, which will increase the cost of the lidar.

[0033] This disclosure provides a laser emitting circuit. The laser emitting circuit includes a laser, a driving circuit, and a pre-biasing circuit. The laser includes a multilayer PN junction. The driving circuit is connected to a voltage source and one end of the laser to provide a first voltage to the laser. The pre-biasing circuit is connected to the other end of the laser to provide a second voltage to the laser. The second voltage is a negative voltage.

[0034] The laser emitting circuit disclosed herein employs a multilayer junction laser, which can improve the power density and light extraction efficiency of the laser, thereby enhancing the range-finding capability of the lidar. By providing a first voltage to the laser through a driving circuit and a second voltage that is negative through a pre-bias circuit, the driving capability of the multilayer junction laser can be improved. At the same time, it can reduce the requirement for improving the withstand voltage performance of each component in the laser emitting circuit, effectively controlling the cost of the emitting circuit.

[0035] Figure 1 A schematic diagram of an exemplary laser emitting circuit 100 consistent with some embodiments of this disclosure is shown. Figure 1 As shown, the laser emitting circuit 100 includes a laser 102, a driving circuit 104, and a pre-biasing circuit 106. The laser 102 includes multiple PN junctions. The number of PN junction layers in the laser is greater than or equal to two. The driving circuit 104 connects a voltage source S to one end of the laser 102. The driving circuit 104 provides a first voltage V1 to the laser 102. The pre-biasing circuit 106 connects to the other end of the laser 102. The pre-biasing circuit 106 provides a second voltage V2 to the laser 102. The second voltage V2 is a negative voltage. The laser 102 can emit a probe beam under the drive of the driving circuit 104.

[0036] In the embodiments of this disclosure, the laser employs a multilayer PN junction structure, which improves the laser's power density and light extraction efficiency. Simultaneously, the embodiments of this disclosure include a pre-bias circuit to provide a negative voltage to the laser's cathode. This increases the voltage difference across the laser to meet the operational requirements of the multilayer PN junction structure, ensuring stable laser operation. Furthermore, the pre-bias circuit reduces the voltage required for the laser anode while maintaining the voltage difference across the laser, thereby lowering the high-voltage requirements on components in the laser emitting circuit (e.g., the driver circuit) and helping to control the cost of the emitting circuit.

[0037] In some embodiments, laser 102 may include a semiconductor laser, such as a vertical-cavity surface-emitting laser (VCSEL), an edge-emitting laser (EEL), or other semiconductor lasers capable of generating laser light.

[0038] In some embodiments, the laser 102 has 3 or more PN junction layers. Having 3 or more PN junction layers can significantly improve the power density and light extraction efficiency of the laser 102. For example, the laser 102 may have 3, 4, 5, 6, or 7 PN junction layers, etc.

[0039] In some embodiments, the number of PN junction layers in the laser 102 is greater than or equal to 8. Having a PN junction layer number greater than or equal to 8 further improves the power density and light extraction efficiency of the laser 102. For example, the number of PN junction layers in the laser 102 can be any number greater than or equal to 8, such as 8, 9, 10, 11, or 12 layers.

[0040] In some embodiments, the pre-bias circuit 106 may be a Boost circuit or other circuit capable of generating a negative voltage.

[0041] Figure 2 A schematic diagram of an exemplary laser emitting circuit 200 consistent with some embodiments of this disclosure is shown. Figure 2 As shown, the laser emitting circuit 200 includes a laser 202, a driving circuit 204, and a pre-biasing circuit 206. The driving circuit 204 includes a switch 2041. The first terminal of the switch 2041 is connected to a voltage source S. The second terminal of the switch 2041 is connected to the anode of the laser 202. The pre-biasing circuit 206 is connected to the cathode of the laser 202. The switch 2041 also includes a control terminal. The control terminal of the switch 2041 can be connected to a control circuit. The control circuit can send a control signal to the switch 2041 to control the switch 2041 to turn it on or off, thereby controlling whether the laser 202 emits light or not. For example, when the switch 2041 is on, the laser 202 emits light. When the switch 2041 is off, the laser 202 does not emit light. The laser 202 is the same as or similar to the laser 102. The pre-biasing circuit 206 is the same as or similar to the pre-biasing circuit 106.

[0042] In some embodiments, switch 2041 includes at least one of metal-oxide-semiconductor field-effect transistor (MOSFET), gallium nitride (GaN) switch, or switch transistor.

[0043] In some embodiments, the control circuitry can be integrated into the laser emitting circuit 200 or externally located within it. In some embodiments, the control circuitry may include a central processing unit (CPU), and may also include other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or similar devices. The general-purpose processor may be a microcontroller unit (MCU) or any conventional processor. The configuration can be tailored to specific requirements in practical applications.

[0044] In some embodiments, the driving circuit 204 further includes a switch driver 2042. The switch driver 2042 includes a first input terminal P1, a second input terminal P2, and an output terminal P3. The input voltage V3 of the first input terminal P1 is greater than or equal to the voltage of the voltage source S. For example, the first input terminal P1 is connected to the voltage source S. Alternatively, the first input terminal P1 is connected to another power supply terminal, and the voltage supplied to the first input terminal P1 by the other power supply terminal is greater than or equal to the voltage S of the voltage source. The second input terminal P2 is connected to ground. For example, the second input terminal P2 is directly connected to ground. Alternatively, the second input terminal P2 is indirectly connected to ground through other electronic devices. The output terminal P3 is connected to the control terminal of the switch 2041. For example, the output terminal P3 is directly connected to the control terminal of the switch 2041. Alternatively, the output terminal P3 is indirectly connected to the control terminal of the switch 2041 through other electronic devices.

[0045] Continue to refer to Figure 2 The driving circuit 204 includes a switch 2041 and a switch driver 2042. The switch driver 2042 is connected to the control terminal of the switch 2041, and can control the switch 2041 to turn on or off. The first input terminal P1 of the switch driver 2042 can be connected to the power supply terminal, and the second input terminal P2 of the switch driver can be connected to ground. The voltage of the power supply terminal connected to the first input terminal P1 is greater than or equal to the voltage of the voltage source S. This ensures that the control signal output by the switch driver 2042 can normally control the switch 2041 to turn on or off. The pre-bias circuit 206 can reduce the voltage of the voltage source S in the laser emitting circuit 200 while ensuring the operating voltage requirements of the laser 202, thereby reducing the voltage required at the first input terminal P1 of the switch driver 2042. This reduces the voltage withstand requirement of the switch driver 2042, effectively controlling the cost of the laser emitting circuit while increasing the output power of the laser 202.

[0046] When switch 2041 is in the ON state, drive circuit 204 provides a first voltage V1 to laser 202. Pre-bias circuit 206 provides a second voltage V2 to laser 202. For example, the first voltage V1 is a positive voltage HV, and the second voltage V2 is a negative voltage NHV. In this case, the anode voltage of laser 202 is HV, and the cathode voltage is NHV. The voltage difference between the anode and cathode of laser 202 is HV + |NHV|. In other words, the actual driving voltage of laser 202 is HV + |NHV|. This increases the voltage difference between the anode and cathode of laser 202, thereby increasing the luminous power of laser 202. For example, if the first voltage V1 is 30V and the second voltage V2 is -4V, then the actual driving voltage of the laser is 30 + |-4| = 34V. Or, for example, if the first voltage V1 is 20V and the second voltage V2 is -3V, then the actual driving voltage of the laser is 20 + |-3| = 23V. The input voltage V3 at the first input terminal P1 of the switch driver 2042 is greater than or equal to the voltage of the voltage source S. Compared to the scheme where the laser cathode is connected to ground voltage, the actual driving voltage of the laser 202 in this embodiment is increased to HV+|NHV|, so the withstand voltage requirement of the switch driver 2042 can be maintained or increased only slightly. Thus, the requirement for improving the withstand voltage performance of the switch driver can be reduced while increasing the laser output power, effectively controlling circuit costs.

[0047] In some embodiments, the absolute value of the second voltage V2 is less than the threshold voltage of the laser 202. When switch 2041 is off, drive circuit 204 stops supplying the first voltage V1 to laser 202. Pre-bias circuit 206 still supplies the second voltage V2 to laser 202. For example, the second voltage V2 is a negative voltage NHV. In this case, the anode voltage of laser 202 is approximately 0V. The cathode voltage of laser 202 remains NHV. The voltage difference between the anode and cathode of laser 202 is |NHV|. Since the voltage difference |NHV| across laser 202 is less than the threshold voltage (or turn-on voltage) of laser 202, it can reduce or prevent switch 2041 from losing control over the on / off state of laser 202, and reduce or prevent laser 202 from emitting light when switch 2041 is off. For example, the threshold voltage of laser 202 is 10V, and the second voltage V2 can be -4V. In this configuration, when switch 2041 is turned off, when the first voltage V1 is about 0V, the voltage across laser 202 is 4V, which is lower than the threshold voltage. Almost no current flows through laser 202, and laser 202 does not emit light.

[0048] It should be noted that the specific values ​​of the aforementioned first voltage, second voltage, and laser threshold voltage are merely illustrative examples and are not intended to limit this disclosure. In practical applications, they can be set according to requirements.

[0049] In some embodiments, the first voltage V1 can be an adjustable positive voltage. For example, the first voltage V1 can include at least two voltage levels. For instance, the first voltage V1 can include two voltage levels, such as HV / 2 and HV respectively. For instance, the first voltage V1 can include three voltage levels, such as HV / 3, 2HV / 3, and HV respectively. It should be noted that the first voltage V1 can include three or other numbers of voltage levels. The different levels of the first voltage V1 allow the driving circuit to provide different first voltages to the laser. For another example, the first voltage V1 can be a continuously adjustable positive voltage. For instance, the first voltage V1 can be adjusted according to a preset voltage curve. For example, the range of the first voltage V1 can be 0~HV.

[0050] In some embodiments, the second voltage V2 can be an adjustable negative voltage. For example, the second voltage V2 can include at least two voltage levels. For instance, the second voltage V2 can include two voltage levels, such as NHV / 2 and NHV. For instance, the second voltage V2 can include three voltage levels, such as NHV / 3, 2NHV / 3, and NHV. It should be noted that the second voltage V2 can include three or other numbers of voltage levels. The different levels of the second voltage V2 allow the pre-bias circuit to provide different second voltages to the laser. For another example, the second voltage V2 can be a continuously adjustable negative voltage. For instance, the second voltage V2 can be adjusted according to a preset voltage curve. For example, the range of the second voltage V2 can be 0~NHV.

[0051] In some embodiments, the first voltage V1 can be adjusted, while the second voltage V2 remains constant. In some embodiments, the first voltage V1 can remain constant, while the second voltage V2 can be adjusted. In some embodiments, both the first voltage V1 and the second voltage V2 can be adjusted. In this way, the voltage difference across the laser can be adjusted, thereby adjusting the actual driving voltage of the laser and achieving flexible adjustment of the driving capability. The laser emitting circuit has excellent dynamic adjustment performance, which is beneficial for adapting to complex environmental changes.

[0052] In some embodiments, the actual driving voltage of the laser 202 can be maintained at HV+|NHV|. In this way, the laser emitting circuit can maintain the expected driving performance under noise interference, exhibiting excellent robustness.

[0053] In some embodiments, the laser emitting circuit may include a single laser or multiple lasers. Multiple lasers may be arranged in a one-dimensional or two-dimensional array. Figure 3A A partial schematic diagram of an exemplary laser emitting circuit 300 consistent with some embodiments of this disclosure is shown. Figure 3AAs shown, the laser emitting circuit 300 includes multiple lasers 302, multiple switches 3041, and multiple pre-bias circuits 306. The multiple switches 3041 can be configured on the same or different drive circuits. The lasers 302, switches 3041, and pre-bias circuits 306 are connected in a one-to-one correspondence. The on / off state of each switch 3041 can drive and control its corresponding laser 302. The laser 302 is the same as or similar to laser 102. The pre-bias circuit 306 is the same as or similar to pre-bias circuit 106. The switch 3041 is the same as or similar to switch 2041. In some embodiments, the laser emitting circuit 300 may include a switch driver that is the same as or similar to switch driver 2042.

[0054] Figure 3B A partial schematic diagram of an exemplary laser emitting circuit 300 consistent with some embodiments of this disclosure is shown. Figure 3B As shown, the laser emitting circuit 300 includes multiple lasers 302, a switch 3041, and a pre-bias circuit 306. The multiple lasers 302 are connected to the switch 3041 and the pre-bias circuit 306. The on / off state of the switch 3041 can synchronously drive and control the multiple lasers 302.

[0055] Figure 3C A partial schematic diagram of an exemplary laser emitting circuit 300 consistent with some embodiments of this disclosure is shown. Figure 3C As shown, the laser emitting circuit 300 includes multiple lasers 302, a switch 3041, and multiple pre-bias circuits 306. The multiple lasers 302 are connected to the switch 3041. Each laser 302 is connected to a pre-bias circuit 306 in a one-to-one correspondence. The switching on and off of the switch 3041 can synchronously drive and control the multiple lasers 306. The multiple pre-bias circuits 306 are used to provide the same or different negative voltages to the lasers 302 connected to them.

[0056] Figure 3D A partial schematic diagram of an exemplary laser emitting circuit 300 consistent with some embodiments of this disclosure is shown. Figure 3D As shown, the laser emitting circuit 300 includes multiple lasers 302, multiple switches 3041, and a pre-bias circuit 306. The multiple switches 3041 can be located on the same or different driving circuits. The driving circuit can provide the same or different first voltages to the multiple lasers 302. Each laser 302 is connected to one of the multiple switches 3041. The multiple lasers 302 are collectively connected to a pre-bias circuit 306. The multiple pre-bias circuits 306 are used to provide the same negative voltage to the lasers 302 connected to them.

[0057] In some embodiments, such as Figures 3A to 3DAs shown, changing at least one of the first voltage or the second voltage can adjust the driving voltage of the laser 302. For example, increasing the first voltage, or decreasing the second voltage (i.e., increasing the absolute value of the second voltage), or increasing the first voltage and decreasing the second voltage, can increase the driving voltage of the laser 302. Conversely, decreasing the first voltage, or increasing the second voltage (i.e., decreasing the absolute value of the second voltage), or decreasing the first voltage and increasing the second voltage, can decrease the driving voltage of the laser 302.

[0058] In some embodiments, when the laser emitting circuit 300 is applied to a lidar, the driving voltage of the laser can be adjusted according to the lidar's field of view. For example, for the region of interest (ROI) in the lidar's field of view, the driving voltage of the corresponding laser 302 can be increased to improve the signal strength of the detection beam emitted by the laser 302 and enhance the lidar's rangefinding capability. For the non-ROI, the driving voltage of the corresponding laser 302 can be decreased to save computing power and energy consumption. In some embodiments, the ROI region can be located in the central region of the lidar's field of view. The non-ROI region can be located in the edge region of the lidar's field of view. In some embodiments, the ROI region can include the region where an object is detected. The non-ROI region can correspond to the region where no object is detected. In practical applications, the ROI region and the non-ROI region can be set according to requirements.

[0059] The laser emitting circuit disclosed herein can improve the driving capability of the multilayer PN junction laser by pre-biasing the multilayer PN junction laser, thereby increasing the power density and light output efficiency of the laser. At the same time, it can reduce the need to improve the withstand voltage performance of each component in the laser emitting circuit and effectively control the cost of the emitting circuit.

[0060] This disclosure also provides a lidar. Figure 4 A schematic diagram of an exemplary lidar 400 consistent with some embodiments of this disclosure is shown. Figure 4 As shown, the lidar 400 includes laser emitting circuits 100 / 200 / 300. Each laser emitting circuit 100 / 200 / 300 includes one or more lasers 102 / 202 / 302. The multiple lasers 102 / 202 / 302 can be arranged in a one-dimensional or two-dimensional array. The lasers 102 / 202 / 302 can include vertical-cavity surface mount lasers (VCSELs), edge-emitting lasers, or other semiconductor lasers capable of generating laser light.

[0061] Figure 5 A schematic diagram of an exemplary lidar 500 consistent with some embodiments of this disclosure is shown. Figure 5As shown, the lidar 500 also includes a scanner 510. The scanner 510 is located downstream of the optical path of the laser emitting circuits 100 / 200 / 300. The scanner 510 is used to change the emission direction of the detection beam L emitted by the lasers 102 / 202 / 302. The scanner 510 may include a rotating mirror or a tilting mirror. The rotating mirror or tilting mirror can perform rotational or reciprocating motion to enable the lidar to perform scanning detection in different directions.

[0062] In some embodiments, the lidar 500 may include a detector (not shown). The detector may utilize the photoelectric effect to convert the echo of the detection beam L reflected by an object into an electrical signal. The detector may include a photodetector circuit, an avalanche photodiode (APD), a single-photon avalanche diode (SPAD), a silicon photomultiplier (SiPM), or a similar device. The detectors may be arranged in a one-dimensional or two-dimensional array. For example, each detector may be individually controlled.

[0063] In some embodiments, the lidar 500 may include processing circuitry (not shown). The processing circuitry may be coupled to the laser emitting circuitry 100 / 200 / 300, providing drive control signals to the drive circuitry to drive the laser to emit a detection beam L. The processing circuitry may be coupled to the scanner 510, controlling the scanner 510 to rotate or reciprocate. The processing circuitry may be coupled to the detector, receiving electrical signals output by the detector and generating point cloud data based on the electrical signals. The processing circuitry may determine one or more pieces of information, such as the distance to an object or its reflectivity, based on the electrical signals. The processing circuitry may be the same as or similar to the control circuitry.

[0064] In some embodiments, the lidar can be mounted on a device. The lidar and the device can communicate with each other. The lidar can send the detected sensing data to the device. The device can use the sensing data to perform one or more functions such as analysis, decision-making, or control. The device may include vehicles, ships, aircraft (e.g., flying vehicles, or drones), robots (e.g., industrial robots or home robots), etc.

[0065] The lidar disclosed herein, by employing the aforementioned laser emitting circuit, can enhance the driving capability of the laser, thereby improving the lidar's range measurement performance and effectively controlling costs.

[0066] It should be noted that although the laser emitting circuit and several modules of the lidar have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules described above can be implemented in one module. Conversely, the features and functions of one module described above can be further divided and embodied by multiple modules.

[0067] It should be noted that the laser emitting circuit and lidar disclosed herein are not limited to... Figure 1-5 The state shown. This disclosure may include only the state shown. Figure 1-5 Any one or more features of any one or more embodiments. In other words, not all. Figure 1-5 All of the features must be implemented simultaneously in the laser emitting circuit and the lidar disclosed herein.

[0068] Finally, it should be noted that the above descriptions are merely some embodiments of this disclosure and are not intended to limit this disclosure. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A laser emitting circuit, characterized in that, include: A laser, the laser comprising a multilayer PN junction; A driving circuit, wherein the driving circuit is connected to a voltage source and one end of the laser, and is used to provide a first voltage to the laser; and A pre-bias circuit, connected to the other end of the laser, is used to provide a second voltage to the laser, the second voltage being a negative voltage.

2. The laser emitting circuit according to claim 1, characterized in that, The driving circuit includes a switch, the first end of which is connected to the voltage source, and the second end of which is connected to the anode of the laser; the pre-bias circuit is connected to the cathode of the laser.

3. The laser emitting circuit according to claim 2, characterized in that, The switch includes at least one of a metal-oxide-semiconductor field-effect transistor, a gallium nitride switch, or a switching transistor.

4. The laser emitting circuit according to claim 2, characterized in that, The driving circuit further includes a switch driver; the switch driver includes a first input terminal, a second input terminal, and an output terminal; the input voltage of the first input terminal is greater than or equal to the voltage of the voltage source; the second input terminal is connected to ground; and the output terminal is connected to the control terminal of the switch.

5. The laser emitting circuit according to claim 1, characterized in that, The first voltage includes at least two voltage levels; and / or, The second voltage includes at least two voltage levels.

6. The laser emitting circuit according to claim 1, characterized in that, The absolute value of the second voltage is less than the threshold voltage of the laser.

7. The laser emitting circuit according to claim 1, characterized in that, The laser has a PN junction layer number greater than or equal to 3.

8. The laser emitting circuit according to claim 7, characterized in that, The laser has 8 or more PN junction layers.

9. A lidar, characterized in that, Includes the laser emitting circuit as described in any one of claims 1-8.

10. The lidar according to claim 9, characterized in that, The laser includes a vertical cavity surface laser or an edge-emitting laser.

11. The lidar according to claim 10, characterized in that, It also includes a scanner for changing the exit direction of the detection beam emitted by the laser; The scanner includes a rotating mirror or a tilting mirror.

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