Laser emission assembly with stacked structure, emission module and laser radar

Abstract

The invention provides a laser emission assembly with a stacked structure, and the assembly comprises a laser chip which is integrated with a plurality of lasers, and the plurality of lasers are arranged in a two-dimensional array; a switch chip in which a plurality of first switches are integrated, the laser being connected to the first switches; the first driving chip is connected to the switch chip and is configured to control on or off of the first switch; wherein the switch chip is stacked between the laser chip and the first driving chip. According to the laser emission assembly disclosed by the invention, the laser can realize high-efficiency and high-power light emission.

Description

Technical Field

[0001] The present disclosure relates to the field of laser radar, and in particular to a laser emitting assembly, an emitting module and a laser radar with a stacked structure. Background Art

[0002] LiDAR (LiDAR) is a radar system that uses laser beams to detect target characteristics such as position and velocity. It is an advanced detection method that combines laser technology with photoelectric detection technology. Due to its advantages such as high resolution, good concealment, strong resistance to active interference, excellent low-altitude detection performance, small size, and light weight, LiDAR is widely used in autonomous driving, transportation communications, drones, intelligent robots, resource exploration, and other fields.

[0003] In order to make the laser radar have better detection performance, how to make the laser achieve high-efficiency and high-power light emission is crucial to the laser radar field.

[0004] The contents of the background technology section are merely the technologies known to the inventors and do not necessarily represent the existing technologies in this field. Summary of the Invention

[0005] In response to one or more problems existing in the prior art, the present disclosure provides a laser emitting assembly with a stacked structure, which enables the laser to achieve high-efficiency and high-power light emission.

[0006] The laser emission assembly includes a laser chip, a switch chip, and a first driver chip. The laser chip integrates multiple lasers arranged in a two-dimensional array; the switch chip integrates multiple first switches, to which the lasers are connected; and a first driver chip is connected to the switch chip and configured to control the on / off switching of the first switches. The switch chip is stacked between the laser chip and the first driver chip.

[0007] Optionally, the first driving chip includes a plurality of first drivers, wherein the first switch is connected to the first driver, and the first driver is configured to control the on or off of the first switch.

[0008] Optionally, the laser comprises a vertical cavity surface emitting laser; the first switch comprises a gallium nitride transistor; and the first driver is connected to a gate of the gallium nitride transistor.

[0009] Optionally, the laser chip includes metal contacts, which are located on a surface opposite to a light-emitting surface of the laser chip, and the laser chip is electrically connected to the switch chip via the metal contacts.

[0010] Optionally, the switch chip includes a via hole, and the first driver chip is electrically connected to the switch chip through the via hole.

[0011] The present disclosure also provides another laser emitting component with a stacked structure, the laser emitting component including a laser chip and a plurality of second driver chips; the laser chip integrates a plurality of lasers, and the plurality of lasers are arranged in a two-dimensional array; the plurality of second driver chips are connected to the laser chip, and the second driver chip integrates a plurality of second switches; at least one second switch in the second driver chip is connected to at least one second switch in other second driver chips; the plurality of driver chips are stacked, and the laser chip is stacked on the plurality of second driver chips.

[0012] Optionally, the laser includes a vertical cavity surface emitting laser; and the second switch includes a metal oxide semiconductor field effect transistor.

[0013] Optionally, at least one of the plurality of second driver chips further includes a plurality of second drivers, and the second drivers are configured to control the on or off of the second switch.

[0014] Optionally, at least one of the second switches in the second driver chip is connected in parallel with at least one of the second switches in other second driver chips; the multiple second driver chips include multiple second switch groups, and the second switch groups include multiple second switches in parallel; the laser emitting assembly includes at least one light-emitting path, and the light-emitting path includes the laser and the second switch group, and the laser is connected to the second switch group.

[0015] Optionally, the plurality of second switches in the same second switch group are configured to be turned on or off synchronously.

[0016] Optionally, the second driver chip includes a via hole, and the second driver chip is electrically connected to the laser chip through the via hole.

[0017] The present disclosure also provides another laser emitting component with a stacked structure, the laser emitting component including a laser chip and a third driver chip; the laser chip integrates multiple lasers, and the multiple lasers are arranged in a two-dimensional array; the third driver chip is connected to the laser chip, and the third driver chip integrates multiple third switches and multiple third drivers; wherein, the third switch connects multiple lasers, and the laser chips are stacked on the third driver chip.

[0018] Optionally, the laser includes a vertical cavity surface emitting laser; and the third switch includes a metal oxide semiconductor field effect transistor.

[0019] Optionally, among the plurality of lasers connected to the same third switch, one of the cathode and the anode thereof is connected to the same third switch, and the other of the cathode and the anode thereof is connected separately.

[0020] The present disclosure also relates to a transmitting module of a laser radar, which comprises the laser transmitting assembly as described above, and the laser transmitting assembly is configured to be connected to a power supply.

[0021] Optionally, the transmitting module further includes a voltage limiter, which is connected to both ends of the first switch or the second switch or the third switch in the laser transmitting assembly, and the voltage limiter is configured to limit the voltage across both ends of the first switch or the second switch or the third switch to be less than a preset voltage, and the preset voltage is less than the voltage of the power supply.

[0022] Optionally, the voltage limiter includes a resistor or a metal oxide semiconductor field effect transistor.

[0023] Optionally, the transmitting module further includes a bootstrap capacitor; the bootstrap capacitor is configured to be connected between a first end of the first switch, the second switch, or the third switch and a second preset voltage source.

[0024] The present disclosure also provides a laser radar, which includes a transmitting module, a receiving module and a processor as described above; the transmitting module is configured to transmit a detection beam; the receiving module is configured to receive an echo generated after the detection beam is reflected on an object and generate an electrical signal; the processor is connected to the receiving module and is configured to determine at least one of the distance and reflectivity of the object based on the electrical signal.

[0025] The present disclosure, by stacking a first driver chip, a switch chip, and a laser chip, can shorten the length of the connecting wires in the light-emitting circuit, reduce the resistance in the light-emitting circuit, increase the upper limit of the current allowed to flow through the laser, improve the electro-optical conversion efficiency of the laser in the light-emitting path, and increase the light-emitting power of the laser, so that the laser can achieve high-efficiency, high-power light emission. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure and do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0027] Figure 1 A circuit connection diagram of a laser array according to some embodiments of the present disclosure is shown.

[0028] Figure 2 Schematic diagrams of circuit connections of laser arrays according to other embodiments of the present disclosure are shown.

[0029] Figure 3 A schematic diagram of a laser emitting assembly according to some embodiments of the present disclosure is shown.

[0030] Figure 4 A schematic diagram of a laser chip according to some embodiments of the present disclosure is shown.

[0031] Figure 5 A schematic diagram of a switch chip according to some embodiments of the present disclosure is shown.

[0032] Figure 6 A schematic diagram of a first driver chip according to some embodiments of the present disclosure is shown.

[0033] Figure 7 A connection diagram of a laser, a first switch, and a first driver in some embodiments of the present disclosure is shown.

[0034] Figure 8 Schematic diagram of a laser emitting assembly according to some other embodiments of the present disclosure is shown.

[0035] Figure 9 A schematic diagram of a second driver chip according to some embodiments of the present disclosure is shown.

[0036] Figure 10 Schematic diagrams of a second driver chip according to other embodiments of the present disclosure are shown.

[0037] Figure 11 A schematic diagram of the connection between a laser and a second switch group according to some embodiments of the present disclosure is shown.

[0038] Figure 12 A circuit connection diagram of a second switch group according to some embodiments of the present disclosure is shown.

[0039] Figure 13 A schematic diagram of a laser emitting assembly according to some embodiments of the present disclosure is shown.

[0040] Figure 14 Schematic diagrams of laser chips according to other embodiments of the present disclosure are shown.

[0041] Figure 15 Schematic diagrams of laser chips according to further embodiments of the present disclosure are shown.

[0042] Figure 16 A schematic diagram of a third driver chip according to some embodiments of the present disclosure is shown.

[0043] Figure 17 A schematic diagram of connecting multiple lasers and a third switch according to some embodiments of the present disclosure is shown.

[0044] Figure 18 A schematic diagram showing the corresponding relationship between multiple lasers and a third switch according to some embodiments of the present disclosure is shown.

[0045] Figure 19 A schematic diagram of a transmitting module according to some embodiments of the present disclosure is shown.

[0046] Figure 20 A schematic diagram of the circuit structure of a transmitting module according to some embodiments of the present disclosure is shown.

[0047] Figure 21 A schematic diagram of the circuit structure of a transmitting module according to some other embodiments of the present disclosure is shown.

[0048] Figure 22 A schematic diagram of the circuit structure of a transmitting module according to some further embodiments of the present disclosure is shown.

[0049] Figure 23 A schematic diagram of the circuit structure of a transmitting module according to some further embodiments of the present disclosure is shown.

[0050] Figure 24 A schematic diagram of a lidar according to some embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0051] Hereinafter, only certain exemplary embodiments are described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present disclosure. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0052] In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the present disclosure and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present disclosure. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present disclosure, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0053] In the description of this disclosure, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, removable, or integral connections; mechanical, electrical, or intercommunication connections; direct or indirect connections through an intermediary; and internal connectivity between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure based on specific circumstances.

[0054] In this disclosure, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact via another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or diagonally above the second feature, or may simply mean that the first feature is at a higher level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or diagonally below the second feature, or may simply mean that the first feature is at a lower level than the second feature.

[0055] The disclosure below provides many different embodiments or examples for realizing different structures of the present disclosure. In order to simplify the disclosure of the present disclosure, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present disclosure. In addition, the present disclosure may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present disclosure provides examples of various specific processes and materials, but those of ordinary skill in the art will appreciate the application of other processes and / or the use of other materials.

[0056] Exemplary embodiments of the present disclosure are described below in conjunction with the accompanying drawings. It should be understood that the exemplary embodiments described herein are only used to illustrate and explain the present disclosure, and are not used to limit the present disclosure.

[0057] The electrical model of a laser can be equivalent to a diode model. The laser's luminous power can characterize the overall driving capability of the driver and laser. The laser's luminous power is positively correlated with the current passing through the laser. Increasing the upper limit of the current flowing through the laser can increase the laser's maximum luminous power. The circuit model that drives the laser to emit light can be equivalent to a model in which the power supply controls the on or off state of the laser through a switch. Switching the switch from the off state to the on state can drive the laser to emit light pulses. The connection lines between the various devices in the laser light-emitting circuit have resistance, such as the resistance of the connection line between the switch and the laser, the resistance of the connection line inside the laser chip, and the internal resistance of the switch driver. The resistance of the connection line may limit the upper limit of the current in the laser light-emitting circuit. The current density capability of the switch in the laser light-emitting circuit may also limit the upper limit of the current in the laser light-emitting circuit, limiting the maximum luminous power of the laser.

[0058] In an addressable two-dimensional laser array, as the number of addressable light-emitting regions increases, the wiring connecting each light-emitting region may grow, increasing the resistance in the light-emitting circuit, thereby limiting the upper limit of current in the laser emission circuit and the maximum light-emitting power of the laser. Increasing the number of light-emitting regions also reduces the area of ​​each light-emitting region, reducing the area of ​​the driver circuit containing the switch corresponding to each light-emitting region, reducing the current density capability of the switch, and thus limiting the upper limit of current in the laser emission circuit and the maximum light-emitting power of the laser. To increase the upper limit of current in the laser emission circuit and meet the high-power emission requirements of the light-emitting regions, the resistance introduced by the wiring in the laser emission circuit can be reduced, and the current density capability of the driver circuit that independently drives each light-emitting region can also be increased.

[0059] Figure 1 FIG1 shows a circuit connection diagram of a laser array according to some embodiments of the present disclosure. It should be noted that: Figure 1 Only one circuit connection diagram of the laser array is shown in FIG. Figure 1 The multiple lasers 101 / 601 in the embodiment can be arranged in one dimension or in two dimensions. Figure 1 As shown, the anode of the laser 101 / 601 is connected to the power supply HV, the cathode of the laser is connected to the switch K, and the switch K is connected to the switch drive circuit Q. For example, the switch K can be a field effect transistor, and the gate G (Grid) of the switch K can be connected to the switch drive circuit Q. The switch drive circuit can control the conduction or disconnection of the switch, thereby controlling whether the laser emits light. The switch drive circuit can be a switch driver or other circuit that can control the conduction or disconnection of the switch.

[0060] Figure 2 FIG1 shows a circuit connection diagram of a laser array according to some other embodiments of the present disclosure. It should be noted that: Figure 2 Only one circuit connection diagram of the laser array is shown in FIG. Figure 2 The multiple lasers (such as L11 to L44) in the laser array can be arranged in one dimension or in two dimensions. The cathodes of all or some of the lasers in the laser array can share the same cathode bus, and the anodes of the lasers sharing the same cathode bus are connected to different anode buses. For example, lasers L11, L21, L31, and L41 are connected to the cathode bus CA1, and the anodes are connected to the anode bus AN1, anode bus AN2, anode bus AN3, and anode bus AN4, respectively. Multiple lasers can also share the same anode bus, and the cathodes of the lasers sharing the same anode bus are connected to different cathode buses. For example, lasers L11, L12, L13, and L14 are connected to the anode bus AN1, and the cathodes are connected to the cathode bus CA1, cathode bus CA2, cathode bus CA3, and cathode bus CA4, respectively. The cathodes of the lasers sharing the same cathode bus are connected to the same switch K. The anodes of the lasers sharing the same anode bus are connected to the same switch K. By turning on the switch K on the anode bus side and the switch K on the cathode bus side, the corresponding connected lasers can emit light. Switch K can be connected to the switch drive circuit Q. For example, switch K can be a field-effect transistor, and the gate G of switch K can be connected to a switch drive circuit Q. The switch drive circuit can control the on / off state of the switch, thereby controlling whether the laser emits light. The switch drive circuit can be a switch driver or other circuit capable of controlling the on / off state of the switch.

[0061] The laser array of the present disclosure can achieve laser activation through single-side addressing, such as Figure 1 The circuit connection diagram shown can also be used to activate the laser by bipolar addressing, for example Figure 2 The circuit connection diagram is shown. The laser array can be a one-dimensional laser array or a two-dimensional laser array, and the present disclosure does not limit the number of lasers.

[0062] The present disclosure provides a laser emitting component with a stacked structure, which includes a laser chip, a switch chip and a first driver chip. The laser chip is integrated with a plurality of lasers, and the plurality of lasers are arranged in a two-dimensional array. The switch chip is integrated with a plurality of first switches, which are connected to the laser. The first driver chip is connected to the switch chip and is configured to control the conduction or disconnection of the first switch. The switch chip is stacked between the laser chip and the first driver chip. The present disclosure can shorten the length of the connecting line in the light-emitting circuit, reduce the resistance in the light-emitting circuit, increase the upper limit of the current allowed to flow through the laser, improve the electro-optical conversion efficiency of the laser in the light-emitting path, and improve the light-emitting power of the laser, so that the laser can achieve high-efficiency and high-power light emission.

[0063] Figure 3 A schematic diagram of a laser emitting assembly with a stacked structure according to some embodiments of the present disclosure is shown. Figure 4 shows a schematic diagram of a laser chip according to some embodiments of the present disclosure, Figure 5 shows a schematic diagram of a switch chip according to some embodiments of the present disclosure, Figure 6 shows a schematic diagram of a first driver chip according to some embodiments of the present disclosure, Figure 7 FIG1 shows a connection diagram of a laser, a first switch and a first driver in some embodiments of the present disclosure. Figures 3 to 7 As shown, the laser emission assembly 1000 includes a laser chip 100, a switch chip 200, and a first driver chip 300. The laser chip 100 integrates multiple lasers 101, which are arranged in a two-dimensional array. The switch chip 200 integrates multiple first switches 201, which are connected to the lasers 101. The first driver chip 300 is connected to the switch chip 200 and is configured to control the conduction or disconnection of the first switches 201. The switch chip 200 is stacked between the laser chip 100 and the first driver chip 300.

[0064] In some embodiments, the laser chip 100 includes a metal contact C1. The metal contact C1 is located on the surface of the laser chip 100 opposite the light-emitting surface. In other words, the metal contact C1 is located on the surface of the laser chip 100 near the switch chip 200. The laser chip 100 can be electrically connected to the switch chip 200 via the metal contact C1. In other embodiments, the metal contact C1 can also be provided on the surface of the switch chip 200 near the laser chip 100, thereby electrically connecting the switch chip 200 to the laser chip 100.

[0065] In some embodiments, the switch chip 200 may include a via (not shown in the figure), and the first driver chip 300 may be electrically connected to the switch chip 200 through the via. For example, the switch chip 200 may include a metal contact C1. The metal contact C1 may be provided on the surface of the switch chip 200 opposite to the laser chip 100. The switch chip 200 may be connected to the first driver chip 300 located on its lower side through the metal contact C1 and a lead passing through the via, or the switch chip 200 may be electrically connected to the first driver chip 300 through the metal contact C2 by pouring conductive metal into the via and forming a metal contact C2 on the surface of the switch chip 200 close to the first driver chip 300. It should be noted that the present disclosure does not limit the specific number and distribution of the metal contacts, and can be flexibly arranged according to needs.

[0066] In the laser emission component disclosed herein, the laser chip can be stacked vertically with the switch chip and the first driver chip, which can shorten the length of the connecting wires in the light-emitting circuit, reduce the resistance in the light-emitting circuit, reduce the adverse effects of the resistance introduced by the connecting wires, increase the upper limit of the current allowed to flow through the laser, increase the maximum light-emitting power of the laser, and improve the electro-optical conversion efficiency in the laser light-emitting circuit.

[0067] In some embodiments, multiple lasers 101 may form a two-dimensional laser array, such as Figure 4 In the example M*N array, M and N are positive integers. All or part of the lasers 101 in the two-dimensional laser array can be controlled individually. In some embodiments, the two-dimensional laser array may include multiple laser groups, each laser group may include at least one laser 101, and each laser group may be controlled individually. The laser 101 may be a vertical-cavity surface-emitting laser (VCSEL). The laser L may be emitted perpendicular to the top surface of the laser chip 100. A plurality of VCSELs may constitute a two-dimensional VCSEL array.

[0068] In some embodiments, the switch chip 200 may comprise III-V semiconductor materials, such as GaN, GaAs, GaSb, InAs, InSb, InAsSb, InGaAs, AlGaSb, InAlSb, AlGaAsSb, GaInAsSb, etc., which have high conductivity, can improve the current density capability of the first switch 201, can reduce the equivalent resistance of the first switch, can increase the current limit in the laser light-emitting circuit, increase the maximum light-emitting power of the laser, and improve the electro-optical conversion efficiency of the laser. For example, the first switch 201 may be a gallium nitride transistor. When the switch chip 200 (or the laser emitting assembly 1000) is applied to a laser radar, it can improve the range-finding performance of the laser radar and reduce the total power consumption of the laser radar.

[0069] In some embodiments, the switch chip 200 may include a metal oxide semiconductor material, such as a silicon-based semiconductor material. For example, the first switch 201 may be a metal oxide semiconductor field-effect transistor (MOSFET). For example, the first switch 201 may be an N-type metal oxide semiconductor (NMOS) transistor or a P-type metal oxide semiconductor (PMOS) transistor. The first switch 201 may function as a low-side switch or a high-side switch.

[0070] In some embodiments, the switch chip 200 integrates a plurality of first switches 201, and the plurality of first switches 201 may be arranged in a two-dimensional array, such as Figure 5 In the example M*N array, M and N are positive integers. The first switch 201 can be connected to at least one laser 101. For example, the first switches 201 are connected to the lasers 101 in a one-to-one correspondence, with each first switch 201 connected to one of the lasers 101 to control the operation of its corresponding laser 101. When the first switch 201 is controlled to be turned on, current flows through the corresponding laser 101, causing it to emit light. For another example, the first switch 201 can be connected to multiple lasers 101. When the first switch 201 is controlled to be turned on, the multiple lasers connected to it are driven to emit light.

[0071] In some embodiments, the first driver chip 300 may include multiple first drivers 301 (or driver circuits). The first driver chip 300 is, for example, a complementary metal oxide semiconductor (CMOS) chip. The first driver 301 is connected to the first switch 201 to control the on / off state of the first switch 201. The first driver 301 may be a gate driver, and the first driver 301 may be connected to the gate G of the first switch 201. For example, the first switch 201 may be a gallium nitride transistor, and the first driver 301 may be connected to the gate of the gallium nitride transistor. For another example, the first switch 201 may be a MOSFET, and the first driver 301 may be connected to the gate of the MOSFET. When the first driver 301 controls the first switch 201 to be on, the laser 101 connected to the first switch 201 may emit light. When the first driver 301 controls the first switch 201 to be off, the laser 101 connected to the first switch 201 does not emit light. Optionally, the first driver 301 may also be connected to the source or drain of the first switch 201 , which may be flexibly configured according to actual conditions in practical applications, and all of these are within the scope of protection of the present disclosure.

[0072] In some embodiments, the first driver chip 300 may include a plurality of first drivers 301. The plurality of first drivers 301 may be arranged in a two-dimensional array, such as Figure 6 In the example M*N array, M and N are positive integers. The first driver 301 can be connected to at least one first switch 201. For example, the first drivers 301 can be connected to the first switches 201 in a one-to-one correspondence, with each first driver 301 connected to one of the first switches 201 to control the on / off state of the connected first switch 201. For another example, the first driver 301 can be connected to multiple first switches 201 to control the on / off state of the connected first switches 201.

[0073] Figure 7 FIG1 shows a connection diagram of a laser, a first switch and a first driver in some embodiments of the present disclosure. Figure 7 As shown, the anode of the laser 101 is connected to the high voltage source HV, and the cathode is connected to the first switch 201 and grounded through the first switch 201. The first driver 301 is connected to the gate G of the first switch 201 and controls the on and off of the first switch 201. When the first driver 301 controls the first switch 201 to be on, the laser 101 connected thereto emits light. When the first driver 301 controls the first switch 201 to be off, the laser 101 connected thereto does not emit light.

[0074] In some embodiments, the laser chip, the switch chip, and the first driver chip can all be partitioned. A laser can serve as a light-emitting partition, a first switch can serve as a switch partition, and a first driver can serve as a driver partition. For example, a driver partition can be connected to a switch partition, and a switch partition can be connected to a light-emitting partition. For another example, a driver partition can be connected to a switch partition, and a switch partition can be connected to multiple light-emitting partitions. For another example, a driver partition can be connected to multiple switch partitions, and a switch partition can be connected to one or more light-emitting partitions. The first driver of the driver partition can control the independent drive or overall drive of the laser of the corresponding light-emitting partition by controlling the conduction or disconnection of the first switch of the corresponding switch partition.

[0075] To achieve higher electro-optical conversion efficiency for the laser, the resistance of the connecting lines between the various components in the laser's light-emitting circuit can be reduced. By stacking the switch chip above the first driver chip, the drive circuit can be shortened, reducing the resistance of the connecting lines in the laser's light-emitting path. This reduces energy loss caused by the resistance of the connecting lines in the laser's light-emitting circuit, thereby improving the laser's electro-optical conversion efficiency. Reducing the resistance of the connecting lines in the laser's light-emitting circuit can also increase the upper limit of the current allowed to pass through the laser, thereby increasing the laser's maximum light-emitting power.

[0076] In order to further increase the maximum luminous power of the laser, the driving current provided to the laser can be increased. However, due to the large number of luminous partitions of the laser chip and the small area of ​​a single luminous partition, the requirements for the current density capability of a single switch partition that independently drives a single luminous partition under the stacking structure are greatly increased. The laser emitting component disclosed in the present invention can increase the area of ​​the first switch in a single switch partition of the switch chip by stacking the switch chip and the first driver chip, improve the current density capability of the first switch, increase the current upper limit in the laser light-emitting circuit, increase the maximum luminous power of the laser, and realize high-efficiency, high-power luminescence of an addressable two-dimensional laser array, so that the light pulse waveform emitted by the laser is sharper, which is beneficial to improving the detection performance of the laser radar, such as the ranging capability, anti-interference capability, and accuracy of the detection results.

[0077] like Figure 7As shown, to increase the current of the light-emitting sub-area (e.g., laser 101), the anode of laser 101 is connected to a high-voltage source HV (e.g., 30V, 40V, etc.). To ensure normal operation of the circuit, the first driver 301 needs to have a high voltage resistance. Some first driver chips 300 use MOSFETs on silicon-based CMOS chips as the laser switch. MOSFETs typically have low current density capabilities under high voltages. The current density of a MOSFET is negatively correlated with its voltage resistance. The higher the voltage resistance of the MOSFET, the lower the current density, the lower the upper limit of the current that the MOSFET can pass, the lower the upper limit of the current that can flow through the laser, and the lower the maximum luminous power of the laser. The current density of the MOSFET is lower than the current density required by a laser (e.g., a VCSEL) at its highest luminous power. When the switching sub-area and the light-emitting sub-area have the same area, the current density of the MOSFET is approximately 25% of that of the laser. Given the same area, the MOSFET's higher equivalent resistance limits the maximum current that can flow through the laser, reducing the laser's electro-optical conversion efficiency and limiting the laser's maximum luminous power. Compared with silicon-based CMOS chips, under the same voltage resistance requirements, the gallium nitride transistors used in the switch chips in some embodiments of the present disclosure have a higher current density and better high voltage resistance, which can meet the voltage resistance requirements and current density requirements at the same time, reduce the contradiction between the driving current capability and voltage resistance of the first driver chip, make up for the problem of insufficient driving current of the first driver chip, increase the upper limit of the current allowed to flow through the laser, improve the electro-optical conversion efficiency of the laser in the light-emitting path, and increase the maximum light-emitting power of the laser, so that the laser can achieve high-efficiency and high-power light emission.

[0078] The present disclosure also provides another laser emission assembly having a stacked structure. The laser emission assembly includes a laser chip and multiple second driver chips. The laser chip integrates multiple lasers, and the multiple lasers are arranged in a two-dimensional array. Multiple second driver chips are connected to the laser chip. The second driver chip integrates multiple second switches. At least one second switch in a second driver chip is connected to at least one second switch in another second driver chip. The multiple second driver chips are stacked, and the laser chip is stacked on the multiple second driver chips.

[0079] Figure 8 A schematic diagram of another laser emitting assembly with a stacked structure according to some embodiments of the present disclosure is shown. Figure 9 shows a schematic diagram of a second driver chip according to some embodiments of the present disclosure, Figure 10 shows a schematic diagram of a second driver chip according to some other embodiments of the present disclosure, Figure 11 shows a schematic diagram of the connection between a laser and a second switch group according to some embodiments of the present disclosure, Figure 12FIG. 1 shows a circuit connection diagram of a second switch group according to some embodiments of the present disclosure. Figure 4 、 Figures 8 to 12 As shown, the laser emitting assembly 2000 includes a laser chip 100 and a plurality of second driving chips 400 ( Figure 8 4 second driver chips are shown as an example, and other numbers greater than or equal to 2 may also be used). Multiple second driver chips 400 are stacked, and the laser chip 100 is stacked on the multiple second driver chips 400. The laser chip 100 integrates multiple lasers 101, and the multiple lasers 101 are arranged in a two-dimensional array, such as Figure 4 In the exemplary M*N array, M and N are positive integers. Multiple second driver chips 400 are connected to the laser chip 100. Multiple second switches 401 are integrated into the second driver chips 400. At least one second switch 401 in a second driver chip 400 is connected to at least one second switch 401 in another second driver chip 400. At least one second switch 401 in a second driver chip 400 is connected to at least one second switch 401 in another second driver chip 400 to form a second switch group 401B.

[0080] In some embodiments, the second driver chip 400 includes a plurality of second switches 401, and the plurality of second switches 401 may be arranged in a two-dimensional array, such as Figure 9 The example is an M*N array, where M and N are positive integers.

[0081] In some embodiments, the second driver chip 400 may be a MOSFET chip, such as a silicon-based MOSFET chip. The second switch 401 may include a metal oxide semiconductor field effect transistor (MOSFET). For example, the second switch 401 may be an N-type metal oxide semiconductor (NMOS) transistor or a P-type metal oxide semiconductor (PMOS) transistor. The second switch 401 may function as a low-side switch or a high-side switch. The laser 101 may be a VCSEL. The laser light L may be emitted perpendicular to the top surface of the laser chip 100.

[0082] In some embodiments, as Figure 10As shown, at least one of the plurality of second driver chips 400 may further include a plurality of second drivers 402 (or driver circuits). For example, among the plurality of second driver chips 400, one or more of the second driver chips 400 include a plurality of second switches 401 and a plurality of second drivers 402, and the remaining second driver chips 400 include only a plurality of second switches 401 but no second drivers 402. For another example, among the plurality of second driver chips 400, each second driver chip 400 includes a plurality of second switches 401 and a plurality of second drivers 402. Figure 9 When the second driver chip 400 only includes the second switch 401 but does not include the second driver 402, the second driver chip 400 may include a III-V semiconductor material such as GaN. The second switch 401 may be a gallium nitride transistor, similar to Figure 5 Schematic diagram of the switch chip 200 and the first switch 201. Figure 10 When the second driver chip 400 includes a second switch 401 and a second driver 402, the second driver chip 400 can be a MOSFET chip or a silicon-based CMOS chip, and the second switch 401 can be a MOSFET. The second driver 402 is connected to the second switch 401. The second driver 402 is configured to control the conduction or disconnection of the second switch 401. The second driver 402 can be a gate driver. The second driver 402 can be connected to the gate G of the second switch 401 to control the conduction or disconnection of the second switch 401. Optionally, the second driver 402 can also be connected to the source or drain of the second switch 401. In actual applications, this can be flexibly set according to actual conditions.

[0083] In some embodiments, at least one second switch 401 in a second driver chip 400 is connected in parallel with at least one second switch 401 in another second driver chip 400. Multiple second driver chips 400 include at least one second switch group 401B, each second switch group 401B including multiple parallel-connected second switches 401. Laser emitting assembly 200 includes at least one light emitting path, which includes laser 101 and second switch group 401B, with the laser connected to second switch group 401B.

[0084] For example, Figure 11 The light emission path corresponding to one of the lasers is shown. Figure 12 FIG. 1 shows a schematic diagram of the circuit connection of the second switch group. Figure 11 and Figure 12As shown, a laser 101 is connected to a second switch group 401B, which is in turn connected to a second driver 402. The second switch group 401B includes a plurality of, for example, four, parallel second switches 401, which may be from four second driver chips 400. In this light-emitting path, the second switch group 401B is connected in series with the laser 101, for example, connected to the cathode of the laser 101. The four second switches 401 in the second switch group 401B form a shunt structure that can share the current flowing through the laser 101, thereby increasing the upper limit of the current allowed to pass through the laser 101 and enabling the laser to emit light with high efficiency and high power.

[0085] It should be noted that the multiple second switches in the second switch group can come from all the second driver chips in the laser emission assembly, or from some of the second driver chips in the laser emission assembly. For example, the laser emission assembly includes 3 second driver chips, the second switch group can include 3 second switches, and the 3 second switches can come from 3 second driver chips respectively. For another example, the laser emission assembly includes 5 second driver chips, the second switch group can include 3 second switches, and the 3 second switches can come from 3 second driver chips respectively, etc. The present disclosure does not limit the number of second driver chips, nor does it limit the specific number and source of the second switches in the second switch group, which can be flexibly adjusted according to actual conditions.

[0086] In some embodiments, multiple second switches of the same second switch group are configured to be turned on or off synchronously. In the same light emitting path, multiple parallel second switches corresponding to one laser can be turned on or off synchronously. For example, Figure 11 In the exemplary light-emitting path, the four second switches 401 of the second switch group 401B can be turned on or off synchronously. In this light-emitting path, the four parallel second switches 401 corresponding to the laser 101 can be turned on or off synchronously. This example of a second switch group 401B including four second switches is used herein and does not constitute a limitation of the present disclosure.

[0087] In one light emitting path, the second switch group 401B may be connected to the second driver 402 , and the second driver 402 may control the plurality of second switches 401 in the second switch group 401B to be turned on or off synchronously.

[0088] For example, in one light-emitting path, multiple second switches 401 from the same second switch group 401B can be connected to the same second driver 402. The second driver 402 can be connected to the gates of the multiple second switches 401 connected in parallel, and can control the multiple second switches 401 connected in parallel to be turned on or off synchronously, so as to control whether the laser 101 connected to the multiple second switches 401 connected in parallel emits light.

[0089] For another example, in a light-emitting path, multiple second switches 401 from the same second switch group 401B can each be connected to a different second driver 402. One second switch 401 can be connected to one second driver 402. Each second driver 402 can be connected to the gate of its corresponding second switch 401. Each second driver 402 controls the on / off state of its corresponding second switch 401. Multiple second drivers 402 control the simultaneous on / off state of multiple second switches 401 in the second switch group 401B.

[0090] For another example, in a light-emitting path, multiple second switches 401 from the same second switch group 401B can be partially connected to the same second driver 402 and partially connected to other second drivers 402. Each second driver 402 can be connected to the gate of its corresponding second switch 401. Each second driver 402 can control the on or off state of its corresponding second switch 401. The multiple second drivers 402 control the multiple second switches 401 in the second switch group 401B to be turned on or off synchronously.

[0091] In some embodiments, the second driver chip 400 may include a via hole. The second driver chip 400 may be electrically connected to the laser chip 100 through the via hole. For example, Figure 8 The second driver chip 400 shown in the figure includes a via (not shown), through which a lead 1 can be passed, or a conductive metal can be poured into the via to form a metal contact C on the surface of the second driver chip 400. The lead 1 or the metal contact C can be used to form an electrical connection between the laser chip 100 and the corresponding second driver chip 400. It is understood that the surface of the laser chip 100 close to the second driver chip 400 (the surface opposite the light-emitting surface) can also include a metal contact C to electrically connect to the second driver chip 400.

[0092] In some embodiments, the number of stacked second driver chips can be appropriately adjusted based on the current requirements of the laser chip and the current supply capabilities of the second driver chip. The more stacked second driver chips there are, the smaller the equivalent resistance of the multiple second switches connected in parallel, the greater the upper limit of current allowed to flow through the laser, the higher the maximum luminous power of the laser, and the higher the electro-optical conversion efficiency. By increasing the number of stacked second driver chips, the problem of insufficient driving current in a single layer of second driver chips can be compensated, achieving high-efficiency, high-power light emission in a two-dimensional laser array.

[0093] The present disclosure also provides another laser emitting assembly with a stacked structure. The laser emitting assembly includes a laser chip and a third driver chip. The laser chip integrates multiple lasers, which are arranged in a two-dimensional array. The third driver chip is connected to the laser chip, and the third driver chip integrates multiple third switches and multiple third drivers. The third switch connects to multiple lasers, and the laser chips are stacked on the third driver chip.

[0094] Figure 13 A schematic diagram of a laser emitting assembly with a stacked structure according to some embodiments of the present disclosure is shown. Figure 14 shows a schematic diagram of a laser chip according to some other embodiments of the present disclosure, Figure 15 shows a schematic diagram of a laser chip according to some further embodiments of the present disclosure, Figure 16 shows a schematic diagram of a third driver chip according to some embodiments of the present disclosure, Figure 17 shows a schematic diagram of connecting multiple lasers and a third switch according to some embodiments of the present disclosure, Figure 18 FIG. 1 shows a schematic diagram of the corresponding relationship between multiple lasers and a third switch according to some embodiments of the present disclosure. Figures 13 to 18 As shown, the laser emission assembly 3000 includes a laser chip 600 and a third driver chip 500. The laser chip 600 integrates multiple lasers 601, which are arranged in a two-dimensional array. The third driver chip 500 is connected to the laser chip 600, and the third driver chip 500 integrates multiple third switches 501 and multiple third drivers 502. Among them, the third switch 501 is connected to the multiple lasers 601. The laser chip 600 is stacked on the third driver chip 500.

[0095] In some embodiments, the third driver chip 500 may be a MOSFET chip, such as a silicon-based MOSFET chip. The third switch 501 may be arranged in a two-dimensional array. The third switch 501 may include a metal oxide semiconductor field effect transistor (MOSFET). For example, the third switch 501 may be an NMOS transistor or a PMOS transistor. The third switch 501 may function as a low-side switch or a high-side switch. The laser 601 may be arranged in a two-dimensional array. The laser 601 may be a VCSEL. The laser light L may be emitted perpendicular to the top surface of the laser chip 600.

[0096] In some embodiments, multiple lasers may be connected to the same third switch. Among the multiple lasers connected to the same third switch, one of the cathode and anode thereof is connected to the same third switch, and the other of the cathode and anode thereof is connected in common.

[0097] For example, Figure 14 and Figure 16As shown, among the multiple lasers 601 connected to the same third switch 501, the multiple lasers 601 can share a common anode, and the cathodes of the multiple lasers 601 can be connected to the same third switch 501. For another example, the multiple lasers 601 can share a common cathode, and the anodes of the multiple lasers 601 can be connected to the same third switch 501. By turning on the third switch 501, the multiple lasers 601 connected to the same third switch 501 can emit light simultaneously.

[0098] In some embodiments, among the plurality of lasers connected to the same third switch, one of the cathode and anode thereof is connected to the same third switch, and the other of the cathode and anode thereof is connected separately.

[0099] For example, Figure 15 and Figure 16 As shown, among the multiple lasers 601 connected to the same third switch 501, the cathodes of the multiple lasers 601 can be connected to the same third switch 501, and the anodes of the multiple lasers 601 can be connected to different anode buses. Taking an M*N laser array as an example, where M and N are positive integers, the cathodes of every four lasers 601 can be connected to the same third switch 501, and the anodes of these four lasers 601 can be connected to four anode buses respectively. This example only uses four lasers and does not constitute a limitation of the present disclosure. By activating the anode buses and the third switch 501 of the lasers 601, individual control of the lasers 601 can be achieved.

[0100] For another example, among multiple lasers 601 connected to the same third switch 501, the anodes of the multiple lasers 601 can be connected to the same third switch 501, and the cathodes of the multiple lasers 601 can be connected to different cathode buses. Taking an M*N laser array as an example, where M and N are positive integers, the anodes of a column of M lasers 601 can be connected to the same third switch 501, and the cathodes can be connected to M cathode buses respectively. By activating the cathode buses of the lasers 601 and the third switches 501, individual control of the lasers 601 can be achieved.

[0101] The third switch 501 is connected to a third driver 502. The third driver 502 can control the on / off state of the third switch 501 to which it is connected. The third driver 502 can be a gate driver and can be connected to the gate G of the third switch 501 to control the on / off state of the third switch 501, thereby controlling whether a single laser 601 among multiple lasers 601 connected to the same third switch 501 emits light or not. Optionally, the third driver 502 can also be connected to the source or drain of the third switch 501. In practical applications, this can be flexibly configured based on actual conditions.

[0102] Figure 17FIG. 1 shows a schematic diagram of the connection between multiple lasers and a third switch according to some embodiments of the present disclosure. Figure 17 As shown, the cathodes of multiple (for example, 4) lasers 601 can be connected to the same third switch 501, and the anodes of multiple (for example, 4) lasers 601 can be connected to different anode buses HV1, HV2, HV3, and HV4. It should be noted that Figure 17 The example of four lasers is used only and does not constitute a limitation of the present disclosure. The lasers connected to the same third switch can be all lasers in the laser array, or a portion of the lasers. Different lasers not connected to the same third switch can be connected to the same anode bus or to different anode buses. Figure 17 , multiple lasers 601 may be connected to a common cathode. Multiple lasers 601 may also be connected to a common anode. The anodes of the multiple lasers 601 may be connected to the same third switch, and the cathodes may be connected to different cathode buses.

[0103] exist Figures 8 to 12 In the laser emitting assembly 2000 of the embodiment, one second switch 401 in the second driver chip 400 corresponds to one laser 101, and the area of ​​one second switch 401 corresponds to the area of ​​one laser 101. For an M*N two-dimensional laser array, if one second switch 401 corresponds to one laser 101, the number of second switches 401 in the second driver chip 400 is M*N, where M and N are positive integers.

[0104] Figures 13 to 18In the laser emission assembly 3000 of the embodiment, one third switch 501 in the third driver chip 500 can correspond to four lasers 601, and the area of ​​one third switch 501 corresponds to the sum of the areas of the four lasers 601. For an M*N two-dimensional laser array, if one third switch 501 corresponds to four lasers 601, that is, every four lasers 601 share one third switch 501, then the number of third switches 501 in the third driver chip 500 is (M / 4)*N, where M and N are positive integers. Sharing one switch for multiple lasers can reduce the number of switches in the driver chip, increase the occupied area of ​​each switch, and improve the current density of the switch. When one third switch corresponds to more lasers, the area of ​​one third switch corresponds to the sum of the areas of more lasers. The number of third switches required by the third driver chip is smaller, which can further increase the occupied area of ​​the switch and further improve the current density of the switch. Reducing the number of switches can not only improve the current driving capability of the third driver chip, but also reduce costs. Increasing the area occupied by a switch can increase the current density of the switch, increase the upper limit of the current allowed to flow through the laser, improve the electro-optical conversion efficiency of the laser in the light-emitting path, and increase the maximum light-emitting power of the laser, so that the laser can emit light with high power and high efficiency.

[0105] In summary, the laser emission assembly 1000 / 2000 / 3000 disclosed in the present invention has been introduced. In practical applications, appropriate laser emission assemblies can be selected according to different needs. By stacking multiple layers of chips, the length of the connecting wires of the laser emission assembly can be shortened by an order of magnitude, such as from the order of mm to the order of 0.1 mm, which greatly reduces the adverse effects of the parasitic effects (parasitic resistance, parasitic inductance, etc.) of the connecting wires, can improve the driving capability, increase the upper limit of the current flowing through the laser, improve the electro-optical conversion efficiency and maximum luminous power of the laser, reduce the crosstalk of the circuit, and help improve the luminous quality of the laser and help reduce the occupied area of ​​the laser emission assembly.

[0106] The present disclosure also relates to a transmitting module of a laser radar. Figure 19 Schematic diagram of a transmitting module according to some embodiments of the present disclosure is shown. Figure 19 As shown, the transmitting module 4000 includes any one of the laser transmitting components 1000 / 2000 / 3000 described above. The laser transmitting component 1000 / 2000 / 3000 is configured to be connected to a power source (such as Figure 20 The transmitting module disclosed herein, by adopting the above-mentioned laser transmitting assembly, can improve the maximum luminous power and electro-optical conversion efficiency of the transmitting module and reduce the occupied area of ​​the transmitting module.

[0107] Figure 20 FIG. 1 shows a schematic diagram of the circuit structure of a transmitting module according to some embodiments of the present disclosure. Figure 20 As shown, the anode of the laser 101 / 601 is connected to the power supply HV, and the cathode is connected to the first switch 201 or the second switch 401 or the third switch 501. Before the laser 101 / 601 emits light, the voltage drop borne by the first switch 201 or the second switch 401 or the third switch 501 is HV. In order to increase the luminous intensity (or luminous power) of the laser, the power supply HV can be set to a higher value, but the withstand voltage requirement for the first switch 201 or the second switch 401 or the third switch 501 will be increased, limiting the current capacity (current density) of the first switch 201 or the second switch 401 or the third switch 501. In some embodiments of the present disclosure, the voltage drop borne by the first switch 201 or the second switch 401 or the third switch 501 can be reduced by providing a preset bias voltage to the laser, thereby reducing the voltage requirement for the withstand voltage of the first switch 201 or the second switch 401 or the third switch 501 and improving the current density of the first switch 201 or the second switch 401 or the third switch 501.

[0108] In some embodiments of the present disclosure, the transmitting module may further include a voltage limiter, which may be connected to both ends of the first switch, the second switch, or the third switch in the laser transmitting assembly. The voltage limiter is configured to limit the voltage across both ends of the first switch, the second switch, or the third switch to be less than a preset voltage, and is configured to limit the preset voltage to be less than the voltage of the power supply. Figure 21 and Figure 22 The voltage limiters according to different embodiments of the present disclosure are shown respectively. Figure 21 and Figure 22 Detailed description.

[0109] In some embodiments of the present disclosure, Figure 21As shown, the voltage limiter may include a resistor 4444. Resistor 4444 is connected in parallel across the first switch 201, the second switch 401, or the third switch 501. When the laser 101 / 601 is not emitting light, the first switch 201, the second switch 401, or the third switch 501 is disconnected, and current flows through resistor 4444. Resistor 4444 divides the voltage with the laser 101 / 601, causing the voltage across resistor 4444 to be less than a preset voltage. This also causes the voltage across the first switch 201, the second switch 401, or the third switch 501 to be less than a preset voltage, which is less than the power supply voltage HV. It should be noted that the specific magnitude of the preset voltage is related to the voltage withstand capability of the first switch, the second switch, or the third switch, and can be determined based on actual conditions. When the laser is not emitting light, the current in the circuit is less than the current required for the laser to emit light. When laser 101 / 601 emits light, first switch 201, second switch 401, or third switch 501 is turned on, and its on-resistance is very low. Current flows through first switch 201, second switch 401, or third switch 501, further reducing the voltage across first switch 201, second switch 401, or third switch 501. By providing resistor 4444, the voltage across first switch 201, second switch 401, or third switch 501 can be reduced, thereby lowering the withstand voltage requirements for first switch 201, second switch 401, or third switch 501, improving its current density capability, and increasing the upper limit of current flowing through laser 101 / 601. This increases the upper limit of current of the transmitting module, thereby improving the maximum luminous power and electro-optical conversion efficiency of the transmitting module. Optionally, resistor 4444 can be an adjustable resistor.

[0110] In other embodiments of the present disclosure, Figure 22 As shown, the voltage limiter may include a metal oxide semiconductor field effect transistor 4445. The metal oxide semiconductor field effect transistor 4445 is connected in parallel across the first switch 201, the second switch 401, or the third switch 501. By controlling the gate voltage of the metal oxide semiconductor field effect transistor 4445, the resistance between the source and the drain of the metal oxide semiconductor field effect transistor 4445 can be adjusted, thereby adjusting the voltage across the first switch 201, the second switch 401, or the third switch 501. The principle is similar to Figure 21 The embodiments shown are similar and will not be described again here.

[0111] By setting the voltage limiter, such as Figure 21 and Figure 22As shown, when a preset bias voltage is provided to the laser 101 / 601 so that it is biased near the voltage threshold Vth (a laser such as a VCSEL does not emit light below the voltage threshold Vth), the voltage drop Vov that the first switch 201 or the second switch 401 or the third switch 501 can withstand is (HV-Vth). Compared with not providing a preset bias voltage to the laser, the voltage drop borne by the first switch 201 or the second switch 401 or the third switch 501 can be reduced from HV to (HV-Vth). Reducing the voltage drop of the first switch 201 or the second switch 401 or the third switch 501 can reduce the withstand voltage requirement of the first switch 201 or the second switch 401 or the third switch 501, thereby increasing the current density of the first switch 201 or the second switch 401 or the third switch 501, improving the current driving capability of the light-emitting circuit, increasing the current flowing through the laser, and improving the maximum light-emitting power and electro-optical conversion efficiency of the laser, so that the laser can emit light with high power and high efficiency.

[0112] When the first, second, or third switch is not conducting, the voltage limiter can limit the voltage across the laser to less than a voltage threshold Vth, preventing the laser from emitting light before the first, second, or third switch is conducting. It should be noted that the specific value of the voltage threshold Vth is related to the voltage withstand capability of the laser and can be determined based on actual conditions.

[0113] In some embodiments, the transmitter module 4000 may also include a bootstrap capacitor. The operating principle of the bootstrap capacitor is based on the characteristic that the voltage across the capacitor cannot change suddenly. When the voltage across the capacitor is maintained at a certain level, by increasing the voltage at the negative terminal of the capacitor, the voltage at the positive terminal will maintain the original voltage difference with the negative terminal, which effectively "lifts" the voltage at the positive terminal. This bootstrap process causes the capacitor discharge voltage to be superimposed on the power supply voltage, thereby raising the voltage level of the entire system.

[0114] Figure 23 FIG. 1 shows a schematic diagram of the circuit structure of a transmitting module according to some embodiments of the present disclosure. Figure 23 As shown, the transmitting module 4000 includes a bootstrap capacitor C. The bootstrap capacitor C can be connected between the first end of the first switch 201 or the second switch 401 or the third switch 501 (such as the end a in the figure) and the second preset voltage source Vb. It should be noted that the "first end" here can be the end of the first switch 201 or the second switch 401 or the third switch 501 away from the laser 101 / 601 (such as the end a in the figure). It should be understood that the "first end" can also be the end of the first switch 201 or the second switch 401 or the third switch 501 close to the laser 101 / 601 (such as the end b in the figure). The "connection" here can be through other devices (for example, Figure 23The switches K1 and K2 shown in FIG. 1 and FIG. 2 may be connected (the switches K1 and K2 may be either on or off). Optionally, the “connection” here may also be a direct connection without going through other devices, depending on the actual situation.

[0115] In some embodiments, as Figure 23 As shown, one end of the bootstrap capacitor C is connected to the first end (end a) of the first switch 201 or the second switch 401 or the third switch 501 through the switch K1, and the other end of the bootstrap capacitor is connected to the second preset voltage source Vb through the switch K2. The transmitting module 4000 may also include switches K3, K4, and K5. Switch K3 is connected to the cathode of the laser emitting assembly 1000 / 2000 / 3000, and the laser emitting assembly 1000 / 2000 / 3000 is grounded through the switch K3. Switches K4 and K5 can be connected to the left and right ends of the bootstrap capacitor C. It can be understood that Figure 23 Switches K1 and K4 can be replaced by a single-pole double-throw switch, and switches K2 and K5 can also be replaced by a single-pole double-throw switch.

[0116] When switch K3 is turned on, similar to Figure 20 , the peak current value of the laser 101 / 601 is (HV-Vth) / R, where R is the total resistance in the light emitting path.

[0117] When switches K2 and K4 are on and switches K1 and K5 are off, the preset voltage source Vb can charge the bootstrap capacitor C. After reaching steady state, the voltage between the left and right terminals of the bootstrap capacitor C reaches Vb. When switches K1 and K5 are on, the right terminal of the bootstrap capacitor C is grounded. Due to the characteristic that the voltage across the capacitor cannot change suddenly, the voltage at the left terminal of the bootstrap capacitor C becomes -Vb. When the first switch 201, the second switch 401, or the third switch 501 is turned on and the laser 101 / 601 is driven to emit light, the bootstrap capacitor C can provide the laser 101 / 601 with a reverse pulse -Vb, so that the transient voltage difference of the laser 101 / 601 in the light-emitting path is HV-(-Vb)=(HV+Vb). The transient current value of the laser 101 / 601 in the light-emitting path is: (HV+Vb-Vth) / R, R=Rsw+Rlaser+Rline, where R is the total resistance in the light-emitting path, Rsw is the equivalent resistance of the first switch 201, the second switch 401, or the third switch 501, Rlaser is the equivalent resistance after the laser is turned on, and Rline is the equivalent resistance of the connecting wire in the circuit. Without increasing the withstand voltage of the switch, the use of the transient negative pulse solution can increase the transient current of the laser, increase the peak current of the laser, and increase the maximum light-emitting power of the laser.

[0118] The present disclosure also provides a laser radar. Figure 24Schematic diagram of a laser radar according to some embodiments of the present disclosure is shown. Figure 24 As shown, the laser radar 5000 includes the transmitting module 4000, the receiving module 5300 and the processor 5600 as described above. The transmitting module 4000 includes any one of the laser transmitting assemblies 1000 / 2000 / 3000 as described above. The transmitting module 4000 is configured to transmit a detection beam Light. The receiving module 5300 is configured to receive the echo Light' generated after the detection beam Light is reflected on the object OB and generate an electrical signal. The processor 5600 is connected to the receiving module 5300 and is configured to determine at least one of the distance and reflectivity of the object OB based on the electrical signal.

[0119] In some embodiments, the processor 5600 is further connected to the transmitting module 4000 and configured to control the operation of the transmitting module 4000. In some embodiments, the processor 5600 can also be configured to control the operation of the laser transmitting assembly 1000 / 2000 / 3000.

[0120] Optionally, the receiving module 5300 may include one or more detectors (not shown), and the multiple detectors may be arranged in a one-dimensional array or a two-dimensional array. The detectors may include one or more of a single photon avalanche diode (SPAD), a silicon photomultiplier (SiPM), and an avalanche photodiode (APD).

[0121] Optionally, the processor 5600 includes a central processing unit (CPU), and may also include other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., depending on actual conditions.

[0122] Optionally, the laser radar disclosed in the present invention may be a solid-state laser radar or a mechanical scanning laser radar.

[0123] The laser radar disclosed herein, by adopting the above-mentioned transmitting module, can improve the current driving capability, realize high-power, high-efficiency, narrow-pulse laser emission, improve the laser radar's detection performance such as ranging capability, accuracy, and anti-interference capability, and reduce the size of the laser radar.

[0124] It should be noted that although several modules of the lidar are mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more modules described above can be implemented in a single module. Conversely, the features and functions of a single module described above can be further divided and embodied by multiple modules.

[0125] Finally, it should be noted that the above descriptions are merely some embodiments of the present disclosure and are not intended to limit the present disclosure. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present disclosure shall be included within the scope of protection of the present disclosure.

Claims

1. A laser emitting assembly with a stacked structure, characterized in that: The laser emission assembly includes: a laser chip, in which a plurality of lasers are integrated, and the plurality of lasers are arranged in a two-dimensional array; a switch chip in which a plurality of first switches are integrated, wherein the laser is connected to the first switches; and a first driver chip, connected to the switch chip and configured to control the on or off of the first switch; Wherein, the switch chip is stacked between the laser chip and the first driver chip.

2. The laser emitting assembly according to claim 1, characterized in that: The first driving chip includes a plurality of first drivers, wherein the first switches are connected to the first drivers, and the first drivers are configured to control the on or off of the first switches.

3. The laser emitting assembly according to claim 2, characterized in that: The laser comprises a vertical cavity surface emitting laser; the first switch comprises a gallium nitride transistor; and the first driver is connected to a gate of the gallium nitride transistor.

4. The laser emitting assembly according to any one of claims 1 to 3, characterized in that: The laser chip includes metal contacts, which are located on a surface opposite to a light-emitting surface of the laser chip. The laser chip is electrically connected to the switch chip via the metal contacts.

5. The laser emitting assembly according to any one of claims 1 to 3, characterized in that: The switch chip includes a via hole, and the first driver chip is electrically connected to the switch chip through the via hole.

6. A laser emission assembly with a stacked structure, characterized in that: The laser emission assembly includes: a laser chip, in which a plurality of lasers are integrated, and the plurality of lasers are arranged in a two-dimensional array; a plurality of second driver chips, the plurality of second driver chips being connected to the laser chip, the second driver chips being integrated with a plurality of second switches; at least one second switch in the second driver chip being connected to at least one second switch in other second driver chips; The plurality of second driving chips are stacked, and the laser chip is stacked on the plurality of second driving chips.

7. The laser emitting assembly according to claim 6, characterized in that: The laser includes a vertical cavity surface emitting laser; the second switch includes a metal oxide semiconductor field effect transistor.

8. The laser emitting assembly according to claim 6, characterized in that: At least one of the plurality of second driving chips further includes a plurality of second drivers, and the second drivers are configured to control the on or off of the second switch.

9. The laser emitting assembly according to claim 6, characterized in that: At least one second switch in the second driver chip is connected in parallel to at least one second switch in other second driver chips; The plurality of second driving chips include a plurality of second switch groups, and the second switch groups include a plurality of second switches connected in parallel; The laser emitting assembly includes at least one light emitting path, the light emitting path includes the laser and the second switch group, and the laser is connected to the second switch group.

10. The laser emitting assembly according to claim 9, characterized in that: The plurality of second switches in the same second switch group are configured to be turned on or off synchronously.

11. The laser emitting assembly according to any one of claims 6 to 9, characterized in that: The second driver chip includes a via hole, and the second driver chip is electrically connected to the laser chip through the via hole.

12. A laser emitting assembly with a stacked structure, characterized in that: The laser emission assembly includes: A laser chip, in which a plurality of lasers are integrated, wherein the plurality of lasers are arranged in a two-dimensional array; A third driver chip, connected to the laser chip, wherein the third driver chip integrates a plurality of third switches and a plurality of third drivers; The third switch is connected to a plurality of the lasers, and the laser chips are stacked on the third driver chip.

13. The laser emitting assembly according to claim 12, characterized in that: The laser includes a vertical cavity surface emitting laser; and the third switch includes a metal oxide semiconductor field effect transistor.

14. The laser emitting assembly according to claim 12, characterized in that: Among the plurality of lasers connected to the same third switch, one of the cathode and the anode thereof is connected to the same third switch, and the other of the cathode and the anode thereof is connected separately.

15. A laser radar transmitting module, characterized in that: The transmitting module includes: The laser emitting assembly according to any one of claims 1 to 14, wherein the laser emitting assembly is configured to be connected to a power source.

16. The transmitting module according to claim 15, characterized in that: The transmitting module also includes a voltage limiter, which is connected to both ends of the first switch, the second switch, or the third switch in the laser transmitting assembly. The voltage limiter is configured to limit the voltage across both ends of the first switch, the second switch, or the third switch to be less than a preset voltage, which is less than the voltage of the power supply.

17. The transmitting module according to claim 16, characterized in that: The voltage limiter includes a resistor or a metal oxide semiconductor field effect transistor.

18. The transmitting module according to claim 15, characterized in that: Also includes bootstrap capacitors; The bootstrap capacitor is configured to be connected between a first end of the first switch, the second switch, or the third switch and a second preset voltage source.

19. A laser radar, characterized in that: The laser radar includes: The transmitting module according to any one of claims 15 to 18, configured to transmit a detection beam; a receiving module configured to receive an echo generated after the detection beam is reflected on an object and generate an electrical signal; A processor is coupled to the receiving module and configured to determine at least one of a distance and a reflectivity of the object according to the electrical signal.

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