Circuitry and laser emission module for a vcSEL light source

Abstract

Disclosed is a circuit system for VCSEL light source and a laser emission module, wherein the circuit system for VCSEL light source comprises a switch integrator, at least two driving branch circuits and a driving circuit. The switch integrator comprises at least two switch units, and the at least two driving branch circuits are electrically connected to the at least two switch units respectively. Each of the driving branch circuits is adapted to electrically connect at least one VCSEL light emitting unit. Each of the driving branch circuits comprises an energy storage capacitor and a switch diode, so as to effectively avoid that other blocks are lighted when preselected blocks of the VCSEL light source are lighted. In addition, the circuit system for VCSEL light source adopts a central management control mode to control the conduction of each block of the VCSEL light source, and the consistency of the driving circuit corresponding to each block can be ensured.

Description

Technical Field

[0001] This application relates to the field of VCSELs, and more specifically, to a circuit system and laser emitting module for a VCSEL light source. Background Technology

[0002] A VCSEL (Vertical-Cavity Surface-Emitting Laser) is a semiconductor laser that emits laser light in a direction perpendicular to the substrate. VCSELs feature small divergence angle, beam symmetry, high wavelength thermal stability, stable beam quality, single longitudinal mode output, high photoelectric conversion efficiency, small size, low threshold current, low power consumption, and ease of integration. They are suitable for widespread application as a light source, for example, as a laser source for lidar.

[0003] Laser radar (LiDAR) is a device that uses laser light to detect the position, velocity, and other characteristics of a target object. Specifically, LiDAR detects the relative position of the target object and the LiDAR by emitting a laser beam towards the target object and receiving the reflected signal, thereby enabling the detection, tracking, and identification of the target object. For example, using Time-of-Flight (TOF) technology, a laser pulse is emitted towards a target area in a very short time. A detector receives the laser pulse reflected back from obstacles within the target area. The time difference between half the emitted pulse and the received pulse, multiplied by the speed of light, gives the distance between the obstacle and the LiDAR.

[0004] In recent years, lidar has been widely used in fields such as intelligent transportation, environmental monitoring, and military security. For example, lidar can be applied to new technologies such as autonomous driving, driver assistance, and active braking, enabling vehicles to automatically avoid obstacles under computer control to ensure driving safety. Correspondingly, lidar can also enable obstacle avoidance for unmanned aerial vehicles (UAVs).

[0005] LiDAR uses VCSEL light sources as its laser source. Benefiting from the excellent light output performance of VCSELs, its detection capabilities can be effectively enhanced. Furthermore, LiDAR can use the VCSEL light source to scan the target object in sections step by step. Compared to scanning the target object by rotating the VCSEL light source with a rotary motor, this improves scanning stability and simplifies subsequent 3D modeling. However, in practical applications, the above solution suffers from problems such as inconsistent channel illumination intervals, channel crosstalk, high cost, long pulse rise times, and low ranging accuracy.

[0006] Therefore, a circuit system suitable for VCSEL light sources is needed. Summary of the Invention

[0007] One advantage of this application is that it provides a circuit system and laser emitting module for a VCSEL light source, wherein the circuit system for the VCSEL light source can effectively avoid channel crosstalk in practical applications, that is, prevent other blocks from being lit when controlling the lighting of a pre-selected block of the VCSEL light source.

[0008] Another advantage of this application is that it provides a circuit system and laser emitting module for a VCSEL light source. The circuit system for the VCSEL light source adopts a centrally managed control mode to control the driving branch circuits corresponding to each block of the VCSEL light source, which can ensure the consistency of the driving circuits corresponding to each block, and thus ensure the consistency of the lighting interval when lighting multiple blocks of the VCSEL light source in the same timing sequence.

[0009] Another advantage of this application is that it provides a circuit system and laser emitting module for a VCSEL light source. The circuit system for the VCSEL light source can reduce parasitic inductance by controlling the electrical connection structure between various electronic devices. In this way, the voltage of the DC power supply that powers the circuit system for the VCSEL light source can be reduced, the pulse width of the pulse signal can be reduced, and the rise time can be shortened.

[0010] To achieve at least one of the aforementioned advantages or other advantages and objectives, according to one aspect of this application, a circuit system for a VCSEL light source is provided, comprising: a switching integrator including at least two switching units; at least two driving branch circuits respectively electrically connected to the at least two switching units, wherein each of the driving branch circuits is adapted to electrically connect at least one VCSEL light-emitting unit, each VCSEL light-emitting unit forming a parasitic capacitance in parallel with the VCSEL light-emitting unit; and a driving circuit, all of the driving branch circuits being connected to the same driving circuit; wherein each of the driving branch circuits includes an energy storage capacitor and a switching diode.

[0011] In the circuit system for a VCSEL light source according to this application, in each of the driving branch circuits, the ratio between the reverse junction capacitance of the switching diode and the parasitic capacitance of the VCSEL light-emitting unit is less than or equal to 1%.

[0012] A switching integrator includes at least two switching units; at least two drive branch circuits electrically connected to the at least two switching units, wherein each drive branch circuit is adapted to electrically connect at least one VCSEL light-emitting unit, each VCSEL light-emitting unit forming a parasitic capacitance in parallel with the VCSEL light-emitting unit; and a drive circuit, all of the drive branch circuits being connected to the same drive circuit. Each of the driving branch circuits includes an energy storage capacitor and a switching diode.

[0013] In the circuit system for a VCSEL light source according to this application, in each of the driving branch circuits, the ratio between the reverse junction capacitance of the switching diode and the parasitic capacitance of the VCSEL light-emitting unit is less than or equal to 1%.

[0014] In the circuit system for a VCSEL light source according to this application, the reverse junction capacitance of the switching diode is less than or equal to 2pF.

[0015] In the circuit system for a VCSEL light source according to this application, the switching diode is a Schottky diode.

[0016] In the circuit system for a VCSEL light source according to this application, the switching diode of each of the driving branch circuits is electrically connected between the VCSEL light-emitting unit and the energy storage capacitor.

[0017] In the circuit system for a VCSEL light source according to this application, the reverse junction capacitance values ​​of each of the switching diodes are equal.

[0018] In the circuit system for a VCSEL light source according to this application, at least two of the said switching diodes have unequal reverse junction capacitance values.

[0019] In the circuit system for a VCSEL light source according to this application, the switch integrator is a switch chip.

[0020] In the circuit system for a VCSEL light source according to this application, the cathodes of each VCSEL light-emitting unit electrically connected to each of the driving branch circuits are integrally connected, so that a common cathode is formed among the various VCSEL light-emitting units.

[0021] In the circuit system for a VCSEL light source according to this application, the driving circuit and the switching integrator are adapted to control the energy storage capacitor of the first driving branch circuit to enter a discharging state after the energy storage capacitor of the first driving branch circuit has completed charging.

[0022] In the circuit system for a VCSEL light source according to this application, the driving circuit includes a control switch electrically connected to all the driving branch circuits. The control switch and the switching unit connected to the first driving branch circuit are configured to operate in an alternating on / off manner. When the switching unit is in the on state and the control switch is in the off state, the driving circuit and the switch integrator are configured to charge the energy storage capacitor of the first driving branch circuit. When the switching unit is in the off state and the control switch is in the on state, the driving circuit and the switch integrator are configured to control the energy storage capacitor of the first driving branch circuit to discharge.

[0023] According to another aspect of this application, a laser emitting module is proposed, comprising: a common cathode VCSEL light source including a plurality of VCSEL light-emitting units; and a circuit system electrically connected to the VCSEL light source as described above, wherein each of the driving branch circuits of the circuit system for the VCSEL light source is electrically connected to at least one VCSEL light-emitting unit.

[0024] In the laser emitting module according to this application, the switching diode of each of the driving branch circuits is electrically connected between the VCSEL light-emitting unit and the energy storage capacitor of the circuit system for the VCSEL light source.

[0025] In the laser emitting module according to this application, the VCSEL light-emitting unit and the switching diode are electrically connected to each other via gold wire.

[0026] In the laser emitting module according to this application, the common cathode VCSEL light source includes 96*28 VCSEL light-emitting units.

[0027] The further objectives and advantages of this application will become fully apparent from the following description and accompanying drawings.

[0028] These and other objects, features and advantages of this application are fully apparent from the following detailed description, the accompanying drawings and the claims. Attached Figure Description

[0029] Figure 1 The figure shows a schematic block diagram of a circuit system for a VCSEL light source according to an embodiment of this application.

[0030] Figure 2 The figure shows a schematic diagram of a circuit system for a VCSEL light source according to an embodiment of this application.

[0031] Figure 3The figure shows a partial schematic diagram of a VCSEL light source with a circuit system for a VCSEL light source according to an embodiment of the present application.

[0032] Figure 4 The figure shows a partial perspective view of a VCSEL light source with a circuit system for a VCSEL light source according to an embodiment of the present application. Detailed Implementation

[0033] The following description is intended to disclose this application and enable those skilled in the art to implement it. The embodiments described below are merely examples, and other obvious variations will arise for those skilled in the art. The basic principles of this application defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of this application.

[0034] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0035] While ordinal numbers such as "first," "second," etc., will be used to describe various components, there is no limitation on which components are used here. The term is used only to distinguish one component from another. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component, without departing from the teachings of the application concept. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0036] The terminology used herein is for the purpose of describing various embodiments only and is not intended to be limiting. As used herein, the singular form also includes the plural form, unless the context clearly indicates otherwise. It will also be understood that the terms “comprising” and / or “having” as used in this specification specify the presence of the described features, numbers, steps, operations, components, elements or combinations thereof, without excluding the presence or addition of one or more other features, numbers, steps, operations, components, elements or groups thereof.

[0037] Application Overview As mentioned earlier, the lidar can scan the target object step by step in sections with the help of the VCSEL light source. Compared with scanning the target object by rotating the VCSEL light source by a rotating motor, it can improve the scanning stability and simplify the difficulty of subsequent 3D modeling.

[0038] Specifically, the lidar can use an addressable VCSEL light source as its laser source. The addressable VCSEL light source forms multiple independently controllable blocks through its structure. Each block includes at least one light-emitting unit. The lidar can control the pre-conducted control channel through a circuit system adapted to the addressable VCSEL chip, thereby controlling the illuminated blocks of the addressable VCSEL light source and their illumination sequence. The lidar can select the illuminated blocks of the addressable VCSEL light source and their illumination sequence for different scanning modes according to the application scenario.

[0039] However, the above scheme has problems in practical applications, such as inconsistent lighting intervals between channels, channel crosstalk, high cost, long pulse rise time, and low ranging accuracy.

[0040] Specifically, existing driving schemes for addressable VCSEL light sources employ a distributed control mode to control the conduction of each control channel, thereby controlling the conduction of each block of the VCSEL light source. More specifically, each control channel is configured with a separate driving circuit for each block of the addressable VCSEL light source. Differences exist between these driving circuits in terms of circuit design and component parameters. This means that even if the control timing of each driving circuit is consistent, the lighting intervals of the corresponding blocks of the addressable VCSEL light source may be inconsistent, affecting the performance of the lidar, such as its ranging accuracy. Furthermore, configuring a separate driving circuit for each block of the addressable VCSEL light source also results in a larger number of electronic components in the overall circuit system, a larger circuit board area, and higher costs.

[0041] As can be seen from the structure of a VCSEL light source, each VCSEL light-emitting unit has a P-electrode and an N-electrode, and a parasitic capacitance is formed in parallel between the P-electrode and the N-electrode, connected to the VCSEL light-emitting unit. In some existing driving schemes for addressable VCSEL light sources, the cathodes of the VCSEL light-emitting units in each block of the VCSEL light source are electrically connected to each other. Since each pre-selected block of the VCSEL light source has a parallel parasitic capacitance, these parasitic capacitances form a charging electrical connection channel. Thus, when the energy storage capacitor in the control channel electrically connected to the pre-selected block of the VCSEL light source is charging, the energy storage capacitors in the control channels of other blocks of the VCSEL light source are also charged. Therefore, when the pre-selected block of the VCSEL light source is lit, the other blocks are also lit.

[0042] Accordingly, to address the issue of inconsistent lighting intervals across channels, this application proposes a centrally managed control mode to control the driving branch circuits corresponding to each block of the VCSEL light source. Specifically, the conduction of each block of the VCSEL light source is controlled by the same driving circuit, that is, the same driving circuit is configured for each block of the VCSEL light source. To address the channel crosstalk problem, this application proposes arranging switching diodes in each driving branch circuit suitable for electrical connection to each VCSEL light-emitting unit to block the charging electrical connection channels between the parasitic capacitors formed in each block. Specifically, switching diodes are connected in series between the energy storage capacitor of each driving branch circuit and each VCSEL light-emitting unit, utilizing the unidirectional conductivity of the switching diodes to block the charging electrical connection channels formed between the parasitic capacitors.

[0043] Based on this, this application proposes a circuit system for a VCSEL light source, comprising: a switching integrator, at least two driving branch circuits, and a driving circuit. The switching integrator includes at least two switching units, and the at least two driving branch circuits are electrically connected to the at least two switching units respectively. Each driving branch circuit is adapted to be electrically connected to at least one VCSEL light-emitting unit. Each VCSEL light-emitting unit forms a parasitic capacitance in parallel with that VCSEL light-emitting unit. All driving branch circuits are connected to the same driving circuit. Each driving branch circuit includes an energy storage capacitor and a switching diode.

[0044] Exemplary circuit system Reference manual attached Figures 1 to 4 A circuit system for a VCSEL light source 100 according to an embodiment of this application is described, wherein the circuit system for the VCSEL light source 100 includes a switching integrator 10, at least two drive branch circuits 20, and a drive circuit 30. Specifically, the circuit system for the VCSEL light source 100 is suitable for addressable VCSEL light sources 100 and can control the illuminated blocks of the addressable VCSEL light source 100 and their illumination sequence.

[0045] Specifically, Figure 3 and Figure 4 The illustration shows a specific example of a VCSEL light source 100 that meets the application requirements of this application. In this specific example, the VCSEL light source 100 includes a light-emitting region and an addressable structure 120 electrically connected to the light-emitting region, the light-emitting region being divided into a plurality of selectively energized blocks 110.

[0046] In this specific example, each block 110 includes at least one VCSEL light-emitting unit 111 (i.e., a light-emitting point). Each VCSEL light-emitting unit 111 includes, from bottom to top, a substrate layer 1111, a negative conductive layer 1112, an N-DBR layer 1113, an active region 1114, a confinement layer 1115 with a confinement hole, a P-DBR layer 1116, and a positive conductive layer 1117. The addressable structure 120 includes a plurality of positively charged connection structures 121 connected to the plurality of VCSEL light-emitting units 111 and a plurality of negatively charged connection structures 122 connected to the plurality of VCSEL light-emitting units 111, wherein the plurality of positively charged connection structures 121 respectively form the anode of the plurality of VCSEL light-emitting units 111, and the plurality of negatively charged connection structures 122 respectively form the cathode of the plurality of VCSEL light-emitting units 111. The preselected block 110 can be powered on by electrically connecting the addressable structure 120 to the preselected block 110, that is, the anode and cathode of the VCSEL light-emitting unit 111 of the preselected block 110. The VCSEL light source 100 may also use other addressable VCSEL chips, which is not limited to this application.

[0047] In this embodiment of the application, the option to use is... Figure 3 and Figure 4 The VCSEL light source 100 shown serves as the VCSEL light source 100 for the LiDAR. Based on the requirements of actual application scenarios, in a specific example, the parameters of the VCSEL light source 100 are configured as follows: the VCSEL light source 100 contains 96*28 VCSEL light-emitting units 111, that is, the VCSEL light source 100 includes 28 rows, with each row containing 96 VCSEL light-emitting units 111. The VCSEL light source 100 is suitable for automotive LiDAR.

[0048] As mentioned earlier, existing driving schemes for addressable VCSEL light sources 100 employ a distributed control mode to control each block 110 of the VCSEL light source 100. More specifically, each block 110 of the addressable VCSEL light source 100 is configured with a separate driving circuit 30. These driving circuits 30 differ in circuit design and component parameters, which means that even if the control timing of each driving circuit 30 is consistent, the lighting intervals of the corresponding blocks 110 of the addressable VCSEL light source 100 may be inconsistent. This will affect the performance of the lidar, such as its ranging accuracy. Furthermore, configuring a separate driving circuit 30 for each block 110 of the addressable VCSEL light source 100 also results in a larger number of electronic components in the overall circuit system, a larger circuit board area, and higher costs.

[0049] Accordingly, this application proposes to adopt a centrally managed control mode to control the drive branch circuits 20 corresponding to each block 110 of the VCSEL light source 100. Specifically, in the embodiments of this application, the switch integrator 10 includes at least two switch units, each switch unit being electrically connected to each drive branch circuit 20, and each switch unit and its corresponding drive branch circuit 20 forming a control channel. Each of the aforementioned driving branch circuits 20 is electrically connected to a block 110 of the VCSEL light source 100. The block 110 includes at least one VCSEL light-emitting unit 111. All driving branch circuits 20 are connected to the same driving circuit 30. This eliminates the differences in circuit design and device parameters between driving circuits 30 as seen in conventional driving circuits 30 used to drive addressable VCSEL light sources 100. This ensures the consistency of the driving circuits 30 corresponding to the blocks 110 electrically connected to each control channel, thereby guaranteeing the consistency of the lighting interval when multiple VCSEL light sources 100 are lit simultaneously. This improves the performance of the lidar, for example, increasing the ranging accuracy. Furthermore, driving each driving branch circuit 20 with a single driving circuit 30 reduces the number of electronic components, the area of ​​the circuit board, and the cost.

[0050] More specifically, each of the driving branch circuits 20 includes an energy storage capacitor 21. The circuit system for the VCSEL light source sequentially controls the charging process of the energy storage capacitor 21 in the driving branch circuit corresponding to the pre-conduction block through the switching units of the switching integrator 10, and sequentially controls the discharging process of the energy storage capacitor in each driving branch circuit 20 through the single-path driving circuit 30, thereby sequentially illuminating each block 110 of the VCSEL light source. Specifically, the at least two driving branch circuits 20 include a first driving branch circuit and a second driving branch circuit, and the switching integrator 10 includes a first switching unit corresponding to the first driving branch circuit and a second switching unit corresponding to the second driving branch circuit. During the alternating charging and discharging process of at least two drive branch circuits 20, after the first drive branch circuit completes charging, the first switch unit connected to the first drive branch circuit in the switch integrator 10 switches to the off state. Then, the control switch of the drive circuit 30 switches to the on state, causing the energy storage capacitor 21 of the first drive branch circuit to discharge. Subsequently, when the second switch unit in the switch integrator 10 is switched to the on state, the energy storage capacitor 21 in the second drive branch circuit enters the charging state. After charging is completed, the second switch unit connected to the second drive branch circuit in the switch integrator 10 switches to the off state. Then, the control switch of the drive circuit 30 switches to the on state, causing the energy storage capacitor 21 of the second drive branch circuit to discharge. In this way, the alternating charging and discharging of the energy storage capacitor 21 in at least two drive branch circuits 20 is achieved. Here, the first drive branch circuit and the second drive branch circuit are only used to illustrate two different drive branch circuits and distinguish one drive branch circuit from another, and do not specifically refer to any two drive branch circuits; similarly, the first switch unit and the second switch unit do not specifically refer to any two switch units.

[0051] Accordingly, the driving circuit 30 is adapted to control the energy storage capacitor of the first driving branch circuit to enter the discharge state after the energy storage circuit of the first driving branch circuit has completed charging and the switch switching unit electrically connected to the first driving branch circuit has switched to the off state.

[0052] The drive circuit 30 includes a control switch, which is electrically connected to all the drive branch circuits. The control switch and the switch unit connected to the first drive branch circuit are configured to operate in an alternating on / off manner. When the switch unit is in the on state and the control switch is in the off state, the switch unit is configured to charge the energy storage capacitor of the first drive branch circuit. When the switch unit is in the off state and the control switch is in the on state, the control switch is configured to discharge the energy storage capacitor of the first drive branch circuit.

[0053] In this embodiment, the switch integrator 10 can be implemented as a switch chip, which integrates multiple switch units. By switching the state (on / off) of each switch unit, the charging process of the energy storage capacitor 21 in each of the drive branch circuits 20 can be controlled in sequence.

[0054] The control switch of the driving circuit 30 can be implemented as a GaN field-effect transistor or as other types of switches, and is not limited to this application.

[0055] Furthermore, as mentioned earlier, each VCSEL light-emitting unit 111 of the VCSEL light source 100 has a P electrode (i.e., the anode of the VCSEL light-emitting unit 111) and an N electrode (i.e., the cathode of the VCSEL light-emitting unit 111), and a parasitic capacitance is formed between the P electrode and the N electrode connected in parallel to the VCSEL light-emitting unit 111. In some existing driving schemes for driving the addressable VCSEL light source 100, the cathodes of the VCSEL light-emitting units 111 of each block 110 of the VCSEL light source 100 are electrically connected to each other. Since each preselected block 110 of the VCSEL light source 100 has a parallel parasitic capacitance, each parasitic capacitance constitutes a charging electrical connection channel for a parasitic capacitance, which can easily lead to channel crosstalk. When the energy storage capacitor 21 in the control channel of the preselected block of the VCSEL light source 100 is charging, the energy storage capacitors in the control channels of other blocks of the VCSEL light source 100 will also be charged. Therefore, when the pre-selected block of the VCSEL light source 100 is lit, the other blocks are also lit.

[0056] For example, in a specific example of this application, the cathodes of the VCSEL light-emitting units 111 of each block 110 of the VCSEL light source 100 are integrally connected, so that a common cathode is formed among the various VCSEL light-emitting units 111.

[0057] In another specific example of this application, the cathodes of the VCSEL light-emitting units 111 of each block 110 of the VCSEL light source 100 are electrically connected to the same driving circuit 30, and the cathodes of the VCSEL light-emitting units 111 of each block 110 of the VCSEL light source 100 are electrically connected to each other.

[0058] Accordingly, this application proposes to arrange switching diodes 22 in each driving branch circuit 20 to block the charging connection path between the parasitic capacitors formed in each block.

[0059] In this embodiment, the switching diode 22 is disposed between the parasitic capacitor and other driving branch circuits 20, and the reverse junction capacitance of the switching diode 22 is smaller than the capacitance value of the parasitic capacitor, which can prevent the charging electrical connection channel formed by each parasitic capacitor from charging the energy storage capacitor 21 in the control channel of the non-preselected block electrical connection, thereby preventing the non-preselected block from being lit. The reverse junction capacitance of the switching diode 22 refers to the capacitance value of the switching diode 22 when a reverse bias voltage is applied.

[0060] Specifically, in this embodiment, the switching diode 22 is implemented as a Schottky diode, a type of diode with extremely low reverse junction capacitance. The Schottky diode is a metal-semiconductor device made by using a noble metal (gold, silver, aluminum, platinum, etc.) as the positive electrode and an N-type semiconductor as the negative electrode, utilizing the rectification characteristics of the potential barrier formed at their interface. This results in the ratio between the reverse junction capacitance of the switching diode 22 and the parasitic capacitance of the VCSEL light-emitting unit 111 being less than or equal to 1%. In a specific example of this application, the reverse junction capacitance of the switching diode 22 is less than or equal to 2 pF, and can even be as low as 1 pF. In modified embodiments of this application, the switching diode 22 can be implemented as other types of diodes, and this is not a limitation of this application.

[0061] In this embodiment, the reverse junction capacitance value of each of the switching diodes 22 can be set according to actual needs. The reverse capacitance values ​​of the switching diodes 22 of each driving branch circuit 20 can be equal or unequal, as long as they are much lower than the parasitic capacitance value.

[0062] The specific location of the switching diode 22 is not limited to this application. In one specific example of this application, the switching diode 22 is adapted to be electrically connected between the VCSEL unit and the energy storage capacitor 21, with its positive electrode connected to the positive electrode of the energy storage capacitor 21 and its negative electrode connected to the positive electrode (anode) of the VCSEL unit. In other specific examples of this application, the switching diode 22 may be located in other positions.

[0063] In this embodiment, the circuit system for the VCSEL light source 100 further includes a power supply circuit 40 that supplies power to the entire circuit system. The power supply circuit 40 includes a DC power supply 41 and a charging resistor 42 connected in series with the DC power supply 41. The voltage of the DC power supply 41 is greater than 0V and less than or equal to 100V, and can be used to adjust the energy of the energy storage capacitor 21, thereby adjusting the output power of the VCSEL light source 100.

[0064] It is worth mentioning that when the circuit system is turned on, the electrical connection structure between the various components will form a parasitic inductance 50, affecting the voltage of the DC power supply 41 and the pulse width and rising edge of the pulse signal. In the conventional driving circuit 30 for the VCSEL light source 100, the electrical connection between various electronic components is usually achieved through PCB (Printed Circuit Board) traces. In this embodiment, the VCSEL light-emitting unit 111 and the switching diode 22 are electrically connected to each other through gold wires. That is, gold wires are used to replace the PCB traces between the VCSEL light source 100 and the switching diode 22. In this way, the parasitic inductance 50 formed by the electrical connection structure between the VCSEL light-emitting unit 111 and the switching diode 22 is reduced, thereby reducing the voltage of the DC power supply 41, reducing the pulse width of the pulse signal, shortening the rising edge, and improving eye safety.

[0065] Application Example 1 Figure 2 The illustration shows a specific example of a VCSEL light source 100 according to an embodiment of this application. In this specific example, the circuit system for the VCSEL light source 100 includes: a DC power supply V... IN Charging resistor R IN The components include a switch chip, energy storage capacitor C1, switching diode, loop parasitic inductance L1, and drive circuit.

[0066] In this specific example, the charging resistor R IN Connected in series with the DC power supply V IN The DC power supply VIN and the charging resistor R IN A charging circuit 40 is formed.

[0067] The Switch chip is electrically connected to the charging circuit 40. The Switch chip includes multiple integrated switching units, each of which is electrically connected to a drive branch circuit 20. The addressable circuitry allows multiple channels to be turned on sequentially in any order, or only certain channels to be turned on sequentially, thereby charging the energy storage capacitor C1.

[0068] Each drive branch circuit 20 is adapted to be electrically connected to the common cathode VCSEL array D L At least one block 110, each block 110 including at least one VCSEL unit 111, each block 110 forming a parasitic capacitance connected in parallel to the block 110. Each drive branch circuit 20 includes an energy storage capacitor C1 electrically connected to the switching unit and a switching diode, wherein the switching diode is adapted to be electrically connected to the energy storage capacitor C1 and the common cathode VCSEL array D. L At least one VCSEL unit 111 is used between them to avoid channel crosstalk.

[0069] Specifically, common cathode VCSEL array D L The cathodes of the VCSEL blocks in each channel are connected. When a certain main channel is turned on for charging, because each VCSEL device in each channel has a large parasitic capacitance, if a switching diode with a very low reverse junction capacitance is not connected in series between the anode of each VCSEL block and the energy storage capacitor C1, any other channel will also be reverse charged through the parasitic capacitance of its own VCSEL device. Therefore, when the drive circuit is turned on, not only will the VCSEL block of the main channel light up, but the VCSEL blocks of any other channel will also light up, causing crosstalk problems.

[0070] All drive branch circuits 20 are electrically connected to the same drive circuit, which includes at least one control switch Q1, which is implemented as a gallium nitride (GaN) field-effect transistor.

[0071] After the energy storage capacitor C1 of the VCSEL main channel is fully charged, the single-channel drive circuit 30 inputs a high-level nanosecond-level narrow pulse to the GaN field-effect transistor through the gate drive control command, turns on the GaN field-effect transistor to discharge, and realizes the lighting (i.e., conduction) of the main channel.

[0072] The magnitude of the loop parasitic inductance L1 will affect the DC power supply voltage V. INNarrow pulse width in the nanosecond range and its rising edge. By optimizing the internal design of the VCSEL chip to reduce the size of the power supply components, and by using multiple parallel gold wires to replace the PCB traces between the anode and cathode of the VCSEL block to reduce the parasitic inductance L1 of the circuit board, the DC power supply voltage V can be reduced. IN This reduces the width of the nanosecond-level narrow pulse and its rising edge.

[0073] In summary, the circuit system for the VCSEL light source 100 has been explained. In practical applications, this circuit system effectively avoids crosstalk between control channels, preventing other areas from being illuminated when a pre-selected block of the VCSEL light source 100 is being controlled to light up. Furthermore, the circuit system for the VCSEL light source 100 employs a centrally managed control mode to control the drive branch circuits 20 corresponding to each block 110 of the VCSEL light source 100, ensuring the consistency of the drive circuits 30 corresponding to each block 110, thereby guaranteeing the consistency of the lighting interval when multiple VCSEL light sources 100 are illuminated in the same timing sequence.

[0074] According to another aspect of this application, this application proposes a laser emitting module, wherein the laser emitting module includes a common cathode VCSEL light source 100, including a plurality of VCSEL light-emitting units 111 and a circuit system electrically connected to the VCSEL light source 100 as described above, wherein each of the driving branch circuits 20 of the circuit system for the VCSEL light source 100 is electrically connected to at least one VCSEL light-emitting unit 111.

[0075] The laser emitting module's performance can be improved by optimizing the circuit system used for the VCSEL light source 100. The laser emitting module can be used in lidar, thereby improving the lidar's laser projection performance.

[0076] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

Claims

1. A circuit system for a VCSEL light source, characterized in that, include: A switch integrator comprising at least two switch units; At least two drive branch circuits are electrically connected to the at least two switching units, respectively, wherein each drive branch circuit is adapted to electrically connect to at least one VCSEL light-emitting unit, and each VCSEL light-emitting unit forms a parasitic capacitance in parallel with the VCSEL light-emitting unit; and The driving circuit, wherein all the driving branch circuits are connected to the same driving circuit; Each of the driving branch circuits includes an energy storage capacitor and a switching diode; wherein, in each of the driving branch circuits, the reverse junction capacitance of the switching diode is less than the parasitic capacitance of the VCSEL light-emitting unit.

2. The circuit system for a VCSEL light source according to claim 1, wherein, In each of the driving branch circuits, the ratio between the reverse junction capacitance of the switching diode and the parasitic capacitance of the VCSEL light-emitting unit is less than or equal to 1%.

3. The circuit system for a VCSEL light source according to claim 2, wherein, The reverse junction capacitance of the switching diode is less than or equal to 2pF.

4. The circuit system for a VCSEL light source according to claim 2, wherein, The switching diode is a Schottky diode.

5. The circuit system for a VCSEL light source according to claim 2, wherein, The switching diode of each of the driving branch circuits is electrically connected between the VCSEL light-emitting unit and the energy storage capacitor.

6. The circuit system for a VCSEL light source according to claim 2, wherein, The reverse junction capacitance values ​​of each of the aforementioned switching diodes are equal.

7. The circuit system for a VCSEL light source according to claim 2, wherein, At least two of the aforementioned switching diodes have unequal reverse junction capacitance values.

8. The circuit system for a VCSEL light source according to claim 1, wherein, The switch integrator is a Switch chip.

9. The circuit system for a VCSEL light source according to claim 1, wherein, The cathodes of each VCSEL light-emitting unit electrically connected to each of the driving branch circuits are integrally connected, so that a common cathode is formed among the various VCSEL light-emitting units.

10. The circuit system for a VCSEL light source according to claim 1, wherein, The drive circuit and the switch integrator are adapted to control the energy storage capacitor of the first drive branch circuit to enter the discharge state after the energy storage capacitor of the first drive branch circuit has completed charging.

11. The circuit system for a VCSEL light source according to claim 10, wherein, The drive circuit includes a control switch electrically connected to all the drive branch circuits. The control switch and the switch unit connected to the first drive branch circuit are configured to operate in an alternating on / off manner. When the switch unit is on and the control switch is off, the drive circuit and the switch integrator are configured to charge the energy storage capacitor of the first drive branch circuit. When the switch unit is off and the control switch is on, the drive circuit and the switch integrator are configured to control the energy storage capacitor of the first drive branch circuit to discharge.

12. A laser emitting module, characterized in that, include: common A common cathode VCSEL light source, comprising multiple VCSEL light-emitting units; and The circuit system for the VCSEL light source as described in any one of claims 1 to 11 is electrically connected to the common cathode VCSEL light source, wherein each of the driving branch circuits of the circuit system for the VCSEL light source is electrically connected to at least one VCSEL light-emitting unit.

13. The laser emitting module according to claim 12, wherein, The VCSEL light-emitting unit and the switching diode are electrically connected to each other via gold wire.

14. The laser emitting module according to claim 12, wherein, The common cathode VCSEL light source includes 96*28 VCSEL light-emitting units.

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