A light source system for a lidar, a lidar

Abstract

The application relates to the technical field of laser radars, and discloses a light source system for a laser radar and the laser radar, which comprise a pump source, a seed source, a pulse generator and a main controller. The current of the pump source has different gears, wherein the current corresponding to an ultra-low gear is lower than a current threshold for exciting the seed source to emit light. The main controller is used for controlling the pulse generator to generate a pulse signal with a corresponding pulse width and driving the seed source according to the rotating position of a multi-faceted rotating mirror, and simultaneously controlling the current of the pump source to switch to a corresponding gear. When the emitting light spot approaches the edge of the multi-faceted rotating mirror, the current of the pump source is controlled to switch to the ultra-low gear. In this way, the different gear switching of the pump source current is controlled according to the rotating process of the multi-faceted rotating mirror. When the light spot emitted by the seed source approaches the edge of the multi-faceted rotating mirror, the current of the pump source is controlled to switch to the ultra-low gear, so that the laser light source does not emit light, the stray light at the edge of the rotating mirror can be improved, the negative influence caused by the stray light can be weakened, and the electric power consumption can be saved.

Description

Technical Field

[0001] This invention relates to the field of lidar technology, and in particular to a light source system for lidar and lidar. Background Technology

[0002] LiDAR (Light Detection and Ranging) is a target detection technology that uses a laser to emit a laser beam. When this beam encounters a target object, it undergoes diffuse reflection. The characteristics of the target object are determined by analyzing the reflected beam and the characteristics of the emitted beam. The performance of the light source system used in LiDAR significantly affects its measurement accuracy and range. Among these components, the multi-faceted high-speed rotating mirror is a key element of the light source system. However, when the emitted light spot strikes the edge of the multi-faceted high-speed rotating mirror, it introduces unwanted stray light, interfering with the detection of the actual object—a common problem with rotating mirror LiDAR systems.

[0003] Therefore, how to solve the aforementioned problem of unnecessary stray light is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a light source system and a lidar for use in lidar, which can reduce stray light and save power consumption. The specific solution is as follows:

[0005] A light source system for lidar includes: a pump source, a seed source, a pulse generator, and a main controller electrically connected to the pump source and the pulse generator, respectively.

[0006] The pump source has different current levels, with the ultra-low level corresponding to a current lower than the current threshold required by the pump source to excite the seed source to emit light.

[0007] The main controller is used to control the pulse generator to generate a pulse signal with a corresponding pulse width and drive the seed source according to the rotation position of the multifaceted rotating mirror in the lidar. At the same time, it controls the current of the pump source to switch to the corresponding level. When the light spot emitted by the laser source approaches the edge of the multifaceted rotating mirror, it controls the current of the pump source to switch to the ultra-low level.

[0008] Preferably, in the above-described light source system for lidar provided in the embodiments of the present invention, a heat-sensing element is disposed within the seed source;

[0009] The light source system further includes: a temperature control drive circuit that is electrically connected to the main controller and the heat-sensing element respectively;

[0010] The main controller is also used to receive the temperature detection result of the thermal sensing element and control the temperature control drive circuit to adjust the temperature of the seed source according to the temperature detection result.

[0011] Preferably, the light source system for lidar provided in the embodiments of the present invention further includes: a driver chip electrically connected to the main controller and the pump source respectively;

[0012] The driving chip is used to drive the pump source under the control of the main controller, and to receive the voltage and current feedback from the pump source, and control the current output of the pump source to be stable.

[0013] Preferably, in the above-described light source system for lidar provided in the embodiments of the present invention, the driving chip is a DC-DC chip.

[0014] Preferably, the light source system for lidar provided in the embodiments of the present invention further includes: a pulse fiber amplifier;

[0015] The pulse fiber amplifier includes a gain fiber disposed between the pulse generator and the pump source; the gain fiber includes a high-gain fiber and a low-gain fiber.

[0016] Preferably, in the above-described light source system for lidar provided in the embodiments of the present invention, the pulse fiber amplifier further includes a combiner located on the side of the high-gain fiber and the low-gain fiber away from the pulse generator.

[0017] Preferably, in the above-described light source system for lidar provided in the embodiments of the present invention, when the pulse fiber amplifier is in forward amplification, the high-gain fiber is located between the pulse generator and the low-gain fiber; the low-gain fiber and the pump source are both connected to one end of the combiner.

[0018] Preferably, in the above-described light source system for lidar provided in the embodiments of the present invention, when the pulse fiber amplifier is in reverse amplification, the low-gain fiber is located between the pulse generator and the high-gain fiber; the high-gain fiber is connected to one end of the combiner, and the pump source is connected to the other end of the combiner.

[0019] Preferably, in the above-described light source system for lidar provided in the embodiments of the present invention, the pulse fiber amplifier further includes a first isolator located between the pulse generator and the gain fiber, and a second isolator located on the side of the combiner away from the pulse generator.

[0020] This invention also provides a lidar system, including the light source system and multi-faceted rotating mirror described above in this invention.

[0021] As can be seen from the above technical solution, the light source system for lidar provided by the present invention includes: a pump source, a seed source, a pulse generator, and a main controller electrically connected to the pump source and the pulse generator respectively; the pump source has different current levels, wherein the current corresponding to the ultra-low level is lower than the current threshold for the pump source to excite the seed source to emit light; the main controller is used to control the pulse generator to generate a pulse signal with a corresponding pulse width and drive the seed source according to the rotation position of the multifaceted rotating mirror in the lidar, and at the same time control the pump source current to switch to the corresponding level, and when the light spot emitted by the laser source approaches the edge of the multifaceted rotating mirror, control the pump source current to switch to the ultra-low level.

[0022] The above-mentioned light source system for lidar provided by this invention, from the perspective of controlling the pulse generator and pump source, through the action of the main controller, controls the pulse generator to generate pulse signals with corresponding pulse widths and drive the seed source for different scanning positions of the multi-faceted rotating mirror. At the same time, it controls the switching of different levels of the pump source current to achieve flexible configuration of laser power. When the light spot emitted by the laser source approaches the edge of the multi-faceted rotating mirror, the pump source current is switched to an ultra-low level. At this time, the pump source current is lower than the current threshold for the pump source to excite the seed source to emit light, so that the laser source does not emit light and there is no light spot directly facing the edge of the multi-faceted rotating mirror. This solves the stray light problem at the edge of the rotating mirror, can improve the stray light at the edge of the rotating mirror, reduce the negative impact of stray light, and save power consumption, achieving the best balance between power consumption and effectiveness.

[0023] Furthermore, the present invention also provides a corresponding lidar for a light source system used in lidar, further making the aforementioned light source system more practical, and the lidar has corresponding advantages. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a light source system for lidar provided in an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of a six-sided rotating mirror provided in an embodiment of the present invention;

[0027] Figure 3 A schematic diagram illustrating the pump source gear selection during the rotation of a six-sided rotating mirror, as provided in an embodiment of the present invention.

[0028] Figure 4A schematic diagram showing the connection between the pulse generator, LD, temperature control drive circuit and main controller provided in an embodiment of the present invention;

[0029] Figure 5 A schematic diagram illustrating the connection between the pump source, the drive chip, and the main controller provided in an embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram showing the connection between the pulse fiber amplifier, the pulse generator, and the pump source when the pulse fiber amplifier is in forward amplification, as provided in an embodiment of the present invention.

[0031] Figure 7 This is a schematic diagram showing the connection between the pulse fiber amplifier, the pulse generator, and the pump source when the pulse fiber amplifier is in reverse amplification, as provided in an embodiment of the present invention. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] This invention provides a light source system for lidar, such as... Figure 1 As shown, it includes: a pump source 1, a seed source 2, a pulse generator 3, and a main controller 4 electrically connected to the pump source 1 and the pulse generator 3 respectively;

[0034] The current of pump source 1 has different levels, among which the current corresponding to the ultra-low level is lower than the current threshold for pump source 1 to excite seed source 2 to emit light.

[0035] The main controller 4 is used to control the pulse generator 3 to generate a pulse signal with a corresponding pulse width and drive the seed source 2 according to the rotation position of the multi-faceted rotating mirror in the lidar. At the same time, it controls the current of the pump source 1 to switch to the corresponding level. When the light spot emitted by the laser source approaches the edge of the multi-faceted rotating mirror, the current of the pump source 1 is controlled to switch to the ultra-low level.

[0036] It should be noted that the multi-faceted rotating mirror of the present invention can be a two-faced rotating mirror, a three-faced rotating mirror, a four-faced rotating mirror, a five-faced rotating mirror, a six-faced rotating mirror, etc. The pulse signal generated by the pulse generator of the present invention has a certain correspondence with the rotation angle of the multi-faceted rotating mirror. Preferably, the present invention can control the rotation angle of the multi-faceted rotating mirror based on the rotational speed of the multi-faceted rotating mirror per minute, through the emission interval of the pulse signal generated by the pulse generator.

[0037] Figure 2A schematic diagram of the six-sided rotating mirror is shown, wherein the shaded area (i.e., the edges of the six-sided rotating mirror) corresponds to the ultra-low gear t2 to t3 of pump source 1. Figure 2 In the diagram, A represents the ultra-low setting t2, and B represents the ultra-low setting t3. Between A and B, the current of pump source 1 is lower than the current threshold required for pump source 1 to excite seed source 2 to emit light. This current threshold refers to the minimum current value required for seed source 2 to be excited by pump source 1. That is, when pump source 1 is in the ultra-low setting, seed source 2 is not excited by pump source, so the laser source does not emit light at this time.

[0038] Figure 3 A schematic diagram illustrating the pump source current selection during the rotation of the six-sided rotating mirror is shown. Preferably, facing different scanning orientations of the multi-sided rotating mirror, the main controller 4 can control the switching of different current levels of the pump source 1, divided into high, medium, and ultra-low levels. On the one hand, switching between high and medium levels allows the lidar to detect details in the region of interest, such as... Figure 3 As shown: t0~t1 is the medium setting, t1~t2 is the high setting. When pump source 1 is in the medium or high setting, seed source 2 will be excited by pump source 1, resulting in a corresponding light spot on the multifaceted rotating mirror. On the other hand, at the edge of the multifaceted rotating mirror, the ultra-low setting t2~t3 has a certain duty cycle, such as... Figure 3 As shown: t2~t3 is the ultra-low setting. When the pump source 1 is in the ultra-low setting, the seed source 2 is not excited by the pump source 1, the laser source does not emit light, and no light spot will appear on the multi-faceted rotating mirror. This not only reduces the negative impact of stray light, but also saves power consumption.

[0039] In practical applications, the current range corresponding to the ultra-low setting can be set to 0A to 0.5A, the current range corresponding to the medium setting can be set to 1A to 2A, and the current range corresponding to the high setting can be set to 3A to 4A.

[0040] In the above-described LiDAR light source system provided in this embodiment of the invention, from the perspective of controlling the pulse generator 3 and the pump source 1, the main controller 4 controls the pulse generator 3 to generate pulse signals with corresponding pulse widths and drive the seed source 2 for different scanning orientations of the multi-faceted rotating mirror. At the same time, it controls the switching of different current levels of the pump source 1 to achieve flexible configuration of laser power, increase the laser power in the region of interest, and reduce the laser power in the region of no interest. When the light spot emitted by the laser source approaches the edge of the multi-faceted rotating mirror, the current of the pump source 1 is switched to an ultra-low level. At this time, the current of the pump source 1 is lower than the current threshold for the pump source 1 to excite the seed source 2 to emit light, so that the laser source does not emit light and there is no light spot facing the edge of the multi-faceted rotating mirror. This solves the stray light problem at the edge of the rotating mirror, improves the stray light at the edge of the rotating mirror, reduces the negative impact of stray light, and saves power consumption, achieving the best balance between power consumption and effectiveness.

[0041] Furthermore, in a specific implementation, in the above-mentioned light source system for lidar provided in the embodiments of the present invention, since the excessive power consumption of lidar will cause heat dissipation difficulties, in order to reduce the power consumption of each component of lidar, a heat-sensing element can be provided in the seed source 2 (such as a laser diode, LD), and the light source system can also include: a temperature control drive circuit that is electrically connected to the main controller 4 and the heat-sensing element respectively.

[0042] The main controller 4 is also used to receive the temperature detection results of the thermal sensing element and control the temperature control drive circuit to adjust the temperature of the seed source 2 according to the temperature detection results.

[0043] Preferably, the pulse generator 3 generates an electrically modulated pulse signal with adjustable repetition rate, adjustable pulse width, and adjustable wavelength from 1520nm to 1570nm.

[0044] Figure 4 A schematic diagram showing the connection between the pulse generator, LD, temperature control drive circuit, and main controller constitutes the precise temperature control circuit for the pulse signal light of this invention. This invention employs this precise temperature control circuit, ensuring that the wavelength of the light source system used in lidar remains unaffected in harsh environments, such as high and low temperatures or high temperatures and humidity, and uses active temperature control to lock the laser emission wavelength. Figure 4 As shown, the pulse generator receives an external trigger signal and generates a narrow pulse signal whose pulse width can be set by the main controller 4. This signal is used to drive the LD. The LD has a thermal sensing element inside, and the parameters of the thermal sensing element will change with the temperature. Generally speaking, when the temperature increases by 1°C, the wavelength of the LD increases by 0.3nm. This temperature change information is fed back to the main controller 4 through the temperature detection circuit. The main controller 4 can adjust the temperature control drive circuit according to the temperature detection result of the LD to control the heating and cooling of the LD thermal sensing element, so as to achieve closed-loop feedback control of the LD temperature and thus achieve precise control of the wavelength.

[0045] It should be noted that the light source system of the present invention combines the scanning characteristics of multi-faceted rotating mirrors with the application scenario requirements of lidar. It can be approached from two angles: controlling the pump source current and optimizing the internal optical path of the laser source. On the one hand, by adjusting the pump source current in multiple levels, stray light at the edges of the multi-faceted rotating mirrors is reduced, while the power consumption of the laser source is reduced. On the other hand, by actively controlling the wavelength stability of the LD, the radar can adapt to a wider operating temperature range (e.g., -40℃ to 85℃). Finally, the internal optical path structure of the laser is optimized to improve the light conversion efficiency, thereby saving power consumption.

[0046] In a specific implementation, the light source system for lidar provided in the embodiments of the present invention may further include: a driver chip electrically connected to the main controller 4 and the pump source 1 respectively;

[0047] The driver chip is used to drive the pump source 1 under the control of the main controller 4, and to receive the voltage and current feedback from the pump source 1 to control the current output of the pump source 1 to stabilize.

[0048] Preferably, the driver chip can be a DC-to-DC converter (DCDC) chip, which can improve the efficiency of voltage conversion.

[0049] Figure 5 A schematic diagram showing the connection between the pump source, drive chip, and main controller is provided. Figure 5 As shown, the pump source 1 driver uses a highly integrated DC-DC chip capable of outputting low voltage as the power controller. Through dual closed-loop control of voltage and current feedback from pump source 1, stable control of the pump source 1 current is achieved, further enabling rapid switching of the corresponding current levels. The feedback network, through zero-pole compensation design, meets the requirements of stability and fast current switching speed of the closed-loop system, achieving the goal of stable output current. The current switching function is directly affected by the external interrupt response of the main controller 4, ensuring a rapid response to current switching requirements.

[0050] In a specific implementation, the light source system for lidar provided in the embodiments of the present invention may further include: a pulse fiber amplifier;

[0051] The pulse fiber amplifier includes a gain fiber disposed between the pulse generator 4 and the pump source 1; the gain fiber includes a high-gain fiber 5 and a low-gain fiber 6. That is, the gain fiber is disposed in the transmission optical path of the pulse signal, and the pulse signal can be transmitted through the gain fiber. The pump light generated by the pump source 1 is injected into the gain fiber to amplify the pulse signal.

[0052] Preferably, the high-gain fiber 5 can be erbium-doped fiber or erbium-ytterbium co-doped fiber, with an absorption coefficient > adB, where a is generally above 60 dB. The low-gain fiber 6 can be erbium-doped fiber or erbium-ytterbium co-doped fiber, with an absorption coefficient > 1 / 2 dB and an absorption coefficient > 1 / 3 dB; the core diameter and numerical aperture of the gain fiber are similar.

[0053] It should be noted that, from the perspective of the laser optical path, when the pump light is injected into the active fiber, a large number of rare earth ions are extracted and transported to the upper energy level, forming population inversion. This process is not linear. When the pulse signal light passes through, the population of the upper energy level is rapidly consumed. Since the signal light is weak and has limited absorption capacity, the number of particles required in the early stage of optical amplification is greater than that in the later stage. Therefore, this invention uses a combination of high- and low-gain optical fibers to improve the utilization of the seed light for the inverted population and improve the optical conversion efficiency. In high-gain fiber, in order to quickly accumulate the inverted particle number and to rapidly consume matching at the rising edge of the seed light, the number of remaining particles available at the trailing edge of the pulse is reduced because too many particles are consumed at the rising edge of the pulse. For the trailing edge, an excessively long high-gain fiber contributes little to optical amplification and cannot absorb light. Instead, it introduces amplified spontaneous emission (ASE) or is reabsorbed by the high-gain fiber. Low-gain fiber has lower absorption efficiency and can be matched to amplify at the trailing edge of the pulse. Thus, the mixed use of high-gain and low-gain fibers is low-cost, requires no grating, is simple to operate, and improves amplification efficiency.

[0054] In specific implementations, in the above-described light source system for lidar provided in the embodiments of the present invention, such as... Figure 6 and Figure 7 As shown, the pulsed fiber amplifier may also include a combiner 7 located on the side of the high-gain fiber 5 and the low-gain fiber 6 away from the pulse generator 4. This combiner 7 can be a (1+1)*1 structure, coupling the pump light and the pulsed signal light into the gain fiber. In practical applications, a wavelength division multiplexing (WDM) can also be used instead of the combiner 7.

[0055] In specific implementations, in the above-described light source system for lidar provided in the embodiments of the present invention, such as... Figure 6 As shown, when the pulse fiber amplifier is in forward amplification, the high-gain fiber 5 can be located between the pulse generator 4 and the low-gain fiber 6; both the low-gain fiber 6 and the pump source 1 can be connected to one end of the combiner 7.

[0056] In specific implementations, in the above-described light source system for lidar provided in the embodiments of the present invention, such as... Figure 7 As shown, when the pulse fiber amplifier is in reverse amplification, the low-gain fiber 6 can be located between the pulse generator 4 and the high-gain fiber 5; the high-gain fiber 5 can be connected to one end of the combiner 7, and the pump source 1 can be connected to the other end of the combiner 7.

[0057] In specific implementations, in the above-described light source system for lidar provided in the embodiments of the present invention, such as... Figure 6 and Figure 7As shown, the pulse fiber amplifier may further include a first isolator 8 located between the pulse generator 4 and the gain fiber, and a second isolator 9 located on the side of the combiner away from the pulse generator. The first isolator 8 can be used to protect the pulse signal light from interference by the reverse amplified light. The second isolator 9 allows the amplified light to propagate in the forward direction and prevents it from passing through in the reverse direction.

[0058] Based on the same inventive concept, embodiments of the present invention also provide a lidar, including the light source system and multi-faceted rotating mirror described above in the embodiments of the present invention. Since the principle by which this lidar solves the problem is similar to that of the aforementioned light source system for lidar, the implementation of this lidar can refer to the implementation of the light source system for lidar, and repeated details will not be elaborated further.

[0059] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0060] In summary, the present invention provides a light source system for lidar, comprising: a pump source 1, a seed source 2, a pulse generator 3, and a main controller 4 electrically connected to the pump source 1 and the pulse generator 3 respectively; the pump source 1 has different current levels, wherein the ultra-low level corresponds to a current lower than the current threshold for the pump source 1 to excite the seed source to emit light; the main controller 4 is used to control the pulse generator 3 to generate a pulse signal with a corresponding pulse width and drive the seed source 2 according to the rotation position of the multifaceted rotating mirror, and at the same time control the current of the pump source 1 to switch to the corresponding level, and when the light spot emitted by the laser source approaches the edge of the multifaceted rotating mirror, the current of the pump source 1 is controlled to switch to the ultra-low level. The aforementioned light source system for lidar, through the action of the main controller 4, controls the switching of different current levels of the pump source 1 during the rotation of the multifaceted rotating mirror, achieving flexible configuration of laser power. When the light spot emitted by the seed source 2 approaches the edge of the multifaceted rotating mirror, the current of the pump source 1 is switched to an ultra-low level. At this time, the current of the pump source 1 is lower than the current threshold for exciting the seed source to emit light, so that the laser source does not emit light, and there is no light spot directly facing the edge of the multifaceted rotating mirror. This solves the stray light problem at the edge of the rotating mirror, improves the stray light at the edge of the rotating mirror, reduces the negative impact of stray light, and saves power consumption, achieving the best balance between power consumption and effectiveness. In addition, this invention also provides a corresponding lidar for the light source system used in lidar, further making the above-mentioned light source system more practical. This lidar has corresponding advantages.

[0061] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0062] The above provides a detailed description of the light source system for lidar provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A light source system for lidar, characterized in that, include: A pump source, a seed source, a pulse generator, and a main controller electrically connected to the pump source and the pulse generator, respectively; The pump source has different current levels, with the ultra-low level corresponding to a current lower than the current threshold required by the pump source to excite the seed source to emit light. The main controller is used to control the pulse generator to generate a pulse signal with a corresponding pulse width and drive the seed source according to the rotation position of the multifaceted rotating mirror in the lidar. At the same time, it controls the current of the pump source to switch to the corresponding level. When the light spot emitted by the laser source approaches the edge of the multifaceted rotating mirror, it controls the current of the pump source to switch to the ultra-low level.

2. The light source system for lidar according to claim 1, characterized in that, The seed source is equipped with a heat-sensing element; The light source system further includes a temperature control drive circuit that is electrically connected to the main controller and the heat-sensing element, respectively; The main controller is also used to receive the temperature detection result of the thermal sensing element and control the temperature control drive circuit to adjust the temperature of the seed source according to the temperature detection result.

3. The light source system for lidar according to claim 2, characterized in that, Also includes: A drive chip electrically connected to the main controller and the pump source, respectively; The driving chip is used to drive the pump source under the control of the main controller, and to receive the voltage and current feedback from the pump source, and control the current output of the pump source to be stable.

4. The light source system for lidar according to claim 3, characterized in that, The driving chip is a DC-DC chip.

5. The light source system for lidar according to claim 1, characterized in that, Also includes: Pulse fiber amplifier; The pulse fiber amplifier includes a gain fiber disposed between the pulse generator and the pump source; The gain fiber includes high-gain fiber and low-gain fiber.

6. The light source system for lidar according to claim 5, characterized in that, The pulsed fiber amplifier also includes a combiner located on the side of the high-gain fiber and the low-gain fiber away from the pulse generator.

7. The light source system for lidar according to claim 6, characterized in that, When the pulse fiber amplifier is in forward amplification, the high-gain fiber is located between the pulse generator and the low-gain fiber; the low-gain fiber and the pump source are both connected to one end of the combiner.

8. The light source system for lidar according to claim 7, characterized in that, When the pulse fiber amplifier is in reverse amplification mode, the low-gain fiber is located between the pulse generator and the high-gain fiber; the high-gain fiber is connected to one end of the combiner, and the pump source is connected to the other end of the combiner.

9. The light source system for lidar according to claim 8, characterized in that, The pulse fiber amplifier further includes a first isolator located between the pulse generator and the gain fiber, and a second isolator located on the side of the combiner away from the pulse generator.

10. A lidar, characterized in that, Includes the light source system and multi-faceted rotating mirror for lidar as described in any one of claims 1 to 9.

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