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CN114252867B - Laser radar light source and repetition frequency switching method thereof - Google Patents

Laser radar light source and repetition frequency switching method thereof Download PDF

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Publication number
CN114252867B
CN114252867B CN202210186956.XA CN202210186956A CN114252867B CN 114252867 B CN114252867 B CN 114252867B CN 202210186956 A CN202210186956 A CN 202210186956A CN 114252867 B CN114252867 B CN 114252867B
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Prior art keywords
polarization
pulse signal
signal light
control signal
light source
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CN114252867A (en
Inventor
张党卫
丁广雷
张哨峰
凌吉武
于农村
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Fujian Haichuang Photoelectric Technology Co ltd
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Fujian Haichuang Photoelectric Technology Co ltd
Shenzhen Haichuang Optics Co ltd
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/484—Transmitters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/88—Lidar systems specially adapted for specific applications
    • G01S17/93—Lidar systems specially adapted for specific applications for anti-collision purposes
    • G01S17/931—Lidar systems specially adapted for specific applications for anti-collision purposes of land vehicles
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/486—Receivers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/005—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/005—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping
    • H01S5/0071—Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping for beam steering, e.g. using a mirror outside the cavity to change the beam direction
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
    • H01S5/0607—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying physical parameters other than the potential of the electrodes, e.g. by an electric or magnetic field, mechanical deformation, pressure, light, temperature
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
    • H01S5/0607—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying physical parameters other than the potential of the electrodes, e.g. by an electric or magnetic field, mechanical deformation, pressure, light, temperature
    • H01S5/0608—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying physical parameters other than the potential of the electrodes, e.g. by an electric or magnetic field, mechanical deformation, pressure, light, temperature controlled by light, e.g. optical switch

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Optics & Photonics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Lasers (AREA)

Abstract

The invention discloses a laser radar light source and a repetition frequency switching method thereof, wherein the laser radar light source comprises: a pulse signal transmitting system for transmitting pulse signal light of different repetition frequencies; the pumping system is used for amplifying the pulse signal light emitted by the pulse signal emitting system to generate amplified pulse signal light; a control signal emitting system for emitting control signal light to consume a part of pump light power of the pump system; the central control system is respectively electrically connected with the pulse signal transmitting system, the pumping system and the control signal transmitting system and is used for controlling the pulse signal light to switch the pulse signal light with different repetition frequencies; controlling a pumping system to emit pumping light; and controlling the control signal emitting system to emit the control signal light. When the repetition frequency is switched, the control signal system and the pumping system are matched with each other, so that the power of the pumping light is always kept matched with the repetition frequency of the pulse signal light, and the pulse energy is unchanged when the repetition frequency is switched.

Description

Laser radar light source and repetition frequency switching method thereof
Technical Field
The invention relates to the field of laser radars, in particular to a laser radar light source and a repetition frequency switching method thereof.
Background
At present, for a common vehicle-mounted laser radar, only laser pulses with the same repetition frequency are transmitted to detect a target object, the vehicle-mounted laser radar transmitting the single repetition frequency is suitable for being applied to a single vehicle condition, when a plurality of vehicles simultaneously go on the road, the laser repetition frequencies transmitted between the vehicles are the same, the laser radars between the vehicles can interfere with each other, and therefore the purpose of accurate detection cannot be achieved.
At present, there is a method of adjusting the repetition frequency of pulses emitted by a pulse light source of a vehicle-mounted laser radar, that is, pulse trains with different repetition frequencies are emitted in different time periods, so as to avoid interference with other vehicles, but this method needs to ensure that the pulse energy of pulses with different repetition frequencies remains unchanged when the repetition frequencies are switched, so that the pump light power of a pump light source needs to be changed when the pulse repetition frequencies are switched, however, the lifetime of erbium ions in pump light emitted by the pump light source is in the order of milliseconds, so that the time for adjusting the pulse energy emitted by the laser radar light source by changing a pump is also in the order of milliseconds, but the time for switching the pulse trains with different repetition frequencies is in the order of microseconds, which causes that after the pulse light source switches the repetition frequencies, the pump light source does not complete the change of the pump light power yet, so that the initial pulse energy output by the pulse light source after switching the repetition frequencies is decreased, resulting in degraded detection performance.
The above is only for the purpose of assisting understanding of the technical aspects of the present invention, and does not represent an admission that the above is prior art.
Disclosure of Invention
The present invention mainly aims to provide a laser radar light source and a repetition frequency switching method thereof, which aim to solve the problems mentioned in the background art.
To achieve the above object, the present invention provides a laser radar light source, comprising:
a pulse signal transmitting system for transmitting pulse signal lights of different repetition frequencies;
the pumping system is used for amplifying the pulse signal light emitted by the pulse signal emitting system to generate amplified pulse signal light;
a control signal emitting system for emitting control signal light to consume a part of pump light power of the pump system;
the central control system is electrically connected with the pulse signal transmitting system, the pumping system and the control signal transmitting system respectively, and is used for:
controlling the pulse signal light to switch pulse signal light with different repetition frequencies;
controlling the pumping system to emit pumping light; and
and controlling the control signal transmitting system to transmit control signal light.
In an embodiment of the present application, the central control system is further configured to: and before controlling the pulse signal emission system to increase the repetition frequency, controlling the pumping system to increase the power of the pump light, and controlling the control signal emission system to emit control signal light.
In an embodiment of the present application, the central control system is further configured to: and after the pump light power of the pump system is increased to a preset value, closing the control signal transmitting system.
In an embodiment of the present application, the central control system is further configured to: and after controlling the pulse signal emission system to reduce the repetition frequency, controlling the pumping system to reduce the power of the pumping light, and controlling the control signal emission system to emit control signal light.
In an embodiment of the present application, the central control system is further configured to: and after the pump light power of the pump system is reduced to a preset value, the control signal transmitting system is closed.
In this embodiment of the present application, the polarization direction of the pulse signal light emitted by the pulse signal emission system is perpendicular to the polarization direction of the control signal light emitted by the control signal emission system.
In the embodiment of the present application, the pulse signal transmitting system is provided with: the device comprises a pulse signal light source, a first polarization beam splitter prism, a first collimator, a polarization-maintaining gain optical fiber and a second collimator, wherein the pulse signal light source is used for transmitting pulse signal light with different repetition frequencies to the first polarization beam splitter prism, and the pulse signal light sequentially passes through the first polarization beam splitter prism, the first collimator, the polarization-maintaining gain optical fiber and the second collimator;
the pumping system comprises a first polarization-maintaining beam combiner and a first pumping light source, wherein the first pumping light source is used for emitting pumping light to the first polarization-maintaining beam combiner, and the first polarization-maintaining beam combiner is used for coupling the pumping light to the polarization-maintaining gain fiber;
the control signal transmitting system comprises a control light source and a second polarization beam splitter prism, the pulse signal light source is used for transmitting control signal light to the first polarization beam splitter prism, the control signal light sequentially penetrates through the first collimator, the polarization maintaining gain optical fiber and the second collimator after being reflected by the first polarization beam splitter prism, and the second polarization beam splitter prism is used for separating the pulse signal light and the control signal light which penetrate through the second collimator.
In this embodiment, the pulse signal transmitting system further includes: the first Faraday rotator and the first half-wave plate are arranged between the pulse signal light source and the first polarization splitting prism;
the control signal transmission system further includes: the second Faraday rotator and the second half-wave plate are arranged between the control light source and the first polarization splitting prism.
In this embodiment of the application, when the pump light emitted from the first pump light source to the first polarization maintaining beam combiner is opposite to the propagation direction of the pulse signal light, the first polarization maintaining beam combiner is disposed between the first collimator and the second collimator, and the polarization maintaining gain fiber is disposed between the first collimator and the first polarization maintaining beam combiner;
when the propagation direction of the pump light emitted by the first pump light source to the first polarization maintaining beam combiner is the same as the propagation direction of the pulse signal light, the first polarization maintaining beam combiner is arranged between the first collimator and the second collimator, and the polarization maintaining gain fiber is arranged between the first polarization maintaining beam combiner and the second collimator.
In this embodiment, the pumping system further includes a second pumping light source and a second polarization maintaining beam combiner, where the second polarization maintaining beam combiner is configured to couple pumping light emitted by the second pumping light source to the polarization maintaining gain fiber, and the first polarization maintaining beam combiner and the second polarization maintaining beam combiner are respectively disposed on two sides of the polarization maintaining gain fiber.
In this embodiment, the optical distances from the pulse signal light source and the control signal light source to the first polarization splitting prism are the same.
In the embodiment of the present application, the pulse signal transmitting system is provided with: the polarization maintaining device comprises a pulse signal light source, a third polarization beam splitter prism, a third normal-tension first rotator, a third half-wave plate, a fourth polarization beam splitter prism, a third collimator, a non-polarization maintaining gain optical fiber and a fourth collimator, wherein the pulse signal light source is also used for transmitting pulse signal light with different repetition frequencies to the third polarization beam splitter prism;
the pumping system comprises a non-polarization-maintaining beam combiner and a third pumping light source, the non-polarization-maintaining beam combiner is arranged between the third collimator and the fourth collimator, and the third pumping light source is used for emitting pumping light to the non-polarization-maintaining beam combiner;
the control signal transmitting system comprises a control light source, a fifth polarization beam splitter prism, a fourth half-wave plate, a fourth Faraday rotator, a fifth Faraday rotator and a first reflector, wherein the fifth polarization beam splitter prism, the fourth half-wave plate and the fourth Faraday rotator are arranged between the control light source and the fourth polarization beam splitter prism, the fifth Faraday rotator and the first reflector are sequentially arranged behind the fourth collimator, and the pulse signal light source is used for transmitting control signal light to the fifth polarization beam splitter prism;
the pulse signal light sequentially passes through the third polarization beam splitter prism, the third normal-pulling first rotator, the third half-wave plate, the fourth polarization beam splitter prism, the third collimator, the non-polarization-maintaining gain optical fiber, the non-polarization-maintaining beam combiner and the fourth collimator;
the control signal light is reflected by the fifth polarization beam splitter prism, then sequentially passes through the fourth half-wave plate and the fourth Faraday rotator, and is reflected by the fourth polarization beam splitter prism, then sequentially passes through the third collimator, the non-polarization-maintaining gain optical fiber, the non-polarization-maintaining beam combiner and the fourth collimator;
the control signal light and the pulse signal light pass through the fourth collimator, then pass through the fifth Faraday rotator, are reflected by the first reflector, then sequentially pass through the fifth Faraday rotator, the fourth collimator, the non-polarization-maintaining beam combiner, the non-polarization-maintaining gain optical fiber and the third collimator, and are separated by the fourth polarization splitting prism.
The embodiment of the present application further provides a laser radar light source repetition frequency switching method, which is applied to any one of the above laser radar light sources, and includes:
when the pulse signal emitting system needs to increase the pulse signal light from a first repetition frequency to a second repetition frequency at a first moment, controlling the pumping system to gradually increase the power of the pumping light from a first power matched with the first repetition frequency to a second power matched with the repetition frequency within a first preset time period before the first moment, controlling the control signal emitting system to emit gradually increased control signal light, and turning off the control signal emitting system at the first moment;
when the pulse signal emitting system needs to reduce the pulse signal light to a third repetition frequency at a second moment, in a preset second time period after the second moment, the pumping system is controlled to gradually reduce the power of the pumping light to a third power matched with the third repetition frequency, and simultaneously the control signal emitting system is controlled to emit the gradually reduced control signal light in the preset second time period, and the control signal emitting system is closed at the second moment.
The laser radar light source system provided by the invention is provided with a control signal transmitting system, when the pulse signal transmitting system switches the repetition frequency of the transmitted pulse signal light, the control signal transmitting system transmits a control signal light to change the power of the pump light transmitted by a pump system, for example, when the laser radar light source system needs to increase the repetition frequency of the pulse signal light, the pump light power needs to be correspondingly increased in order to keep the pulse energy unchanged, in order to be synchronously switched with the pulse signal light, the pump light power can be increased before the pulse signal light repetition frequency is switched, and simultaneously, the control signal light system is opened to transmit the control signal light to counteract the increased pump light power, and when the pump light power is increased to proper power, the control signal light system is closed and the repetition frequency of the pulse signal light is switched; or when the laser radar light source system needs to reduce the repetition frequency of the pulse signal light, the pump light power needs to be correspondingly reduced in order to keep the pulse energy unchanged, and in order to keep synchronous switching with the pulse signal light, the pump light power can be reduced when the repetition frequency of the pulse signal light is switched, the control signal light system is turned on to emit the control signal light so as to counteract the redundant pump light power, and when the pump light power is reduced to a proper value, the control signal emitting system is turned off. Therefore, no matter the repetition frequency needs to be increased or decreased, the control signal light can be emitted through the control system, so that the power of the pump light source is always matched with that of the pulse signal light, and the pulse energy is ensured to be unchanged.
Drawings
FIG. 1 is a block diagram of a lidar light source according to an embodiment of the present disclosure;
FIG. 2 is a schematic structural diagram of a lidar light source according to an embodiment of the present disclosure;
FIG. 3 is a schematic structural diagram of a lidar light source according to another embodiment of the present disclosure;
FIG. 4 is a schematic structural diagram of a lidar light source according to another embodiment of the present disclosure;
FIG. 5 is a schematic structural diagram of a lidar light source according to another embodiment of the present disclosure;
FIG. 6 is a schematic structural diagram of a lidar light source according to another embodiment of the present disclosure;
fig. 7 is a timing diagram of emission of a control signal light, a pulse signal light, and a pump light in a lidar light source according to an embodiment of the present disclosure.
Reference numbers: 100-central control system
200-a pulse signal transmitting system, 210-a pulse signal light source, 211-a first polarization beam splitter prism, 212-a first collimator, 213-a polarization-maintaining gain optical fiber, 214-a second collimator, 215-a first Faraday rotator, 216-a first half wave plate, 217-a third polarization beam splitter prism, 218-a third Faraday rotator, 219-a third half wave plate, 220-a fourth polarization beam splitter prism, 221-a non-polarization-maintaining gain optical fiber and 222-a fourth collimator;
300-pumping system, 310-first pumping light source, 311-first polarization maintaining beam combiner, 320-second pumping light source, 321-second polarization maintaining beam combiner, 330-non-polarization maintaining beam combiner;
400-control signal transmission system, 410-control signal light source, 411-second polarization splitting prism, 412-second half-wave plate, 413-second faraday rotator, 414-fifth polarization splitting prism, 415-fourth half-wave plate, 416-fourth faraday rotator, 417-fifth faraday rotator, 418-first reflector.
Detailed Description
The principles and spirit of the present invention will be described with reference to several exemplary embodiments. It is understood that these embodiments are given solely for the purpose of enabling those skilled in the art to better understand and to practice the invention, and are not intended to limit the scope of the invention in any way. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
According to the embodiment of the invention, a laser radar light source and a repetition frequency switching method thereof are provided.
In this document, it is to be understood that any number of elements in the figures are provided by way of illustration and not limitation, and any nomenclature is used for differentiation only and not in any limiting sense.
The principles and spirit of the present invention are explained in detail below with reference to several representative embodiments of the invention.
Exemplary devices
As shown in fig. 1, the present exemplary embodiment proposes a laser radar light source including:
a pulse signal transmitting system 200 for transmitting pulse signal light of different repetition frequencies;
a pumping system 300 for amplifying the pulse signal light emitted from the pulse signal emitting system 200 to generate an amplified pulse signal light;
a control signal emitting system 400 for emitting control signal light to consume a part of the pump light power of the pumping system 300;
a central control system 100 electrically connected to the pulse signal emitting system 200, the pumping system 300, and the control signal emitting system 400, respectively, wherein the central control system 100 is configured to:
controlling the pulse signal light to switch pulse signal light with different repetition frequencies;
controlling the pumping system 300 to emit pumping light; and
the control signal transmission system 400 is controlled to transmit the control signal light.
As shown in fig. 1, in this embodiment, the central control system 100 can control the pulse signal emitting system 200 to emit the pulse signal light, control the pumping system 300 to emit the pumping light, and control the control signal emitting system 400 to emit the control signal light, and can also control to switch the pulse signal light with different repetition frequencies, increase or decrease the power of the pumping light, and the control signal light emitted by the control signal emitting system 400 can be used to consume the power of the pumping light emitted by the pumping system 300.
For example, in the embodiment of the present application, the central control system 100 is further configured to: before controlling the pulse signal emission system 200 to increase the repetition frequency, the pumping system 300 is controlled to increase the power of the pumping light, and the control signal emission system 400 is controlled to emit the control signal light. For example, when it is required to increase the repetition frequency of the pulse signal light emitted by the pulse signal emitting system, the central control system 100 may control the pumping system 300 to increase the power of the pumping light and simultaneously turn on the control signal light system to emit the control signal light before controlling the repetition frequency of the pulse signal light to increase. The central control system 100 is further configured to: after the pump light power of the pump system 300 is increased to a preset value, the control signal transmitting system 400 is turned off. For example, when the pump light power is increased to a suitable power, the central control system 100 turns off the control signal light system, and the repetition frequency of the pulse signal light can be switched. In the process of increasing the repetition frequency of the pulse signal light, firstly, the pumping system 300 is controlled to increase the repetition frequency, the control signal light emitted by the control signal light system is used for counteracting the pumping light power increased by the pumping system 300, when the pumping light power is increased to a proper value, the control signal emitting system 400 is closed, the pulse signal emitting system 200 is controlled to be switched to the repetition frequency required to be increased, the whole process is always kept, the pumping light power is matched with the repetition frequency of the pulse signal light, the pulse energy is kept unchanged, and the synchronous switching of the pulse signal light and the pumping light is realized.
In the embodiment of the present application, the central control system 100 is further configured to: after controlling the pulse signal emission system 200 to decrease the repetition frequency, the pumping system 300 is controlled to decrease the pumping light power, and the control signal emission system 400 is controlled to emit the control signal light. For example, when the laser radar light source system needs to reduce the repetition frequency of the pulse signal light, the central control system 100 first reduces the repetition frequency of the pulse signal light, and simultaneously turns on the control signal emitting system 400 to emit the control signal light, and controls the pumping system 300 to reduce the power of the pumping light. In addition, the central control system 100 is further configured to: after the pump light power of the pump system 300 is reduced to a preset value, the control signal transmitting system 400 is turned off. Such as turning off the control signal transmission system 400 when the pump light power is reduced to a suitable value. Therefore, no matter the repetition frequency of the pulse signal light is reduced, the power of the pump light source is always matched with that of the pulse signal light, pulse energy is guaranteed to be unchanged, and synchronous switching of the repetition frequency of the pulse signal light and the power of the pump light is achieved.
In the embodiment of the present application, the pulse signal light emitted by the pulse signal emitting system 200 and the polarization direction of the control signal light emitted by the control signal emitting system 400 are perpendicular to each other.
As shown in fig. 2, in the embodiment of the present application, the pulse signal transmitting system 200 is provided with: the pulse signal light source 210 is configured to emit pulse signal light with different repetition frequencies to the first polarization beam splitter 211, and the pulse signal light sequentially passes through the first polarization beam splitter 211, the first collimator 212, the polarization maintaining gain fiber 213, and the second collimator 214;
the pumping system 300 comprises a first polarization maintaining beam combiner 311 and a first pumping light source 310, the first pumping light source 310 is configured to emit pumping light to the first polarization maintaining beam combiner 311, the first polarization maintaining beam combiner 311 is configured to couple the pumping light to the polarization maintaining gain fiber 213;
the control signal transmitting system 400 includes a control light source and a second polarization beam splitter prism 411, the pulse signal light source 210 is configured to transmit control signal light to the first polarization beam splitter prism 211, the control signal light passes through the first collimator 212, the polarization maintaining gain fiber 213, and the second collimator 214 after being reflected by the first polarization beam splitter prism 211, and the second polarization beam splitter prism 411 is configured to separate the pulse signal light and the control signal light after passing through the second collimator 214.
In this embodiment, the pulse signal light source 210, the control light source, and the pump light source may all be semiconductor lasers, wherein the wavelength of the pulse signal light is selected from 1530 nm to 1560 nm, the wavelength of the control signal light is selected from 1530 nm to 1560 nm, the wavelength of the pump light is selected from 900nm to 1000nm, the gain fiber may be erbium-doped fiber or erbium-ytterbium co-doped fiber, and the type of the fiber is single-mode fiber.
As shown in fig. 2, in the present embodiment, the pulse signal light source 210 and the control light source respectively emit pulse signal light and control signal light to the first polarization splitting prism 211 from two directions, wherein the first polarization splitting prism 211 is used to separate different linear polarization lights, in the present embodiment, the pulse signal light may be horizontal linear polarization pulse signal light, and the control signal light may be vertical linear polarization control signal light, so that after the pulse signal light is respectively incident to the first polarization splitting prism in the direction shown in fig. 2, the pulse signal light passes through the first polarization splitting prism 211 to the first collimator 212, the control signal light is reflected from the first polarization splitting prism 211 to the first collimator 212, it should be noted that, in other embodiments, the positions of the pulse signal light source 210 and the control signal light source 410 may be changed by changing the setting direction of the first polarization splitting prism 211 and the linear polarization direction of the control signal light, for example, meanwhile, the pulse signal light is changed into the vertical line offset, the control signal light is changed into the horizontal line offset, the control signal light can penetrate through the first polarization splitting prism 211 to enter the first collimator 212, the pulse signal light can be reflected by the first polarization splitting prism 211 to enter the first collimator 212, the setting directions of the specific pulse signal light, the control signal light and the first polarization splitting prism 211 can be determined according to actual conditions, and the embodiment of the application is not particularly limited.
With reference to fig. 2, for the pulse signal light, the pulse signal light passes through the first polarization splitting prism 211, then is collimated by the first collimator 212, passes through the first collimator 212, and then enters the polarization maintaining gain fiber 213, and the first polarization maintaining beam combiner 311 couples the pump light to the polarization maintaining gain fiber 213, so that the pulse signal light is amplified in the polarization maintaining gain fiber 213. The amplified pulse signal light enters the first polarization maintaining beam combiner 311 from the polarization maintaining gain fiber 213, passes through the first polarization maintaining beam combiner 311, enters the second collimator 214, is collimated by the second collimator 214, and finally passes through the second polarization splitting prism 411 to be emitted.
With reference to fig. 2, for the control signal light, the control signal light passes through the first polarization splitting prism 211, enters the first collimator 212 for collimation, passes through the first collimator 212, enters the polarization maintaining gain fiber 213, can consume a part of the pump light and generate an invalid amplification control signal light, exits from the polarization maintaining gain fiber 213, enters the first polarization maintaining beam combiner 311, passes through the first polarization maintaining beam combiner 311, enters the second collimator 214, passes through the second collimator 214 for collimation, and is finally reflected and emitted through the second polarization splitting prism 411. Wherein the second polarization beam splitter prism 411 is used to separate the invalid amplification control signal light generated by the control signal light and the amplified pulse signal light generated by the pulse signal light, in the present embodiment, the amplified pulse signal light passes through the second polarization beam splitter prism 411, the invalid amplification control signal light is reflected from the second polarization beam splitter prism 411, and in other embodiments, the amplified pulse signal light is reflected from the second polarization beam splitter prism 411, and the invalid amplification control signal light passes through the second polarization beam splitter prism 411.
As shown in fig. 3, in the embodiment, the pulse signal transmitting system 200 further includes: a first faraday rotator 215 and a first half-wave plate 216, wherein the first faraday rotator 215 and the first half-wave plate 216 are arranged between the pulse signal light source 210 and the first polarization splitting prism 211;
the control signal transmission system 400 further includes: a second faraday rotator 413 and a second half-wave plate 412, wherein the second faraday rotator 413 and the second half-wave plate 412 are arranged between the control light source and the first polarization splitting prism 211.
In this embodiment, for example, the pulse signal light source 210 emits the horizontally polarized pulse signal light, and the control signal light source 410 emits the vertically polarized control signal light, for the horizontally polarized pulse signal light, the horizontally polarized pulse signal light is emitted from the pulse signal light source 210 and then enters the first faraday rotator 215, the first faraday rotator 215 is used for performing the non-reciprocal rotation of the polarization direction of the light, so that the horizontally polarized pulse signal light passes through the first faraday rotator 215, and then the polarization direction thereof is rotated clockwise by 45 degrees as viewed in the transmission direction thereof, and then enters the first half wave plate 216, the first half wave plate 216 is used for performing the reciprocal rotation of the polarization direction of the light, so that the linearly polarized pulse signal light rotated by 45 degrees passes through the first half wave plate 216, and then the polarization direction thereof is rotated counterclockwise by 45 degrees as viewed in the transmission direction thereof, and is converted into the horizontally polarized pulse signal light again, then, the horizontal polarization pulse signal light enters the first polarization splitting prism 211, enters the first collimator 212 after passing through the first polarization splitting prism 211, enters the polarization maintaining gain fiber 213 after passing through the first collimator 212, and is coupled to the polarization maintaining gain fiber 213 by the first polarization maintaining beam combiner 311, so that the horizontal polarization pulse signal light is amplified in the polarization maintaining gain fiber 213. The amplified horizontal polarization pulse signal light is emitted from the polarization maintaining gain fiber 213, then enters the first polarization maintaining beam combiner 311, passes through the first polarization maintaining beam combiner 311, enters the second collimator 214, is collimated by the second collimator 214, enters the second polarization splitting prism 411, passes through the second polarization splitting prism 411, and then is emitted.
For the vertically polarized control signal light, after being emitted from the control signal light source 410, the vertically polarized control signal light is incident on the second half wave plate 412, the second half wave plate 412 is used for reciprocally rotating the polarization direction of the light, after passing through the second half wave plate 412, the vertically polarized control signal light is observed along the transmission direction, the polarization direction thereof is rotated clockwise by 45 degrees, and then the vertically polarized control signal light is incident on the second faraday rotator 413, the second faraday rotator 413 is used for non-reciprocally rotating the polarization direction of the light, after passing through the second faraday rotator 413, the linearly polarized control signal light rotated by 45 degrees is observed along the transmission direction, the polarization direction thereof is rotated counterclockwise by 45 degrees, and is converted into the vertically polarized control signal light, and then the vertically polarized control signal light is incident on the first polarization splitting prism 211, after being reflected by the first polarization splitting prism 211, the vertically polarized control signal light is incident on the first collimator 212, the amplified vertical linear polarization control signal light which is invalid is emitted from the polarization maintaining gain fiber 213, then is emitted to the first polarization maintaining beam combiner 311, passes through the first polarization maintaining beam combiner 311, is emitted to the second collimator 214, is collimated by the second collimator 214, is emitted to the second polarization splitting prism 411, and is reflected by the second polarization splitting prism 411.
This application embodiment is through setting up first Faraday rotator 215 and second Faraday rotator 413, can avoid harmful reverberation to cause optical damage to the laser radar light source, improves the system stability of laser radar light source.
As shown in fig. 3, in the embodiment of the present application, when the pump light emitted from the first pump light source 310 to the first polarization maintaining beam combiner 311 is in the opposite direction to the propagation direction of the pulse signal light, the first polarization maintaining beam combiner 311 is disposed between the first collimator 212 and the second collimator 214, and the polarization maintaining gain fiber 213 is disposed between the first collimator 212 and the first polarization maintaining beam combiner 311. As shown in fig. 3, the pump system 300 emits pump light from the right side of the first polarization maintaining beam combiner 311, and the pulse signal light propagates from the left side of the first polarization maintaining beam combiner 311 to the right side, at this time, the polarization maintaining gain fiber 213 is disposed between the first collimator 212 and the first polarization maintaining beam combiner 311, the pulse signal light enters the polarization maintaining gain fiber 213 after being collimated by the first collimator 212, the first polarization maintaining beam combiner 311 couples the pump light to the polarization maintaining gain fiber 213, and population inversion is generated in the polarization maintaining gain fiber 213, so that the pulse signal light is amplified.
As shown in fig. 4, in the embodiment of the present application, when the pump light emitted from the first pump light source 310 to the first polarization maintaining beam combiner 311 has the same propagation direction as the pulse signal light, the polarization maintaining gain fiber 213 is disposed between the first polarization maintaining beam combiner 311 and the second collimator 214. As shown in fig. 4, the pumping system 300 emits pumping light from the left side of the first polarization maintaining beam combiner 311, and the pulse signal light also propagates from the left side to the right side of the first polarization maintaining beam combiner 311, at this time, the first polarization maintaining beam combiner 311 is disposed between the second collimators 214, and the polarization maintaining gain fiber 213 is disposed between the first polarization maintaining beam combiner 311 and the second collimators 214, the pulse signal light enters the polarization maintaining gain fiber 213 after passing through the collimators 212 and 311, the pumping light is coupled to the polarization maintaining gain fiber 213 through the first polarization maintaining beam combiner 311, and population inversion is generated in the polarization maintaining gain fiber 213, so that the pulse signal light is amplified. As shown in fig. 5, in the embodiment of the present application, the pumping system 300 further includes a second pumping light source 320 and a second polarization maintaining beam combiner 321, the second polarization maintaining beam combiner 321 is configured to couple pumping light emitted by the second pumping light source 320 to the polarization maintaining gain fiber 213, and the first polarization maintaining beam combiner 311 and the second polarization maintaining beam combiner 321 are respectively disposed on two sides of the polarization maintaining gain fiber 213. As shown in fig. 5, the first pump light source 310 and the first polarization maintaining beam combiner 311 are disposed on the left side of the polarization maintaining gain fiber 213, the second polarization maintaining beam combiner 321 and the second pump light source 320 are disposed on the right side of the polarization maintaining gain fiber 213, and the pump light emitted by the first pump light source 310 and the second pump light source 320 is coupled to the polarization maintaining gain fiber 213 from the left side and the right side, respectively, so as to increase the optical power of the amplified pulse signal.
In the embodiment of the present application, the optical paths from the pulse signal light source 210 and the control signal light source 410 to the first polarization beam splitter prism 211 are the same, as shown in fig. 2 to 5, the optical paths from the pulse signal light source 210 and the control signal light source 410 to the first polarization beam splitter prism 211 are the same, so that the pulse signal light and the control signal light can simultaneously reach the polarization maintaining gain fiber 213, thereby facilitating the central control system 100 to control the timing of turning on and off the control signal system when switching the pulse signal repetition frequency.
As shown in fig. 6, in the embodiment of the present application, the pulse signal transmitting system 200 is provided with: the device comprises a pulse signal light source 210, a third polarization beam splitter prism 217, a third normal-tension first rotator 218, a third half-wave plate 219, a fourth polarization beam splitter prism 220, a third collimator, a non-polarization-maintaining gain fiber 221 and a fourth collimator 222, wherein the pulse signal light source 210 is further used for emitting pulse signal light with different repetition frequencies to the third polarization beam splitter prism 217;
the pumping system 300 comprises a non-polarization-maintaining beam combiner 330 and a third pump light source, the third pump light source is configured to emit pump light to the non-polarization-maintaining beam combiner 330, and the non-polarization-maintaining beam combiner 330 is configured to couple the pump light to the non-polarization-maintaining gain fiber 221;
the control signal transmitting system 400 includes a control light source, a fifth polarization beam splitter prism 414, a fourth half-wave plate 415, a fourth faraday rotator 416, a fifth faraday rotator 417 and a first reflector 418, the fifth polarization beam splitter prism 414, the fourth half-wave plate 415 and the fourth faraday rotator 416 are disposed between the control light source and the fourth polarization beam splitter prism 220, the fifth faraday rotator 417 and the first reflector 418 are sequentially disposed behind the fourth collimator 222, and the pulse signal light source 210 is configured to transmit control signal light to the fifth polarization beam splitter prism 414;
the pulse signal light sequentially passes through the third polarization beam splitter prism 217, the third normal-pulling first rotator 218, the third half-wave plate 219, the fourth polarization beam splitter prism 220, the third collimator, the non-polarization-maintaining gain fiber 221, the non-polarization-maintaining beam combiner 330 and the fourth collimator 222;
after being reflected by the fifth polarization beam splitter prism 414, the control signal light sequentially passes through the fourth half-wave plate 415 and the fourth faraday rotator 416, and after being incident to the fourth polarization beam splitter prism 220 and reflected, the control signal light sequentially passes through the third collimator, the non-polarization-maintaining gain fiber 221, the non-polarization-maintaining beam combiner 330 and the fourth collimator 222;
the control signal light and the pulse signal light pass through the fourth collimator 222, then pass through the fifth faraday rotator 417, are reflected by the first reflector 418, then pass through the fifth faraday rotator 417, the fourth collimator 222, the non-polarization-maintaining beam combiner 330, the non-polarization-maintaining gain fiber 221, and the third collimator in sequence, and are separated by the fourth polarization beam splitter prism 220.
With continued reference to fig. 6, in the present embodiment,
in this embodiment, for example, the pulsed signal light source 210 emits a horizontally polarized pulsed signal light, the control signal light source 410 emits a vertically polarized control signal light, and for the horizontally polarized pulsed signal light, the horizontally polarized pulsed signal light is emitted from the pulsed signal light source 210, enters the third polarization beam splitter 217, passes through the third polarization beam splitter 217, enters the third faraday rotator 218, and is configured to perform non-reciprocal rotation on the polarization direction of the light, so that the horizontally polarized pulsed signal light passes through the third faraday rotator 218, and is viewed along the transmission direction, the polarization direction of the horizontally polarized pulsed signal light rotates clockwise by 45 degrees, and then enters the third half-wave plate 219, and the third half-wave plate 219 is configured to perform reciprocal rotation on the polarization direction of the light, so that the linearly polarized pulsed signal light rotated by 45 degrees passes through the third half-wave plate 219, and is viewed along the transmission direction, the polarization direction of the light is rotated counterclockwise by 45 degrees, and is converted into a horizontal polarization pulse signal light again, and then the horizontal polarization pulse signal light enters the fourth polarization beam splitter prism 220, passes through the fourth polarization beam splitter prism 220, enters the third collimator, is collimated by the third collimator, enters the non-polarization-maintaining gain fiber 221, and the pump light is coupled to the non-polarization-maintaining gain fiber 221 through the non-polarization-maintaining beam combiner 330, so that the pulse signal light and the pump light meet each other in the non-polarization-maintaining gain fiber 221, the pulse signal light is amplified and emitted from the non-polarization-maintaining gain fiber 221, enters the non-polarization-maintaining beam combiner 330, passes through the non-polarization-maintaining beam combiner 330, enters the fourth collimator 222, is collimated by the fourth collimator 222, and enters the fifth faraday rotator 417, the fifth faraday rotator 417 is used for performing non-reciprocal rotation on the polarization direction of the light, and the amplified horizontal polarization pulse signal light passes through the fifth faraday rotator 417, the polarization direction of the pulse signal light is rotated by 45 degrees clockwise along the transmission direction thereof, and then the pulse signal light is incident to the first reflecting mirror 418, the first reflecting mirror 418 can reflect the pulse signal light, so that the pulse signal light rotated by 45 degrees is totally reflected by the reflecting mirror to the fifth faraday rotator 417, the reflected pulse signal light passes through the fifth faraday rotator 417, and then the polarization direction thereof is rotated by 45 degrees counterclockwise along the transmission direction thereof due to the non-reciprocity of the faraday rotator, thereby becoming a vertical linear polarization pulse signal light, the vertical linear polarization pulse signal light passes through the fourth collimator 222, the non-polarization-maintaining beam combiner 330, and the non-polarization-maintaining gain fiber 221 in sequence, is re-amplified, then passes through the third collimator, and is incident to the fourth polarization splitting prism 220, the vertical linear polarization pulse signal light is reflected by the fourth polarization splitting prism 220, and then is incident to the fourth faraday rotator 416, the fourth faraday rotator 416 is configured to perform non-reciprocal rotation on the polarization direction of light, the vertical linear polarization pulse signal light transmits through the fourth faraday rotator 416, and then the polarization direction of the vertical linear polarization pulse signal light is rotated by 45 degrees clockwise as viewed along the transmission direction, and then enters the fourth half-wave plate 415, the fourth half-wave plate 415 is configured to perform reciprocal rotation on the polarization direction of light, so that the linear polarization pulse signal light rotated by 45 degrees transmits through the fourth half-wave plate 415, and then the polarization direction of the linear polarization pulse signal light is rotated by 45 degrees clockwise as viewed along the transmission direction, and then the linear polarization pulse signal light becomes horizontal linear polarization pulse signal light, and then enters the fifth polarization beam splitter 414, the fifth polarization beam splitter 414 is configured to separate different linear polarizations, and the horizontal linear polarization pulse signal light transmits through the fifth polarization beam splitter 414 and then outputs amplified pulse signal light.
With continued reference to fig. 6, for the vertical polarization control signal light, the control signal light is emitted from the control signal light source 410, enters the fifth polarization splitting prism 414, is reflected from the fifth polarization splitting prism 414 to the fourth half-wave plate 415, passes through the fourth half-wave plate 415, is rotated by 45 degrees clockwise in the polarization direction as viewed in the transmission direction, then enters the third faraday rotator 218, passes through the third faraday rotator 218, is rotated by 45 degrees counterclockwise in the polarization direction as viewed in the transmission direction, is converted into the vertical polarization control signal light again, and then enters the fourth polarization splitting prism 220, the vertical polarization control signal light is reflected to the third collimator by the fourth polarization splitting prism 220, is collimated by the third collimator, enters the non-polarization-maintaining gain fiber 221, and the pump light is coupled to the non-polarization maintaining gain fiber 221 by the non-polarization maintaining beam combiner 330, therefore, the control signal light can consume a part of the pump light and is amplified into the invalid amplification control signal light, the invalid amplification control signal light is emitted from the non-polarization-maintaining gain fiber 221, enters the non-polarization-maintaining beam combiner 330, passes through the non-polarization-maintaining beam combiner 330, enters the fourth collimator 222, is collimated by the fourth collimator 222, enters the fifth faraday rotator 417, passes through the fifth faraday rotator 417, is rotated by 45 degrees clockwise in the polarization direction along the transmission direction, and then enters the first mirror 418, the first mirror 418 can reflect the control signal light, so that the control signal light rotated by 45 degrees is totally reflected by the mirror to the fifth faraday rotator 417, the reflected control signal light is rotated by 45 degrees clockwise in the polarization direction along the transmission direction after passing through the fifth faraday rotator 417, thereby becoming the horizontal polarization control signal light, which is amplified again after passing through the fourth collimator 222, the non-polarization-maintaining beam combiner 330 and the non-polarization-maintaining gain fiber 221 in sequence, then enters the fourth polarization beam splitter prism 220 after passing through the third collimator, the horizontal polarization control signal light enters the third half-wave plate 219 after passing through the fourth polarization beam splitter prism 220, and is observed along the transmission direction after passing through the third half-wave plate 219, the polarization direction thereof is rotated counterclockwise by 45 degrees and then is incident to the third normal-draw first rotator 218, passes through the third normal-draw first rotator 218, and is viewed in the transmission direction thereof, the polarization direction thereof is rotated counterclockwise by 45 degrees to become vertical polarization control signal light, and then is incident to the third polarization splitting prism 217, the vertical linear polarization control signal light is reflected by the third polarization splitting prism 217 and then outputs an invalid amplification control signal light.
In the embodiment of the present application, the first reflecting mirror 418 is arranged to reflect the pulse signal and the control signal light, so that the pulse signal and the control signal light can be amplified twice, and the third polarization beam splitter 217, the third faraday rotator 218, the third half-wave plate 219, the fourth polarization wind/solar prism, the fourth faraday rotator 416, the fifth polarization beam splitter 414, and the fifth faraday rotator 417 are arranged to pass through some rotation polarization directions and to transmit or reflect the amplified pulse signal light and the invalid amplified control signal light, so that the pulse signal light source 210 and the control signal light source 410 are not influenced to transmit subsequent pulse signal light and control signal light.
Fig. 7 shows a timing diagram of the emission timing of the pulse signal light source 210, the control signal light source 410, and the pump light source when the repetition frequency switching method of the laser radar light source is applied to the laser radar light source in any of the above embodiments. The method comprises the following steps: when the pulse signal emitting system 200 needs to increase the pulse signal light to a second repetition frequency at a first time, in a first preset time period before the first time, controlling the pump system 300 to gradually increase the first power to a second power matched with the repetition frequency, controlling the control signal emitting system 400 to emit the gradually increased control signal light, and turning off the control signal emitting system 400 at the first time;
when the pulse signal emitting system 200 needs to reduce the pulse signal light to a third repetition frequency at a second time, in a preset second time period after the second time, the pumping system 300 is controlled to gradually reduce the first power to a third power matched with the third repetition frequency, and simultaneously the control signal emitting system 400 is controlled to emit the gradually reduced control signal light in the preset second time period, and the control signal emitting system 400 is turned off at the second time.
In the embodiment of the present application, as shown in fig. 7, the lidar light source may emit a pulse signal train with repetition frequencies of f1, f2, and f3, wherein the pulse signal light repetition frequency is f1 during the time period t0 to t2, the pulse signal light repetition frequency is f2 during the time period t2 to t4, and the pulse signal light repetition frequency is f3 during the time period t4 to t 6.
At the time t0, pulse signal light and continuous pump light are emitted simultaneously, the power of the pump light is Pp1, and the amplified pulse energy is Es;
at time t2 (i.e. the first time), the repetition frequency of the pulse signal light needs to be switched from f1 to f2, because the switching time required by the pump light and the pulse signal is not in the same order, if the switching is performed simultaneously, when the repetition frequency of the pulse signal is switched to f2, the pump light power does not rise to the required target power Pp2, and thus the pulse energy changes, and the detection is unstable, therefore, in the present application, the control signal light starts to be emitted at time t1 before time t2, and the pump light power starts to be raised at the same time, during time t1-t2 (i.e. the first preset time), the pump light power gradually rises to the target power Pp2, the control signal light power also gradually rises, the gradually-raised pump light power is lost, and the total power of the pump light source kept in time t1-t2 is kept as Pp1 after the total power of the control signal light is lost, the pulse energy of the pulse signal light is not affected, and the pulse energy in the period t1-t2 can be maintained at Es.
At time t2, the pump light can provide proper power to the signal light with repetition frequency f2, and the control signal light is turned off, so that a pulse sequence with pulse energy Es and repetition frequency f2 is obtained, and the pulse sequence lasts until time t 4.
At time t4 (i.e., at the second time), the repetition frequency of the pulsed signal light needs to be reduced from f2 to f3, since the pump light source cannot reduce the pump light power to the target power Pp3 matched with the repetition frequency f3 of the pulsed signal light in synchronization with the pulsed signal light, the control signal light is started to emit at time t4, and simultaneously the pump light power starts to be reduced, the pump light power gradually decreases to the target power Pp3 during a time period t4-t5 (i.e., a second preset time period), the control signal light power also gradually decreases, and the control signal light consumes the pump light power exceeding Pp3, so that the pulse energy of the pulsed signal light is not affected during the time period t4-t5, and the pump light decreases to the target power Pp3 at time t5, and at this time, the control signal light is turned off, so that a pulse sequence with pulse energy Es and repetition frequency f3 is obtained.
According to the embodiment of the application, the control signal light is introduced before the pulse signal light raises the repetition frequency, so that the pump light has enough time to reach the required pump light power, and the pulse energy is ensured to be kept unchanged, or the control signal light is introduced when the pulse signal light lowers the repetition frequency, so that the extra pump light which is not lowered to the target power is offset, and the pulse energy is kept unchanged. The control method can effectively reduce the stability time of the pulse energy during the switching of the repetition frequency, and is improved from millisecond magnitude to microsecond magnitude.
Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present invention, which are used for illustrating the technical solutions of the present invention and not for limiting the same, and the protection scope of the present invention is not limited thereto, although the present invention is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: those skilled in the art can still make modifications or changes to the embodiments described in the foregoing embodiments, or make equivalent substitutions for some features, within the scope of the disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Moreover, while the operations of the method of the invention are depicted in the drawings in a particular order, this does not require or imply that the operations must be performed in this particular order, or that all of the illustrated operations must be performed, to achieve desirable results. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step execution, and/or one step broken down into multiple step executions.

Claims (12)

1. A lidar light source comprising:
a pulse signal transmitting system for transmitting pulse signal lights of different repetition frequencies;
the pumping system is used for amplifying the pulse signal light emitted by the pulse signal emitting system to generate amplified pulse signal light;
the control signal transmitting system is used for transmitting control signal light to consume part of the pump light power of the pump system, and the pulse signal light transmitted by the pulse signal transmitting system is vertical to the polarization direction of the control signal light transmitted by the control signal transmitting system;
the central control system is electrically connected with the pulse signal transmitting system, the pumping system and the control signal transmitting system respectively, and is used for:
controlling the pulse signal light to switch pulse signal light with different repetition frequencies;
controlling the pumping system to emit pumping light; and
and controlling the control signal transmitting system to transmit control signal light.
2. The lidar light source of claim 1, wherein the central control system is further configured to: and before controlling the pulse signal emission system to increase the repetition frequency, controlling the pumping system to increase the power of the pump light, and controlling the control signal emission system to emit control signal light.
3. The lidar light source of claim 2, wherein the central control system is further configured to: and after the pump light power of the pump system is increased to a preset value, closing the control signal transmitting system.
4. The lidar light source of claim 1, wherein the central control system is further configured to: and after controlling the pulse signal transmitting system to reduce the repetition frequency, controlling the pumping system to reduce the power of the pumping light, and controlling the control signal transmitting system to transmit the control signal light.
5. The lidar light source of claim 4, wherein the central control system is further configured to: and after the pump light power of the pump system is reduced to a preset value, closing the control signal transmitting system.
6. Lidar light source according to any of claims 1 to 5, wherein said pulse signal transmission system is provided with, in its transmission direction: the device comprises a pulse signal light source, a first polarization beam splitter prism, a first collimator, a polarization-preserving gain optical fiber and a second collimator, wherein the pulse signal light source is used for transmitting pulse signal light with different repetition frequencies to the first polarization beam splitter prism, and the pulse signal light sequentially passes through the first polarization beam splitter prism, the first collimator, the polarization-preserving gain optical fiber and the second collimator;
the pumping system comprises a first polarization-maintaining beam combiner and a first pumping light source, wherein the first pumping light source is used for emitting pumping light to the first polarization-maintaining beam combiner, and the first polarization-maintaining beam combiner is used for coupling the pumping light to the polarization-maintaining gain fiber;
the control signal transmitting system comprises a control light source and a second polarization beam splitter prism, the control light source is used for transmitting control signal light to the first polarization beam splitter prism, the control signal light sequentially penetrates through the first collimator, the polarization maintaining gain optical fiber and the second collimator after being reflected by the first polarization beam splitter prism, and the second polarization beam splitter prism is used for separating the pulse signal light and the control signal light which penetrate through the second collimator.
7. The lidar light source of claim 6, wherein the pulsed signal transmission system further comprises: the first Faraday rotator and the first half-wave plate are arranged between the pulse signal light source and the first polarization splitting prism;
the control signal transmission system further includes: the second Faraday rotator and the second half-wave plate are arranged between the control light source and the first polarization splitting prism.
8. The lidar light source of claim 6, wherein the first polarization maintaining beam combiner is disposed between the first collimator and the second collimator, and the polarization maintaining gain fiber is disposed between the first collimator and the first polarization maintaining beam combiner when the pump light emitted by the first pump light source to the first polarization maintaining beam combiner is in a direction opposite to a propagation direction of the pulsed signal light;
when the propagation direction of the pump light emitted by the first pump light source to the first polarization maintaining beam combiner is the same as the propagation direction of the pulse signal light, the first polarization maintaining beam combiner is arranged between the first collimator and the second collimator, and the polarization maintaining gain fiber is arranged between the first polarization maintaining beam combiner and the second collimator.
9. The lidar optical source of claim 8, wherein the pump system further comprises a second pump optical source and a second polarization maintaining beam combiner, the second polarization maintaining beam combiner is configured to couple the pump light emitted from the second pump optical source to the polarization maintaining gain fiber, and the first polarization maintaining beam combiner and the second polarization maintaining beam combiner are respectively disposed at two sides of the polarization maintaining gain fiber.
10. The lidar light source of claim 6, wherein the optical distances from the pulse signal light source and the control signal light source to the first polarization beam splitter prism are the same.
11. Lidar light source according to any of claims 1 to 5,
the pulse signal transmitting system is provided with: the polarization maintaining device comprises a pulse signal light source, a third polarization beam splitter prism, a third normal-tension first rotator, a third half-wave plate, a fourth polarization beam splitter prism, a third collimator, a non-polarization maintaining gain optical fiber and a fourth collimator, wherein the pulse signal light source is also used for transmitting pulse signal light with different repetition frequencies to the third polarization beam splitter prism;
the pumping system comprises a non-polarization-maintaining beam combiner and a third pumping light source, the non-polarization-maintaining beam combiner is arranged between the third collimator and the fourth collimator, and the third pumping light source is used for emitting pumping light to the polarization-maintaining beam combiner;
the control signal transmitting system comprises a control light source, a fifth polarization beam splitter prism, a fourth half-wave plate, a fourth Faraday rotator, a fifth Faraday rotator and a first reflector, wherein the fifth polarization beam splitter prism, the fourth half-wave plate and the fourth Faraday rotator are arranged between the control light source and the fourth polarization beam splitter prism, the fifth Faraday rotator and the first reflector are sequentially arranged behind the fourth collimator, and the pulse signal light source is used for transmitting control signal light to the fifth polarization beam splitter prism;
the pulse signal light sequentially passes through the third polarization beam splitter prism, the third normal-pulling first rotator, the third half-wave plate, the fourth polarization beam splitter prism, the third collimator, the non-polarization-maintaining gain optical fiber, the non-polarization-maintaining beam combiner and the fourth collimator;
the control signal light is reflected by the fifth polarization splitting prism, then sequentially passes through the fourth half-wave plate and the fourth Faraday rotator, and is reflected by the fourth polarization splitting prism, then sequentially passes through the third collimator, the non-polarization-maintaining gain optical fiber, the non-polarization-maintaining beam combiner and the fourth collimator;
the control signal light and the pulse signal light pass through the fourth collimator, then pass through the fifth Faraday rotator, are reflected by the first reflector, then sequentially pass through the fifth Faraday rotator, the fourth collimator, the non-polarization-maintaining beam combiner, the non-polarization-maintaining gain optical fiber and the third collimator, and are separated by the fourth polarization splitting prism.
12. A laser radar light source repetition frequency switching method, for use with a laser radar light source according to any one of claims 1 to 11, comprising:
when the pulse signal emitting system needs to increase the pulse signal light from a first repetition frequency to a second repetition frequency at a first moment, controlling the pumping system to gradually increase the power of the pumping light from a first power matched with the first repetition frequency to a second power matched with the repetition frequency within a first preset time period before the first moment, controlling the control signal emitting system to emit gradually increased control signal light, and turning off the control signal emitting system at the first moment;
when the pulse signal emitting system needs to reduce the pulse signal light to a third repetition frequency at a second moment, in a preset second time period after the second moment, the pumping system is controlled to gradually reduce the power of the pumping light to a third power matched with the third repetition frequency, and simultaneously the control signal emitting system is controlled to emit the gradually reduced control signal light in the preset second time period, and the control signal emitting system is closed at the second moment.
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6038241A (en) * 1997-10-24 2000-03-14 Coherent, Inc. Pulsed-laser with first-pulse control
CN1328637A (en) * 1998-09-22 2001-12-26 英国国防部 Optical phase detector
CN102971923A (en) * 2010-06-28 2013-03-13 住友电气工业株式会社 Laser apparatus
CN104505699A (en) * 2014-12-05 2015-04-08 中国科学院西安光学精密机械研究所 Narrow-linewidth all-fiber ultrashort pulse amplification system with adjustable pulse width and repetition frequency
CN108603758A (en) * 2015-11-30 2018-09-28 卢米诺技术公司 The pulse laser of laser radar system and laser radar system with distribution type laser device and multiple sensor heads
CN109119875A (en) * 2018-09-21 2019-01-01 深圳市杰普特光电股份有限公司 Bicrystal infrared laser
WO2020204839A1 (en) * 2019-04-05 2020-10-08 Optotek D.O.O. A simple laser with an improved pump system for generating laser pulses on demand
CN113671509A (en) * 2021-08-16 2021-11-19 南京牧镭激光科技有限公司 Large-energy multichannel laser radar beam switching method

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6038241A (en) * 1997-10-24 2000-03-14 Coherent, Inc. Pulsed-laser with first-pulse control
CN1328637A (en) * 1998-09-22 2001-12-26 英国国防部 Optical phase detector
CN102971923A (en) * 2010-06-28 2013-03-13 住友电气工业株式会社 Laser apparatus
CN104505699A (en) * 2014-12-05 2015-04-08 中国科学院西安光学精密机械研究所 Narrow-linewidth all-fiber ultrashort pulse amplification system with adjustable pulse width and repetition frequency
CN108603758A (en) * 2015-11-30 2018-09-28 卢米诺技术公司 The pulse laser of laser radar system and laser radar system with distribution type laser device and multiple sensor heads
CN109119875A (en) * 2018-09-21 2019-01-01 深圳市杰普特光电股份有限公司 Bicrystal infrared laser
WO2020204839A1 (en) * 2019-04-05 2020-10-08 Optotek D.O.O. A simple laser with an improved pump system for generating laser pulses on demand
CN113671509A (en) * 2021-08-16 2021-11-19 南京牧镭激光科技有限公司 Large-energy multichannel laser radar beam switching method

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