CN216390018U

CN216390018U - Optical fiber amplifier and laser radar

Info

Publication number: CN216390018U
Application number: CN202122946622.1U
Authority: CN
Inventors: 胡小波; 刘颖
Original assignee: LeiShen Intelligent System Co Ltd
Current assignee: LeiShen Intelligent System Co Ltd
Priority date: 2021-11-26
Filing date: 2021-11-26
Publication date: 2022-04-26
Anticipated expiration: 2031-11-26

Abstract

An optical fiber amplifier and a laser radar relate to the technical field of laser. The optical fiber amplifier includes: the seed source is used for transmitting at least two beams of pulse laser with different wavelengths; a first wavelength division multiplexer for wavelength division multiplexing the pulsed laser; the first end of the signal transmission module is connected with the output end of the first wavelength division multiplexer; the first-stage amplification module is connected with the second end of the signal transmission module and is used for amplifying the pulse laser power output by the signal transmission module to obtain a first power amplification signal; the second-stage amplification module is connected with the third end of the signal transmission module and is used for power amplifying the first power amplification signal to obtain a second power amplification signal; the third-stage amplification module is connected with the output end of the second-stage amplification module and is used for power amplifying the second power amplification signal to obtain a third power amplification signal and outputting the third power amplification signal; the second-stage amplification module and the third-stage amplification module share one pumping source, and the pumping source supplies energy to the second-stage amplification module and the third-stage amplification module according to the beam splitting ratio.

Description

Optical fiber amplifier and laser radar

Technical Field

The utility model relates to the technical field of laser, in particular to an optical fiber amplifier and a laser radar.

Background

Optical fiber amplifiers have become a critical device in optical fiber communication systems. The optical fiber amplifier can effectively compensate the attenuation caused by long-distance transmission and wave division of signal light, and greatly promotes the development of an optical fiber communication system. As the requirements for efficiency and average power for industrial applications continue to increase, the gain of a single amplifier stage is difficult to meet the requirements for industrial applications.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide an optical fiber amplifier and a laser radar, wherein the optical fiber amplifier and the laser radar can output high-power laser by carrying out three-stage amplification on at least two kinds of pulse laser emitted by a seed source, and the multiple requirement of a single amplification module is reduced; and the signal-to-noise ratio of the output laser can be improved by splitting light according to the power ratio through a common pump source, and the volume of the optical fiber amplifier is reduced.

The embodiment of the utility model is realized by the following steps:

in one aspect of the present invention, there is provided an optical fiber amplifier including: the seed source comprises at least two lasers, wherein the at least two lasers are used for emitting at least two beams of pulse lasers with different wavelengths; the first wavelength division multiplexer is used for carrying out wavelength division multiplexing processing on at least two beams of pulse laser with different wavelengths; the first end of the signal transmission module is connected with the output end of the first wavelength division multiplexer; the first-stage amplification module is connected with the second end of the signal transmission module and used for performing power amplification on the pulse laser output by the signal transmission module to obtain a first power amplification signal, and enabling the first power amplification signal to be output after sequentially passing through the second end of the signal transmission module and the third end of the signal transmission module; the second-stage amplification module is connected with the third end of the signal transmission module and used for receiving and carrying out power amplification on the first power amplification signal so as to obtain a second power amplification signal; the third-stage amplification module is connected with the output end of the second-stage amplification module and used for receiving and carrying out power amplification on the second power amplification signal so as to obtain and output a third power amplification signal; the second-stage amplification module and the third-stage amplification module share one pumping source, and the pumping source supplies power to the second-stage amplification module and the third-stage amplification module respectively according to the beam splitting ratio.

Optionally, the beam splitting ratio of the pump source is in a range of 3:17 to 7: 13.

Optionally, the second stage amplification module comprises: the second pump source is used for supplying power to the second-stage amplification module; the input end of the beam splitter is connected with the output end of the second pumping source, and the beam splitter splits the output light of the second pumping source according to a splitting ratio; the input end of the second gain optical fiber is connected with the third end of the signal transmission module; and the first input end of the first beam combiner is connected with the output end of the second gain optical fiber, the second input end of the first beam combiner is connected with the first output end of the beam splitter, and the output end of the first beam combiner is used for outputting a second power amplification signal amplified by the second gain optical fiber, wherein the directions of second pump light emitted by the second pump source and the first power amplification signal which are respectively incident to the first beam combiner are opposite.

Optionally, the second-stage amplification module further includes: the input end of the second isolator is connected with the third end of the signal transmission module; the input end of the first filter is connected with the output end of the second isolator, the output end of the first filter is connected with the input end of the second gain optical fiber, and the first filter is used for filtering noise in the first power amplification signal.

Optionally, the optical fiber amplifier further includes a second heat dissipation device, and the second heat dissipation device is configured to cool the second pump source.

Optionally, the third stage amplifying module includes: the input end of the third gain optical fiber is connected with the output end of the first beam combiner; and a first input end of the second beam combiner is connected with an output end of the third gain fiber, a second input end of the second beam combiner is connected with a second output end of the beam splitter, and an output end of the second beam combiner is used for outputting a third power amplification signal amplified by the third gain fiber, wherein the directions of the second pump light and the second power amplification signal which are respectively incident to the second beam combiner are opposite.

Optionally, the third-stage amplifying module further includes: the input end of the third isolator is connected with the output end of the first beam combiner; and the input end of the second filter is connected with the output end of the third isolator, the output end of the second filter is connected with the input end of the third gain optical fiber, and the second filter is used for filtering noise in the second power amplification signal.

Optionally, the third-stage amplification module further includes a collimator, and the collimator is connected to the output end of the second beam combiner and is configured to collimate the third power amplification signal output by the second beam combiner.

Optionally, the second pump source is a multimode pump source, and the second gain fiber and the third gain fiber are erbium ytterbium co-doped fibers.

Optionally, the first stage amplifying module includes: a first pump source for emitting first pump light; the first end of the second wavelength division multiplexer is connected with the second end of the signal transmission module, the second end of the second wavelength division multiplexer is connected with the first pumping source, and the second wavelength division multiplexer is used for performing wavelength division multiplexing processing on the first pumping light and the pulse laser output by the signal transmission module; the first gain fiber is used for carrying out power amplification on the pulse laser twice, and the first power amplification is used for carrying out power amplification on the pulse laser output by the second wavelength division multiplexer; and the reflector is connected with the second end of the first gain optical fiber and is used for reflecting the pulse laser output by the first gain optical fiber after the first power amplification back to the first gain optical fiber, so that the first gain optical fiber performs the second power amplification on the pulse laser after the first power amplification to obtain a first power amplification signal.

Optionally, the optical fiber amplifier further includes at least two first isolators, the at least two first isolators are connected to the output end of each laser in a one-to-one correspondence, and the output end of each first isolator is connected to each input end of the first wavelength division multiplexer in a one-to-one correspondence.

Optionally, the first pump source is a single-mode pump source, and the first gain fiber is an erbium-doped fiber; or the first pump source is a multimode pump source, and the first gain fiber is erbium-ytterbium co-doped fiber.

Optionally, the first-stage amplification module further includes a first heat dissipation device, and the first heat dissipation device is configured to perform cooling processing on the first pump source.

In another aspect of the utility model, a lidar is provided that includes the fiber amplifier described above.

The beneficial effects of the utility model include:

the optical fiber amplifier provided by the application comprises a seed source, a first wavelength division multiplexer, a signal transmission module, a first-stage amplification module, a second-stage amplification module and a third-stage amplification module. The seed source comprises at least two lasers, and the at least two lasers are used for emitting at least two beams of pulse lasers with different wavelengths; the first wavelength division multiplexer is used for carrying out wavelength division multiplexing processing on at least two beams of pulse laser with different wavelengths; the first end of the signal transmission module is connected with the output end of the first wavelength division multiplexer; the first-stage amplification module is connected with the second end of the signal transmission module and used for performing power amplification on the pulse laser output by the signal transmission module to obtain a first power amplification signal, and enabling the first power amplification signal to sequentially pass through the second end of the signal transmission module and the third end of the signal transmission module and then be output; the second-stage amplification module is connected with the third end of the signal transmission module and is used for receiving and carrying out power amplification on the first power amplification signal so as to obtain a second power amplification signal; the third-stage amplification module is connected with the output end of the second-stage amplification module and is used for receiving and carrying out power amplification on the second power amplification signal so as to obtain and output a third power amplification signal; the second-stage amplification module and the third-stage amplification module share one pumping source, and the pumping source supplies power to the second-stage amplification module and the third-stage amplification module respectively according to the beam splitting ratio. According to the seed source amplification device, the initial pulse laser emitted by the seed source is amplified for three times by arranging the first-stage amplification module, the second-stage amplification module and the third-stage amplification module. On one hand, under the same target power, the total amplification factor requirement can be respectively distributed to the first-stage amplification module, the second-stage amplification module and the third-stage amplification module, so that the respective amplification factor requirements of the first-stage amplification module, the second-stage amplification module and the third-stage amplification module can be effectively reduced to prolong the service life of the optical fiber amplifier; on the other hand, under the condition that the requirement of each amplification factor is not changed, the three-stage power amplification is set, so that the initial pulse laser emitted by the seed source can be amplified for multiple times, and the output power can be effectively improved; in addition, the second-stage amplification module and the third-stage amplification module share one pump source, so that light can be split according to the power ratio to improve the signal-to-noise ratio of output laser and reduce the volume of the optical fiber amplifier.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic diagram of an optical fiber amplifier according to some embodiments of the present invention;

fig. 2 is a second schematic structural diagram of an optical fiber amplifier according to some embodiments of the present invention;

fig. 3 is a third schematic structural diagram of an optical fiber amplifier according to some embodiments of the present invention.

Icon: 10-a seed source; 11-a laser; 20-a first wavelength division multiplexer; 30-a signal transmission module; 40-a first stage amplification module; 41-a first pump source; 42-a second wavelength division multiplexer; 43-a first gain fiber; 44-a reflector; 45-a first heat sink; 50-a second stage amplification module; 51-a second pump source; 52-a second gain fiber; 53-a first combiner; 54-a second isolator; 55-a first filter; 56-a second heat sink; 60-a third stage amplification module; 61-a beam splitter; 62-a third gain fiber; 63-a second combiner; 64-a third isolator; 65-a second filter; 66-a collimator; 70-first isolator.

Detailed Description

To facilitate an understanding of the present application, the present application is described in more detail below with reference to the accompanying drawings and detailed description. It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may be present. As used in this specification, the terms "upper," "lower," "left," "right," "inner," "outer," and the like are used in the positional or orientational relationships as shown in the drawings for the purpose of convenience in describing the application and simplifying the description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the utility model herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In addition, the technical features mentioned in the different embodiments of the present application described below may be combined with each other as long as they do not conflict with each other.

First embodiment

Referring to fig. 1, the present embodiment provides an optical fiber amplifier, which includes a seed source 10, a first wavelength division multiplexer 20, a signal transmission module 30, a first-stage amplification module 40, a second-stage amplification module 50, and a third-stage amplification module 60. The seed source 10 comprises at least two lasers 11, wherein the at least two lasers 11 are used for emitting at least two beams of pulse lasers with different wavelengths; the first wavelength division multiplexer 20 is configured to perform wavelength division multiplexing on at least two pulse lasers with different wavelengths; a first end of the signal transmission module 30 is connected with an output end of the first wavelength division multiplexer 20; the first-stage amplification module 40 is connected to the second end of the signal transmission module 30, and is configured to perform power amplification on the pulse laser output by the signal transmission module 30 to obtain a first power amplification signal, and enable the first power amplification signal to sequentially pass through the second end of the signal transmission module 30 and the third end of the signal transmission module 30 and then be output; the second-stage amplification module 50 is connected to the third end of the signal transmission module 30, and is configured to receive and perform power amplification on the first power amplification signal to obtain a second power amplification signal; the third-stage amplification module 60 is connected to the output end of the second-stage amplification module 50, and is configured to receive and perform power amplification on the second power amplification signal to obtain and output a third power amplification signal; the second-stage amplification module and the third-stage amplification module share one pumping source, and the pumping source supplies power to the second-stage amplification module and the third-stage amplification module respectively according to the beam splitting ratio.

Wherein, the seed source 10 can adopt a DFB direct-modulation pulse seed source 10 which can output center wavelengths of 1550nm and 1064 nm. The seed source 10 can emit pulsed laser with peak power of 10mW through circuit modulation.

Illustratively, referring to fig. 2, the seed source 10 includes at least two lasers 11 integrated together, and the at least two lasers 11 are used for emitting at least two pulsed lasers with different wavelengths. For example, the seed source 10 may include two lasers 11 integrated into a single body, the two lasers 11 being respectively used for emitting pulsed laser light with different wavelengths; alternatively, the seed source 10 may include three lasers 11 integrated together, and the three lasers 11 are respectively used for emitting pulsed laser light with different wavelengths (at least two of the three lasers 11 may also emit pulsed laser light with different wavelengths). That is, when the seed source 10 includes a plurality of lasers 11 integrated together, the wavelengths of the pulsed laser light emitted by any two lasers 11 may be different, or the wavelengths of the pulsed laser light emitted by at least two lasers 11 may be different.

It should be noted that the seed source 10 includes at least two lasers 11 integrated together, which means that all the lasers 11 are packaged together to form the seed source 10, so that the size of the optical fiber amplifier can be greatly reduced compared to the case where different lasers 11 are separately provided. The seed source 10 of the present application includes at least two lasers 11 integrated in one body, and the at least two lasers 11 are used for emitting at least two pulsed lasers with different wavelengths. In this way, the seed source 10 can not only emit at least two beams of pulsed laser with different wavelengths, but also reduce the volume of the seed source 10, and thus the volume of the whole optical fiber amplifier.

In the present embodiment, the first wavelength division multiplexer 20 has at least two input terminals and one output terminal, the number of the input terminals thereof is the same as the number of the lasers 11, and each laser 11 may correspond to each input terminal of the first wavelength division multiplexer 20 one by one. The first wavelength division multiplexer 20 is used for coupling the pulsed laser light with different wavelengths emitted from the seed source 10, so that the pulsed laser light with different wavelengths is coupled to the signal transmission module 30.

The first end of the signal transmission module 30 is connected to the first wavelength division multiplexer 20, the second end of the signal transmission module 30 is connected to the first-stage amplification module 40, and the third end of the signal transmission module 30 is connected to the second-stage amplification module 50. Optionally, the signal transmission module 30 is a circulator.

The first-stage amplification module 40, the second-stage amplification module 50 and the third-stage amplification module 60 are arranged, wherein the first-stage amplification module 40 is connected to the second end of the signal transmission module 30 and is used for carrying out first-stage amplification on pulse laser emitted by the seed source 10 to obtain a first power amplification signal. The second-stage amplification module 50 is connected to the third end of the signal transmission module 30, so that the first power amplified signal can be received by the second-stage amplification module 50 after passing through the second end of the signal transmission module 30 and the third end of the signal transmission module 30 in sequence. The second-stage amplifying module 50 is configured to perform a second-stage amplification on the first power amplified signal output by the first-stage amplifying module 40 to obtain a second power amplified signal. The third-stage amplifying module 60 is connected to the output end of the second-stage amplifying module 50, and is configured to perform third-stage amplification on the second power amplified signal output by the second-stage amplifying module 50 to obtain a third power amplified signal and output the third power amplified signal. The optical fiber amplifier provided by the application amplifies pulse laser emitted by the seed source 10 in three stages, so that high-power pulse laser can be output.

The second-stage amplification module and the third-stage amplification module share one pumping source, and the pumping source supplies power to the second-stage amplification module and the third-stage amplification module respectively according to the beam splitting ratio. That is, in the present embodiment, the pump source (hereinafter, the second pump source 51) is split into two parts with different power ratios, one part is incident to the second-stage amplification module 50 for the second-stage amplification, and the other part is incident to the third-stage amplification module 60 for the third-stage amplification.

Optionally, the beam splitting ratio of the pump source ranges from 3:17 to 7: 13. Specifically, those skilled in the art can select an appropriate splitting ratio within the range according to actual requirements, and the application is not limited.

In summary, the optical fiber amplifier provided by the present application includes a seed source 10, a first wavelength division multiplexer 20, a signal transmission module 30, a first stage amplification module 40, a second stage amplification module 50, and a third stage amplification module 60. The seed source 10 comprises at least two lasers 11, wherein the at least two lasers 11 are used for emitting at least two beams of pulse lasers with different wavelengths; the first wavelength division multiplexer 20 is configured to perform wavelength division multiplexing on at least two pulse lasers with different wavelengths; a first end of the signal transmission module 30 is connected with an output end of the first wavelength division multiplexer 20; the first-stage amplification module 40 is connected to the second end of the signal transmission module 30, and is configured to perform power amplification on the pulse laser output by the signal transmission module 30 to obtain a first power amplification signal, and enable the first power amplification signal to sequentially pass through the second end of the signal transmission module 30 and the third end of the signal transmission module 30 and then be output; the second-stage amplification module 50 is connected to the third end of the signal transmission module 30, and is configured to receive and perform power amplification on the first power amplification signal to obtain a second power amplification signal; the third-stage amplification module 60 is connected to the output end of the second-stage amplification module 50, and is configured to receive and perform power amplification on the second power amplification signal to obtain and output a third power amplification signal; the second-stage amplification module and the third-stage amplification module share one pumping source, and the pumping source supplies power to the second-stage amplification module and the third-stage amplification module respectively according to the beam splitting ratio. According to the application, the initial pulse laser emitted by the seed source 10 is amplified for three times by arranging the first-stage amplification module 40, the second-stage amplification module 50 and the third-stage amplification module 60. On one hand, under the same target power, the total amplification factor requirement can be respectively distributed to the first-stage amplification module 40, the second-stage amplification module 50 and the third-stage amplification module 60, so that the individual amplification factor requirements of the first-stage amplification module 40, the second-stage amplification module 50 and the third-stage amplification module 60 can be effectively reduced to prolong the service life of the optical fiber amplifier; on the other hand, under the condition that the requirement of each amplification factor is not changed, the three-stage power amplification is set, so that the initial pulse laser emitted by the seed source 10 can be amplified for multiple times, and the output power can be effectively improved; in addition, the present application can perform light splitting according to a power ratio to improve the signal-to-noise ratio of the output laser and reduce the size of the fiber amplifier by using a pump source in common for the second-stage amplification module 50 and the third-stage amplification module 60.

Referring to fig. 2, in this embodiment, in order to prevent the seed source 10 from being damaged by the return light of the pulse laser emitted by itself, optionally, the optical fiber amplifier may further include at least two first isolators 70, where the at least two first isolators 70 are connected to the output end of each laser 11 in a one-to-one correspondence, and the output end of each first isolator 70 is connected to each input end of the first wavelength division multiplexer 20 in a one-to-one correspondence.

Referring to fig. 1 and 3, the second stage amplification module 50 includes a second pump source 51, a beam splitter 61, a second gain fiber 52, and a first beam combiner 53. Wherein the second pump source 51 is used for powering the second stage amplification module 50; the input end of the beam splitter 61 is connected with the output end of the second pump source 51, and the beam splitter 61 splits the output light of the second pump source 51 according to a splitting ratio; the input end of the second gain fiber 52 is connected with the third end of the signal transmission module 30; a first input end of the first beam combiner 53 is connected to an output end of the second gain fiber 52, a second input end of the first beam combiner 53 is connected to a first output end of the beam splitter 61, and an output end of the first beam combiner 53 is configured to output a second power amplification signal amplified by the second gain fiber 52, where a second pump light emitted by the second pump source 51 and the first power amplification signal are incident on the first beam combiner 53 in opposite directions, respectively.

It should be noted that, in this embodiment, the directions of the second pump light and the first power amplification signal respectively incident on the first beam combiner 53 are opposite, that is, the second-stage amplification module 50 adopts a reverse pumping manner, so that the efficiency of the second-stage amplification module 50 can be further improved.

In order to protect the signal transmission module 30, prevent the signal transmission module 30 from being damaged by the return light, and filter the noise in the first power amplified signal of the first stage amplification module 40, in the present embodiment, the second stage amplification module 50 further includes a second isolator 54 and a first filter 55. Wherein, the input end of the second isolator 54 is connected with the third end of the signal transmission module 30; an input end of the first filter 55 is connected to an output end of the second isolator 54, an output end of the first filter 55 is connected to an input end of the second gain fiber 52, and the first filter 55 is used for filtering noise in the first power amplified signal. Illustratively, the noise filtered by the first filter 55 may be amplifier spontaneous emission noise.

Referring to fig. 3, optionally, the optical fiber amplifier further includes a second heat dissipation device 56, where the second heat dissipation device 56 is used to cool the second pump source 51. The second heat sink 56 may be an air-cooled heat sink or a water-cooled heat sink.

Referring to fig. 1 and 3, in the present embodiment, the third stage amplification module 60 includes a third gain fiber 62 and a second beam combiner 63. Wherein, the input end of the third gain fiber 62 is connected with the output end of the first beam combiner 53; a first input end of the second beam combiner 63 is connected to an output end of the third gain fiber 62, a second input end of the second beam combiner 63 is connected to a second output end of the beam splitter 61, and an output end of the second beam combiner 63 is configured to output a third power amplification signal amplified by the third gain fiber 62, where directions of the second pump light and the second power amplification signal respectively incident to the second beam combiner 63 are opposite.

In this embodiment, the second pump source 51 is a multimode pump source, and the second gain fiber 52 and the third gain fiber 62 are erbium ytterbium co-doped fibers. Please refer to fig. 1, an input end of the beam splitter 61 is connected to the second pump source 51, and two output ends of the beam splitter 61 are respectively connected to the first beam combiner 53 and the second beam combiner 63. In this embodiment, the second pump source 51 is split into two parts with different power ratios, one part is incident on the first beam combiner 53 of the second-stage amplification module 50 for the second-stage amplification, and the other part is incident on the second beam combiner 63 of the third-stage amplification module 60 for the third-stage amplification.

The directions of the second pump light and the first power amplification signal incident on the first beam combiner 53 are opposite, and the directions of the second pump light and the second power amplification signal incident on the second beam combiner 63 are opposite. That is, the second-stage amplification module 50 and the third-stage amplification module 60 provided by the present application both adopt a reverse pumping mode, so that the pumping efficiency can be improved, the optical path can be protected, and finally the power can be amplified to 5W to 20W.

Similarly, in order to protect the first beam combiner 53 from the return light and to filter the noise in the second power amplified signal of the second stage amplification module 50, in the present embodiment, the third stage amplification module 60 further includes a third isolator 64 and a second filter 65. Wherein, the input end of the third isolator 64 is connected with the output end of the first beam combiner 53; an input end of the second filter 65 is connected to an output end of the third isolator 64, an output end of the second filter 65 is connected to an input end of the third gain fiber 62, and the second filter 65 is configured to filter noise in the second power amplified signal. Illustratively, the noise filtered by the second filter 65 may be amplifier spontaneous emission noise.

In order to collimate the light beam output from the optical fiber amplifier, optionally, the third stage amplification module 60 further includes a collimator 66, and the collimator 66 is connected to the output end of the second beam combiner 63, and is configured to collimate the third power amplified signal output from the second beam combiner 63.

In this embodiment, the first-stage amplification module 40 includes a first pump source 41, a second wavelength division multiplexer 42, a first gain fiber 43, and a reflector 44. Wherein, the first pump source 41 is used for emitting the first pump light; a first end of the second wavelength division multiplexer 42 is connected to a second end of the signal transmission module 30, a second end of the second wavelength division multiplexer 42 is connected to the first pumping source 41, and the second wavelength division multiplexer 42 is configured to perform wavelength division multiplexing processing on the first pumping light and the pulse laser output by the signal transmission module 30; the first end of the first gain optical fiber 43 is connected with the third end of the second wavelength division multiplexer 42, the first gain optical fiber 43 is used for performing power amplification twice on the pulse laser, and the first power amplification is performed on the pulse laser output by the second wavelength division multiplexer 42; the reflector 44 is connected to the second end of the first gain fiber 43, and is configured to reflect the pulse laser output by the first gain fiber 43 after the first power amplification back to the first gain fiber 43, so that the first gain fiber 43 performs the second power amplification on the pulse laser after the first power amplification, so as to obtain a first power amplified signal.

Wherein, the first pump source 41 is a single-mode pump source, and the first gain fiber 43 is an erbium-doped fiber; alternatively, the first pump source 41 is a multimode pump source and the first gain fiber 43 is an erbium ytterbium co-doped fiber. Specifically, those skilled in the art can select the appropriate types of the first pump source 41 and the first gain fiber 43 according to actual needs, and the application is not limited thereto.

Illustratively, when the first pump source 41 is a single-mode pump source, the first pump source 41 may be a semiconductor laser 11 with a central wavelength of 976 nm.

In addition, the reflector 44 may be a mirror, a high reflection grating, or the like, and specifically, may be selected by those skilled in the art as needed.

It should be noted that, the light beam output by the second wavelength division multiplexer 42 enters the first gain fiber 43 and then performs first power amplification on the light beam, and then passes through the reflector 44 and then reflects the light beam back to the first gain fiber 43, and then performs second power amplification on the light beam through the first gain fiber 43, so as to obtain a first power amplified signal. That is, the first-stage amplification module 40 provided by the present application can perform power amplification twice on the initial pulse laser emitted from the seed source 10. In this embodiment, the first power amplified signal obtained after the two times of power amplification sequentially passes through the second end of the signal transmission module 30 and the third end of the signal transmission module 30 and then enters the second-stage amplification module 50.

Referring to fig. 3, the first-stage amplification module 40 further includes a first heat dissipation device 45, and the first heat dissipation device 45 is used for cooling the first pump source 41. The first heat dissipation device 45 may be a water-cooled heat dissipation device or an air-cooled heat dissipation device, and the water-cooled heat dissipation technology and the air-cooled heat dissipation technology are mature at present, so that the present application is not described herein again. Through setting up first heat abstractor 45, can be so that the operating condition of first pump source 41 is more stable, avoid first pump source 41 to receive the influence of high temperature environment and then shorten the life-span.

Second embodiment

In another aspect of the utility model, a lidar is provided that includes the fiber amplifier described above. Since the specific structure and the advantageous effects of the optical fiber amplifier have been described in detail in the foregoing, the detailed description of the present application is omitted.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; within the idea of the utility model, also technical features in the above embodiments or in different embodiments may be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the utility model as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical fiber amplifier, comprising:

the seed source comprises at least two lasers, wherein the at least two lasers are used for emitting at least two different pulse lasers;

the first wavelength division multiplexer is used for carrying out wavelength division multiplexing processing on at least two beams of pulse laser with different wavelengths;

the first end of the signal transmission module is connected with the output end of the first wavelength division multiplexer;

the first-stage amplification module is connected with the second end of the signal transmission module and used for performing power amplification on the pulse laser output by the signal transmission module to obtain a first power amplification signal, and enabling the first power amplification signal to sequentially pass through the second end of the signal transmission module and the third end of the signal transmission module and then be output;

the second-stage amplification module is connected with the third end of the signal transmission module and used for receiving and performing power amplification on the first power amplification signal to obtain a second power amplification signal;

the third-stage amplification module is connected with the output end of the second-stage amplification module and used for receiving and carrying out power amplification on the second power amplification signal so as to obtain and output a third power amplification signal;

the second-stage amplification module and the third-stage amplification module share one pumping source, and the pumping source supplies energy to the second-stage amplification module and the third-stage amplification module respectively according to a beam splitting ratio.

2. The optical fiber amplifier of claim 1, wherein the pump source has a splitting ratio in a range of 3:17 to 7: 13.

3. The fiber amplifier of claim 1 or 2, wherein the second stage amplification module comprises:

the second pump source is used for supplying power to the second-stage amplification module;

the input end of the beam splitter is connected with the output end of the second pumping source, and the beam splitter splits the output light of the second pumping source according to a splitting ratio;

the input end of the second gain optical fiber is connected with the third end of the signal transmission module;

a first input end of the first beam combiner is connected with an output end of the second gain fiber, a second input end of the first beam combiner is connected with a first output end of the beam splitter, an output end of the first beam combiner is used for outputting the second power amplification signal amplified by the second gain fiber, wherein a second pumping light emitted by the second pumping source and the first power amplification signal are respectively incident to the first beam combiner in opposite directions.

4. The fiber amplifier of claim 3, wherein the second stage amplification module further comprises:

the input end of the second isolator is connected with the third end of the signal transmission module;

the input end of the first filter is connected with the output end of the second isolator, the output end of the first filter is connected with the input end of the second gain optical fiber, and the first filter is used for filtering noise in the first power amplification signal.

5. The fiber amplifier of claim 3, further comprising a second heat sink for cooling the second pump source.

6. The fiber amplifier of claim 3, wherein the third stage amplification module comprises:

the input end of the third gain fiber is connected with the output end of the first beam combiner;

a first input end of the second beam combiner is connected with an output end of the third gain fiber, a second input end of the second beam combiner is connected with a second output end of the beam splitter, an output end of the second beam combiner is used for outputting the third power amplification signal amplified by the third gain fiber, wherein the directions of the second pump light and the second power amplification signal respectively incident to the second beam combiner are opposite.

7. The fiber amplifier of claim 6, wherein the third stage amplification module further comprises:

the input end of the third isolator is connected with the output end of the first beam combiner;

and the input end of the second filter is connected with the output end of the third isolator, the output end of the second filter is connected with the input end of the third gain optical fiber, and the second filter is used for filtering noise in the second power amplification signal.

8. The fiber amplifier according to claim 6 or 7, wherein the third stage amplification module further comprises a collimator, and the collimator is connected to the output end of the second beam combiner and is configured to collimate the third power-amplified signal output by the second beam combiner.

9. The fiber amplifier of claim 8, wherein the second pump source is a multimode pump source, and wherein the second gain fiber and the third gain fiber are erbium ytterbium co-doped fibers.

10. The fiber amplifier of claims 1, 2, 4, 5, 6, 7, or 9, wherein the first stage amplification module comprises:

a first pump source for emitting first pump light;

a first end of the second wavelength division multiplexer is connected with a second end of the signal transmission module, a second end of the second wavelength division multiplexer is connected with the first pumping source, and the second wavelength division multiplexer is used for performing wavelength division multiplexing processing on the first pumping light and the pulse laser output by the signal transmission module;

the first gain fiber is used for carrying out power amplification on the pulse laser twice, and the first power amplification is used for carrying out power amplification on the pulse laser output by the second wavelength division multiplexer;

and the reflector is connected with the second end of the first gain optical fiber and is used for reflecting the pulse laser output by the first gain optical fiber after the first power amplification back to the first gain optical fiber, so that the first gain optical fiber performs the second power amplification on the pulse laser after the first power amplification to obtain the first power amplification signal.

11. The fiber amplifier of claims 1, 2, 4, 5, 6, 7, or 9, further comprising at least two first isolators, at least two of the first isolators being connected to an output of each laser in a one-to-one correspondence, and an output of each of the first isolators being connected to each input of the first wavelength division multiplexer in a one-to-one correspondence.

12. A lidar comprising the fiber amplifier of any of claims 1 to 11.