CN113258422A - Seed source of pulse optical fiber laser and pulse adjusting method - Google Patents
Seed source of pulse optical fiber laser and pulse adjusting method Download PDFInfo
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- CN113258422A CN113258422A CN202110793377.7A CN202110793377A CN113258422A CN 113258422 A CN113258422 A CN 113258422A CN 202110793377 A CN202110793377 A CN 202110793377A CN 113258422 A CN113258422 A CN 113258422A
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- 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
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/06—Construction or shape of active medium
- H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
- H01S3/067—Fibre lasers
- H01S3/0675—Resonators including a grating structure, e.g. distributed Bragg reflectors [DBR] or distributed feedback [DFB] fibre lasers
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- 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
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/09—Processes or apparatus for excitation, e.g. pumping
- H01S3/091—Processes or apparatus for excitation, e.g. pumping using optical pumping
- H01S3/094—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
- H01S3/094076—Pulsed or modulated pumping
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- 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
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/11—Mode locking; Q-switching; Other giant-pulse techniques, e.g. cavity dumping
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Abstract
The application discloses a seed source of a pulse fiber laser and a pulse adjusting method, wherein the seed source generates quadrilateral pulses through a modulator outside a first resonant cavity, and the modulator can also be used as a Q switch in a second resonant cavity, so that Gaussian or Gaussian-like-shaped pulses are generated, namely in the same seed source, the pulse shape can be adjusted by adjusting the pumping power; on the other hand, when the modulator outside the first resonant cavity generates quadrilateral pulses, the pulse width is controlled according to the light-on time of the modulator, the pulse repetition frequency is controlled according to the repetition frequency of the modulator, the pulse width and the repetition frequency are more flexibly changed, and the tunable range is larger.
Description
Technical Field
The application relates to the field of laser, in particular to a seed source of a pulse optical fiber laser and a pulse adjusting method.
Background
The fiber laser has the advantages of good beam quality, high efficiency, good heat dissipation, compact structure, high reliability, easy maintenance and the like, and is widely concerned by people. The pulse laser with high energy, adjustable repetition frequency, adjustable pulse width and adjustable waveform plays an important role in the laser field, and the nanosecond pulse fiber laser is widely applied to the fields of laser processing, optical fiber communication, military and national defense safety, medical mechanical instruments and the like at present.
In the seed source of the pulse fiber laser, a resonant cavity formed based on grating feedback is modulated by adding an electro-optic modulator, an acousto-optic modulator or a saturable absorber. In the modulation method, the repetition frequency adjustment has certain limitation, and the waveform is generally a single gaussian waveform or a gaussian-like waveform because the pulse width changes with the repetition frequency. The modulation mode has certain limitation in practical application, so that a pulse fiber laser seed source capable of realizing adjustable repetition frequency, adjustable pulse width and adjustable waveform is needed to be provided.
Disclosure of Invention
In view of this, the present application provides a pulse laser seed source with adjustable repetition frequency, adjustable pulse width and adjustable waveform and an adjusting method thereof.
In a first aspect, the present application provides a pulsed fiber laser seed source, including:
the grating optical fiber modulator comprises a first grating, a first gain optical fiber, a second grating, a modulator, a second gain optical fiber, a third grating and an output device which are connected in sequence;
different ends of the modulator are respectively connected with a first pumping source and a second pumping source, the first pumping source is connected with a pumping input end of the first optical fiber beam combiner and is used for providing pumping light for the first gain optical fiber through the first optical fiber beam combiner; the second pump source is connected to the pump input end of the second optical fiber combiner and is used for providing pump light to the second gain optical fiber through the second optical fiber combiner.
Optionally, a common end of the first optical fiber combiner is connected to one end of the first grating; the other end of the first grating is connected with one end of the first gain optical fiber; the other end of the first gain optical fiber is connected with one end of the second grating; the other end of the second grating is connected with one end of the modulator; the other end of the modulator is connected with one end of the second gain optical fiber; the other end of the second gain fiber is connected with one end of the third grating; the other end of the third grating is connected with the common end of the second optical fiber beam combiner; and the signal end of the second optical fiber beam combiner is connected with one end of the output device.
Optionally, a common end of the first optical fiber combiner is connected to one end of the first grating; the other end of the first grating is connected with one end of the first gain optical fiber; the other end of the first gain optical fiber is connected with one end of the second grating; the other end of the second grating is connected with one end of the modulator; the other end of the modulator is connected with one end of the second gain optical fiber; the other end of the second gain optical fiber is connected with the common end of the second optical fiber beam combiner; and the signal end of the second optical fiber beam combiner is connected with one end of the third grating, and the other end of the third grating is connected with the output device.
Optionally, one end of the first grating is connected to one end of the first gain fiber; the other end of the first gain optical fiber is connected with one end of the second grating; the other end of the second grating is connected with the common end of the first optical fiber beam combiner; the signal end of the first optical fiber beam combiner is connected with one end of the modulator; the other end of the modulator is connected with one end of the second gain optical fiber; the other end of the second gain fiber is connected with one end of the third grating; the other end of the third grating is connected with the common end of the second optical fiber beam combiner; and the signal end of the second optical fiber beam combiner is connected with one end of the output device.
Optionally, one end of the first grating is connected to one end of the first gain fiber; the other end of the first gain optical fiber is connected with one end of the second grating; the other end of the second grating is connected with the common end of the first optical fiber beam combiner; the signal end of the first optical fiber beam combiner is connected with one end of the modulator; the other end of the modulator is connected with one end of the second gain optical fiber; the other end of the second gain optical fiber is connected with the common end of the second optical fiber beam combiner; and the signal end of the second optical fiber beam combiner is connected with one end of the third grating, and the other end of the third grating is connected with the output device.
Optionally, the optical fiber grating coupler further includes a third pump source and a third optical fiber combiner, where the third optical fiber combiner is located between the second grating and the modulator, and a pump input end of the third optical fiber combiner is connected to the third pump source.
Optionally, the first grating, the second grating, and the third grating are reflective fiber bragg gratings, reflectances of the first grating, the second grating, and the third grating are greater than 0 and less than 1, the first grating is a high-reflectivity grating, and the second grating and the third grating are partially reflective gratings.
Optionally, the modulator is an acousto-optic modulator or an electro-optic modulator.
In a second aspect, the present application further provides a pulse adjusting method for a seed source of a pulse fiber laser according to the first aspect, including:
adjusting the pump light power of the second pump source according to the required pulse waveform;
if the required pulse waveform is quadrilateral, adjusting the power of the pumping light of the second pumping source to be smaller than a preset threshold value;
if the required pulse waveform is Gaussian or Gaussian-like, adjusting the pumping light power of the second pumping source to be larger than a preset threshold value;
the first grating and the second grating form a first resonant cavity, and the size of the preset threshold value needs to satisfy: when the pump light power of the second pump source is greater than a preset threshold value, the pulse generated by the continuous laser in the first resonant cavity through the modulator cannot generate gain, and when the pump light power of the second pump source is less than the preset threshold value, the pulse generated by the continuous laser in the first resonant cavity through the modulator can generate gain.
Optionally, when the pulse waveform is modulated to be a quadrilateral, the method further includes: adjusting the switching time of the modulator according to the required pulse width; and/or adjusting the repetition frequency of the modulator according to the required pulse repetition frequency.
The application provides a laser seed source and an adjusting method, wherein a first grating and a second grating of the seed source can form a first resonant cavity, the first grating and a third grating can form a second resonant cavity, the seed source can generate quadrilateral-shaped pulses through an external modulator of the first resonant cavity, and the modulator can also serve as a Q switch in the second resonant cavity by adjusting the pumping power of the second pumping source, so that the seed source can generate Gaussian or quasi-Gaussian-shaped pulses. In the same seed source, pulses in different shapes can be generated by adjusting the pumping power, so that a pulse laser seed source with adjustable waveform is obtained; on the other hand, when the waveform generated by the seed source is a quadrilateral pulse, the pulse width can be controlled according to the light-on time of the modulator, and the pulse repetition frequency can be controlled according to the modulator repetition frequency, so that compared with the traditional seed source, the pulse width and repetition frequency change is more flexible, and the tunable range is larger; in addition, this application design is nimble, simple, compact structure, and the design of full optic fibre is favorable to realizing the industrialization, and the practicality is strong.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings used in the description of the embodiments will be briefly introduced below.
FIG. 1 is a schematic diagram of a first structure of a seed source of a pulse fiber laser provided in an embodiment of the present application;
FIG. 2 is a schematic diagram of a second structure of a seed source of a pulse fiber laser provided in an embodiment of the present application;
FIG. 3 is a schematic diagram of a third structure of a seed source of a pulse fiber laser provided in an embodiment of the present application;
FIG. 4 is a schematic diagram of a fourth structure of a seed source of a pulse fiber laser provided in an embodiment of the present application;
FIG. 5 is a fifth structural diagram of a seed source of a pulse fiber laser provided in an embodiment of the present application;
FIG. 6 is a sixth structural diagram of a seed source of a pulse fiber laser provided in an embodiment of the present application;
FIG. 7 is a theoretical diagram of a quadrilateral pulse provided by an embodiment of the present application;
fig. 8 is a theoretical diagram of a gaussian or gaussian-like pulse provided by an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.
The embodiment of the application provides a pulse tunable laser seed source and a tuning method. The following are detailed below. It should be noted that the following description of the embodiments is not intended to limit the preferred order of the embodiments.
First, referring to fig. 1 to 6, the present application provides a laser including: the optical fiber grating comprises a first grating 5, a second grating 6, a third grating 7, a first pumping source 1, a second pumping source 2, a first optical fiber beam combiner 3, a second optical fiber beam combiner 4, a first gain optical fiber 8, a second gain optical fiber 9, a modulator 10 and an output device 11;
the first grating 5, the first gain fiber 8, the second grating 6, the modulator 10, the second gain fiber 9, the third grating 7 and the output device 11 are connected in sequence;
the first pump source 1 and the second pump source 2 are located at different ends of the modulator 10, the first pump source 1 is connected to the pump input end of the first optical fiber combiner 3 and is used for providing pump light to the first gain optical fiber 8 through the first optical fiber combiner 3; the second pump source 2 is connected to the pump input end of the second optical fiber combiner 4, and is used to provide pump light to the second gain fiber 9 through the second optical fiber combiner 4.
It should be noted that the first pump source 1 and the second pump source 2 are located at "different ends" of the modulator 10, which means that the first pump source 1 and the second pump source 2 do not share the same end of the modulator 10. That is, the first pump source 1 and the second pump source 2 are respectively located at two sides of the modulator 10, the first pump source 1 may be connected to the first grating 5, the first gain fiber 8, or the second grating 6 at one side of the modulator 10 through the first fiber combiner 3, and the second pump source 2 may be connected to the second gain fiber 9, the third grating 7, and the output device 11 at the other side of the modulator 10 through the second fiber combiner 4. Specifically, in this embodiment, for example, as shown in fig. 1, the first grating 5, the first gain fiber 8, the second grating 6, the modulator 10, the second gain fiber 9, the third grating 7, and the output device 11 are sequentially connected from left to right, with the modulator 10 as a center, the first pump source 1 and the first optical fiber combiner 3 correspondingly connected are located on the left side of the modulator 10, and the second pump source 2 and the second optical fiber combiner 4 correspondingly connected are located on the right side of the modulator 10.
The first grating 5 and the second grating 6 form a first resonant cavity; the first grating 5 and the third grating 7 form a second resonant cavity.
The pump light generated by the first pump source 1 is coupled into the first resonant cavity through the first optical fiber beam combiner 3, generates continuous laser under the action of the first gain optical fiber 8, then enters the modulator 10 to cut the wave and generate quadrilateral pulse, passes through the second gain optical fiber 9, and then is divided into the following two situations:
when the pumping power generated by the second pumping source 2 is low, the generated quadrilateral pulse is amplified by the second gain fiber 9 and then output through the third grating 7 and the output device 11 respectively, and the quadrilateral pulse is output at the moment;
when the pumping power generated by the second pumping source 2 is high, the returned pumping light can cause that the quadrilateral pulse formed by the wave chopping of the modulator 10 can not obtain gain, at the moment, the modulator 10 is equivalent to a Q switch arranged in a second resonant cavity, the laser generated in the second resonant cavity is subjected to mode selection through the first resonant cavity, and at the moment, a gaussian or quasi-gaussian pulse is generated in the second resonant cavity and is output through the output device 11.
Thus, the seed source can generate quadrilateral-shaped pulses through the external modulator of the first resonant cavity, and the modulator can also be used as a Q switch in the second resonant cavity by adjusting the pumping power of the second pumping source, so that the seed source can generate Gaussian or Gaussian-shaped pulses. In the same seed source, pulses in different shapes can be generated by adjusting the pumping power, so that a pulse laser seed source with adjustable waveform is obtained; on the other hand, when the waveform generated by the seed source is a quadrilateral pulse, the pulse width can be controlled according to the light-on time of the modulator, and the pulse repetition frequency can be controlled according to the modulator repetition frequency, so that compared with the traditional seed source, the pulse width and repetition frequency change is more flexible, and the tunable range is larger; in addition, this application design is nimble, simple, compact structure, and the design of full optic fibre is favorable to realizing the industrialization, and the practicality is strong.
The first grating 5, the second grating 6, the third grating 7, the first gain fiber 8, the second gain fiber 9, the modulator 10, and the output device 11 may be connected directly or indirectly. The positions of the first pump source 1, the second pump source 2, the first optical fiber combiner 3, and the second optical fiber combiner 4 may be disposed between the first grating 5, the second grating 6, the third grating 7, the first gain optical fiber 8, the second gain optical fiber 9, the modulator 10, and the output device 11 according to actual needs, and it only needs to be satisfied that the first pump source 1 and the second pump source 2 are located at different ends of the modulator 10, and the first pump source 1 may provide pump light to the first gain optical fiber 8 through the first optical fiber combiner 3, and the second pump source 2 may provide pump light to the second gain optical fiber 9 through the second optical fiber combiner 4, which is not limited herein.
For example, referring to fig. 1, fig. 1 shows a first structural schematic diagram of a pulsed fiber laser seed source in an embodiment of the present application. The specific connection relationship is as follows: the common end of the first optical fiber combiner 3 is connected with one end of the first grating 5; the other end of the first grating 5 is connected with one end of the first gain optical fiber 8; the other end of the first gain fiber 8 is connected with one end of the second grating 6; the other end of the second grating 6 is connected with one end of the modulator 10; the other end of the modulator 10 is connected with one end of the second gain fiber 9; the other end of the second gain fiber 9 is connected with one end of the third grating 7; the other end of the third grating 7 is connected with the common end of the second optical fiber combiner 4; and the signal end of the second optical fiber combiner 4 is connected with one end of the output device 11.
For example, referring to fig. 2, fig. 2 shows a second structural schematic diagram of a pulsed fiber laser seed source in an embodiment of the present application. The basic structure is similar to that of fig. 1, except that the second pump source 2 and the second fiber combiner 4 of this embodiment are located between the third grating 7 and the second gain fiber 9. The specific connection relationship is as follows: the common end of the first optical fiber combiner 3 is connected with one end of the first grating 5; the other end of the first grating 5 is connected with one end of the first gain optical fiber 8; the other end of the first gain fiber 8 is connected with one end of the second grating 6; the other end of the second grating 6 is connected with one end of the modulator 10; the other end of the modulator 10 is connected with one end of the second gain fiber 9; the other end of the second gain fiber 9 is connected with the common end of the second fiber combiner 4; the signal end of the second optical fiber combiner 4 is connected with one end of the third grating 7, and the other end of the third grating 7 is connected with the output device 11.
For example, referring to fig. 3, fig. 3 shows a third structural schematic diagram of a seed source of a pulsed fiber laser in the embodiment of the present application. The basic structure is similar to that of fig. 1, except that in this embodiment the first pump source 1 and the first fiber combiner 3 are located between the second grating 6 and the modulator 10. The specific connection relationship is as follows: one end of the first grating 5 is connected with one end of the first gain optical fiber 8; the other end of the first gain fiber 8 is connected with one end of the second grating 6; the other end of the second grating 6 is connected with the common end of the first optical fiber beam combiner 3; the signal end of the first optical fiber combiner 3 is connected with one end of the modulator 10; the other end of the modulator 10 is connected with one end of the second gain fiber 9; the other end of the second gain fiber 9 is connected with one end of the third grating 7; the other end of the third grating 7 is connected with the common end of the second optical fiber combiner 4; and the signal end of the second optical fiber combiner 4 is connected with one end of the output device 11.
For example, referring to fig. 4, fig. 4 shows a fourth structural diagram of a seed source of a pulsed fiber laser in the embodiment of the present application. The basic structure is similar to that of fig. 3, except that the second pump source 2 and the second fiber combiner 4 in this embodiment are located between the third grating 7 and the second gain fiber 9. The specific connection mode is as follows: one end of the first grating 5 is connected with one end of the first gain optical fiber 8; the other end of the first gain fiber 8 is connected with one end of the second grating 6; the other end of the second grating 6 is connected with the common end of the first optical fiber beam combiner 3; the signal end of the first optical fiber combiner 3 is connected with one end of the modulator 10; the other end of the modulator 10 is connected with one end of the second gain fiber 9; the other end of the second gain fiber 9 is connected with the common end of the second fiber combiner 4; the signal end of the second optical fiber combiner 4 is connected with one end of the third grating 7, and the other end of the third grating 7 is connected with the output device 11.
It should be noted that the above embodiment only exemplifies the case where there is one pump source at each of the different ends of the modulator 10, but is not limited thereto, and the number of the pump sources of the laser may be more than two, as long as there is at least one pump source at each of the different ends of the modulator 10, and the specific embodiment is not limited herein.
For example, referring to fig. 5, fig. 5 shows a fifth structural schematic diagram of a seed source of a pulsed fiber laser in the embodiment of the present application. The basic structure is similar to that of fig. 1, except that a third pump source 12 and a third optical fiber combiner 13 are further added between the second grating 6 and the modulator 10 in this embodiment. The pumping input end of the third optical fiber combiner 13 is connected with the third pumping source 12; the common end of the third optical fiber combiner 13 is connected with the second grating 6; the signal end of the third optical fiber combiner 13 is connected to the modulator 10.
For example, referring to fig. 6, fig. 6 shows a sixth structural schematic diagram of a seed source of a pulsed fiber laser in the embodiment of the present application. The basic structure is similar to that of fig. 2, except that a third pump source 12 and a third optical fiber combiner 13 are further added between the second grating 6 and the modulator 10 in this embodiment. The pumping input end of the third optical fiber beam combiner 13 is connected with the third pumping source 12; the common end of the third optical fiber combiner 13 is connected with the second grating 6; the signal end of the third optical fiber combiner 13 is connected to the modulator 10.
In the embodiment of the present application, the first grating 5, the second grating 6, the third grating 7, the first gain fiber 8, the second gain fiber 9, the modulator 10, the output device 11, the first pump source 1, the second pump source 2, the first fiber combiner 3, and the second fiber combiner 4 may be of a type commonly used in the art. For example:
in some embodiments, the first gain fiber 8 and the second gain fiber 9 are each independently selected from rare earth element doped fibers or photonic crystal fibers, wherein the doped rare earth element is one or more of ytterbium (Yb), erbium (Er), holmium (Ho), thulium (Tm), samarium (Sm), and bismuth (Bi). That is, the first gain fiber 8 and the second gain fiber 9 may be the same type of rare-earth-doped fiber, for example: both the first gain fiber 8 and the second gain fiber 9 may be ytterbium (Yb) -doped fibers; different types of rare earth doped fibers are also possible, for example: the first gain fiber 8 is an ytterbium (Yb) -doped fiber, and the second gain fiber 9 is an erbium (Er) -doped fiber.
In some embodiments, the first grating 5, the second grating 6 and the third grating 7 are all reflective fiber bragg gratings; and the reflectivities of the first grating 5 and the second grating 6 are greater than 0 and less than 1, in one embodiment, the second grating 6 and the third grating 7 are partially reflective gratings, preferably having a reflectivity of less than or equal to 90%. The first grating 5 is a high-inversion grating, preferably having a reflectivity of 99% or more.
In some embodiments, the first pump source 1 is any one of a semiconductor laser, a fiber laser, a solid laser, a gas laser, or a raman laser, and the second pump source 2 is any one of a semiconductor laser, a fiber laser, a solid laser, a gas laser, and a raman laser.
The central wavelength of the pump light output by the first pump source 1 and the second pump source 2 is 600nm (nanometer) to 2000nm, such as 600nm, 700nm, 800nm, 900nm, 1000nm, 1100nm, 1200nm, 1300nm, 1400nm, 1500nm, 1600nm, 1700nm, 1800nm, 1900nm, 2000 nm; the pumping mode of the first pumping source 1 is any one of fiber core single-ended pumping, fiber core double-ended pumping, cladding single-ended pumping or cladding double-ended pumping, and the pumping mode of the second pumping source 2 is any one of fiber core single-ended pumping, fiber core double-ended pumping, cladding single-ended pumping or cladding double-ended pumping.
In some embodiments, the first optical fiber combiner 3 is any one of (1 + 1) × 1, (2 + 1) × 1 or (6 + 1) × 1, and the second optical fiber combiner 4 is any one of (1 + 1) × 1, (2 + 1) × 1 or (6 + 1) × 1.
In some embodiments, the modulator 10 may be a modulator or Q-switching device known in the art, such as an acousto-optic modulator or electro-optic modulator.
In some embodiments, the output device 11 may be an output device known in the art, such as an optical isolator, and may be a polarization independent isolator.
For better understanding of the embodiments of the present application, the present application further provides a pulse adjusting method of a seed source of a pulse fiber laser, the method including:
s10, adjusting the pump light power of the second pump source according to the required pulse waveform;
if the required pulse waveform is quadrilateral, adjusting the power of the pumping light of the second pumping source to be smaller than a preset threshold value;
if the required pulse waveform is Gaussian or Gaussian-like, adjusting the pumping light power of the second pumping source to be larger than a preset threshold value;
the predetermined threshold is determined by the actual situation, for example, in some embodiments, the predetermined threshold is influenced by the structure of the first and second resonators and the output power of the first and second pump sources 1 and 2. It is only necessary to have the magnitude of the preset threshold meet: when the pump light power of the second pump source 2 is greater than a preset threshold, the pulse generated by the continuous laser in the first resonant cavity through the modulator 10 cannot generate a gain, and when the pump light power of the second pump source 2 is less than the preset threshold, the pulse generated by the continuous laser in the first resonant cavity through the modulator 10 may generate a gain, which is not limited herein.
The quadrangular pulse specifically refers to a rectangular pulse or a trapezoidal pulse, but is not limited thereto, and may be other quadrangular pulses known in the art, such as a general quadrangular pulse (i.e., a trapezoidal pulse). For better understanding, please refer to fig. 7 to 8, which are schematic diagrams of rectangular pulses, trapezoidal pulses and generally quadrangular pulses from left to right as shown in fig. 7. As shown in fig. 8, the pulse has a gaussian shape and a gaussian-like shape from left to right.
Therefore, the pulse adjusting method for the seed source of the pulse fiber laser provided by the embodiment of the application can achieve the adjustment of the required pulse waveform by adjusting the pump light power of the second pump source in the same seed source, and realize the conversion of the waveform.
On the basis of the above embodiment, further, when the pulse waveform is modulated to be a quadrangle, the method further includes:
s20, adjusting the switching time of the modulator according to the required pulse width; and/or adjusting the repetition frequency of the modulator according to the required pulse repetition frequency.
Therefore, when the waveform generated by the seed source is a pulse in a quadrilateral shape, the pulse width can be controlled according to the light-on time of the modulator, and the pulse repetition frequency can be controlled according to the modulation repetition frequency, so that compared with the traditional seed source, the pulse width and repetition frequency change is more flexible, and the tunable range is larger.
The present application will be described in detail below with reference to examples.
The first embodiment,
The present embodiment provides a seed source of a pulse fiber laser, the structure of which is shown in fig. 1, and the seed source includes: the optical fiber grating comprises a first grating 5, a second grating 6, a third grating 7, a first pumping source 1, a second pumping source 2, a first optical fiber beam combiner 3, a second optical fiber beam combiner 4, a first gain optical fiber 8, a second gain optical fiber 9, a modulator 10 and an output device 11.
The first pumping source 1 and the second pumping source 2 are semiconductor laser diodes with central wavelength of 915nm or 976 nm; a first optical fiber combiner 3 and a second optical fiber combiner 4, wherein (2 + 1) 1 optical fiber combiners are selected, such as 10/125 type and 20/125 type; the first grating 5, the second grating 6 and the third grating 7 are reflection type fiber Bragg gratings, the first grating 5 is a high-reflection type grating, the second grating 6 and the third grating 7 are partial reflection type gratings, and the reflectivity is larger than 0 and smaller than 1; the first gain fiber 8 and the second gain fiber 9 are rare earth doped fibers, and are ytterbium doped fibers with fiber core diameter of 10 micrometers or 20 micrometers produced by Rui core company in China; the modulator 10 is an acousto-optic modulator; the output device is a polarization independent optical isolator.
The specific connection mode of this embodiment is as follows: the first pumping source 1 is connected with the pumping input end of the first optical fiber beam combiner 3; the second pumping source 2 is connected with the pumping input end of the second optical fiber beam combiner 4; the common end of the first optical fiber beam combiner 3 is connected with one end of the first grating 5; the other end of the first grating 5 is connected with one end of a first gain optical fiber 8; the other end of the first gain fiber 8 is connected with one end of the second grating 6; the other end of the second grating 6 is connected with one end of the modulator 10; the other end of the modulator 10 is connected with one end of a second gain fiber 9; the other end of the second gain fiber 9 is connected with one end of the third grating 7; the other end of the third grating 7 is connected with the common end of the second optical fiber beam combiner 4; the signal end of the second optical fiber combiner 4 is connected with one end of the output device 11.
The pump light generated by the first pump source 1 passes through the first grating 5 through the pump end of the first optical fiber beam combiner 3, the grating is a high-reflection grating, the reflectivity of the grating is greater than or equal to 99%, then the grating enters the first gain optical fiber 8 and reaches the second grating 6, the grating is a partial reflection grating, the reflectivity of the grating is less than or equal to 90%, the first grating 5 and the second grating 6 form a first resonant cavity, continuous laser with the wavelength corresponding to the center of the grating is generated in the first resonant cavity, and then the continuous laser is subjected to wave chopping through the modulator 10 to generate quadrilateral pulses.
The following is divided into two cases:
in the first case: when the power of the pump light generated by the second pump source 2 is low, the pump light enters the second gain fiber 9 through the second fiber combiner 4, the population of the second gain fiber 9 is inverted, the signal light passing through the acousto-optic modulator 10 enters the second gain fiber 9 for amplification, and is output through the third grating 7, the second fiber combiner 4 and the output device 11 in sequence, and at the moment, a quadrilateral pulse is output;
in the second case: when the power of the pump light generated by the second pump source 2 is high, the pump light enters the second gain fiber 9 through the second fiber combiner 4, the population of the second gain fiber 9 is reversed, the generated reverse ASE (Amplified Spontaneous Emission) forms laser with corresponding central wavelength through the third grating 7, the returned laser can cause that the quadrilateral pulse formed by the wave chopping of the modulator 10 can not obtain gain, at the moment, the modulator 10 is equivalent to a Q switch arranged in a second resonant cavity formed by the first grating 5 and the third grating 7, the laser generated in the second resonant cavity is subjected to mode selection through the first resonant cavity, and at the moment, gaussian or gaussian-like pulses are generated in the second resonant cavity and are output through the second fiber combiner 4 and the output device 11 respectively.
Example II,
The present embodiment provides a second kind of pulse fiber laser seed source, whose structure is shown in fig. 2, and the basic structure is similar to that of fig. 1, except that the positions of the second pump source 2 and the second fiber combiner 4 are different, and in this embodiment, the second pump source 2 and the second fiber combiner 4 are disposed between the third grating 7 and the second gain fiber 9.
Example III,
The present embodiment provides a third kind of pulse fiber laser seed source, whose structure is shown in fig. 3, and the basic structure is similar to that of fig. 1, except that the positions of the first pump source 1 and the first fiber combiner 3 are different, and in this embodiment, the first pump source 1 and the first fiber combiner 3 are disposed between the second grating 6 and the modulator 10.
Example four,
The present embodiment provides a fourth kind of pulse fiber laser seed source, whose structure is shown in fig. 4, and the basic structure is similar to that of fig. 3, except that the present embodiment places the second pump source 2 and the second fiber combiner 4 between the third grating 7 and the second gain fiber 9.
Example V,
The present embodiment provides a fifth kind of pulse fiber laser seed source, whose structure is shown in fig. 5, and the basic structure is similar to that of fig. 1, except that a third pump source 12 and a third fiber combiner 13 are added between the second grating 6 and the modulator 10 in this embodiment.
Example six,
The present embodiment provides a sixth kind of pulse fiber laser seed source, whose structure is shown in fig. 6, and the basic structure is similar to fig. 5, except that the present embodiment places the second pump source 2 and the second fiber combiner 4 between the third grating 7 and the second gain fiber 9.
In summary, the present application provides a seed source of a pulse fiber laser and a pulse adjusting method, where a first resonant cavity may be formed by a first grating and a second grating of the seed source, a second resonant cavity may be formed by the first grating and a third grating, the seed source may generate a quadrilateral pulse by an external modulator of the first resonant cavity, and the modulator may also be used as a Q-switch in the second resonant cavity by adjusting a pumping power of the second pumping source, so that the seed source may generate a gaussian or gaussian-like pulse. In the same seed source, quadrilateral or Gaussian-like pulse can be generated by adjusting the pumping power, so that the pulse laser seed source with adjustable waveform is obtained; on the other hand, when the waveform generated by the seed source is a quadrilateral pulse, the pulse width can be controlled according to the light-on time of the modulator, and the pulse repetition frequency can be controlled according to the modulator repetition frequency, so that compared with the traditional seed source, the pulse width and repetition frequency change is more flexible, and the tunable range is larger; in addition, this application design is nimble, simple, compact structure, and the design of full optic fibre is favorable to realizing the industrialization, and the practicality is strong.
The seed source of the pulse fiber laser and the pulse adjusting method provided by the embodiment of the application are described in detail, a specific example is applied in the description to explain the principle and the implementation of the application, and the description of the embodiment is only used for helping to understand the method and the core idea of the application; meanwhile, for those skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.
Claims (10)
1. A pulsed fiber laser seed source, comprising:
the grating optical fiber modulator comprises a first grating, a first gain optical fiber, a second grating, a modulator, a second gain optical fiber, a third grating and an output device which are connected in sequence;
different ends of the modulator are respectively connected with a first pumping source and a second pumping source, the first pumping source is connected with a pumping input end of a first optical fiber beam combiner and is used for providing pumping light for the first gain optical fiber through the first optical fiber beam combiner; the second pump source is connected to a pump input end of a second optical fiber combiner and is used for providing pump light to the second gain optical fiber through the second optical fiber combiner.
2. The pulsed fiber laser seed source of claim 1, wherein a common end of the first fiber combiner is connected to one end of the first grating; the other end of the first grating is connected with one end of the first gain optical fiber; the other end of the first gain optical fiber is connected with one end of the second grating; the other end of the second grating is connected with one end of the modulator; the other end of the modulator is connected with one end of the second gain optical fiber; the other end of the second gain fiber is connected with one end of the third grating; the other end of the third grating is connected with the common end of the second optical fiber beam combiner; and the signal end of the second optical fiber beam combiner is connected with one end of the output device.
3. The pulsed fiber laser seed source of claim 1, wherein a common end of the first fiber combiner is connected to one end of the first grating; the other end of the first grating is connected with one end of the first gain optical fiber; the other end of the first gain optical fiber is connected with one end of the second grating; the other end of the second grating is connected with one end of the modulator; the other end of the modulator is connected with one end of the second gain optical fiber; the other end of the second gain optical fiber is connected with the common end of the second optical fiber beam combiner; and the signal end of the second optical fiber beam combiner is connected with one end of the third grating, and the other end of the third grating is connected with the output device.
4. The pulsed fiber laser seed source of claim 1, wherein one end of the first grating is connected to one end of the first gain fiber; the other end of the first gain optical fiber is connected with one end of the second grating; the other end of the second grating is connected with the common end of the first optical fiber beam combiner; the signal end of the first optical fiber beam combiner is connected with one end of the modulator; the other end of the modulator is connected with one end of the second gain optical fiber; the other end of the second gain fiber is connected with one end of the third grating; the other end of the third grating is connected with the common end of the second optical fiber beam combiner; and the signal end of the second optical fiber beam combiner is connected with one end of the output device.
5. The pulsed fiber laser seed source of claim 1, wherein one end of the first grating is connected to one end of the first gain fiber; the other end of the first gain optical fiber is connected with one end of the second grating; the other end of the second grating is connected with the common end of the first optical fiber beam combiner; the signal end of the first optical fiber beam combiner is connected with one end of the modulator; the other end of the modulator is connected with one end of the second gain optical fiber; the other end of the second gain optical fiber is connected with the common end of the second optical fiber beam combiner; and the signal end of the second optical fiber beam combiner is connected with one end of the third grating, and the other end of the third grating is connected with the output device.
6. The pulsed fiber laser seed source of claim 2 or 3, further comprising: the third optical fiber beam combiner is positioned between the second grating and the modulator, and the pump input end of the third optical fiber beam combiner is connected with the third pump source.
7. The pulsed fiber laser seed source of claim 1, wherein the first, second and third gratings are reflective fiber bragg gratings, the reflectivity of the first, second and third gratings is greater than 0 and less than 1, and the first grating is a high-reflectivity grating and the second and third gratings are partially reflective gratings.
8. The pulsed fiber laser seed source of claim 1, wherein the modulator is an acousto-optic modulator or an electro-optic modulator.
9. The method of pulse conditioning of a pulsed fiber laser seed source of claim 1, comprising:
adjusting the pump light power of the second pump source according to the required pulse waveform;
if the required pulse waveform is quadrilateral, adjusting the power of the pumping light of the second pumping source to be smaller than a preset threshold value;
if the required pulse waveform is Gaussian or Gaussian-like, adjusting the pumping light power of the second pumping source to be larger than a preset threshold value;
the first grating and the second grating form a first resonant cavity, and the size of the preset threshold value needs to satisfy: when the pump light power of the second pump source is greater than a preset threshold value, the pulse generated by the continuous laser in the first resonant cavity through the modulator cannot generate gain, and when the pump light power of the second pump source is less than the preset threshold value, the pulse generated by the continuous laser in the first resonant cavity through the modulator can generate gain.
10. The adjustment method according to claim 9, wherein when the pulse waveform is adjusted to be a quadrangle, the adjustment method further comprises: adjusting the switching time of the modulator according to the required pulse width; and/or adjusting the repetition frequency of the modulator according to the required pulse repetition frequency.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113839298A (en) * | 2021-11-25 | 2021-12-24 | 武汉锐科光纤激光技术股份有限公司 | Light beam processor, light beam processing method, storage medium, and electronic apparatus |
| CN115693362A (en) * | 2023-01-04 | 2023-02-03 | 武汉锐科光纤激光技术股份有限公司 | Seed source of pulse laser and laser |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150010025A1 (en) * | 2011-12-30 | 2015-01-08 | Datalogic Automation S.R.L. | Pulsed fiber laser with double- pass pumping |
| CN105720465A (en) * | 2016-04-20 | 2016-06-29 | 成都瀚辰光翼科技有限责任公司 | 4-8[mu]m-pulse Raman all-fiber laser |
| US20160240993A1 (en) * | 2013-10-25 | 2016-08-18 | Nikon Corporation | Laser device, and exposure device and inspection device provided with the laser device |
| CN107317219A (en) * | 2017-07-07 | 2017-11-03 | 西北大学 | Dual wavelength pulse optical fiber laser based on rhenium disulfide saturable absorber |
| CN206878307U (en) * | 2017-05-11 | 2018-01-12 | 上海瀚宇光纤通信技术有限公司 | A kind of high pulse energy optical fiber laser light path applied to coherent wind radar system |
| CN108493747A (en) * | 2018-03-12 | 2018-09-04 | 中国科学院上海光学精密机械研究所 | 2 μm of high-energy pure-tone pulse lasers based on optical fiber solid Cascaded amplification |
| CN111541135A (en) * | 2020-05-07 | 2020-08-14 | 无锡锐科光纤激光技术有限责任公司 | Q-switched pulse fiber laser and preparation method thereof |
| CN112350140A (en) * | 2020-10-23 | 2021-02-09 | 密尔医疗科技(深圳)有限公司 | Mixed mode pulse laser |
| CN112952538A (en) * | 2019-12-10 | 2021-06-11 | 苏州创鑫激光科技有限公司 | Optical fiber laser |
-
2021
- 2021-07-14 CN CN202110793377.7A patent/CN113258422B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150010025A1 (en) * | 2011-12-30 | 2015-01-08 | Datalogic Automation S.R.L. | Pulsed fiber laser with double- pass pumping |
| US20160240993A1 (en) * | 2013-10-25 | 2016-08-18 | Nikon Corporation | Laser device, and exposure device and inspection device provided with the laser device |
| CN105720465A (en) * | 2016-04-20 | 2016-06-29 | 成都瀚辰光翼科技有限责任公司 | 4-8[mu]m-pulse Raman all-fiber laser |
| CN206878307U (en) * | 2017-05-11 | 2018-01-12 | 上海瀚宇光纤通信技术有限公司 | A kind of high pulse energy optical fiber laser light path applied to coherent wind radar system |
| CN107317219A (en) * | 2017-07-07 | 2017-11-03 | 西北大学 | Dual wavelength pulse optical fiber laser based on rhenium disulfide saturable absorber |
| CN108493747A (en) * | 2018-03-12 | 2018-09-04 | 中国科学院上海光学精密机械研究所 | 2 μm of high-energy pure-tone pulse lasers based on optical fiber solid Cascaded amplification |
| CN112952538A (en) * | 2019-12-10 | 2021-06-11 | 苏州创鑫激光科技有限公司 | Optical fiber laser |
| CN111541135A (en) * | 2020-05-07 | 2020-08-14 | 无锡锐科光纤激光技术有限责任公司 | Q-switched pulse fiber laser and preparation method thereof |
| CN112350140A (en) * | 2020-10-23 | 2021-02-09 | 密尔医疗科技(深圳)有限公司 | Mixed mode pulse laser |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113839298A (en) * | 2021-11-25 | 2021-12-24 | 武汉锐科光纤激光技术股份有限公司 | Light beam processor, light beam processing method, storage medium, and electronic apparatus |
| CN115693362A (en) * | 2023-01-04 | 2023-02-03 | 武汉锐科光纤激光技术股份有限公司 | Seed source of pulse laser and laser |
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