CN112345208B - Method and device for measuring mode instability threshold of single-mode fiber oscillator based on high-reflectivity grating leakage light - Google Patents
Method and device for measuring mode instability threshold of single-mode fiber oscillator based on high-reflectivity grating leakage light Download PDFInfo
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Abstract
The invention discloses a method and a device for measuring a mode unstable threshold of a single-mode fiber oscillator based on high-reflection grating leakage light. The device comprises a first laser power meter for recording the high-reflecting-grating leakage light power of the optical fiber oscillator, a single-mode optical fiber oscillator and a second laser power meter for recording the output laser power of the optical fiber oscillator. The method and the device can quickly judge whether the mode of the optical fiber oscillator is unstable or not and accurately measure the mode unstable threshold, do not need to perform complex calculation on data, and have simple structure and simple and convenient operation.
Description
Technical Field
The invention belongs to the technical field of laser, relates to a method and a device for measuring a mode instability threshold of a single-mode fiber oscillator, and particularly relates to a method and a device for measuring a mode instability threshold of a single-mode fiber oscillator based on high-reflectivity grating leakage light.
Background
The mode instability in the fiber laser means that after the output power or power density of the fiber laser exceeds a specific threshold, the laser mode output by the fiber laser has obvious random change related to time, the main phenomenon is that the power component of a high-order mode is increased sharply, the quality of a light beam is seriously degraded along with the reduction of the power, and the further improvement of the output power of the fiber laser is limited, so that the mode instability in the fiber laser is observed, judged and restrained, and the mode instability in the fiber laser has important significance for improving the power of the fiber laser.
At present, the mode of combining a photoelectric detector and an oscilloscope is mostly adopted to observe and judge whether the mode instability effect occurs, and the principle is as follows: the mode instability effect is accompanied by violent oscillation of the output optical signal, the electric signal obtained after the optical-electric signal conversion of the photoelectric detector is bound to have rapid oscillation, and the signal can generate obvious oscillation signals on an oscilloscope.
Based on the above principle, document 1(m.m.johansen, m.laurila, m.d.maack, d.noordegraaf, c.jakob sen, t.t.alkekjeld, j.lagsgaard, "Frequency resolved transform mode instability in fiber amplifiers", optical Express, 201321 (19), 21847-. However, this method is not only complicated in structure, but also very sensitive to external environment vibration due to spatial coupling, and meanwhile, the normal operation of the inserted components under high power is a great challenge, which also has certain problems for the safety of measurement. In addition, complex spectrum analysis is required to be performed on the obtained electric signal to judge whether the mode instability phenomenon occurs.
In order to avoid the adoption of a complex structure, chinese patent document No. CN104034515B (document 2) discloses an on-line monitoring method for detecting a mode instability phenomenon in a high-power fiber laser based on a scattered light, the method adopts a fiber laser of a step-index distribution fiber with an all-fiber structure to measure the mode instability effect, mainly uses a photoelectric detector to directly measure the scattered light of the target surface of a power meter to observe the mode instability, the structure is simpler than that of the document 1, other additional elements are not required to be inserted, the device is relatively insensitive to the vibration of the external environment, the structure and the system stability are improved compared with the document 1, but the safety problem of measurement under high power still exists, meanwhile, when the scattered light is measured, the position of the photoelectric detector still needs to be adjusted for many times to accurately capture the scattered light signal, so that the operation complexity of the whole measuring system is increased. In addition, the system still needs to perform spectrum analysis on the signal to determine whether rapid fluctuation occurs, so as to determine whether the mode instability phenomenon occurs.
Similarly, chinese patent publication No. CN107968310A discloses a device and a method for observing mode instability in a fiber laser based on backward return light, the device including: the method comprises the steps of obtaining return light signals, sequentially converting the return light signals into electric signals, judging whether the electric signals are direct current level signals or not, if so, determining that the mode of the optical fiber laser is not unstable, and otherwise, determining that the mode of the optical fiber laser is unstable. Compared with the document 2, the system can judge whether the mode is unstable or not only by measuring the low-power return light time sequence characteristic, the safety is obviously improved, but the system still needs to perform spectrum analysis on the signal so as to judge whether rapid fluctuation occurs or not.
The commonalities of the above documents can be summarized as: (1) the output laser needs to be sampled, and an optical signal is converted into an electric signal through a photoelectric detector, so that the spatial coupling debugging difficulty is high, and the external interference is easy to cause; (2) complex spectral analysis of the signal is required to determine whether rapid oscillations occur.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, particularly aims at the technical problems of complex operation, low safety and complex signal processing of the prior art, and provides a device and a method for measuring the mode instability threshold of a single-mode fiber oscillator based on high-reflectivity grating leakage light, which are simple and quick, do not need to perform complex calculation on data and have good safety.
In order to solve the technical problems, the invention adopts the following technical scheme.
A method for measuring a mode instability threshold of a single-mode fiber oscillator based on high-reflectivity grating leakage light comprises the steps of increasing the pumping power of the fiber oscillator, wherein the fiber oscillator is a single-mode fiber oscillator, a high-reflectivity fiber grating is arranged in the fiber oscillator, the output laser power of the fiber oscillator and the high-reflectivity grating leakage light power are recorded at the same time, when the high-reflectivity grating leakage light power decreases along with the increase of the pumping power, the mode instability phenomenon of the fiber oscillator is judged, and the output laser power corresponding to the inflection point of the high-reflectivity grating leakage light power from rising to falling is the mode instability threshold of the fiber oscillator.
As a general technical concept, the present invention further provides a device for measuring a mode instability threshold of a single mode fiber oscillator based on high reflective grating leakage light, which includes a first laser power meter for recording the high reflective grating leakage light power of the fiber oscillator, a fiber oscillator, and a second laser power meter for recording the output laser power of the fiber oscillator, wherein the fiber oscillator is a single mode fiber oscillator, and a high reflectivity fiber grating is disposed in the fiber oscillator.
In the above apparatus for measuring the mode instability threshold of the single-mode fiber oscillator based on the highly reflective grating leakage light, preferably, the fiber oscillator is a forward-pumped fiber oscillator, a backward-pumped fiber oscillator or a bidirectional-pumped fiber oscillator.
The device for measuring the mode instability threshold of the single-mode fiber oscillator based on the high-reflectivity grating leakage light is preferred, the forward pumping fiber oscillator comprises a forward semiconductor laser, a return light output fiber, a forward cladding power stripper, a forward fiber pumping signal combiner, a high-reflectivity fiber grating, an ytterbium-doped active fiber, a low-reflectivity fiber grating, a backward cladding power stripper and a QBH output fiber which are sequentially welded, and the output fiber of the forward semiconductor laser is welded with the pumping fiber of the forward fiber pumping signal combiner.
Preferably, the feedback output fiber, the input fiber and the output fiber of the forward cladding power stripper, the signal fiber and the output fiber of the forward fiber pump signal combiner, the high-reflectivity fiber grating, the ytterbium-doped active fiber, the low-reflectivity fiber grating, the signal fiber and the output fiber of the backward fiber pump signal combiner, and the input fiber and the output fiber of the backward cladding power stripper, and the QBH output fiber are double-clad fibers, a core diameter, a core numerical aperture, an inner cladding diameter, and an inner cladding numerical aperture of each double-clad fiber are correspondingly equal, in each double-clad fiber, the core diameter is between 10 μm and 30 μm, and the core numerical aperture is between 0.06 and 0.075, the diameter of the inner cladding is 125-400 μm, and the numerical aperture of the inner cladding is 0.44-0.46;
the output optical fiber of the forward semiconductor laser and the pumping optical fiber of the forward optical fiber pumping signal beam combiner are single-clad optical fibers, the fiber core diameter and the fiber core numerical aperture of each single-clad optical fiber are correspondingly equal, in each single-clad optical fiber, the fiber core diameter is between 100 and 220 micrometers, and the fiber core numerical aperture is between 0.18 and 0.22.
The device based on unstable threshold of high reflection grating leakage light measurement single mode fiber oscillator mode, it is preferred that backward pumping fiber oscillator includes backward semiconductor laser and the return light output fiber, the forward cladding power stripper, the high reflectivity fiber grating, the ytterbium-doped active fiber, the low reflectivity fiber grating, backward fiber pumping signal combiner, backward cladding power stripper and the QBH output fiber of butt fusion in proper order, backward semiconductor laser's output fiber with the pumping fiber fusion of backward fiber pumping signal combiner.
Preferably, the feedback output fiber, the input fiber and the output fiber of the forward cladding power stripper, the signal fiber and the output fiber of the forward fiber pump signal combiner, the high-reflectivity fiber grating, the ytterbium-doped active fiber, the low-reflectivity fiber grating, the signal fiber and the output fiber of the backward fiber pump signal combiner, and the input fiber and the output fiber of the backward cladding power stripper, and the QBH output fiber are double-clad fibers, a core diameter, a core numerical aperture, an inner cladding diameter, and an inner cladding numerical aperture of each double-clad fiber are correspondingly equal, in each double-clad fiber, the core diameter is between 10 μm and 30 μm, and the core numerical aperture is between 0.06 and 0.075, the diameter of the inner cladding is 125-400 μm, and the numerical aperture of the inner cladding is 0.44-0.46;
the output optical fiber of the forward semiconductor laser and the pumping optical fiber of the forward optical fiber pumping signal beam combiner are single-clad optical fibers, the fiber core diameter and the fiber core numerical aperture of each single-clad optical fiber are correspondingly equal, in each single-clad optical fiber, the fiber core diameter is between 100 and 220 micrometers, and the fiber core numerical aperture is between 0.18 and 0.22.
Foretell device based on unstable threshold of high reflection grating leakage light measurement single mode fiber oscillator mode, it is preferred, two-way pump fiber oscillator includes forward semiconductor laser, backward semiconductor laser and the return light output fiber of butt fusion in proper order, preceding cladding power stripper, forward fiber pump signal beam combiner, high reflectivity fiber grating, mix ytterbium active fiber, low reflectivity fiber grating, backward fiber pump signal beam combiner, backward cladding power stripper and QBH output fiber, forward semiconductor laser's output fiber with the pump fiber butt fusion of forward fiber pump signal beam combiner, backward semiconductor laser's output fiber with the pump fiber butt fusion of backward fiber pump signal beam combiner.
Preferably, the feedback output fiber, the input fiber and the output fiber of the forward cladding power stripper, the signal fiber and the output fiber of the forward fiber pump signal combiner, the high-reflectivity fiber grating, the ytterbium-doped active fiber, the low-reflectivity fiber grating, the signal fiber and the output fiber of the backward fiber pump signal combiner, and the input fiber and the output fiber of the backward cladding power stripper, and the QBH output fiber are double-clad fibers, a core diameter, a core numerical aperture, an inner cladding diameter, and an inner cladding numerical aperture of each double-clad fiber are correspondingly equal, in each double-clad fiber, the core diameter is between 10 μm and 30 μm, and the core numerical aperture is between 0.06 and 0.075, the diameter of the inner cladding is 125-400 μm, and the numerical aperture of the inner cladding is 0.44-0.46;
the output optical fiber of the front semiconductor laser, the output optical fiber of the rear semiconductor laser, the pump optical fiber of the forward optical fiber pump signal beam combiner and the pump optical fiber of the rear optical fiber pump signal beam combiner are single-clad optical fibers, the fiber core diameter and the fiber core numerical aperture of each single-clad optical fiber are correspondingly equal, in each single-clad optical fiber, the fiber core diameter is between 100 and 220 micrometers, and the fiber core numerical aperture is between 0.18 and 0.22.
In the above device for measuring the mode instability threshold of the single-mode fiber oscillator based on the high-reflectivity grating leakage light, preferably, the high-reflectivity grating leakage light is transmitted to the return light output fiber along the fiber core through the high-reflectivity fiber grating, and is finally emitted out of the return light output fiber; the output laser generated by the fiber oscillator is transmitted to the QBH output fiber along the fiber core through the low-reflectivity fiber grating, and finally is emitted by the QBH output fiber.
In the invention, the corresponding equality of the core diameter, the core numerical aperture, the inner cladding diameter and the inner cladding numerical aperture of each double-clad optical fiber means that the core diameter, the core numerical aperture, the inner cladding diameter and the inner cladding numerical aperture of each double-clad optical fiber are equal.
The corresponding equality of the fiber core diameter and the fiber core numerical aperture of each single cladding optical fiber means that the fiber core diameter and the fiber core numerical aperture of each single cladding optical fiber are equal.
Compared with the prior art, the invention has the advantages that:
by adopting the device and the method for measuring the mode unstable threshold of the single-mode fiber oscillator based on the high-reflection grating leakage light, whether the mode unstable phenomenon occurs in the fiber oscillator and the mode unstable threshold can be judged accurately based on the variation trend of the high-reflection grating leakage light power along with the pumping power by only measuring the output laser power and the high-reflection grating leakage light power, the complex calculation of data is not needed, the system is simple in structure and convenient to operate, and the device and the method are suitable for quickly measuring the mode unstable threshold of the high-power fiber oscillator.
Drawings
Fig. 1 is a schematic structural diagram of an apparatus for measuring a mode instability threshold of a single-mode fiber oscillator based on high-reflectivity grating leakage light in embodiment 1 of the present invention.
Fig. 2 is a schematic structural diagram of a measured optical fiber oscillator in embodiment 1 of the present invention.
Fig. 3 is a graph of the variation trend of the leakage light power and the output laser power of the high reflective grating with the pump power in embodiment 1 of the present invention.
Fig. 4 is a graph comparing the output laser focus spot before and after the mode instability threshold in example 1 of the present invention.
Illustration of the drawings:
1. a first laser power meter; 2. an optical fiber oscillator; 3. a second laser power meter; 21. a return light output fiber; 22. QBH output fiber; 23. a forward cladding power stripper; 24. a forward semiconductor laser; 25. a forward fiber pump signal combiner; 26. high-reflectivity fiber grating; 27. an ytterbium-doped active optical fiber; 28. a low-reflectivity fiber grating; 29. a backward cladding power stripper.
Detailed Description
The invention is further described below with reference to the drawings and specific preferred embodiments of the description, without thereby limiting the scope of protection of the invention. Unless otherwise specified, materials and instruments used in the following examples are commercially available.
Example 1
The invention relates to a method for measuring a mode unstable threshold of a single-mode fiber oscillator based on high-reflectivity grating leakage light, which comprises the steps of increasing the pumping power of the fiber oscillator 2, wherein the fiber oscillator 2 is a single-mode fiber oscillator, a high-reflectivity fiber grating 26 is arranged in the fiber oscillator 2, the output laser power of the fiber oscillator 2 and the high-reflectivity grating leakage light power are recorded simultaneously, the high-reflectivity grating leakage light power is increased along with the increase of the pumping power at first, when the high-reflectivity grating leakage light power is decreased along with the increase of the pumping power, the mode unstable phenomenon of the single-mode fiber oscillator is judged to occur, and the output laser power corresponding to an inflection point where the high-reflectivity grating leakage light power is increased to be decreased is the mode unstable threshold of the single-mode fiber oscillator.
The device diagram for measuring the mode instability threshold of the single-mode fiber oscillator based on the high-reflectivity grating leakage light comprises a first laser power meter 1, a fiber oscillator 2 and a second laser power meter 3, wherein the fiber oscillator 2 is a single-mode fiber oscillator, and a high-reflectivity fiber grating 26 is arranged in the fiber oscillator 2, as shown in fig. 1. The first laser power meter 1 is located on the left side of the optical fiber oscillator 2 and used for recording the high-reflection grating leakage light power of the optical fiber oscillator 2, and the second laser power meter 3 is located on the right side of the optical fiber oscillator 2 and used for recording the output laser power of the optical fiber oscillator 2.
Fig. 2 shows a structure of the fiber oscillator 2 to be measured in this embodiment, which includes a forward semiconductor laser 24, and a return light output fiber 21, a forward cladding power stripper 23, a forward fiber pump signal combiner 25, a high-reflectivity fiber grating 26, an ytterbium-doped active fiber 27, a low-reflectivity fiber grating 28, a backward cladding power stripper 29, and a QBH output fiber 22, which are sequentially welded, where the output fiber of the forward semiconductor laser 24 is welded to the pump fiber of the forward fiber pump signal combiner 25. The first laser power meter 1 and the second laser power meter 3 are respectively arranged at the left side and the right side of the optical fiber oscillator 2, the first laser power meter 1 faces to a return light output optical fiber 21 used for transmitting leakage light of a high-reflectivity grating, and the second laser power meter 3 faces to a QBH output optical fiber 22 used for transmitting output laser.
In the fiber oscillator 2, the high reflective grating leaked light is characterized in that the high reflective grating 26 is transmitted to the return light output fiber 21 along the fiber core and finally emitted from the return light output fiber 21. The output laser light is characterized by being transmitted from the low-reflectivity fiber grating 28 along the fiber core to the QBH output fiber 22 and finally emitted from the QBH output fiber 22.
In this embodiment, the return light output fiber 21, the forward cladding power stripper 23, the forward fiber pump signal combiner 25, the high-reflectivity fiber grating 26, the ytterbium-doped active fiber 27, the low-reflectivity fiber grating 28, the backward cladding power stripper 29, and the QBH output fiber 22 are double-clad fibers, and the double-clad fibers have the same fiber core diameter, the same fiber core numerical aperture, the same inner cladding diameter, and the same inner cladding numerical aperture, and preferably have a fiber core diameter of 20 μm, a fiber core numerical aperture of 0.06, an inner cladding diameter of 400 μm, and an inner cladding numerical aperture of 0.46.
In this embodiment, the output fiber of the forward semiconductor laser 24 and the pump fiber of the forward fiber pump signal combiner 25 are single-clad fibers, and the fiber cores of the single-clad fibers have the same diameter and the same numerical aperture, preferably, the fiber cores have a diameter of 220 μm and a numerical aperture of 0.22.
According to the method of the embodiment, the pumping power of the optical fiber oscillator 2 is increased, and the output laser power of the optical fiber oscillator 2 and the high reflective grating leakage power are recorded at the same time, the high reflective grating leakage power shows a trend of increasing first and then decreasing along with the increase of the pumping power, when the high reflective grating leakage power decreases along with the increase of the pumping power, it is indicated that the mode instability phenomenon has occurred in the optical fiber oscillator 2, and the output laser power corresponding to the inflection point where the high reflective grating leakage power increases to decrease is the mode instability threshold of the optical fiber oscillator 2. Fig. 3 shows the variation trend of the output power and the high reflective grating leakage power with the increase of the pumping power, and it can be seen that when the pumping power reaches 6290W, the high reflective grating leakage power is decreased, and the corresponding output power is 4530W. Meanwhile, as shown in fig. 4, the output spot is also changed from the fundamental mode spot to the multimode spot, that is, the beam quality is obviously degraded, which indicates that the mode instability of the fiber oscillator 2 has occurred at this time, and the mode instability threshold is 4530W.
In this embodiment, only the measurement result of the forward pump fiber oscillator is given, and the apparatus and method of the present invention are also applicable to backward pump fiber oscillators and bidirectional pump fiber oscillators.
The backward pumping fiber oscillator comprises a backward semiconductor laser, a return light output fiber 21, a forward cladding power stripper 23, a high-reflectivity fiber grating 26, an ytterbium-doped active fiber 27, a low-reflectivity fiber grating 28, a backward fiber pumping signal combiner, a backward cladding power stripper 29 and a QBH output fiber 22 which are sequentially welded, wherein the output fiber of the backward semiconductor laser is welded with the pumping fiber of the backward fiber pumping signal combiner. The drawing of the backward pumped fiber oscillator is omitted.
The bidirectional pumping fiber oscillator comprises a forward semiconductor laser 24, a backward semiconductor laser and a return light output fiber 21 which is sequentially welded, a forward cladding power stripper 23, a forward fiber pumping signal combiner 25, a high-reflectivity fiber grating 26, ytterbium-doped active fibers 27, a low-reflectivity fiber grating 28, a backward fiber pumping signal combiner, a backward cladding power stripper 29 and QBH output fibers 22, an output fiber of the forward semiconductor laser 24 is welded with a pumping fiber of the forward fiber pumping signal combiner 25, and an output fiber of the backward semiconductor laser is welded with a pumping fiber of the backward fiber pumping signal combiner. The drawings of the bidirectional pump fiber oscillator are omitted.
By adopting the method and the device designed by the invention, whether the single-mode optical fiber oscillator has the mode instability phenomenon or not and the mode instability threshold value can be accurately measured only by measuring the output laser power and the high-reflection grating leakage power based on the variation trend of the high-reflection grating leakage power along with the pumping power, the complex calculation of data is not needed, the system structure is simple, the operation is simple and convenient, and the method and the device are suitable for quickly measuring the mode instability threshold value of the high-power optical fiber oscillator.
The foregoing is merely a preferred embodiment of the invention and is not intended to limit the invention in any manner. Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make many possible variations and modifications to the disclosed embodiments, or equivalent modifications, without departing from the spirit and scope of the invention, using the methods and techniques disclosed above. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention.
Claims (10)
1. The method for measuring the mode instability threshold of the single-mode fiber oscillator based on the high-reflectivity grating leakage light is characterized by comprising the step of increasing the pumping power of the fiber oscillator (2), wherein the fiber oscillator (2) is a single-mode fiber oscillator, a high-reflectivity fiber grating (26) is arranged in the fiber oscillator (2), the output laser power of the fiber oscillator (2) and the high-reflectivity grating leakage light power are recorded at the same time, when the high-reflectivity grating leakage light power decreases along with the increase of the pumping power, the mode instability phenomenon of the fiber oscillator (2) is judged, and the mode instability threshold of the fiber oscillator (2) is determined as the output laser power corresponding to the inflection point of the high-reflectivity grating leakage light power from rising to falling.
2. The device for measuring the mode instability threshold of the single-mode fiber oscillator based on the high-reflectivity grating leakage light is characterized by comprising a first laser power meter (1) used for recording the high-reflectivity grating leakage light power of the fiber oscillator (2), the fiber oscillator (2) and a second laser power meter (3) used for recording the output laser power of the fiber oscillator (2), wherein the fiber oscillator (2) is a single-mode fiber oscillator, and a high-reflectivity fiber grating (26) is arranged in the fiber oscillator (2).
3. The device for measuring the mode instability threshold of the single mode fiber oscillator based on the highly reflective grating leakage light according to claim 2, wherein the fiber oscillator (2) is a forward-pumped fiber oscillator, a backward-pumped fiber oscillator or a bidirectional-pumped fiber oscillator.
4. The device for measuring the mode instability threshold of the single mode fiber oscillator based on the high reflecting grating leakage light is characterized in that the forward pumping fiber oscillator comprises a forward semiconductor laser (24) and a return light output fiber (21), a forward cladding power stripper (23), a forward pumping signal combiner (25), a high-reflectivity fiber grating (26), an ytterbium-doped active fiber (27), a low-reflectivity fiber grating (28), a backward cladding power stripper (29) and a QBH output fiber (22) which are sequentially welded, and the output fiber of the forward semiconductor laser (24) is welded with the pumping fiber of the forward pumping signal combiner (25).
5. The device for measuring the mode instability threshold of the single mode fiber oscillator based on the highly reflective grating leakage light according to claim 4, wherein the return light output fiber (21), the input fiber and the output fiber of the forward cladding power stripper (23), the signal fiber and the output fiber of the forward fiber pump signal combiner (25), the high-reflectivity fiber grating (26), the ytterbium-doped active fiber (27), the low-reflectivity fiber grating (28), the signal fiber and the output fiber of the backward fiber pump signal combiner, the input fiber and the output fiber of the backward cladding power stripper (29), and the QBH output fiber are double-clad fibers, the core diameters of the double-clad fibers are equal, the core numerical apertures of the double-clad fibers are equal, the inner cladding diameters of the double-clad fibers are equal, The numerical aperture of the inner cladding of each double-clad optical fiber is equal, the diameter of the fiber core in each double-clad optical fiber is between 10 and 30 micrometers, the numerical aperture of the fiber core is between 0.06 and 0.075, the diameter of the inner cladding is between 125 and 400 micrometers, and the numerical aperture of the inner cladding is between 0.44 and 0.46;
the output optical fiber of the forward semiconductor laser (24) and the pumping optical fiber of the forward optical fiber pumping signal beam combiner (25) are single-clad optical fibers, the diameters of fiber cores of the single-clad optical fibers are equal, the numerical apertures of the fiber cores of the single-clad optical fibers are equal, the diameters of the fiber cores in the single-clad optical fibers are between 100 and 220 micrometers, and the numerical apertures of the fiber cores are between 0.18 and 0.22.
6. The device for measuring the mode instability threshold of the single mode fiber oscillator based on the high reflecting grating leakage light is characterized in that the backward pumping fiber oscillator comprises a backward semiconductor laser and a backward light output fiber (21), a forward cladding power stripper (23), a high-reflectivity fiber grating (26), an ytterbium-doped active fiber (27), a low-reflectivity fiber grating (28), a backward fiber pumping signal combiner, a backward cladding power stripper (29) and a QBH output fiber (22) which are sequentially welded, wherein the output fiber of the backward semiconductor laser is welded with the pumping fiber of the backward fiber pumping signal combiner.
7. The device for measuring the mode instability threshold of the single mode fiber oscillator based on the high reflectivity grating leakage light according to claim 6, wherein the return light output fiber (21), the input and output fibers of the forward cladding power stripper (23), the signal and output fibers of the forward fiber pump signal combiner (25), the high reflectivity fiber grating (26), the ytterbium-doped active fiber (27), the low reflectivity fiber grating (28), the signal and output fibers of the backward fiber pump signal combiner, the input and output fibers of the backward cladding power stripper (29), and the QBH output fiber (22) are double-clad fibers, and the core diameters of the double-clad fibers are equal, the core numerical apertures of the double-clad fibers are equal, and the inner cladding diameters of the double-clad fibers are equal, The numerical aperture of the inner cladding of each double-clad optical fiber is equal, the diameter of the fiber core in each double-clad optical fiber is between 10 and 30 micrometers, the numerical aperture of the fiber core is between 0.06 and 0.075, the diameter of the inner cladding is between 125 and 400 micrometers, and the numerical aperture of the inner cladding is between 0.44 and 0.46;
the output optical fiber of the forward semiconductor laser (24) and the pumping optical fiber of the forward optical fiber pumping signal beam combiner (25) are single-clad optical fibers, the diameters of fiber cores of the single-clad optical fibers are equal, the numerical apertures of the fiber cores of the single-clad optical fibers are equal, the diameters of the fiber cores in the single-clad optical fibers are between 100 and 220 micrometers, and the numerical apertures of the fiber cores are between 0.18 and 0.22.
8. The device for measuring the mode instability threshold of the single mode fiber oscillator based on the high grating leakage light according to claim 3, it is characterized in that the bidirectional pumping optical fiber oscillator comprises a forward semiconductor laser (24), a backward semiconductor laser, a return light output optical fiber (21), a forward cladding power stripper (23), a forward optical fiber pumping signal combiner (25), a high-reflectivity optical fiber grating (26), an ytterbium-doped active optical fiber (27), a low-reflectivity optical fiber grating (28), a backward optical fiber pumping signal combiner, a backward cladding power stripper (29) and a QBH output optical fiber (22) which are sequentially welded, the output fiber of the forward semiconductor laser (24) is welded with the pump fiber of the forward fiber pump signal beam combiner (25), and the output optical fiber of the backward semiconductor laser is welded with the pumping optical fiber of the backward optical fiber pumping signal beam combiner.
9. The device for measuring the mode instability threshold of the single mode fiber oscillator based on the high reflectivity grating leakage light of claim 8, wherein the return light output fiber (21), the input and output fibers of the forward cladding power stripper (23), the signal and output fibers of the forward fiber pump signal combiner (25), the high reflectivity fiber grating (26), the ytterbium-doped active fiber (27), the low reflectivity fiber grating (28), the signal and output fibers of the backward fiber pump signal combiner, the input and output fibers of the backward cladding power stripper (29), and the QBH output fiber (22) are double-clad fibers, and the core diameter of each double-clad fiber is equal, the core numerical aperture of each double-clad fiber is equal, and the inner cladding diameter of each double-clad fiber is equal, The numerical aperture of the inner cladding of each double-clad optical fiber is equal, the diameter of the fiber core in each double-clad optical fiber is between 10 and 30 micrometers, the numerical aperture of the fiber core is between 0.06 and 0.075, the diameter of the inner cladding is between 125 and 400 micrometers, and the numerical aperture of the inner cladding is between 0.44 and 0.46;
the output optical fiber of the front semiconductor laser, the output optical fiber of the rear semiconductor laser, the pump optical fiber of the forward optical fiber pump signal beam combiner and the pump optical fiber of the rear optical fiber pump signal beam combiner are single-clad optical fibers, the fiber core diameters of the single-clad optical fibers are equal, the fiber core numerical apertures of the single-clad optical fibers are equal, in each single-clad optical fiber, the fiber core diameter is 100-220 mu m, and the fiber core numerical aperture is 0.18-0.22.
10. The device for measuring the mode instability threshold of the single-mode fiber oscillator based on the high-reflectivity grating leakage light is characterized in that the high-reflectivity grating leakage light is transmitted to the return light output fiber (21) along the fiber core through the high-reflectivity fiber grating (26) and finally exits from the return light output fiber (21); the output laser that fiber oscillator (2) produced is through low reflectivity fiber grating (28) along the fibre core to QBH output fiber (22) transmission, and finally by QBH output fiber (22) outgoing.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7787729B2 (en) * | 2005-05-20 | 2010-08-31 | Imra America, Inc. | Single mode propagation in fibers and rods with large leakage channels |
| US8213077B2 (en) * | 2008-04-22 | 2012-07-03 | Imra America, Inc. | Multi-clad optical fibers |
| CN107623246A (en) * | 2016-07-14 | 2018-01-23 | 中国兵器装备研究院 | Fibre core is the same as band pumped optical fibre laser |
| CN108462023A (en) * | 2018-05-29 | 2018-08-28 | 中国人民解放军国防科技大学 | High-power optical fiber laser amplifier system with high mode instability threshold |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7787729B2 (en) * | 2005-05-20 | 2010-08-31 | Imra America, Inc. | Single mode propagation in fibers and rods with large leakage channels |
| US8213077B2 (en) * | 2008-04-22 | 2012-07-03 | Imra America, Inc. | Multi-clad optical fibers |
| CN107623246A (en) * | 2016-07-14 | 2018-01-23 | 中国兵器装备研究院 | Fibre core is the same as band pumped optical fibre laser |
| CN108462023A (en) * | 2018-05-29 | 2018-08-28 | 中国人民解放军国防科技大学 | High-power optical fiber laser amplifier system with high mode instability threshold |
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