CN217469092U - Thulium-doped Raman mixed gain fiber laser - Google Patents
Thulium-doped Raman mixed gain fiber laser Download PDFInfo
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- CN217469092U CN217469092U CN202221870283.1U CN202221870283U CN217469092U CN 217469092 U CN217469092 U CN 217469092U CN 202221870283 U CN202221870283 U CN 202221870283U CN 217469092 U CN217469092 U CN 217469092U
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Abstract
The application discloses a thulium-doped Raman mixed gain fiber laser, which comprises a pumping source, a signal laser module and a gain unit, wherein the pumping source outputs laser in an erbium wave band, the radiation wavelength range is 1530-1620nm, the wave band of the laser output by the signal laser module is 1650-1800nm of a thulium-doped-Raman cross band, in the embodiment of the application, the thulium-doped Raman mixed gain fiber laser is adopted, the pumping laser wave band output by the pumping source is 1530-1620nm and is positioned in an absorption band of a thulium-doped fiber, the signal laser wave band output by the signal laser module is 1650-1800nm and is positioned in the thulium-Raman cross band, the output power of the signal laser and the pumping-signal conversion efficiency are both improved through the mixed gain of thulium and Raman, and under the dual gain of thulium and Raman, most of the pump laser is converted into signal laser, and the higher power requirement of the signal laser in the 1.7-micron waveband can be met.
Description
Technical Field
The utility model relates to a laser technical field especially relates to a thulium-doped Raman mixed gain fiber laser.
Background
The thulium-doped fiber has a very wide gain bandwidth, the gain range can be from 1.7 micrometers to 2 micrometers, the 2-micrometer waveband fiber laser has realized continuous light output of hundreds of watts, and the output of the mature fiber laser is limited to tens of watts at the 1.7-micrometer waveband. Both for scientific applications and for industrial requirements, there is an ever increasing demand for higher power in this band.
The difficulty in realizing high power in this band is mainly due to the gain characteristic, and the too weak gain of this band results in too low conversion efficiency from pump laser to signal laser; on the other hand, if the optical fiber is too long to provide sufficient gain, the 1.7-micron waveband is reabsorbed by the gain optical fiber and converted into spontaneous radiation, the output spectrum quality is affected, and the output power is difficult to increase.
SUMMERY OF THE UTILITY MODEL
The utility model discloses aim at solving one of the technical problem that exists among the prior art.
The application provides a can realize dual gain, promote thulium-doped Raman mixed gain fiber laser of laser output power, include:
the pumping source is connected with the gain unit and used for outputting pumping laser;
the gain unit is used for receiving the pump laser and triggering a gain mechanism through the pump laser;
the signal laser module is connected with the gain unit and coupled with the pumping source and used for inputting signal laser to the gain unit;
wherein the wavelength band of the pump laser is 1530-1620nm, and the wavelength band of the signal laser is 1650-1800 nm.
Further, the thulium-doped raman hybrid gain fiber laser includes a gain unit, a first gain fiber, a second gain fiber, and a third gain fiber, wherein the first gain fiber is connected to the second gain fiber;
the first gain optical fiber is a thulium-doped optical fiber, and the second gain optical fiber is a Raman optical fiber with the length being more than or equal to 0 m.
Further, it is limited that, the thulium-doped raman mixed gain fiber laser further includes:
a pump-signal light combiner for coupling the pump laser and the signal laser together;
a pump light filter for separating the pump laser light from the signal laser light.
Further defined, the thulium-doped raman hybrid gain fiber laser as described above, wherein the signal laser module includes:
the signal light source is used for outputting the signal laser with the wave band of 1650-1800 nm;
and the optical fiber isolator is used for receiving the signal laser and outputting the signal laser to the gain unit, and the signal light source is prevented from being influenced by reflected reverse light.
Further, the thulium-doped raman hybrid gain fiber laser is limited, wherein the output ends of the pump source and the fiber isolator are respectively connected with the input end of the pump-signal light combiner, the output end of the pump-signal light combiner is sequentially connected with the first gain fiber and the second gain fiber, and the output end of the second gain fiber is connected with the pump light filter.
Further, the thulium-doped raman hybrid gain fiber laser is defined, wherein an output end of the fiber isolator is connected to the pump optical filter, the pump optical filter is sequentially connected to the first gain fiber and the second gain fiber, the second gain fiber is connected to the pump-signal combiner, and the pump-signal combiner is connected to the pump source.
Further, the thulium-doped raman hybrid gain fiber laser is defined, wherein the signal laser module includes a high reflective grating and a low reflective grating, and the high reflective grating and the low reflective grating are respectively connected to two ends of the gain unit and are configured to provide feedback of the signal laser;
wherein, the central wavelength of the reflection of the high-reflection grating and the low-reflection grating is 1650-1800 nm.
Further inject, foretell thulium-doped raman mixed gain fiber laser, wherein, pump source, high reflection grating respectively with pump-signal beam combiner input is connected, and pump-signal beam combiner output connects gradually first gain optic fibre, second gain optic fibre, the second gain optic fibre is connected low anti-grating, low reflection grating is connected the pump light filter.
Further inject, foretell thulium-doped raman mixed gain fiber laser, wherein, high anti-grating with the pump light filter is connected, the pump light filter connects gradually first gain fiber, second gain fiber, the second gain fiber is connected low anti-grating, low reflection grating connects pump-signal beam combiner, pump-signal beam combiner with the pump source is connected.
The utility model discloses possess following beneficial effect:
the pumping laser wave band output by the pumping source is 1530-1620nm and is positioned in the absorption band of the thulium-doped optical fiber, the signal laser wave band output by the signal laser module is 1650-1800nm and is positioned in the crossing band of the thulium-Raman gain, the output power of the signal laser and the pumping-signal conversion efficiency are both improved through the mixed gain of the thulium-doped and Raman gain, most of the pumping laser is converted into the signal laser under the dual gain of the thulium-doped and Raman gain, and the higher power requirement of the signal laser in the wave band of 1.7 microns can be met.
Drawings
Fig. 1 is a schematic structural diagram of a thulium-doped raman mixed gain fiber laser in embodiment 2 of the present application;
fig. 2 is a schematic structural diagram of a thulium-doped raman mixed gain fiber laser in embodiment 3 of the present application;
fig. 3 is a schematic structural diagram of a thulium-doped raman mixed gain fiber laser according to embodiment 4 of the present application;
fig. 4 is a schematic structural diagram of a thulium-doped raman mixed gain fiber laser in embodiment 5 of the present application;
fig. 5 is a typical raman gain spectrum.
Reference numerals
Signal light source-110, optical fiber isolator-120, high reflecting grating-130, low reflecting grating-140, pump source-200, pump-signal light beam combiner-300, first gain fiber-410, second gain fiber-420 and pump light filter-500.
Detailed Description
The technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present disclosure.
The terms first, second and the like in the description and in the claims of the present application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that embodiments of the application may be practiced in sequences other than those illustrated or described herein, and that the terms "first," "second," and the like are generally used herein in a generic sense and do not limit the number of terms, e.g., the first term can be one or more than one. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/" generally means that a preceding and succeeding related objects are in an "or" relationship.
The thulium-doped raman mixed gain fiber laser provided by the embodiment of the present application is described in detail through specific embodiments and application scenarios thereof with reference to the accompanying drawings.
Example 1:
as shown in fig. 1 to 4, an embodiment of the present application provides a thulium-doped raman hybrid gain fiber laser, including a pump source 200, a signal laser module, and a gain unit, where the pump source 200 is connected to the gain unit and used for inducing a gain mechanism of the gain unit, the signal laser module is connected to the gain unit and coupled to the pump source 200 for inputting signal laser with a fixed wavelength band to the gain unit, the gain unit includes a first gain fiber 410 and a second gain fiber 420 that are sequentially connected, the first gain fiber 410 is a thulium-doped fiber, preferably a thulium-doped fiber with a high raman gain coefficient, the second gain fiber 420 is a raman fiber, and since any fiber can provide raman gain, when the raman gain of the first gain fiber 410 is sufficient, there may be no second gain fiber 420, and therefore the length of the second gain fiber 420 is defined as being greater than or equal to 0 m.
The pump source 200 is laser in erbium band, the radiation wavelength is generally 1530-1620nm, this band is in absorption band of thulium doped fiber, it can provide gain through thulium doped fiber, this band is used as pump laser, the calculation formula of stokes laser wavelength generated by raman gain is:
wherein, Delnu is wave number corresponding to Raman peak gain, and lambda p Is the wavelength of the pump light, λ s Is the stokes light wavelength. In the conventional Raman fiber, the wave number Deltaupsilon corresponding to the Raman peak gain is usually 400cm -1 On the left and right, the entire Raman gain is actually very wide, and the gain range can be estimated to be 167- -1 The wavelength of Stokes calculated by the formula can cover the vicinity of 1640-1800nm, the waveband of Raman gain covers the vicinity of 1640-1800nm, the gain range of the thulium-doped optical fiber can cover the vicinity of 1650-2000nm, and the overlapped gain part of the two is the operating wavelength of the laser design.
Namely, the wavelength band of the pump source 200 is 1530-1620nm, and the wavelength band of the laser output by the signal laser module is 1650-1800nm, which is the cross band of thulium-raman gain.
The optical fiber laser system further comprises a pump-signal light beam combiner 300 and a pump light filter 500, wherein the pump-signal light beam combiner 300 is connected with the pump source 200, the signal laser module and the gain unit, the pump-signal light beam combiner 300 is used for optically coupling the pump laser and the signal laser together, and can be a conventional signal light-cladding light beam combiner or a wavelength division multiplexer, and the like, the pump light filter 500 is used for separating the pump laser from the signal laser, and can be a cladding light filter when the system selects cladding pumping, and can be a wavelength division multiplexer when the system selects core pumping.
In the embodiment of the application, by using the thulium-doped raman hybrid gain fiber laser, the pumping laser band output by the pumping source 200 is 1530-1620nm and is located in the absorption band of the thulium-doped fiber, the signal laser band output by the signal laser module is 1650-1800nm and is located in the crossing band of the thulium-doped raman gain, the output power and the pumping-signal conversion efficiency of the signal laser are both improved through the thulium-doped and raman hybrid gain, and most of the pumping laser is converted into the signal laser under the dual gains of thulium-doped and raman, so that the power requirement of the signal laser in the 1.7-micron band can be met.
Example 2:
as shown in fig. 1, in this embodiment, the structure of the present invention is an optical fiber amplifier, including the structural features of the foregoing embodiment 1, wherein the signal laser module includes a signal light source 110 and an optical fiber isolator 120, the signal light source 110 is used to output a signal laser with a wavelength of 1650-1800nm, the optical fiber isolator 120 is connected to the signal laser output end of the signal light source 110, and is used to protect the signal light source 110, avoid the reduction of its spectral purity due to the influence of the reflected reverse light on the signal light source 110, and improve the working stability of the signal light source 110.
The output ends of the pump source 200 and the optical fiber isolator 120 are respectively connected to the input end of the pump-signal optical combiner 300, the output end of the pump-signal optical combiner 300 is sequentially connected to the first gain fiber 410 and the second gain fiber 420, and the output end of the second gain fiber 420 is connected to the pump optical filter 500.
At this time, the laser is in a forward pumping state, the signal laser output by the signal light source 110 is combined with the pumping laser output by the pumping source 200 through the pumping-signal combiner after passing through the optical fiber isolator 120, the combined laser is injected into the first gain fiber 410, under the pumping of the pumping laser, the first fiber provides gain to amplify the signal laser, when passing through the second gain fiber 420, the remaining pumping laser amplifies the signal laser through raman gain, and finally the amplified signal laser and the remaining pumping laser are separated through the pumping light filter 500 to form a high-power signal laser output optical path.
In the embodiment of the present application, in the 1590nm laser pumped high power and high efficiency 1710nm laser system adopting the above scheme, the signal laser output by the laser light source is a single frequency signal of 1710nm, the pump laser output by the pump source 200 is 1590nm, the pump-signal combiner is specifically a first 1710/1590 polarization maintaining WDM, the pump light filter 500 is specifically a second 1710/1590 polarization maintaining WDM, the signal laser of 1710nm passes through the fiber isolator 120 and is coupled into the first gain fiber 410 through the first 1710/1590 polarization maintaining WDM and the 1590nm pump laser, where the first gain fiber 410 is specifically a TDF-4/125 fiber with a large raman gain coefficient, a section of the second gain fiber 420 is welded behind the first gain fiber 410, the second gain fiber 420 is specifically a high nonlinear fiber, and under the pumping of the 1590nm pump laser, the first gain fiber 410 provides the gain and the raman gain of rare earth ions, the second gain fiber 420 provides a higher raman gain, and in order to suppress possible stimulated brillouin scattering, a certain gradient of stress is applied to the second gain fiber 420, and finally, under the dual gain, most of the pump laser is converted into signal laser, and a small part of the pump laser passes through the second 1710/1590 polarization maintaining WDM separation system, so that high-power 1710nm signal laser is output.
Example 3:
as shown in fig. 2, in this embodiment, the structure of the present invention is an optical fiber amplifier, including the structural features of the foregoing embodiment 1, wherein the signal laser module includes a signal light source 110 and an optical fiber isolator 120, the signal light source 110 is used to output a signal laser with a wavelength of 1650-1800nm, the optical fiber isolator 120 is connected to the signal laser output end of the signal light source 110, and is used to protect the signal light source 110, avoid the reduction of its spectral purity due to the influence of the reflected reverse light on the signal light source 110, and improve the working stability of the signal light source 110.
The output end of the optical fiber isolator 120 is connected to the pump light filter 500, the pump light filter 500 is sequentially connected to the first gain fiber 410 and the second gain fiber 420, the second gain fiber 420 is connected to the pump-signal combiner, and the pump-signal combiner is connected to the pump source 200.
At this time, the laser is in a backward pumping state, the signal laser output by the signal light source 110 is injected into the first gain fiber 410 and the second gain fiber 420 through the fiber isolator 120 and the pump light filter 500 for forward transmission, the pump laser output by the pump source 200 is coupled into the system through the pump-signal beam combiner, the pump laser and the signal laser meet in the gain unit, the signal laser is amplified and passes through the pump-signal beam combiner for output, and the remaining pump laser is completely absorbed or led out of the system through the pump light filter 500.
Example 4:
as shown in fig. 3, in this embodiment, the structure of the present invention is an optical fiber oscillator, including the structural features of the foregoing embodiment 1, wherein the signal laser module includes a high reflective grating 130 and a low reflective grating 140, the high reflective grating 130 and the low reflective grating 140 are respectively connected to two ends of the gain unit, the high reflective grating 130 and the low reflective grating 140 are optical fiber gratings, the reflected central wavelength is 1650-1800nm or so, for providing feedback of the signal laser, selecting a longitudinal mode, i.e. selecting an oscillation mode, and the reflectivity of the low reflective grating 140 is lower than that of the high reflective grating 130.
The pump source 200 and the high reflection grating 130 are respectively connected with the input end of the pump-signal light beam combiner 300, the output end of the pump-signal light beam combiner 300 is sequentially connected with the first gain fiber 410 and the second gain fiber 420, the second gain fiber 420 is connected with the low reflection grating 140, and the low reflection grating 140 is connected with the pump light filter 500.
At this time, the laser is in a forward pumping state, the pumping laser output by the pumping source 200 is coupled into the system through the pumping-signal beam combiner, the gain unit initiates a gain mechanism under the action of the pumping laser, the low reflective grating 140 receives the pumping laser and reflects and outputs a signal laser with a center wavelength of 1650 + 1800nm, the signal laser is amplified through the gain unit and is fed back and forth between the low reflective grating 140 and the high reflective grating 130, so that the feedback amplification of the signal laser is realized in a reciprocating manner, the power-amplified signal laser is output by the low reflective grating 140 through the pumping light filter 500, and the pumping light filter 500 separates the signal laser from the residual pumping laser.
Example 5:
as shown in fig. 4, in this embodiment, the structure of the present invention is an optical fiber oscillator, including the structural features of the foregoing embodiment 1, wherein the signal laser module includes a high reflective grating 130 and a low reflective grating 140, the high reflective grating 130 and the low reflective grating 140 are respectively connected to two ends of the gain unit, the high reflective grating 130 and the low reflective grating 140 are optical fiber gratings, the reflected central wavelength is 1650-1800nm or so, for providing feedback of the signal laser, selecting a longitudinal mode, i.e. selecting an oscillation mode, and the reflectivity of the low reflective grating 140 is lower than that of the high reflective grating 130.
The high reflective grating 130 is connected to the pump light filter 500, the pump light filter 500 is sequentially connected to the first gain fiber 410 and the second gain fiber 420, the second gain fiber 420 is connected to the low reflective grating 140, the low reflective grating 140 is connected to the pump-signal light combiner 300, and the pump-signal light combiner is connected to the pump source 200.
At this time, the laser is in a backward pumping state, the pumping laser output by the pumping source 200 is coupled into the system through the pumping-signal combiner, the gain unit initiates a gain mechanism under the action of the pumping laser, the low reflective grating 140 receives the pumping laser and reflects and outputs a signal laser with a center wavelength of 1650-.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. Further, it should be noted that the scope of the methods and apparatus of the embodiments of the present application is not limited to performing the functions in the order illustrated or discussed, but may include performing the functions in a substantially simultaneous manner or in a reverse order based on the functions involved, e.g., the methods described may be performed in an order different than that described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.
While the present embodiments have been described with reference to the accompanying drawings, it is to be understood that the present embodiments are not limited to those precise embodiments, which are intended to be illustrative rather than restrictive, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope of the appended claims.
Claims (9)
1. A thulium-doped raman hybrid gain fiber laser, comprising:
the pumping source is connected with the gain unit and used for outputting pumping laser;
the gain unit is used for receiving the pump laser and inducing a gain mechanism through the pump laser;
the signal laser module is connected with the gain unit and coupled with the pumping source and used for inputting signal laser to the gain unit;
wherein the wavelength band of the pump laser is 1530-1620nm, and the wavelength band of the signal laser is 1650-1800 nm.
2. The thulium-doped raman hybrid gain fiber laser according to claim 1, wherein the gain unit comprises a first gain fiber and a second gain fiber connected to the first gain fiber;
the first gain optical fiber is a thulium-doped optical fiber, and the second gain optical fiber is a Raman optical fiber with the length being more than or equal to 0 m.
3. The thulium-doped raman hybrid gain fiber laser according to claim 2, further comprising:
a pump-signal light combiner for coupling together the pump laser and the signal laser;
a pump light filter for separating the pump laser light from the signal laser light.
4. The thulium-doped raman hybrid gain fiber laser of claim 3, wherein the signal laser module comprises:
the signal light source is used for outputting the signal laser with the wave band of 1650-1800 nm;
and the optical fiber isolator is used for receiving the signal laser and outputting the signal laser to the gain unit, and the signal light source is prevented from being influenced by reflected backward light.
5. The thulium-doped raman hybrid gain fiber laser according to claim 4, wherein the pump source and the output end of the fiber isolator are respectively connected to the input end of the pump-signal optical combiner, the output end of the pump-signal optical combiner is sequentially connected to the first gain fiber and the second gain fiber, and the output end of the second gain fiber is connected to the pump optical filter.
6. The thulium-doped raman hybrid gain fiber laser according to claim 4, wherein the output end of the fiber isolator is connected to the pump light filter, the pump light filter is sequentially connected to the first gain fiber and the second gain fiber, the second gain fiber is connected to the pump-signal combiner, and the pump-signal combiner is connected to the pump source.
7. The thulium-doped Raman mixed gain fiber laser according to claim 3, wherein the signal laser module comprises a high reflective grating and a low reflective grating, the high reflective grating and the low reflective grating are respectively connected to two ends of the gain unit and are used for providing feedback of the signal laser;
wherein, the central wavelength of the reflection of the high-reflection grating and the low-reflection grating is 1650-1800 nm.
8. The thulium-doped raman hybrid gain fiber laser according to claim 7, wherein the pump source and the high reflective grating are respectively connected to the input end of the pump-signal beam combiner, the output end of the pump-signal beam combiner is sequentially connected to the first gain fiber and the second gain fiber, the second gain fiber is connected to the low reflective grating, and the low reflective grating is connected to the pump light filter.
9. The thulium-doped raman hybrid gain fiber laser according to claim 7, wherein the high reflective grating is connected to the pump light filter, the pump light filter is sequentially connected to the first gain fiber and the second gain fiber, the second gain fiber is connected to the low reflective grating, the low reflective grating is connected to the pump-signal beam combiner, and the pump-signal beam combiner is connected to the pump source.
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| CN202221870283.1U CN217469092U (en) | 2022-07-08 | 2022-07-08 | Thulium-doped Raman mixed gain fiber laser |
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| CN202221870283.1U CN217469092U (en) | 2022-07-08 | 2022-07-08 | Thulium-doped Raman mixed gain fiber laser |
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