CN112490833A - Multi-hot-spot distribution single-frequency thulium-doped fiber laser - Google Patents
Multi-hot-spot distribution single-frequency thulium-doped fiber laser Download PDFInfo
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- CN112490833A CN112490833A CN202011356819.3A CN202011356819A CN112490833A CN 112490833 A CN112490833 A CN 112490833A CN 202011356819 A CN202011356819 A CN 202011356819A CN 112490833 A CN112490833 A CN 112490833A
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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
- H01S3/06708—Constructional details of the fibre, e.g. compositions, cross-section, shape or tapering
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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
- H01S3/02—Constructional details
- H01S3/04—Arrangements for thermal management
- H01S3/042—Arrangements for thermal management for solid state 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
- H01S3/05—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
- H01S3/06754—Fibre amplifiers
- H01S3/06783—Amplifying coupler
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- Optics & Photonics (AREA)
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Abstract
The invention discloses a multi-hot-spot distribution single-frequency thulium-doped fiber laser, wherein a gain fiber is formed by welding a plurality of sections of gain fibers with different absorption coefficients, so that the absorption coefficients of the fibers are non-uniformly distributed along the longitudinal direction, the absorption coefficients at two ends of the fibers are the lowest, and the absorption coefficient at the middle section is the highest. The gain optical fiber adopts a double-end pumping scheme, so that the temperature of the hottest points at the two ends of the gain optical fiber can be effectively reduced, heat is dispersed in the longitudinal direction of the optical fiber to form multi-hot-point distribution, the limitation of thermal damage on the output power of an optical fiber system is solved, meanwhile, the reduction of the overall temperature of the optical fiber is also beneficial to inhibiting the mode unstable effect, and the multi-section temperature gradient introduced by the multi-hot-point distribution in the optical fiber also improves the generation threshold of the SBS effect. The scheme can simultaneously solve the problems of thermal effect, mode instability, SBS effect and the like which affect the power improvement of the single-frequency thulium-doped fiber laser.
Description
Technical Field
The invention relates to the technical field of fiber lasers, in particular to a multi-hot-spot distribution single-frequency thulium-doped fiber laser.
Background
The single-frequency laser has important application in a plurality of fields such as coherent optical communication, laser radar, high-resolution spectral analysis, atomic laser cooling and capturing, nonlinear frequency conversion, directional energy, coherence and spectrum synthesis and the like. In order to fully utilize the cross relaxation process, the thulium-doped fiber laser of the 790nm pump has the advantages that the thulium fiber doping concentration is generally higher, the length of a device is only a few meters, and the thermal load of the thulium fiber is serious due to higher quantum loss. The temperature rise caused by heat accumulation brings a series of problems, and the operation stability of the system is influenced. In the end-pumped mode, the hottest point of the gain fiber is located at the end point of the fiber, and when the temperature rise caused by heat accumulation exceeds the melting point of the fiber coating (acrylate coating-105 ℃), the coating can be burnt to further damage the fiber and devices, which becomes an important restriction factor for high-power operation. Serious thermal problems can also cause fiber laser output modes to be unstable.
The single-frequency thulium-doped fiber laser solves the high-power operation problem of a single-frequency thulium-doped fiber laser, needs to solve the thermal problem of a gain fiber, and reduces the power density in a fiber core and the thermal deposition in unit length mainly by increasing the mode field area of the fiber core and the length of the fiber at present. However, for a single-frequency fiber laser system, a large mode field fiber is used as a gain medium, so that the fiber supports multiple oscillation modes, which causes unstable mode effect, and reduces the efficiency of output laser, even causes power surge; increasing the length of the fiber will in turn lower the SBS effect generation threshold.
Disclosure of Invention
The invention aims to solve the problem of high-power operation of a single-frequency thulium-doped fiber laser, provides a multi-hotspot distribution scheme of a gain fiber, and simultaneously solves several limiting factors such as a heat effect, mode instability, SBS effect and the like which influence the power improvement of the single-frequency thulium-doped fiber laser. The heat sink area and temperature of the 'hottest point' of the optical fiber are reduced through the multi-hot-point design, the limitation of thermal damage on the output power level of the optical fiber system is solved, meanwhile, the reduction of the overall temperature of the optical fiber is also beneficial to inhibiting the unstable effect of the mode, and the multi-section temperature gradient introduced by the multi-hot-point distribution in the optical fiber is beneficial to inhibiting the SBS effect.
In order to achieve the purpose, the invention adopts the following technical scheme: a multi-hot-spot distribution single-frequency thulium-doped fiber laser comprises a seed source, a pre-amplification stage, a filter, an isolator and a main amplification stage.
The seed source provides low-power single-frequency laser output;
the pre-amplifier stage comprises a plurality of stages of pre-amplifiers, and the input end of the first stage of pre-amplifier is welded with the output end of the seed source;
the input end of the filter is welded with the output end of the last stage of preamplifier;
the input end of the isolator is welded with the output end of the filter;
the main amplifier consists of a forward optical fiber combiner, a pumping source, a gain optical fiber, a reverse optical fiber combiner and a pumping light stripper. The signal arm of the forward optical fiber combiner is welded with the output end of the isolator, the pump arm of the forward optical fiber combiner is welded with a pump source, the output end of the forward optical fiber combiner is welded with the first end of the gain optical fiber, the second end of the gain optical fiber is welded with the signal arm of the reverse optical fiber combiner, the pump arm of the reverse optical fiber combiner is welded with a pump source, and the output end of the reverse optical fiber combiner is welded with the input end of the pump light stripper;
the gain optical fiber of the main amplifier is formed by fusing N sections of gain optical fibers with different absorption coefficients, wherein N is more than or equal to 3, so that the absorption coefficients of the optical fibers are non-uniformly distributed along the longitudinal direction, the absorption coefficients of two ends of the optical fibers are the lowest, and the absorption coefficient of the middle section is the highest. The double-end pumping scheme is adopted for the gain optical fiber, so that the temperature of the hottest points at two ends of the gain optical fiber can be effectively reduced, multi-hot-point distribution is formed, and heat is dispersed in the longitudinal direction of the optical fiber. The gain optical fiber adopts a double-end pumping scheme, namely two ends of the gain optical fiber are respectively connected with a beam combiner, and pumping arms of the beam combiner are connected with a pumping source.
If N is an odd number, and the index of the middle gain fiber is (N +1)/2, the absorption coefficients of the first gain fiber section to the (N +1)/2 gain fiber sections are sequentially increased, and the absorption coefficients of the (N +1)/2 gain fiber sections to the Nth gain fiber section are sequentially decreased; if N is even number, the labels of the middle gain optical fiber are N/2 and N/2+1, the absorption coefficient of the first gain optical fiber section to the absorption coefficient of the N/2 gain optical fiber section are sequentially increased, and the absorption coefficient of the N/2+1 gain optical fiber section to the absorption coefficient of the N gain optical fiber section are sequentially decreased.
As a preferable technical scheme, the pre-amplification stage comprises 1-4 stages of pre-amplifiers.
Preferably, the gain fiber is a double-clad fiber.
Preferably, the core and the core, and the inner cladding of each section of the gain optical fiber have the same refractive index.
Has the advantages that: compared with the prior art, the technical scheme of the invention has the following beneficial technical effects:
(1) through the multi-hotspot distribution design of the gain fiber, the problems of thermal effect, mode instability, SBS effect and the like which affect the power improvement of the single-frequency thulium-doped fiber laser are solved;
(2) the absorption coefficient is gradually increased from two ends to the middle through the longitudinal distribution design of the absorption coefficient of the gain optical fiber, so that the temperature rise of a pumping end is favorably reduced, and the heat tends to be uniformly distributed in the whole optical fiber;
(3) the absorption coefficient of the optical fiber pumping end is reduced, the absorption coefficient of the middle section of the optical fiber is improved, the total absorption coefficient is kept unchanged, and the laser power extraction efficiency can be ensured while the optical fiber is effectively prevented from being thermally damaged;
(4) the reduction of the overall temperature of the optical fiber is beneficial to inhibiting the mode instability effect;
(5) the multi-section temperature gradient is introduced by the longitudinal multi-heat-point distribution of the optical fiber, which is beneficial to inhibiting the SBS effect.
Drawings
FIG. 1 is a schematic diagram of a gain fiber with a uniformly distributed double-pumped absorption coefficient;
FIG. 2 is a schematic diagram of a double-end pumped longitudinal 4-hot-spot gain fiber;
FIG. 3 is a schematic diagram of a double-end pumped longitudinal 6-hot spot gain fiber;
FIG. 4 is a schematic diagram of optical path connection of a single-frequency thulium-doped fiber laser according to an embodiment.
1, 2, 4, 5, 8, 9-pump light in FIGS. 1-3 above; 3-gain optical fiber with uniformly distributed absorption coefficient; 6. 7, 10, 11, 12, 13-fusion points of optical fibers with different absorption coefficients;
in FIG. 4, 14-seed source; 15-a pre-amplification stage; 16-a filter; 17-an isolator; 18-a pump source; 19-a forward fiber combiner; a 20-gain optical fiber; 21-a reverse fiber combiner; 22-pump light stripper.
Detailed Description
Example (b):
as shown in fig. 4, the present embodiment provides a single-frequency fiber laser including: seed source 14, preamplifier 15, filter 16, isolator 17, pump source 18, forward fiber combiner 19, gain fiber 20, reverse fiber combiner 21, and pump stripper 22. The pump source 18, the forward fiber combiner 19, the gain fiber 20, the backward fiber combiner 21 and the pump stripper 22 form a main amplification stage. The output of the seed source 14 is fused to the input of the preamplifier 15; the input end of the filter 16 is welded with the output end of the preamplifier 15; the input end of the isolator 17 is welded with the output end of the filter 16; the signal arm of the forward optical fiber combiner 19 is welded with the output end of the isolator 17; the pump source 18 is welded with the pump arm of the forward optical fiber combiner 19 or the backward optical fiber combiner 21; the output end of the forward optical fiber combiner 19 is welded to the first end of the gain optical fiber 20, the second end of the gain optical fiber 20 is welded to the signal arm of the backward optical fiber combiner 21, and the output end of the backward optical fiber combiner 21 is welded to the input end of the pump light stripper 22; the output of the pump light stripper 22 serves as the output of the laser.
Fig. 1-3 are schematic diagrams of a double-end pumped gain fiber, where the longitudinal color changes from dark to light, which represents the temperature change of the fiber from high to low under the condition of double-end pumping. Fig. 1 shows the temperature distribution of a gain fiber with uniformly distributed absorption coefficients under a double-end pumping condition, where the temperatures at the two ends of the fiber are the highest, and the temperature in the middle is the lowest, and as the power increases, the temperatures at the two ends gradually increase to reach the damage threshold of the fiber coating, which may cause the laser system to crash. Fig. 2 shows a gain fiber formed by fusing three sections of optical fibers with different absorption coefficients, wherein the absorption coefficients at two ends are low, and the absorption coefficient at the middle section is the highest, and due to the reduction of the absorption coefficients at two end points, the generated heat is correspondingly reduced, and a part of the heat is dispersed to the middle section, so that the four hot spots are distributed, and the temperature peak value of the optical fiber is reduced. FIG. 3 shows a gain fiber formed by fusion splicing five sections of optical fibers with different absorption coefficients, wherein the absorption coefficients at two ends are the lowest, the absorption coefficient at the middle section is the highest, and the absorption coefficients of the gain fiber at the middle section decrease sequentially from the absorption coefficient to the absorption coefficients of the gain fiber at the two ends; and the generated heat is correspondingly reduced due to the reduction of the absorption coefficients of the two end points, and a part of heat is dispersed to the middle three sections to form six hot point distribution, so that the temperature peak value of the optical fiber is further reduced. Under the condition of the same total pump power, the temperature peak value of the gain fiber is reduced along with the increase of the number of hot spots, namely, the temperature peak value of the four-hot-spot distribution scheme is lower than that of the two-hot-spot distribution scheme, and the temperature peak value of the six-hot-spot distribution scheme is lower than that of the four-hot-spot distribution scheme.
This embodiment has demonstrated the feasible scheme of a high power single-frequency thulium-doped fiber laser, and during the actual use, hot spot quantity can be designed according to actual need. The invention should in no way be limited to the specific embodiments described above.
Claims (5)
1. A multi-hot-spot distribution single-frequency thulium-doped fiber laser is characterized by comprising a seed source, a pre-amplification stage, a filter, an isolator and a main amplification stage;
the seed source provides low-power single-frequency laser output;
the pre-amplifier stage comprises a plurality of stages of pre-amplifiers, and the input end of the first stage of pre-amplifier is welded with the output end of the seed source;
the input end of the filter is welded with the output end of the last stage of preamplifier;
the input end of the isolator is welded with the output end of the filter;
the main amplifier comprises a forward optical fiber combiner, a pumping source, a gain optical fiber, a reverse optical fiber combiner and a pumping light stripper, wherein a signal arm of the forward optical fiber combiner is welded with the output end of the isolator, the pumping arm of the forward optical fiber combiner is welded with the pumping source, and the output end of the forward optical fiber combiner is welded with the first end of the gain optical fiber;
the second end of the gain fiber is welded with the signal arm of the reverse fiber combiner, the pump arm of the reverse fiber combiner is welded with a pump source, and the output end of the reverse fiber combiner is welded with the input end of the pump light stripper; the gain optical fiber is formed by sequentially welding N sections of gain optical fibers with different absorption coefficients, wherein N is more than or equal to 3.
2. The multi-hot-spot distribution single-frequency thulium-doped fiber laser as claimed in claim 1, wherein the pre-amplifier stage comprises 1-4 stages of pre-amplifiers.
3. The multi-hot spot distribution single frequency thulium-doped fiber laser according to claim 1 or 2, wherein the gain fiber is a double-clad thulium-doped fiber.
4. The multi-hot-spot distribution single-frequency thulium-doped fiber laser as claimed in claim 1 or 2, wherein N is numbered as 1, 2, …, N-1, N is sequentially welded N sections of gain fibers, if N is an odd number, the index of the middle section of gain fiber is (N +1)/2, the absorption coefficient of the first section of gain fiber increases sequentially to the (N +1)/2 section of gain fiber, and the absorption coefficient of the (N +1)/2 section of gain fiber decreases sequentially to the N section of gain fiber; if N is even number, the labels of the middle gain fiber are N/2 and N/2+1, the absorption coefficient of the first gain fiber increases to the absorption coefficient of the N/2 gain fiber, and the absorption coefficient of the N/2+1 gain fiber decreases to the absorption coefficient of the N gain fiber.
5. The multi-hot spot distribution single-frequency thulium-doped fiber laser as claimed in claim 4, wherein the refractive index of the core and the refractive index of the inner cladding of each segment of the fiber are the same.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011356819.3A CN112490833A (en) | 2020-11-27 | 2020-11-27 | Multi-hot-spot distribution single-frequency thulium-doped fiber laser |
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| CN202011356819.3A CN112490833A (en) | 2020-11-27 | 2020-11-27 | Multi-hot-spot distribution single-frequency thulium-doped fiber laser |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114268010A (en) * | 2022-03-02 | 2022-04-01 | 武汉锐科光纤激光技术股份有限公司 | Optical fiber amplifier |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106129795A (en) * | 2016-08-31 | 2016-11-16 | 山东海富光子科技股份有限公司 | Single frequency optical fiber laser with single-frequency semiconductor laser as seed source |
| CN107591668A (en) * | 2017-08-09 | 2018-01-16 | 武汉锐科光纤激光技术股份有限公司 | A kind of application of Yb dosed optical fiber, laser system and Yb dosed optical fiber |
| CN207021505U (en) * | 2017-07-31 | 2018-02-16 | 深圳瑞焱通光子技术有限公司 | A kind of narrow linewidth linear polarization thulium-doped fiber laser |
| CN111129933A (en) * | 2018-10-31 | 2020-05-08 | 大族激光科技产业集团股份有限公司 | All-fiber air-cooled thulium laser |
-
2020
- 2020-11-27 CN CN202011356819.3A patent/CN112490833A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106129795A (en) * | 2016-08-31 | 2016-11-16 | 山东海富光子科技股份有限公司 | Single frequency optical fiber laser with single-frequency semiconductor laser as seed source |
| CN207021505U (en) * | 2017-07-31 | 2018-02-16 | 深圳瑞焱通光子技术有限公司 | A kind of narrow linewidth linear polarization thulium-doped fiber laser |
| CN107591668A (en) * | 2017-08-09 | 2018-01-16 | 武汉锐科光纤激光技术股份有限公司 | A kind of application of Yb dosed optical fiber, laser system and Yb dosed optical fiber |
| CN111129933A (en) * | 2018-10-31 | 2020-05-08 | 大族激光科技产业集团股份有限公司 | All-fiber air-cooled thulium laser |
Non-Patent Citations (1)
| Title |
|---|
| 申岳国等: "双包层光纤激光器温度分布数值分析", 《南京大学学报（自然科学）》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114268010A (en) * | 2022-03-02 | 2022-04-01 | 武汉锐科光纤激光技术股份有限公司 | Optical fiber amplifier |
| CN114268010B (en) * | 2022-03-02 | 2022-06-14 | 武汉锐科光纤激光技术股份有限公司 | Optical fiber amplifier |
| WO2023165109A1 (en) * | 2022-03-02 | 2023-09-07 | 武汉锐科光纤激光技术股份有限公司 | Optical fiber amplifier |
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Application publication date: 20210312 |