CN102916328B - Compact all-fiber supercontinuum white-light source - Google Patents
Compact all-fiber supercontinuum white-light source Download PDFInfo
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- CN102916328B CN102916328B CN201210381061.8A CN201210381061A CN102916328B CN 102916328 B CN102916328 B CN 102916328B CN 201210381061 A CN201210381061 A CN 201210381061A CN 102916328 B CN102916328 B CN 102916328B
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Abstract
The invention discloses a compact all-fiber supercontinuum white-light source, and relates to the field of white-light laser sources. Theoretically, a nonlinear polarization rotation mode-locked laser adopting an all-fiber structure serves as the oscillating stage, the output seed light is amplified and then coupled into high-nonlinearity photonic crystal fibers for nonlinear broadening so as to obtain supercontinuum white-light output; and structurally, the compact modularized design is adopted to optimize fiber coiling and the layout of other optical devices, the optical devices are integrated on a worktable, and a magnetic tape type fiber coiling tank of which the dimension is optimized is integrated on a base. Compared with a traditional white-light source which has the defects of large size, heavy weight, poor stability, high price, requirement for additional equipment to assist temperature reduction, and the like due to the adoption of a space coupling device, according to the invention, the photonic crystal fibers and single-mode fibers are directly fused through repeated low-current discharge, and the corresponding modularized design is adopted, the above defects are avoided, and both the performance of the whole machine and the compactness are improved.
Description
Technical field
The present invention relates to white light LASER Light Source field, particularly relate to a kind of Compact all-fiber supercontinuum white-light source.
Background technology
The time domain of light pulse in highly nonlinear optical fiber and frequency domain develop, not only be subject to the impact of the multiple nonlinear effects such as such as spontaneous phase-modulation (SPM), Cross-phase Modulation (XPM), four wave mixing (FWM), stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS), also be subject to the impact of optical fiber dispersion characteristic, all these non-linear process can produce new frequency component.For enough strong pulse, can by more than hundreds of for spectrum widening nanometer, this phenomenon is referred to as the generation of ultra-wide spectrum.
Supercontinuum light source can export ultra-wide spectrum laser, and it to have on the field of high request low-coherence light source or spectrum analysis in biology, medical science, physics, national defence and industry etc. and has important application.In current application process, the small size of super continuous wave laser and the pursuit of portability are improved day by day.Full-optical-fiber laser can not only ensure integrally-built compact and heat radiation excellent, more can realize the Laser output of high stable.Therefore the status do not replaced and good development prospect is had in actual applications.
In traditional research that super continuum light spectrum is produced, be carry out stretched-out spectrum with nonlinear crystal.But nonlinear crystal is very easily damaged when draw power improves, thus the average output power of super continuous wave laser is caused to be limited.After this, optical fiber is used in because its area of dissipation is large in further research, and the generation of high-quality super continuous spectrums of the Dispersion Limitation of ordinary optic fibre.The appearance of photonic crystal fiber then opens new chapter for super continuous spectrums generates.The optical fiber parameter of photonic crystal fiber can by designing inside of optical fibre micro-structural thus being controlled, and nonlinear interaction enriches, and dispersion is controlled.Super continuous spectrums technology based on non-linear photon crystal optical fiber studies interest widely because the using value in the fields such as spectroscopy, ultra-short pulse laser technology, frequency measurement and optical coherence tomography (OCT) causes in the world.But photonic crystal fiber also has its remarkable shortcoming, such as, with the problem such as the welding difficulty of ordinary optic fibre, splice loss, splice attenuation is large, fiber manufacturing cost is high, difficult treatment.
Inventor is realizing in process of the present invention, finds at least there is following shortcoming and defect in prior art:
Super continuous laser Theory comparison at present based on photonic crystal fiber is ripe, but it is comparatively large to be used for the general volume of ultrashort pulse laser of excitation photons crystal fiber, and heavier-weight, involves great expense; Meanwhile, many existing apparatus adopt set of lenses to do Space Coupling, and set of lenses design is complicated, and bulky, efficiency is lower, harsh to environmental requirement, is difficult to realize Engineering Reliability requirement; In addition, due to the amount of heat that coupling efficiency lowly produces, must be lost by extra auxiliary equipment such as air-cooled or water-cooleds, this further increases again the volume and weight of complete machine.
Summary of the invention
For solving the problems of the technologies described above, the invention provides a kind of Compact all-fiber supercontinuum white-light source, described below:
A kind of Compact all-fiber supercontinuum white-light source, comprising: laser module, described laser module comprises oscillator stage and amplifying stage two parts,
Oscillator stage structure is that the first pumping source, the first fiber coupler, first be connected successively mixes ytterbium gain fibre, the first optical fiber collimator, λ/4 wave plate, λ/2 wave plate, polarization beam apparatus, the 2nd λ/4 wave plate, birefringent filter, the second optical fiber collimator and fibre optic isolater; Amplifying stage structure is that the second pumping source, the second fiber coupler, second be connected successively mixes ytterbium gain fibre and high non-linear photon crystal optical fiber; Each section of optical fiber is connected by monomode fiber with between above-mentioned device.
The 3rd fiber coupler is adopted to be coupled between described oscillator stage and described amplifying stage.
Described first pumping source and the second pumping source are specially: output wavelength is the semiconductor laser of 970nm.
Be direct welding between described high non-linear photon crystal optical fiber and monomode fiber, adopt repeatedly low discharging current.
Also comprise: base,
Each section of close fiber optic used is coiled in the magnetic tape type fiber reel that integrates with described base in groove; Described first fiber coupler, described second fiber coupler, described 3rd fiber coupler and described fibre optic isolater are also arranged on described magnetic tape type fiber reel in groove; Each section of outer fiber wraps up soft heat-conducting silica gel sheet.
Described magnetic tape type fiber reel is provided with transparent plastic cover plate on groove, and described transparent plastic cover plate bottom is provided with boss, and described boss matches for fixed fiber around groove with described magnetic tape type fiber reel.
Also comprise: the workbench being equipped with fixing counterbore,
Described first optical fiber collimator, described λ/4 wave plate, described λ/2 wave plate, described polarization beam apparatus, described 2nd λ/4 wave plate, described birefringent filter and described second optical fiber collimator are integrated on described workbench.
Also comprise: the side panel being provided with U-shaped hole, described base be also provided with the second V-shaped groove,
The passage that pumping input optical fibre and supercontinuum output optical fibre are fitted in by described second V-shaped groove on the described U-shaped hole on described side panel and described base.
Described base is provided with free curve fixing hole and free curve hole.
Described base is also provided with laser upper cover; Described base is also provided with the first V-shaped groove, and monomode fiber enters described magnetic tape type fiber reel in groove by the guiding of described first V-shaped groove.
The beneficial effect of technical scheme provided by the invention is: complete machine all adopts aluminium alloy to make, while assurance device bulk strength, also can obtain good heat dispersion and light characteristic.In addition, utilize the direct contact type of aluminum alloy base to dispel the heat and can save water-cooled heavy in conventional apparatus or air cooler, reduce machine volume and weight further.Above-mentioned design can make whole laser because adjusting device and few and both little, the compact conformation of volume of servicing unit, and turn increase stability and reliability, modular design simultaneously also makes maintenance and regulates more simple and easy to do; Time stability is good, temperature stability is good, assembling safeguard simply, just with integrated, modularization, cost is low, technique is simple, be easy to industrialization.
Accompanying drawing explanation
Fig. 1 is the exploded perspective view of supercontinuum laser;
Fig. 2 is the structure chart of side panel;
Fig. 3 is the structure chart of workbench;
Fig. 4 is the structure chart of base;
Fig. 5 is the fundamental diagram of supercontinuum laser.
In accompanying drawing, the list of parts representated by each label is as follows:
1: laser upper cover; 2: side panel;
3: transparent plastic cover plate; 4: workbench;
5: free curve hole; 6: base;
7: the first pumping sources; 8: the second pumping sources;
9: the first optical fiber collimators; 10: the one λ/4 wave plates;
11: the one λ/2 wave plates; 12: polarization beam apparatus;
13: the two λ/4 wave plates; 14: birefringent filter;
15: the second optical fiber collimators; Mix ytterbium gain fibre at 16: the first;
17: the first fiber couplers; 18: fibre optic isolater;
19: the second fiber couplers; 20: the three fiber couplers;
Mix ytterbium gain fibre at 21: the second; 22: high non-linear photon crystal optical fiber;
23: monomode fiber; 24: the first V-type grooves;
25: free curve fixing hole; 26: the second V-shaped grooves;
27:U nibs.
Embodiment
For making the object, technical solutions and advantages of the present invention clearly, below embodiment of the present invention is described further in detail.
The embodiment of the present invention is three modules by function i ntegration:
1, shell stuck-module, comprising:
The streamlined laser upper cover 1 of integration, plays the effect that complete machine is supported in protection.Only laser upper cover need be unloaded the mode-lock status that just can utilize the running status of the output light detection laser of polarization beam apparatus (PBS) 12 side easily or be adjusted laser by adjustment wave plate in actual use procedure, remainder still remains on original position;
With the both sides panel 2 in U-shaped hole 27, with the second V-type groove 26 on base 6 with the use of the effect can playing fixing input-output optical fiber;
Transparent plastic dust cover 3, adopts transparent design, can observe directly the state of internal optical fiber and optical fibre device, be convenient to maintaining, play fixing dust-proof effect;
Through dimensionally-optimised magnetic tape type fiber reel around groove, the first V-type groove 24 bootable optical fiber turnover groove at edge, the boss simultaneously on groove and transparent plastic cover plate 3 cooperates optical fiber in holddown groove and optical fibre device;
Place free curve hole 5 in free curve fixing hole 25, be fixed by the pressure of bolt on optical table to white light source, making white light source no matter be placed on optional position on optical table can fix neatly.
2, workbench (bench) 4 module:
Through dimensionally-optimised workbench (bench) 4, reserve the counterbore being used for fixing wave plate, polarization beam apparatus (PBS) 12, optical fiber collimator (collimator), simultaneously bottom is a little more than base 6 lower plane, can easily by its dismounting and change himself or optical element fixed thereon under the prerequisite be not separated with optical table by laser.
3, laser module:
Laser module comprises oscillator stage and amplifying stage two parts, through the nonlinear polarization rotation mode locked fiber laser of numerical simulation of optimum as oscillator stage, produce seed optical pulse, be coupled to mix among ytterbium (Yb) gain fibre amplifying stage and amplify, so be coupled in high non-linear photon crystal optical fiber (PCF) 22 carry out non-linear broadening thus obtain supercontinuum export.
(1) numerical simulation
First based on Ginzburg-Landau equation and Nonlinear Schrodinger Equation, numerical simulation is carried out to the non-linear process of soliton pulse in spread fiber, dispersion process and beneficiating process, each major part is chosen to optimum monomode fiber, mixed ytterbium (Yb) gain fibre, high non-linear photon crystal optical fiber length, to ensure that system can ensure cramped construction and lower cost while realizing high-quality pulse output, the non-linear broadening of frequency spectrum.
(2) experiment is built
Oscillator stage employing output wavelength is single-mode output laser diode 7 pumped laser system of 970nm, the monomode fiber being coated with plastic protective sleeve enters in laser from the U-shaped hole 27 laser side panel 2, magnetic tape type fiber reel is entered in groove by the second V-type groove 26, through the first pumping coupler (WDM) 17 be coupled into first to mix after ytterbium (Yb) gain fibre 16 again through the first V-type groove 24 through transparent plastic cover plate 3, then by after the collimation of first optical fiber collimator (collimator) 9 of the upper installation of workbench bench4 more successively through λ/4 wave plate 10, λ/2 wave plate 11, polarization beam apparatus (PBS) 12, 2nd λ/4 wave plate 13, birefringent filter (BF) 14 and the second optical fiber collimator (collimator) 15, magnetic tape type fiber reel is got back in groove by the transparent dust-proof cover plate 3 that is directed across of the first V-type groove 24, an oscillation circuit is completed finally by fibre optic isolater (ISO) 18.
Soliton pulse in oscillator stage optical fiber the effect of non-linear Kerr effect under can produce nonlinear phase shift.Because nonlinear phase shift is relevant with light intensity, the nonlinear phase shift that thus pulse different piece produces is different, thus the polarization state of pulse each several part is changed.Enable the peak value of light pulse through polarization beam apparatus (PBS) 12 by adjustment wave plate, the more weak front and back of intensity are along then can not through polarization beam apparatus (PBS) 12.Thus making peak value more and more stronger, front and back, along then more and more weak, finally form stable ultrashort pulse.Simultaneously, due to the effect of chirp, pulse different parts has different instantaneous frequencys, introduce filter in systems in which and can provide loss mechanism, the sideband of centre frequency both sides nonlinear effect produced loses, and again import in gain fibre and realize ring cavity structure, light is propagated in a fiber with the form of self similarity and is stablized output.This pulse shaping process is exactly utilize the nonlinear polarization rotation effect of optical fiber to produce a passive mode locking mechanism with the quick saturable absorber of equivalence acted on from amplitude modulation(PAM) (SAM).
Amplifying stage adopts output wavelength to be single-mode output laser diode 8 pumped laser system of 970nm equally; enter the monomode fiber being coated with plastic protective sleeve in laser from the U-shaped hole 27 laser side panel 2 and pass through the 3rd fiber coupler (WDM) 20 from oscillator stage by the seed light that the second fiber coupler (WDM) 19 exports and be coupled into second and mix ytterbium (Yb) gain fibre 21 and realize amplifying; seed light energy in transmitting procedure is constantly amplified; pulsewidth also becomes and is beneficial to greatly non-linear broadening, obtains wider spectrum.Light pulse after amplification enters in high non-linear photon crystal optical fiber 22, because its solitary wave centre wavelength is positioned at the anomalous dispersion region of photonic crystal fiber, can produce multiple non-linear process.When inputting draw power and being lower, obvious soliton self-frequency sh effect can be there is, peak is there is in long wave direction, along with the increase of input draw power, higher-order soliton splits into several base orphan, and red shift gradually under the effect of Raman scattering in pulse, along with the non-orphan's radiation producing blue shift simultaneously.And then along with power raising, the new frequency content that four wave mixing produces makes spectrum tend to smooth and be widened further.
For the high non-linear photon crystal optical fiber that the present invention is used, its mode field diameter, much smaller than the monomode fiber with its welding, limits coupling efficiency and super continuous spectrums broadening degree.For this problem, the welding of small area analysis multiple discharge will be adopted to reduce splice loss, splice attenuation.During experiment is built, adopt experiment light from the mode of monomode fiber incidence, by optimizing the splicing parameters such as discharge parameter, propulsive parameter, side-play amount, and to other end light power Real-Time Monitoring, to determine relatively low-loss welding mode.
It will be appreciated by those skilled in the art that accompanying drawing is the schematic diagram of a preferred embodiment, the invention described above embodiment sequence number, just to describing, does not represent the quality of embodiment.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (9)
1. a Compact all-fiber supercontinuum white-light source, comprising: laser module, it is characterized in that: described laser module comprises oscillator stage and amplifying stage two parts,
Oscillator stage structure is that the first pumping source (7), the first fiber coupler (17), first be connected successively mixes ytterbium gain fibre (16), the first optical fiber collimator (9), λ/4 wave plate (10), λ/2 wave plate (11), polarization beam apparatus (12), the 2nd λ/4 wave plate (13), birefringent filter (14), the second optical fiber collimator (15) and fibre optic isolater (18); Amplifying stage structure is that the second pumping source (8), the second fiber coupler (20), second be connected successively mixes ytterbium gain fibre (21) and high non-linear photon crystal optical fiber (22); Each section of optical fiber is connected by monomode fiber with between above-mentioned device;
Also comprise: the workbench (4) being equipped with fixing counterbore,
Described first optical fiber collimator (9), described λ/4 wave plate (10), described λ/2 wave plate (11), described polarization beam apparatus (12), described 2nd λ/4 wave plate (13), described birefringent filter (14) and described second optical fiber collimator (15) are integrated on described workbench (4).
2. Compact all-fiber supercontinuum white-light source according to claim 1, is characterized in that: adopt the 3rd fiber coupler (19) to be coupled between described oscillator stage and described amplifying stage.
3. Compact all-fiber supercontinuum white-light source according to claim 1, is characterized in that: described first pumping source (7) and the second pumping source (8) are specially: output wavelength is the semiconductor laser of 970nm.
4. Compact all-fiber supercontinuum white-light source according to claim 1, is characterized in that: be direct welding between described high non-linear photon crystal optical fiber (22) and monomode fiber, adopt repeatedly low discharging current.
5. Compact all-fiber supercontinuum white-light source according to claim 2, is characterized in that: also comprise: base (6),
Each section of close fiber optic used is coiled in the magnetic tape type fiber reel that integrates with described base (6) in groove; Described first fiber coupler (17), described second fiber coupler (20), described 3rd fiber coupler (19) and described fibre optic isolater (18) are also arranged on described magnetic tape type fiber reel in groove; Each section of outer fiber wraps up soft heat-conducting silica gel sheet.
6. Compact all-fiber supercontinuum white-light source according to claim 5, it is characterized in that: described magnetic tape type fiber reel is provided with transparent plastic cover plate (3) on groove, described transparent plastic cover plate (3) bottom is provided with boss, and described boss matches for fixed fiber around groove with described magnetic tape type fiber reel.
7. Compact all-fiber supercontinuum white-light source according to claim 5, is characterized in that: also comprise: the side panel (2) being provided with U-shaped hole (27), described base (6) is also provided with the second V-shaped groove (26),
The passage that pumping input optical fibre and supercontinuum output optical fibre are fitted in described second V-shaped groove (26) on described base (6) by the described U-shaped hole (27) on described side panel (2).
8. Compact all-fiber supercontinuum white-light source according to claim 5, is characterized in that: described base (6) is provided with free curve fixing hole (25) and free curve hole (5).
9. Compact all-fiber supercontinuum white-light source according to claim 5, is characterized in that: described base (6) is also provided with laser upper cover (1); Described base (6) is also provided with the first V-shaped groove (24), monomode fiber (23) enters described magnetic tape type fiber reel in groove by the guiding of described first V-shaped groove (24).
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| CN103944042A (en) * | 2014-02-26 | 2014-07-23 | 上海交通大学 | Passive mode-locked fiber laser device |
| CN104300346B (en) * | 2014-10-14 | 2018-08-31 | 上海理工大学 | picosecond pulse laser oscillator |
| CN105896248B (en) * | 2016-05-10 | 2018-11-27 | 西北大学 | A kind of 1.7 μm of mode locked fiber lasers of high power tunable |
| WO2019002212A1 (en) * | 2017-06-27 | 2019-01-03 | Smr Patents Sarl | Laser automotive lamp apparatus |
| CN109818243A (en) * | 2019-02-22 | 2019-05-28 | 深圳技术大学（筹） | A kind of fiber amplifier |
| CN109921269A (en) * | 2019-03-05 | 2019-06-21 | 深圳市杰普特光电股份有限公司 | Laser |
| CN111262118B (en) * | 2020-01-20 | 2023-08-22 | 北京恭科光电科技有限公司 | Device heat radiation structure suitable for near-earth space environment |
| CN112366503B (en) * | 2020-11-09 | 2022-01-25 | 中国工程物理研究院激光聚变研究中心 | Super-continuum spectrum laser output device and system |
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| US6775447B2 (en) * | 2002-09-20 | 2004-08-10 | Fitel Usa Corp. | All fiber low noise supercontinuum source |
| JP2014512019A (en) * | 2011-03-14 | 2014-05-19 | イムラ アメリカ インコーポレイテッド | Broadband generation of mid-infrared coherent continuum using optical fiber |
| CN202797595U (en) * | 2012-10-09 | 2013-03-13 | 天津大学 | Compact-type all-fiber super-continuous white-light source |
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