CN116544761B - System for producing compressible coherent Raman pulse fiber laser - Google Patents
System for producing compressible coherent Raman pulse fiber laser Download PDFInfo
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- CN116544761B CN116544761B CN202310824562.7A CN202310824562A CN116544761B CN 116544761 B CN116544761 B CN 116544761B CN 202310824562 A CN202310824562 A CN 202310824562A CN 116544761 B CN116544761 B CN 116544761B
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/06—Construction or shape of active medium
- H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
- H01S3/067—Fibre lasers
- H01S3/0675—Resonators including a grating structure, e.g. distributed Bragg reflectors [DBR] or distributed feedback [DFB] fibre lasers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—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
- H01S3/06716—Fibre compositions or doping with active elements
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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
- H01S3/06758—Tandem amplifiers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/106—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity
- H01S3/108—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity using non-linear optical devices, e.g. exhibiting Brillouin or Raman scattering
- H01S3/1086—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity using non-linear optical devices, e.g. exhibiting Brillouin or Raman scattering using scattering effects, e.g. Raman or Brillouin effect
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
Abstract
The invention discloses a system for generating compressible coherent Raman pulse fiber laser, which belongs to the technical field of laser and comprises: the pulse laser comprises a pulse laser source, a first pump, a first wavelength division multiplexer/beam combiner, a high-reflection fiber grating, a first gain fiber, a low-reflection fiber grating, an isolator, a second pump, a second wavelength division multiplexer/beam combiner, a second gain fiber, a filter component and a pulse compressor; and introducing a fiber bragg grating type resonant cavity into the amplifying stage, amplifying the signal pulse, generating Raman wavelength laser, providing coherent seed light for subsequent Raman amplification, and finally obtaining ultrashort Raman pulse laser through filtering and compression. The invention has compact structure, simple and convenient operation and low price, can generate high-order Raman pulse to expand the wavelength range in a cascading mode, and has universality and application potential.
Description
Technical Field
The invention relates to the technical field of lasers, in particular to a system for generating compressible coherent Raman pulse fiber laser.
Background
During pulse amplification, stimulated raman scattering acts as a non-linear effect that is difficult to ignore, transferring pulse energy to stokes waves, resulting in loss of signal energy and distortion of pulse shape. In order to suppress the nonlinear effect, a chirped pulse amplification method is generally adopted, but in some cases, people can use stimulated raman scattering to acquire a specific wavelength outside the bandwidth of the gain medium, and the method is applied to the fields of biological imaging, material processing and the like.
Stimulated raman scattering is a process of absorbing signal wavelengths and producing raman wavelengths, which can be seen as gain amplifying the raman wavelengths by signal wavelengths. The raman wavelength generated in the amplifying process is usually the gain amplification of the signal wavelength to the spontaneous noise, and the incoherent characteristic of the noise causes that the generated raman pulse is difficult to compress to the femto second level, and the compressed pulse often has a huge base of tens or hundreds of picoseconds, so that most of energy is distributed in the base, namely the effective energy is low, and the raman pulse with high peak power cannot be obtained, thereby weakening the use effect and limiting the application scene. In recent years, a single-frequency light source having a raman wavelength is used as raman seed light, and the raman seed light is amplified by injection through a wavelength division multiplexer and then filtered and compressed, thereby obtaining hundreds of femtosecond raman pulses ("Femtosecond pulse generation by nonlinear optical gain modulation," DOI: 10.1002/adpr.202100255). However, the above technical solution has the problems of complex structure, complicated operation, high price, and the like, which is mainly caused by the single-frequency light source of the raman wavelength.
Disclosure of Invention
Aiming at the technical problems, the invention provides a system for generating compressible coherent Raman pulse fiber laser, which aims to realize the aims of compact structure, simple and convenient operation, low price and the like in order to avoid using a single-frequency light source with Raman wavelength.
The invention solves the problems by the following technical means: a system for generating compressible coherent Raman pulse fiber laser comprises a pulse laser source, a first pump, a first wavelength division multiplexer/combiner, a high-reflection fiber grating, a first gain fiber, a low-reflection fiber grating, an isolator, a second pump, a second wavelength division multiplexer/combiner, a second gain fiber, a filter component and a pulse compressor, wherein all the parts are connected in a fiber welding or space coupling mode;
the first wavelength division multiplexer/beam combiner couples the ultrashort pulse laser signal provided by the pulse laser source and the pump light provided by the first pump to the same optical path, enters a resonant cavity formed by a high-reflection fiber grating, a first gain fiber and a low-reflection fiber grating which are sequentially connected, so that coherent Raman wavelength laser is generated, the emergent light of the resonant cavity and the pump light of the second pump enter the second gain fiber together through the second wavelength division multiplexer/beam combiner after passing through the isolator, the signal pulse in the emergent light of the resonant cavity is amplified to transfer the energy of the signal pulse to the Raman wavelength laser in the emergent light, the Raman wavelength laser is amplified in a Raman mode as Raman seed light to generate coherent Raman pulse, then residual pump light and the signal pulse are filtered through the filtering component in sequence, and the pulse compressor compresses the coherent Raman pulse, so that the ultrashort Raman pulse laser is finally obtained.
And the reflection center wavelengths of the high-reflection fiber bragg grating and the low-reflection fiber bragg grating are consistent with the Raman wavelength.
The process of producing compressible coherent Raman pulse fiber laser includes the following steps:
the pulse laser source generates signal pulse with the pulse width of picosecond or femtosecond, and the signal pulse and the pumping light are coupled into a resonant cavity formed by the high-reflection fiber bragg grating, the first gain fiber and the low-reflection fiber bragg grating through the wavelength division multiplexer or the beam combiner. The reflection center wavelength of the high-reflection fiber grating and the low-reflection fiber grating is recommended to be consistent with the Raman wavelength, so that the high-reflection fiber grating and the low-reflection fiber grating basically do not reflect the signal wavelength and the pump wavelength, namely the signal pulse and the pump light can directly penetrate through the high-reflection fiber grating, and the signal pulse is amplified by the pump at the first gain fiber and then enters the subsequent optical path through the low-reflection fiber grating. The first gain fiber initially generates spontaneous noise under the action of pumping, after the pumping power is increased and the laser oscillation threshold is reached, the resonant cavity starts to generate coherent Raman wavelength laser and emits the laser from the low-reflection fiber grating along with the signal wavelength, and the grating reflection center wavelength is consistent with the Raman wavelength, so that incoherent spontaneous noise in a near-Raman wavelength range can be suppressed. And then, the signal pulse and the Raman wavelength laser enter a second gain optical fiber together with pump light of a second pump, the second pump, a second wavelength division multiplexer/beam combiner and the second gain optical fiber form a Raman amplification stage, along with the improvement of the second pump power, the energy of the amplified signal pulse is gradually transferred to the Raman wavelength after reaching a Raman threshold, at the moment, the Raman wavelength laser is used as Raman seed light to be Raman amplified, coherent Raman pulse is generated, and the residual pump light and the signal wavelength are filtered and compressed to obtain ultrashort Raman pulse laser.
It follows that the general technical concept of the present invention is: the signal pulse is generated by a resonant cavity consisting of the high-reflection fiber bragg grating, the first gain fiber and the low-reflection fiber bragg grating in the transmission process, and the Raman wavelength laser used as Raman seed light is subjected to Raman amplification by utilizing the signal pulse with high peak power, so that coherent Raman pulse with compression characteristic is generated, the technical problems that the compressed Raman pulse in the background technology has a huge base of tens or hundreds of picoseconds, the effective energy is low, the high peak power cannot be obtained, the using effect is weakened, the application scene is limited and the like are solved, and meanwhile, the single-frequency light source using the Raman wavelength is avoided, and the purposes of compact structure, simplicity and convenience in operation, low price and the like are realized.
Further, the filtering component is composed of a pump power stripper and a filter, wherein the pump power stripper is used for removing residual pump light, and the filter is used for filtering signal pulses.
Further, the first gain optical fiber and the second gain optical fiber are rare earth ion doped optical fibers corresponding to signal wavelengths, and common doped ions include ytterbium, erbium, thulium, holmium and the like.
Further, the center wavelength of the isolator is consistent with the signal wavelength, and its insertion loss to the raman wavelength should be no greater than 3 dB.
Further, the pulse compressor is an optical fiber device or a spatial device capable of performing dispersion compensation on the raman pulse, such as a dispersion optical fiber, a chirped fiber grating, a chirped mirror, a prism pair, or a grating, etc., and the dispersion sign should be opposite to the chirp of the raman pulse.
Further, the n (n is more than or equal to 2) th order raman pulse can be obtained through a cascade resonant cavity structure, and the cascade system structure is as follows:
the pulse laser comprises a pulse laser source, amplifying stages RA-1, RA-2, RA-i, RA-n, a main amplifying stage MA, a filter assembly and a pulse compressor, wherein the parts are sequentially connected in the sequence in a mode of optical fiber fusion or space coupling;
each amplification stage comprises a pump, a wavelength division multiplexer/combiner, a resonant cavity and an isolator;
in the amplification stage RA-i: the wavelength division multiplexer/beam combiner couples the emergent light of the front stage and the pumping light in the current stage to the same light path, enters a resonant cavity formed by a high-reflection fiber grating, a gain fiber and a low-reflection fiber grating which are sequentially connected, generates the i-th Raman wavelength laser with coherence, the reflection center wavelengths of the high-reflection fiber grating and the low-reflection fiber grating of the resonant cavity are consistent with the i-th Raman wavelength, and the emergent light of the resonant cavity is output after passing through the isolator;
the main amplification stage MA comprises a pump, a wavelength division multiplexer/combiner and a gain fiber;
in the main amplification stage MA: the emergent light of the amplifying stage RA-n and MA pump light enter an MA gain optical fiber together after passing through an MA wavelength division multiplexer/beam combiner, signal pulses in the emergent light of the resonant cavity RA-n are amplified to transfer energy to nth-order Raman wavelength laser in the emergent light of the resonant cavity RA-n, the Raman wavelength laser is used as Raman seed light to be Raman amplified to generate coherent Raman pulses, residual pump light and signal pulses are filtered by a filtering component sequentially, and the coherent Raman pulses are compressed by a pulse compressor, so that nth-order Raman pulse laser is finally obtained.
Compared with the prior art, the invention has the beneficial effects that:
in the process of generating the compressible coherent Raman pulse, the invention avoids the use of a Raman wavelength single-frequency light source, and has compact structure, simple and convenient operation and low price; the generation of incoherent spontaneous noise is inhibited while the laser with the Raman wavelength is generated by using a resonant cavity structure formed by fiber gratings, so that the quality of the subsequent coherent Raman pulse is improved; the high-order Raman pulse can be generated in a cascading mode, the usable wavelength range is expanded, and universality and application potential of the high-order Raman pulse are shown.
Drawings
FIG. 1 is a schematic diagram of the optical path structure of a system for generating a compressible coherent Raman pulse fiber laser according to the present invention;
FIG. 2 is a graph of the compression effect of Raman pulses obtained using different seed light, with no pedestals corresponding to coherent Raman wavelength lasers and pedestals corresponding to incoherent spontaneous noise;
fig. 3 is a schematic diagram of an optical path structure for obtaining an nth order raman pulse by cascading resonator structures.
Reference numerals illustrate:
1. a pulsed laser source; 2. a first pump; 3. a first wavelength division multiplexer/combiner; 4. a high reflection fiber grating; 5. a first gain fiber; 6. a low reflection fiber grating; 7. an isolator; 8. a second pump; 9. a second wavelength division multiplexer/combiner; 10. a second gain fiber; 11. a filtering component; 12. a pulse compressor; 13. ultrashort raman pulse laser; r-n. resonant cavity of high-low reflection fiber grating with correspondent n-order Raman wavelength; an amplification stage having an n-order raman wavelength cavity R-n; MA. the main amplifier stage, i.e. the n+1st stage.
Detailed Description
In order to make the above objects, features and advantages of the present invention more comprehensible, the following detailed description of the technical solution of the present invention refers to the accompanying drawings and specific embodiments. It should be noted that the described embodiments are only some embodiments of the present invention, and not all embodiments, and that all other embodiments obtained by persons skilled in the art without making creative efforts based on the embodiments in the present invention are within the protection scope of the present invention.
Examples
As shown in fig. 1, the present invention provides a system for generating a compressible coherent raman pulse fiber laser, comprising a pulse laser source 1, a first pump 2, a first wavelength division multiplexer/combiner 3, a high reflection fiber grating 4, a first gain fiber 5, a low reflection fiber grating 6, an isolator 7, a second pump 8, a second wavelength division multiplexer/combiner 9, a second gain fiber 10, a filter assembly 11 and a pulse compressor 12, which are sequentially connected in the above order by means of optical fiber fusion or spatial coupling.
In this embodiment, the pulsed laser source 1 is a picosecond or femtosecond pulsed laser with a wavelength of 1064 nm; the first pump 2 is a 976 nm single-mode semiconductor pump source; the first wavelength division multiplexer/combiner 3 is a wavelength division multiplexer with a wavelength of 976/1064 nm; the first gain optical fiber 5 is a single-mode ytterbium-doped optical fiber; the central reflection wavelength of the high-reflection fiber grating 4 and the low-reflection fiber grating 6 is 1116 and nm, the reflectivity of the high-reflection fiber grating is close to complete reflection, the reflectivity of the high-reflection fiber grating is not less than 99%, and the low-reflection fiber grating is partially reflective; the isolator 7 is used for preventing laser reflection from damaging the front-end device, the central wavelength of the isolator is 1064 and nm, and the insertion loss at 1116 and nm is less than 3 dB; the second pump 8 is a 976 nm multimode semiconductor pump source; the second wavelength division multiplexer/combiner 9 is a combiner with signal wavelength of 1064 nm and pump wavelength of 976 nm; the second gain fiber 10 is a double-clad ytterbium-doped fiber; the filter assembly 11 consists of a pumping power stripper and a filter, wherein the pumping power stripper adopts a cladding pumping stripper, the residual pumping light of a cladding and the high-order mode signal light can be removed, and the filter adopts a long-pass dichroic mirror with the initial wavelength of 1100 nm; the pulse compressor 12 uses a diffraction grating pair.
The pulse laser source 1 generates picosecond or femtosecond pulse laser with the wavelength of 1064 and nm, and the picosecond or femtosecond pulse laser and 976 nm pump light generated by the first pump 2 are coupled into an optical path together through the first wavelength division multiplexer/combiner 3 to enter a resonant cavity R-1 with a wavelength selection function, wherein the resonant cavity R-1 consists of a high-reflection fiber grating 4, a first gain fiber 5 and a low-reflection fiber grating 6. In the amplifying stage RA-1, the reflection center wavelength of the high-reflection fiber grating and the low-reflection fiber grating is 1116 and nm, which is consistent with the target Raman wavelength, and only the light with the target Raman wavelength is reflected; the signal pulse is pumped and amplified at the first gain fiber 5 after passing through the high reflection fiber grating 4, and then enters the subsequent optical path after passing through the low reflection fiber grating 6 for the signal wavelength and the pumping wavelength, namely 1064 nm and 976 nm; the first gain fiber 5 initially generates spontaneous noise under the pumping action, and as the pumping power is increased, after the laser oscillation threshold is reached, the resonant cavity R-1 starts to generate coherent raman wavelength laser with the wavelength of 1116 nm and emits from the low reflection fiber grating 6, and incoherent spontaneous noise is simultaneously suppressed.
The signal pulse with the wavelength of 1064 nm enters the next amplification stage MA together with the raman wavelength laser with the wavelength of 1116 and nm, and as the power of the 976 nm pump light generated by the second pump 8 increases, the signal pulse is continuously amplified and reaches the raman threshold, and then the energy of the amplified signal pulse is gradually transferred to the raman wavelength. It is noted that in this case there is a coherent raman wavelength laser in the optical path, which is raman amplified as raman seed light in MA, producing a corresponding coherent raman pulse. After filtering out the residual pump light and the signal light, the diffraction grating is used for adjusting the pulse chirp, and the coherent raman pulse is compressed, so that the ultra-short raman pulse laser 13 without the base can be finally obtained, as shown in the left diagram of fig. 2. If there is no coherent raman wavelength laser in the optical path, the raman pulse is generated by spontaneous noise raman amplification, and due to the incoherent nature of spontaneous noise, the phase and intensity of the raman pulse are randomly distributed, and the generated raman pulse cannot be completely compressed by using the diffraction grating pair, so that a raman pulse laser with a large base is finally obtained, as shown in the right graph of fig. 2. It is clear that raman pulses generated by spontaneous noise have poor compressibility, most of the energy exists in the base, the effective energy of the raman pulses is reduced, the increase of peak power is limited, and raman pulses generated by raman wavelength laser have good compressibility, concentrated energy, high peak power and good pulse quality.
This example teaches a method of deriving ultrashort 1 st order raman pulses at a wavelength of 1116 nm from signal pulses at a wavelength of 1064 nm. In order to obtain the nth order raman pulse, as shown in fig. 3, based on this, the nth order raman pulse is obtained by cascading the resonant cavity structure, that is, the high-low reflection fiber gratings with corresponding order raman wavelengths are added before and after the first, second, …, and n gain fibers, so as to form each amplifying stage RA-2, …, RA-n with the resonant cavity of raman wavelength, and finally the nth order raman pulse is obtained after amplifying MA at the n+1th stage.
In the process of generating the compressible coherent Raman pulse, the invention avoids the use of a Raman wavelength single-frequency light source, and has compact structure, simple and convenient operation and low price; the generation of incoherent spontaneous noise is inhibited while the laser with the Raman wavelength is generated by using a resonant cavity structure formed by fiber gratings, so that the quality of the subsequent coherent Raman pulse is improved; the high-order Raman pulse can be generated in a cascading mode, the usable wavelength range is expanded, and universality and application potential of the high-order Raman pulse are shown.
The foregoing examples illustrate only a few embodiments of the invention and are described in detail herein without thereby limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (6)
1. A system for generating compressible coherent raman pulse fiber laser, characterized by comprising a pulse laser source (1), a first pump (2), a first wavelength division multiplexer/combiner (3), a high reflection fiber grating (4), a first gain fiber (5), a low reflection fiber grating (6), an isolator (7), a second pump (8), a second wavelength division multiplexer/combiner (9), a second gain fiber (10), a filter assembly (11) and a pulse compressor (12), wherein all the parts are connected in a fiber welding or space coupling mode;
the first wavelength division multiplexer/beam combiner (3) couples the ultrashort pulse laser signal provided by the pulse laser source (1) and the pump light provided by the first pump (2) to the same optical path, enters a resonant cavity formed by a high-reflection fiber grating (4), a first gain fiber (5) and a low-reflection fiber grating (6) which are sequentially connected, so that coherent Raman wavelength laser is generated, the reflection center wavelengths of the high-reflection fiber grating and the low-reflection fiber grating are consistent with the Raman wavelength, the emergent light of the resonant cavity and the pump light of the second pump (8) enter a second gain fiber (10) together after passing through the isolator (7), the signal pulse in the emergent light of the resonant cavity is amplified to enable the energy of the signal pulse to be transferred to the Raman wavelength laser in the emergent light, the Raman wavelength laser is amplified as Raman seed light to generate coherent Raman pulse, then the residual pump light and the signal pulse are filtered through the filter component (11), and the pulse compressor (12) compresses the coherent Raman pulse, and finally the ultrashort pulse Raman pulse (13) is obtained.
2. The system according to claim 1, characterized in that the filtering assembly (11) consists of a pump power stripper for removing residual pump light and a filter for filtering out signal pulses.
3. The system according to claim 1, characterized in that the first gain fiber (5) and the second gain fiber (10) are rare earth ion doped fibers corresponding to the signal wavelength.
4. The system according to claim 1, characterized in that the center wavelength of the isolator (7) coincides with the signal wavelength and its insertion loss for the raman wavelength should be no more than 3 dB.
5. The system of claim 1, wherein the pulse compressor (12) is a fiber device or a spatial device capable of dispersion compensation of raman pulses, a dispersion fiber, a chirped fiber grating, a chirped mirror, a prism pair, or a grating pair is selected, and the dispersion sign is opposite to the raman pulse chirp.
6. A system for generating compressible coherent Raman pulse fiber laser is characterized in that the system is an n-level cascade system, and n is more than or equal to 2; the pulse laser comprises a pulse laser source, amplifying stages RA-1, RA-2, RA-i, RA-n, a main amplifying stage MA, a filter assembly and a pulse compressor, wherein the parts are sequentially connected in the sequence in a mode of optical fiber fusion or space coupling;
each amplification stage comprises a pump, a wavelength division multiplexer/combiner, a resonant cavity and an isolator;
in the amplification stage RA-i: the wavelength division multiplexer/beam combiner couples the emergent light of the front stage and the pumping light in the current stage to the same light path, enters a resonant cavity formed by a high-reflection fiber grating, a gain fiber and a low-reflection fiber grating which are sequentially connected, generates the i-th Raman wavelength laser with coherence, the reflection center wavelengths of the high-reflection fiber grating and the low-reflection fiber grating of the resonant cavity are consistent with the i-th Raman wavelength, and the emergent light of the resonant cavity is output after passing through the isolator;
the main amplification stage MA comprises a pump, a wavelength division multiplexer/combiner and a gain fiber;
in the main amplification stage MA: the emergent light of the amplifying stage RA-n and MA pump light enter an MA gain optical fiber together after passing through an MA wavelength division multiplexer/beam combiner, signal pulses in the emergent light of the resonant cavity RA-n are amplified to transfer energy to nth-order Raman wavelength laser in the emergent light of the resonant cavity RA-n, the Raman wavelength laser is used as Raman seed light to be Raman amplified to generate coherent Raman pulses, residual pump light and signal pulses are filtered by a filtering component sequentially, and the coherent Raman pulses are compressed by a pulse compressor, so that nth-order Raman pulse laser is finally obtained.
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| CN202310824562.7A CN116544761B (en) | 2023-07-06 | 2023-07-06 | System for producing compressible coherent Raman pulse fiber laser |
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| CN116544761B true CN116544761B (en) | 2023-09-22 |
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| CN106207723A (en) * | 2016-08-28 | 2016-12-07 | 北京工业大学 | A kind of all-fiber pulse laser of multi-resonant chamber coupling |
| CN106374328A (en) * | 2016-11-18 | 2017-02-01 | 合肥工业大学 | Medium-infrared fiber laser system covering any wavelength in band between 2 and 10 microns based on soft glass fiber |
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| CN108666858A (en) * | 2018-04-24 | 2018-10-16 | 上海理工大学 | A kind of multi-wavelength femtosecond Raman fiber lasers |
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| US7773294B2 (en) * | 2007-08-13 | 2010-08-10 | Institut National D'optique | Low-average-power parabolic pulse amplification |
| JP5972356B2 (en) * | 2011-04-25 | 2016-08-17 | オーエフエス ファイテル，エルエルシー | Raman distributed feedback fiber laser and high power laser system using the same |
| US8537866B2 (en) * | 2011-05-20 | 2013-09-17 | Calmar Optcom, Inc. | Generating laser pulses of narrow spectral linewidth based on chirping and stretching of laser pulses and subsequent power amplification |
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| US7991022B1 (en) * | 2008-01-16 | 2011-08-02 | Calmar Optcom, Inc. | Optical pulse amplification based on stimulated Raman scattering |
| CN106207723A (en) * | 2016-08-28 | 2016-12-07 | 北京工业大学 | A kind of all-fiber pulse laser of multi-resonant chamber coupling |
| CN106374328A (en) * | 2016-11-18 | 2017-02-01 | 合肥工业大学 | Medium-infrared fiber laser system covering any wavelength in band between 2 and 10 microns based on soft glass fiber |
| CN107275917A (en) * | 2017-08-10 | 2017-10-20 | 电子科技大学 | Infrared super continuum source in ultra wide band all -fiber |
| CN108666858A (en) * | 2018-04-24 | 2018-10-16 | 上海理工大学 | A kind of multi-wavelength femtosecond Raman fiber lasers |
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