We demonstrate spectral-furcated vector solitons in normal-dispersion fiber lasers comprising a section of polarizationmaintaining fiber.The spectrum of each orthogonal-polarized component is confined by the birefring...We demonstrate spectral-furcated vector solitons in normal-dispersion fiber lasers comprising a section of polarizationmaintaining fiber.The spectrum of each orthogonal-polarized component is confined by the birefringence-related phasematching principle,and the bicorn spectral structure corresponds to the zero-order sidebands of two vector modes.Due to the Hopf bifurcation effect,the vector soliton evolves into a breathing state at the higher pump level,accompanied by an extra set of sub-sidebands that continuously exchange energy with the zero-order sidebands.Simulation results fully reproduce experimental observations of the spectral furcation and soliton breathing,offering comprehensive insights into the pulse-shaping mechanism of the birefringence-managed soliton.展开更多
We present a Brillouin–Raman random fiber laser(BRRFL)with full-open linear cavity structure to generate broadband Brillouin frequency comb(BFC)with double Brillouin-frequency-shift spacing.The incorporation of a reg...We present a Brillouin–Raman random fiber laser(BRRFL)with full-open linear cavity structure to generate broadband Brillouin frequency comb(BFC)with double Brillouin-frequency-shift spacing.The incorporation of a regeneration portion consisting of an erbium-doped fiber and a single-mode fiber enables the generation of broadband BFC.The dynamics of broadband BFC generation changing with the pump power(EDF and Raman)and Brillouin pump(BP)wavelength are investigated in detail,respectively.Under suitable conditions,the bidirectional BRRFL proposed can produce a flatamplitude BFC with 40.7-nm bandwidth ranging from 1531 nm to 1571.7 nm,and built-in 242-order Brillouin Stokes lines(BSLs)with double Brillouin-frequency-shift spacing.Moreover,the linewidth of single BSL is experimentally measured to be about 2.5 kHz.The broadband bidirectional narrow-linewidth BRRFL has great potential applications in optical communication,optical sensing,spectral measurement,and so on.展开更多
The paper summarizes the recent achievements in the area of ultrafast fiber lasers mode-locked with so-called lowdimensional nanomaterials: graphene, topological insulators（Bi2Te3, Bi2Se3, Sb2Te3）, and transition me...The paper summarizes the recent achievements in the area of ultrafast fiber lasers mode-locked with so-called lowdimensional nanomaterials: graphene, topological insulators（Bi2Te3, Bi2Se3, Sb2Te3）, and transition metal sulfide semiconductors, like molybdenum disulfide（MoS2）. The most important experimental achievements are described and compared. Additionally, new original results on ultrashort pulse generation at 1.94 μm wavelength using graphene are presented. The designed Tm-doped fiber laser utilizes multilayer graphene as a saturable absorber and generates 654 fs pulses at 1940 nm wavelength, which are currently the shortest pulses generated from a Tm-doped fiber laser with a graphene-based saturable absorber.展开更多
In this work pulse generation in both the 1.5 and 2 μm spectral ranges using a graphene oxide(GO)-paper-based saturable absorber in Er-and Tm-doped fiber lasers is presented. The article describes the fabrication met...In this work pulse generation in both the 1.5 and 2 μm spectral ranges using a graphene oxide(GO)-paper-based saturable absorber in Er-and Tm-doped fiber lasers is presented. The article describes the fabrication method of GO paper and its characterization. The performance of both lasers is discussed in detail. Stable, mode-locked operation provides 613 fs and 1.36 ps soliton pulses centered at 1565.9 and 1961.6 nm in Er-and Tm-doped fiber lasers, respectively. Furthermore, scaling of spectral width, and hence the pulse duration, by increasing the number of GO paper layers in the Er-doped laser is described. The versatility and simplicity of GO paper fabrication combined with the possibility of scaling the optical spectrum full width at half-maximum are essential features that make it a good candidate for ultrafast low-power mode-locked lasers operating in different spectral regions.展开更多
Tungsten disulfide(WS_2) is a type of anisotropic-layered compound and has broadband saturable absorption features as saturable absorbers(SAs). With WS_2-based SAs, dark solitons in erbium-doped fiber(EDF) lasers are ...Tungsten disulfide(WS_2) is a type of anisotropic-layered compound and has broadband saturable absorption features as saturable absorbers(SAs). With WS_2-based SAs, dark solitons in erbium-doped fiber(EDF) lasers are first obtained. For the generated dark solitons, the center wavelength is measured to be 1530 nm, and the repetition rate is about 116.5 MHz. A series of optical spectra is exhibited. The electrical signal-to-noise ratio is better than 94 d B.Results in this paper demonstrate that WS_2-based SAs are the promising SAs for generating dark solitons in EDF lasers.展开更多
The performance of fiber mode-locked lasers is limited due to the high nonlinearity induced by the spatial confinement of the single-mode fiber core.To massively increase the pulse energy of the femtosecond pulses,amp...The performance of fiber mode-locked lasers is limited due to the high nonlinearity induced by the spatial confinement of the single-mode fiber core.To massively increase the pulse energy of the femtosecond pulses,amplification is performed outside the oscillator.Recently,spatiotemporal mode-locking has been proposed as a new path to fiber lasers.However,the beam quality was highly multimode,and the calculated threshold pulse energy(>100 nJ)for nonlinear beam self-cleaning was challenging to realize.We present an approach to reach high energy per pulse directly in the mode-locked multimode fiber oscillator with a near single-mode output beam.Our approach relies on spatial beam self-cleaning via the nonlinear Kerr effect,and we demonstrate a multimode fiber oscillator with M^2<1.13 beam profile,up to 24 nJ energy,and sub-100 fs compressed duration.Nonlinear beam self-cleaning is verified both numerically and experimentally for the first time in a mode-locked multimode laser cavity.The reported approach is further power scalable with larger core sized fibers up to a certain level of modal dispersion and could benefit applications that require high-power ultrashort lasers with commercially available optical fibers.展开更多
Rogue waves(RWs)are rare,extreme amplitude,localized wave packets,which have received much interest recently in different areas of physics.Fiber lasers with their abundant nonlinear dynamics provide an ideal platform ...Rogue waves(RWs)are rare,extreme amplitude,localized wave packets,which have received much interest recently in different areas of physics.Fiber lasers with their abundant nonlinear dynamics provide an ideal platform to observe optical RW formation.We review recent research progress on rogue waves in fiber lasers.Basic concepts of RWs and the mechanisms of RW generation in fiber lasers are discussed,along with representative experimental and theoretical results.The measurement methods for RW identification in fiber lasers are presented and analyzed.Finally,prospects for future RW research in fiber lasers are summarized.展开更多
We report an erbium-doped fiber laser passively Q-switched by a few-layer molybdenum disulfide（MoS2） saturable absorber（SA）.The few-layer MoS2 is grown by the chemical vapor deposition method and transferred onto ...We report an erbium-doped fiber laser passively Q-switched by a few-layer molybdenum disulfide（MoS2） saturable absorber（SA）.The few-layer MoS2 is grown by the chemical vapor deposition method and transferred onto the end-face of a fiber connector to form a fiber-compatible MoS2 SA.The laser cavity is constructed by using a three-port optical circulator and a fiber Bragg grating（FBG） as the two end-mirrors.Stable Q-switched pulses are obtained with a pulse duration of 1.92 μs at 1560.5 nm.By increasing the pump power from 42 to 204 mW,the pulse repetition rate can be widely changed from 28.6 to 114.8 kHz.Passive Q-switching operations with discrete lasing wavelengths ranging from 1529.8 to 1570.1 nm are also investigated by using FBGs with different central wavelengths.This work demonstrates that few-layer MoS2 can serve as a promising SA for wideband-tunable Q-switching laser operation.展开更多
As a universal phenomenon in nonlinear optical systems,intermittency is usually accompanied by the coherence loss such as soliton explosions in fiber lasers.Based on real-time spectroscopy,we revealed the coherent dis...As a universal phenomenon in nonlinear optical systems,intermittency is usually accompanied by the coherence loss such as soliton explosions in fiber lasers.Based on real-time spectroscopy,we revealed the coherent dissipative soliton intermittency in normal-dispersion fiber lasers.By increasing the pump strength,the intermittency transforms from the transient pulsation to the bo-stable soliton.It is demonstrated that the slow-gain effect dominates such coherent intermittency.Our results provide novel insights into laser physics,offering a promising approach for studying the bi-stable dissipative soliton.展开更多
Two array waveguide grating (AWGs) based fiber ring lasers are experimentally demonstrated. Either of them achieves wavelength discrete tuning of 32 nm, or yields simultaneously lasing up to four channels with -7 dBm ...Two array waveguide grating (AWGs) based fiber ring lasers are experimentally demonstrated. Either of them achieves wavelength discrete tuning of 32 nm, or yields simultaneously lasing up to four channels with -7 dBm output power for each channel.展开更多
Erbium fiber lasers of continuous mode outputs and of pulsed picosecond and sub-picosecond pulses train are reported. Compact all solid state passively modulated microchip lasers are also developed to the same degree.
We present a theoretical analysis and an experimental study of the impacts of external optical feedback on dualfrequency fiber lasers. The external optical feedback can effectively suppress the phase noise of the beat...We present a theoretical analysis and an experimental study of the impacts of external optical feedback on dualfrequency fiber lasers. The external optical feedback can effectively suppress the phase noise of the beat notes of dual-frequency fiber lasers, provided some requirements are satisfied. The polarization of the optical feedback is important for the fiber laser's stability, and it can also tune the beat note frequency. A side effect of external optical feedback, as demonstrated in the experiments, is lowering the sensitivity of the dual-frequency fiber laserbased sensors, although such degradation is not obvious.展开更多
The understanding of soliton dynamics promotes the development of ultrafast laser technology. High-energy purequartic solitons(PQSs) have gradually become a hotspot in recent years. Herein, we numerically study the in...The understanding of soliton dynamics promotes the development of ultrafast laser technology. High-energy purequartic solitons(PQSs) have gradually become a hotspot in recent years. Herein, we numerically study the influence of the gain bandwidth, saturation power, small-signal gain, and output coupler on PQS dynamics in passively mode-locked fiber lasers. The results show that the above four parameters can affect PQS dynamics. Pulsating PQSs occur as we alter the other three parameters when the gain bandwidth is 50 nm. Meanwhile, PQSs evolve from pulsating to erupting and then to splitting as the other three parameters are altered when the gain bandwidth is 10 nm, which can be attributed to the existence of the spectral filtering effect and intra-cavity fourth-order dispersion. These findings provide new insights into PQS dynamics in passively mode-locked fiber lasers.展开更多
Coherent beam combining of 60 fiber lasers by using the stochastic parallel gradient descent algorithm has been demonstrated. The functions of pinhole(s) on the power distributions in the far-field have been systemati...Coherent beam combining of 60 fiber lasers by using the stochastic parallel gradient descent algorithm has been demonstrated. The functions of pinhole(s) on the power distributions in the far-field have been systematically simulated on both in-phase and out-of-phase modes. Only one photoelectric detector was used to detect the combined power in the far-field central lobe of the in-phase mode state. When the phase controller was in a closed loop, the contrast of the far-field intensity pattern was as high as ~97% with residual phase error of ~λ/30, and ~34.7% of the total power was contained in the central lobe.展开更多
Cylindrical vector beams and vortex beams,two types of typical singular optical beams characterized by axially symmetric polarization and helical phase front,possess the unique focusing property and the ability of car...Cylindrical vector beams and vortex beams,two types of typical singular optical beams characterized by axially symmetric polarization and helical phase front,possess the unique focusing property and the ability of carrying orbital angular momentum.We discuss the formation mechanisms of such singular beams in few-mode fibers under the vortex basis and show recent advances in generating techniques that are mainly based on long-period fiber gratings,mode-selective couplers,offset-spliced fibers,and tapered fibers.The performances of cylindrical vector beams and vortex beams generated in fibers and fiber lasers are summarized and compared to give a comprehensive understanding of singular beams and to promote their practical applications.展开更多
Saturable absorbers(SAs)covering wavelengths from near-infrared(NIR)to mid-infrared(MIR)band are required for mode-locking and Q-switching lasers in muti-band wavelengths.Here,broadband nonlinear optical property was ...Saturable absorbers(SAs)covering wavelengths from near-infrared(NIR)to mid-infrared(MIR)band are required for mode-locking and Q-switching lasers in muti-band wavelengths.Here,broadband nonlinear optical property was discovered in Cs_(x)WO_(3) nanorods(NRs),which as a novel non-stoichiometric SA for realizing ultrafast fiber lasers is first demonstrated.The Cs_(x)WO_(3) NRs based SA exhibited good mode-locking ability in three key wavelengths from NIR to MIR region,which is a key advantage over the most reported broadband SAs.The given Cs_(x)WO_(3) NRs showed a broadband optical absorption from 800 to 3,200 nm,and excellent SA properties at 1-μm,1.5-μm,and 2-μm optical bands.Employing such SA,the ultrashort pulse lasers with a pulse duration/repetition rate of 530 fs/37.42 MHz at 1,567 nm and 5.6 ps/41.50 MHz at 1,965 nm from Er-and Tm-doped fiber lasers(TDFL)were realized separately.In addition,a stable mode locked operation at 1,030 nm with a repetition rate of 48.80 MHz was also achieved from Yb-doped fiber laser(YDFL).This work not only offers a new and reliable broadband mode locker for ultrafast laser generation,but also broadens the application of Cs_(x)WO_(3) materials in the field of nonlinear fiber optics.展开更多
In recent years,multi-wavelength fiber lasers play a significant role in plenty of fields,ranging from optical communications to mechanical processing and laser biomedicine,owing to their high beam quality,low cost,an...In recent years,multi-wavelength fiber lasers play a significant role in plenty of fields,ranging from optical communications to mechanical processing and laser biomedicine,owing to their high beam quality,low cost,and excellent heat dissipation properties.Benefitting from increasing maturity of optical elements,the multi-wavelength fiber laser has made rapid developments.In this review,we summarize and analyze diverse implementation methods covering continuous wave and pulsed fiber lasers at room temperature conditions:inserting an optical filter device and intensity-dependent loss structure in the resonant cavity,and applying ultrafast nonlinear optical response of materials and a dual-cavity structure.Finally,future challenges and perspectives of the multi-wavelength fiber laser are discussed and addressed.展开更多
We demonstrate visible-light all-fiber vortex lasers by incorporating the home-made mode selective couplers (MSCs). The MSC at green or red wavebands is fabricated by specially designing and fusing a single-mode fiber...We demonstrate visible-light all-fiber vortex lasers by incorporating the home-made mode selective couplers (MSCs). The MSC at green or red wavebands is fabricated by specially designing and fusing a single-mode fiber (SMF) and a few-mode fiber (FMF). The MSCs inserted into visible fiber cavities act as power splitters and mode converters from the LP01 to LP11 mode at green and red wavelengths, respectively. The red-light all-fiber vortex laser is formed by a 10-cm Pr3+/Yb3+:ZBLAN fiber, a fiber Bragg grating, a fiber end-facet mirror and the MSC at 635 nm, which generates vortex beams with OAM±1 at 634.4 nm and an output power of 13 mW. The green-light all-fiber vortex laser consists of a 12-cm Ho3+:ZBLAN fiber, two fiber pigtail mirrors, and the MSC at 550 nm, which generates vortex beams with OAM±1 at 548.9 nm and an output power of 3 mW.展开更多
We study the exfoliation of ultrathin ReS2 nanosheets from the prepared ReS2 powder and their application to Q-switched Er-doped fiber laser.XRD,Raman,and XPS spectra confirm the successful preparation of the layered ...We study the exfoliation of ultrathin ReS2 nanosheets from the prepared ReS2 powder and their application to Q-switched Er-doped fiber laser.XRD,Raman,and XPS spectra confirm the successful preparation of the layered ReS2.SEM images show that the obtained ReS2 sheets have lateral size below 200 nm.The thickness of the ReS2 nanosheets is smaller than 5 nm according to the AFM results.ReS2/PVA film is applied as a saturable absorber in an Er-doped Q-switched fiber laser,and a minimum pulse duration of 2.4μs and an output power of 1.25 mW are obtained,indicating the potential application to Q-switched lasers.展开更多
We report on mode-locked thulium-doped fiber lasers with high-energy nanosecond pulses,relying on the transmission in a semiconductor saturable absorber(SESA)and a carbon nanotube(CNTs-PVA)film separately.A section of...We report on mode-locked thulium-doped fiber lasers with high-energy nanosecond pulses,relying on the transmission in a semiconductor saturable absorber(SESA)and a carbon nanotube(CNTs-PVA)film separately.A section of an SMF-MMF-SMF structure multimode interferometer with a transmission peak wavelength of^2003 nm was used as a wavelength selector to fix the laser wavelength.When the SESA acted as a saturable absorber(SA),the mode-locked fiber laser had a maximum output power of^461 mW with a pulse energy of^0.14µJ and a pulse duration of^9.14 ns.In a CNT-film-based mode-locked fiber laser,stable mode-locked pulses with the maximum output power of^46 mW,pulse energy of^26.8 nJ and pulse duration of^9.3 ns were obtained.To the best of our knowledge,our experiments demonstrated the first 2µm region‘real’SA-based dissipative soliton resonance with the highest mode-locked pulse energy from a‘real’SA-based all-fiberized resonator.展开更多
基金supported by the National Natural Science Foundation of China(No.12274344)the Natural Science Basic Research Program of Shaanxi Province(No.2021JC-09)the Fundamental Research Funds for the Central Universities(No.3102019JC008)。
文摘We demonstrate spectral-furcated vector solitons in normal-dispersion fiber lasers comprising a section of polarizationmaintaining fiber.The spectrum of each orthogonal-polarized component is confined by the birefringence-related phasematching principle,and the bicorn spectral structure corresponds to the zero-order sidebands of two vector modes.Due to the Hopf bifurcation effect,the vector soliton evolves into a breathing state at the higher pump level,accompanied by an extra set of sub-sidebands that continuously exchange energy with the zero-order sidebands.Simulation results fully reproduce experimental observations of the spectral furcation and soliton breathing,offering comprehensive insights into the pulse-shaping mechanism of the birefringence-managed soliton.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 62175116 and 91950105)the 1311 Talent Plan of Nanjing University of Posts and Telecommunications, Chinathe Postgraduate Research & Practice Innovation Program, Jiangsu Province, China (Grant No. SJCX21_0276)
文摘We present a Brillouin–Raman random fiber laser(BRRFL)with full-open linear cavity structure to generate broadband Brillouin frequency comb(BFC)with double Brillouin-frequency-shift spacing.The incorporation of a regeneration portion consisting of an erbium-doped fiber and a single-mode fiber enables the generation of broadband BFC.The dynamics of broadband BFC generation changing with the pump power(EDF and Raman)and Brillouin pump(BP)wavelength are investigated in detail,respectively.Under suitable conditions,the bidirectional BRRFL proposed can produce a flatamplitude BFC with 40.7-nm bandwidth ranging from 1531 nm to 1571.7 nm,and built-in 242-order Brillouin Stokes lines(BSLs)with double Brillouin-frequency-shift spacing.Moreover,the linewidth of single BSL is experimentally measured to be about 2.5 kHz.The broadband bidirectional narrow-linewidth BRRFL has great potential applications in optical communication,optical sensing,spectral measurement,and so on.
基金supported by the National Science Centre (NCN, Poland) under the research project entitled “Passive mode-locking in dispersion-managed ultrafast thulium-doped fiber lasers” (decision no. DEC-2013/11/D/ST7/03138)
文摘The paper summarizes the recent achievements in the area of ultrafast fiber lasers mode-locked with so-called lowdimensional nanomaterials: graphene, topological insulators（Bi2Te3, Bi2Se3, Sb2Te3）, and transition metal sulfide semiconductors, like molybdenum disulfide（MoS2）. The most important experimental achievements are described and compared. Additionally, new original results on ultrashort pulse generation at 1.94 μm wavelength using graphene are presented. The designed Tm-doped fiber laser utilizes multilayer graphene as a saturable absorber and generates 654 fs pulses at 1940 nm wavelength, which are currently the shortest pulses generated from a Tm-doped fiber laser with a graphene-based saturable absorber.
基金supported by the Polish Ministry of Science and Higher Education under the project entitled “Investigation of saturable absorbers based on graphene oxide and reduced graphene oxide” (project no. IP2012 052072)supported by the National Science Centre (NCN, Poland) under the project “Passive mode synchronization in fiber lasers based on low-dimensional materials—simulations and experiments” (decision no. DEC2014/13/N/ST7/01968)
文摘In this work pulse generation in both the 1.5 and 2 μm spectral ranges using a graphene oxide(GO)-paper-based saturable absorber in Er-and Tm-doped fiber lasers is presented. The article describes the fabrication method of GO paper and its characterization. The performance of both lasers is discussed in detail. Stable, mode-locked operation provides 613 fs and 1.36 ps soliton pulses centered at 1565.9 and 1961.6 nm in Er-and Tm-doped fiber lasers, respectively. Furthermore, scaling of spectral width, and hence the pulse duration, by increasing the number of GO paper layers in the Er-doped laser is described. The versatility and simplicity of GO paper fabrication combined with the possibility of scaling the optical spectrum full width at half-maximum are essential features that make it a good candidate for ultrafast low-power mode-locked lasers operating in different spectral regions.
基金supported by the National Key Basic Research Program of China (grant nos.2012CB821304,2013CB922401,and 2013CB922402)by the National Natural Science Foundation of China (NSFC) (grant nos.61205064,61378040,and 11078022)+1 种基金by the National Key Technology R&D Program of the Ministry of Science and Technology under grant no.2012BAC23B03by the Fund of State Key Laboratory of Information Photonics and Optical Communications (Beijing University of Posts and Telecommunications,grant no.600100161)
文摘Tungsten disulfide(WS_2) is a type of anisotropic-layered compound and has broadband saturable absorption features as saturable absorbers(SAs). With WS_2-based SAs, dark solitons in erbium-doped fiber(EDF) lasers are first obtained. For the generated dark solitons, the center wavelength is measured to be 1530 nm, and the repetition rate is about 116.5 MHz. A series of optical spectra is exhibited. The electrical signal-to-noise ratio is better than 94 d B.Results in this paper demonstrate that WS_2-based SAs are the promising SAs for generating dark solitons in EDF lasers.
文摘The performance of fiber mode-locked lasers is limited due to the high nonlinearity induced by the spatial confinement of the single-mode fiber core.To massively increase the pulse energy of the femtosecond pulses,amplification is performed outside the oscillator.Recently,spatiotemporal mode-locking has been proposed as a new path to fiber lasers.However,the beam quality was highly multimode,and the calculated threshold pulse energy(>100 nJ)for nonlinear beam self-cleaning was challenging to realize.We present an approach to reach high energy per pulse directly in the mode-locked multimode fiber oscillator with a near single-mode output beam.Our approach relies on spatial beam self-cleaning via the nonlinear Kerr effect,and we demonstrate a multimode fiber oscillator with M^2<1.13 beam profile,up to 24 nJ energy,and sub-100 fs compressed duration.Nonlinear beam self-cleaning is verified both numerically and experimentally for the first time in a mode-locked multimode laser cavity.The reported approach is further power scalable with larger core sized fibers up to a certain level of modal dispersion and could benefit applications that require high-power ultrashort lasers with commercially available optical fibers.
基金supported in part by the National Natural Science Foundation of China(No.61705140)the China Postdoctoral Science Foundation(No.2018M643165)the Fonds Wetenschappelijk Onderzoek-Vlaanderen FWO(G0E5819N).
文摘Rogue waves(RWs)are rare,extreme amplitude,localized wave packets,which have received much interest recently in different areas of physics.Fiber lasers with their abundant nonlinear dynamics provide an ideal platform to observe optical RW formation.We review recent research progress on rogue waves in fiber lasers.Basic concepts of RWs and the mechanisms of RW generation in fiber lasers are discussed,along with representative experimental and theoretical results.The measurement methods for RW identification in fiber lasers are presented and analyzed.Finally,prospects for future RW research in fiber lasers are summarized.
基金supported by the National Natural Science Foundation of China (Grant Nos.61378028,61475030,61421002,and 61377037)the National Basic Research Program of China (2012CB315701)the NCET Program (Grant No.NCET-13-0092)
文摘We report an erbium-doped fiber laser passively Q-switched by a few-layer molybdenum disulfide（MoS2） saturable absorber（SA）.The few-layer MoS2 is grown by the chemical vapor deposition method and transferred onto the end-face of a fiber connector to form a fiber-compatible MoS2 SA.The laser cavity is constructed by using a three-port optical circulator and a fiber Bragg grating（FBG） as the two end-mirrors.Stable Q-switched pulses are obtained with a pulse duration of 1.92 μs at 1560.5 nm.By increasing the pump power from 42 to 204 mW,the pulse repetition rate can be widely changed from 28.6 to 114.8 kHz.Passive Q-switching operations with discrete lasing wavelengths ranging from 1529.8 to 1570.1 nm are also investigated by using FBGs with different central wavelengths.This work demonstrates that few-layer MoS2 can serve as a promising SA for wideband-tunable Q-switching laser operation.
基金supported by the National Natural Science Foundation of China (Nos. 61805277, 11634010, and 11874300)Natural Science Basic Research Program of Shaanxi (No. 2019JQ-447)+2 种基金Fundamental Research Funds for the Central Universities (No. 310202011QD003)National Key R&D Program of China (No. 2017YFA0303800)Fundamental Research Funds for the Central Universities (Nos. 3102019JC008 and 3102019PY002)
文摘As a universal phenomenon in nonlinear optical systems,intermittency is usually accompanied by the coherence loss such as soliton explosions in fiber lasers.Based on real-time spectroscopy,we revealed the coherent dissipative soliton intermittency in normal-dispersion fiber lasers.By increasing the pump strength,the intermittency transforms from the transient pulsation to the bo-stable soliton.It is demonstrated that the slow-gain effect dominates such coherent intermittency.Our results provide novel insights into laser physics,offering a promising approach for studying the bi-stable dissipative soliton.
文摘Two array waveguide grating (AWGs) based fiber ring lasers are experimentally demonstrated. Either of them achieves wavelength discrete tuning of 32 nm, or yields simultaneously lasing up to four channels with -7 dBm output power for each channel.
文摘Erbium fiber lasers of continuous mode outputs and of pulsed picosecond and sub-picosecond pulses train are reported. Compact all solid state passively modulated microchip lasers are also developed to the same degree.
基金supported by the National Natural Science Foundation of China(Nos.11474133,61235005,61210006,and61275075)the Guangdong Natural Science Foundation(No.S2013030013302)the BJTU Fundamental Research Funds(No.2014RC016)
文摘We present a theoretical analysis and an experimental study of the impacts of external optical feedback on dualfrequency fiber lasers. The external optical feedback can effectively suppress the phase noise of the beat notes of dual-frequency fiber lasers, provided some requirements are satisfied. The polarization of the optical feedback is important for the fiber laser's stability, and it can also tune the beat note frequency. A side effect of external optical feedback, as demonstrated in the experiments, is lowering the sensitivity of the dual-frequency fiber laserbased sensors, although such degradation is not obvious.
基金the financial support from Science and Technology Project of the Jilin Provincial Department of Education (Grant No. JJKH20231171KJ)。
文摘The understanding of soliton dynamics promotes the development of ultrafast laser technology. High-energy purequartic solitons(PQSs) have gradually become a hotspot in recent years. Herein, we numerically study the influence of the gain bandwidth, saturation power, small-signal gain, and output coupler on PQS dynamics in passively mode-locked fiber lasers. The results show that the above four parameters can affect PQS dynamics. Pulsating PQSs occur as we alter the other three parameters when the gain bandwidth is 50 nm. Meanwhile, PQSs evolve from pulsating to erupting and then to splitting as the other three parameters are altered when the gain bandwidth is 10 nm, which can be attributed to the existence of the spectral filtering effect and intra-cavity fourth-order dispersion. These findings provide new insights into PQS dynamics in passively mode-locked fiber lasers.
基金supported by the National Natural Science Foundation of China (Nos. 61705265 and 61705264)the Innovative Research Groups of Hunan Province(No. 2019JJ10005)the Training Program for Excellent Young Innovators of Changsha (No. KQ1905051)
文摘Coherent beam combining of 60 fiber lasers by using the stochastic parallel gradient descent algorithm has been demonstrated. The functions of pinhole(s) on the power distributions in the far-field have been systematically simulated on both in-phase and out-of-phase modes. Only one photoelectric detector was used to detect the combined power in the far-field central lobe of the in-phase mode state. When the phase controller was in a closed loop, the contrast of the far-field intensity pattern was as high as ~97% with residual phase error of ~λ/30, and ~34.7% of the total power was contained in the central lobe.
基金This work was supported by the National Key R&D Program of China(2017YFA0303800)the National Natural Science Foundation of China(11874300,11634010,61575162,61805277,61675169,91950207)+1 种基金the Fundamental Research Funds for the Central Universities(3102017AX009,3102019PY002,3102019JC008)the Natural Science Basic Research Program of Shaanxi(2018JM6013,2019JQ-447).
文摘Cylindrical vector beams and vortex beams,two types of typical singular optical beams characterized by axially symmetric polarization and helical phase front,possess the unique focusing property and the ability of carrying orbital angular momentum.We discuss the formation mechanisms of such singular beams in few-mode fibers under the vortex basis and show recent advances in generating techniques that are mainly based on long-period fiber gratings,mode-selective couplers,offset-spliced fibers,and tapered fibers.The performances of cylindrical vector beams and vortex beams generated in fibers and fiber lasers are summarized and compared to give a comprehensive understanding of singular beams and to promote their practical applications.
基金This work was supported by the Specialized Fund for the Doctoral Research of Jilin Engineering Normal University under(No.BSKJ201920)the Science and Technology Research Project of Jilin Province's Education Department(No.JJKH20210175KJ)the Project of Science and Technology Plan of Jilin Province(No.YDZJ202101ZYTS178)。
文摘Saturable absorbers(SAs)covering wavelengths from near-infrared(NIR)to mid-infrared(MIR)band are required for mode-locking and Q-switching lasers in muti-band wavelengths.Here,broadband nonlinear optical property was discovered in Cs_(x)WO_(3) nanorods(NRs),which as a novel non-stoichiometric SA for realizing ultrafast fiber lasers is first demonstrated.The Cs_(x)WO_(3) NRs based SA exhibited good mode-locking ability in three key wavelengths from NIR to MIR region,which is a key advantage over the most reported broadband SAs.The given Cs_(x)WO_(3) NRs showed a broadband optical absorption from 800 to 3,200 nm,and excellent SA properties at 1-μm,1.5-μm,and 2-μm optical bands.Employing such SA,the ultrashort pulse lasers with a pulse duration/repetition rate of 530 fs/37.42 MHz at 1,567 nm and 5.6 ps/41.50 MHz at 1,965 nm from Er-and Tm-doped fiber lasers(TDFL)were realized separately.In addition,a stable mode locked operation at 1,030 nm with a repetition rate of 48.80 MHz was also achieved from Yb-doped fiber laser(YDFL).This work not only offers a new and reliable broadband mode locker for ultrafast laser generation,but also broadens the application of Cs_(x)WO_(3) materials in the field of nonlinear fiber optics.
基金partially supported by the Science and Technology Development Fund,Macao Special Administration Region(SAR)(Nos.007/2017/A1 and 132/2017/A3)National Natural Science Foundation of China(NSFC)(Nos.61875138,61435010,61775142,and 6181101252)+1 种基金Science and Technology Innovation Commission of Shenzhen(Nos.KQTD2015032416270385,JCYJ20150625103619275,and JCYJ20170811093453105)Shenzhen Basic Research Project on Subject Layout(No.JCYJ20170412105812811)。
文摘In recent years,multi-wavelength fiber lasers play a significant role in plenty of fields,ranging from optical communications to mechanical processing and laser biomedicine,owing to their high beam quality,low cost,and excellent heat dissipation properties.Benefitting from increasing maturity of optical elements,the multi-wavelength fiber laser has made rapid developments.In this review,we summarize and analyze diverse implementation methods covering continuous wave and pulsed fiber lasers at room temperature conditions:inserting an optical filter device and intensity-dependent loss structure in the resonant cavity,and applying ultrafast nonlinear optical response of materials and a dual-cavity structure.Finally,future challenges and perspectives of the multi-wavelength fiber laser are discussed and addressed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.91750115 and 91750108)the Equipment Pre-research Project of Equipment Development Department of Central Military Commission,China(Grant No.61404140112)the Science and Technology Planning Project of Xiamen City,China(Grant No.3502Z20183003).
文摘We demonstrate visible-light all-fiber vortex lasers by incorporating the home-made mode selective couplers (MSCs). The MSC at green or red wavebands is fabricated by specially designing and fusing a single-mode fiber (SMF) and a few-mode fiber (FMF). The MSCs inserted into visible fiber cavities act as power splitters and mode converters from the LP01 to LP11 mode at green and red wavelengths, respectively. The red-light all-fiber vortex laser is formed by a 10-cm Pr3+/Yb3+:ZBLAN fiber, a fiber Bragg grating, a fiber end-facet mirror and the MSC at 635 nm, which generates vortex beams with OAM±1 at 634.4 nm and an output power of 13 mW. The green-light all-fiber vortex laser consists of a 12-cm Ho3+:ZBLAN fiber, two fiber pigtail mirrors, and the MSC at 550 nm, which generates vortex beams with OAM±1 at 548.9 nm and an output power of 3 mW.
基金Project supported by the Pearl River Talent Program of Guangdong Province,China(No.2017GC010278)the Science and Technology Program of Guangzhou,China(No.202002030027)+1 种基金the National Natural Science Foundation of China(No.61705044)the Distinctive Innovation Project of Regular Colleges in Guangdong Province,China(No.2018KTSCX052)。
文摘We study the exfoliation of ultrathin ReS2 nanosheets from the prepared ReS2 powder and their application to Q-switched Er-doped fiber laser.XRD,Raman,and XPS spectra confirm the successful preparation of the layered ReS2.SEM images show that the obtained ReS2 sheets have lateral size below 200 nm.The thickness of the ReS2 nanosheets is smaller than 5 nm according to the AFM results.ReS2/PVA film is applied as a saturable absorber in an Er-doped Q-switched fiber laser,and a minimum pulse duration of 2.4μs and an output power of 1.25 mW are obtained,indicating the potential application to Q-switched lasers.
基金This work was supported by the National Natural Science Foundation of China(NSFC)(No.61575129).
文摘We report on mode-locked thulium-doped fiber lasers with high-energy nanosecond pulses,relying on the transmission in a semiconductor saturable absorber(SESA)and a carbon nanotube(CNTs-PVA)film separately.A section of an SMF-MMF-SMF structure multimode interferometer with a transmission peak wavelength of^2003 nm was used as a wavelength selector to fix the laser wavelength.When the SESA acted as a saturable absorber(SA),the mode-locked fiber laser had a maximum output power of^461 mW with a pulse energy of^0.14µJ and a pulse duration of^9.14 ns.In a CNT-film-based mode-locked fiber laser,stable mode-locked pulses with the maximum output power of^46 mW,pulse energy of^26.8 nJ and pulse duration of^9.3 ns were obtained.To the best of our knowledge,our experiments demonstrated the first 2µm region‘real’SA-based dissipative soliton resonance with the highest mode-locked pulse energy from a‘real’SA-based all-fiberized resonator.
