Human enterovirus A71(EV-A71)is a major causative agent of hand,foot and mouth disease(HFMD),which poses a significant public health threat,particularly among young children.Mitochondrial antiviral signaling protein(M...Human enterovirus A71(EV-A71)is a major causative agent of hand,foot and mouth disease(HFMD),which poses a significant public health threat,particularly among young children.Mitochondrial antiviral signaling protein(MAVS)and interferon regulatory factor 3(IRF3)are vital proteins for the induction of type I interferons(IFN-I)and downstream interferon-stimulated genes(ISGs)during EVA71 infection.While posttranslational modifications are known to critically influence viral infection processes,the mechanisms by which EV-A71 exploits host deubiquitinases(DUBs)for immune evasion remain poorly understood.In this study,we demonstrated that EV-A71 infection upregulated ubiquitinspecific protease 5(USP5)expression.Knockdown of USP5 not only inhibited EV-A71 replication but also observably increased the production of IFN-I and ISGs.Furthermore,USP5 also regulated the replication of EV-D68 and CVA16 and the production of IFN-I and ISGs.Mechanistically,USP5 physically interacted with MAVS and IRF3 and reduced the K63-linked polyubiquitination of MAVS and IRF3.Conversely,USP5 knockdown increased the K63-linked polyubiquitination of MAVS and IRF3,thereby accelerating the phosphorylation of IRF3 and increasing IFN-I production during EV-A71 infection.Furthermore,pharmacological inhibition of USP5 with the small-molecule inhibitor PR-619 significantly potentiated the antiviral effects of IFN against EV-A71.Collectively,our findings reveal a previously unrecognized role of USP5 in facilitating EV-A71 immune evasion by dampening MAVSand IRF3-mediated antiviral signaling.These insights provide a novel therapeutic avenue for combating EV-A71 infection through targeted modulation of the USP5-IRF3 axis.展开更多
With the widespread adoption of encrypted Domain Name System(DNS)technologies such as DNS over Hyper Text Transfer Protocol Secure(HTTPS),traditional port and protocol-based traffic analysis methods have become ineffe...With the widespread adoption of encrypted Domain Name System(DNS)technologies such as DNS over Hyper Text Transfer Protocol Secure(HTTPS),traditional port and protocol-based traffic analysis methods have become ineffective.Although encrypted DNS enhances user privacy protection,it also provides concealed communication channels for malicious software,compelling detection technologies to shift towards statistical featurebased and machine learning approaches.However,these methods still face challenges in real-time performance and privacy protection.This paper proposes a real-time identification technology for encrypted DNS traffic with privacy protection.Firstly,a hierarchical architecture of cloud-edge-end collaboration is designed,incorporating task offloading strategies to balance privacy protection and identification efficiency.Secondly,a privacy-preserving federated learning mechanismbased on Federated Robust Aggregation(FedRA)is proposed,utilizingMedoid aggregation and differential privacy techniques to ensure data privacy and enhance identification accuracy.Finally,an edge offloading strategy based on a dynamic priority scheduling algorithm(DPSA)is designed to alleviate terminal burden and reduce latency.Simulation results demonstrate that the proposed technology significantly improves the accuracy and realtime performance of encrypted DNS traffic identification while protecting privacy,making it suitable for various network environments.展开更多
There exist a large number of composed documents in universities in the teaching process. Most of them are required to check the similarity for validation. A kind of similarity computation system is constructed for co...There exist a large number of composed documents in universities in the teaching process. Most of them are required to check the similarity for validation. A kind of similarity computation system is constructed for composed documents with images and text information. Firstly, each document is split and outputs two parts as images and text information. Then, these documents are compared by computing the similarities of images and text contents independently. Through Hadoop system, the text contents are easily and quickly separated. Experimental results show that the proposed system is efficient and practical.展开更多
We demonstrated a femtosecond mode-locked Er:Zr F4-Ba F2-La F3-Al F3-Na F(Er:ZBLAN)fiber laser at 2.8μm based on the nonlinear polarization rotation technique.The laser generated an average output power of 317 m W wi...We demonstrated a femtosecond mode-locked Er:Zr F4-Ba F2-La F3-Al F3-Na F(Er:ZBLAN)fiber laser at 2.8μm based on the nonlinear polarization rotation technique.The laser generated an average output power of 317 m W with a repetition rate of 107 MHz and pulse duration as short as 131 fs.To the best of our knowledge,this is the shortest pulse generated directly from a mid-infrared mode-locked Er:ZBLAN fiber laser to date.Numerical simulation and experimental results confirm that reducing the gain fiber length is an effective way to shorten the mode-locked pulse duration in the Er:ZBLAN fiber laser.The work takes an important step towards sub-100-fs mid-infrared pulse generation from mode-locked Er:ZBLAN fiber lasers.展开更多
In past years, rare-earth-doped fluoride fiber lasers(FFLs) have developed rapidly in the mid-infrared(mid-IR)region. However, due to the lack of fiber optic devices and challenge of fluoride fiber splicing, most mid-...In past years, rare-earth-doped fluoride fiber lasers(FFLs) have developed rapidly in the mid-infrared(mid-IR)region. However, due to the lack of fiber optic devices and challenge of fluoride fiber splicing, most mid-IR FFLs have been demonstrated with free-space optic elements, limiting the advantages of all-fiber lasers for flexible delivery, stability, and compactness. Here, we report, to the best of our knowledge, the first pulsed all-fiber FFL in the mid-IR region. By taking advantage of the integration of black phosphorus flake, stable Q-switched and mode-locked pulses were obtained at 2.8 μm wavelength. We believe that this all-fiber design will promote the application of pulsed FFL in the mid-IR region.展开更多
The mode-locked fluoride fiber laser(MLFFL)is an exciting platform for directly generating ultrashort pulses in the mid-infrared(mid-IR).However,owing to difficulty in managing the dispersion in fluoride fiber lasers,...The mode-locked fluoride fiber laser(MLFFL)is an exciting platform for directly generating ultrashort pulses in the mid-infrared(mid-IR).However,owing to difficulty in managing the dispersion in fluoride fiber lasers,MLFFLs are restricted to the soliton regime,hindering pulse-energy scaling.We overcame the problem of dispersion management by utilizing the huge normal dispersion generated near the absorption edge of an infrared-bandgap semiconductor and promoted MLFFL from soliton to breathing-pulse mode-locking.In the breathing-pulse regime,the accumulated nonlinear phase shift can be significantly reduced in the cavity,and the pulse-energy-limitation effect is mitigated.The breathing-pulse MLFFL directly produced a pulse energy of 9.3 nJ and pulse duration of 215 fs,with a record peak power of 43.3 kW at 2.8μm.Our work paves the way for the pulse-energy and peak-power scaling of mid-IR fluoride fiber lasers,enabling a wide range of applications.展开更多
Dissipative solitons have been realized in mode-locked fiber lasers in the theoretical framework of the Ginzburg±Landau equation and have significantly improved the pulse energy and peak power levels of such lase...Dissipative solitons have been realized in mode-locked fiber lasers in the theoretical framework of the Ginzburg±Landau equation and have significantly improved the pulse energy and peak power levels of such lasers.It is interesting to explore whether dissipative solitons exist in optical parametric oscillators in the framework of three-wave coupling equations in order to substantially increase the performance of optical parametric oscillators.Here,we demonstrate a temporalfiltering dissipative soliton in a synchronously pumped optical parametric oscillator.The temporal-gain filtering of the pump pulse combined with strong cascading nonlinearity and dispersion in the optical parametric oscillator enables the generation of a broad spectrum with a nearly linear chirp;consequently,a significantly compressed pulse and high peak power can be realized after dechirping outside the cavity.Furthermore,we realized,for the first time,dissipative solitons in an optical system with a negative nonlinear phase shift and anomalous dispersion,extending the parameter region of dissipative solitons.The findings may open a new research block for dissipative solitons and provide new opportunities for mid-infrared ultrafast science.展开更多
We report on a grating-free fiber chirped pulse amplifier(CPA)at 2.8μm for the first time.The CPA system adopted Er:ZBLAN fiber with large anomalous dispersion as the stretcher and germanium(Ge)rods as the compressor...We report on a grating-free fiber chirped pulse amplifier(CPA)at 2.8μm for the first time.The CPA system adopted Er:ZBLAN fiber with large anomalous dispersion as the stretcher and germanium(Ge)rods as the compressor with a compact structure.High-energy picosecond pulses of 2.07μJ were generated at the repetition rate of 100 kHz.Using highly dispersive Ge rods,the amplified pulses were compressed to 408 fs with a pulse energy of 0.57μJ,resulting in a peak power of approximately 1.4 MW.A spectral broadening phenomenon in the main amplifier was observed,which was caused by the special gain shape of the Er:ZBLAN fiber amplifier in operation and confirmed by our numerical simulation.This compact fiber CPA system at 2.8μm will be practical and meaningful for application fields.展开更多
Spatiotemporal mode-locking creates great opportunity for pulse energy scaling and nonlinear optics research in fiber.Until now,spatiotemporal mode-locking has only been realized in normal-dispersion dissipative solit...Spatiotemporal mode-locking creates great opportunity for pulse energy scaling and nonlinear optics research in fiber.Until now,spatiotemporal mode-locking has only been realized in normal-dispersion dissipative soliton and similariton fiber lasers.In this paper,we demonstrated the first experimental realization of a spatiotemporally mode-locked soliton laser in mid-infrared fluoride fiber with anomalous dispersion.The mode-locked fluoride fiber oscillator directly generated a record pulse energy of 16.1 nJ and peak power of 74.6 kW at 2.8µm wavelength.This work extends the spatiotemporal mode-locking to soliton fiber lasers and should have a wide interest for the laser community.展开更多
We demonstrate the sub-100 fs pulse generation from a dispersion-managed mode-locked Er:ZBLAN fiber laser at2.8μm.Both numerical simulation and experiment demonstrate that stretched-pulse and dissipative soliton mode...We demonstrate the sub-100 fs pulse generation from a dispersion-managed mode-locked Er:ZBLAN fiber laser at2.8μm.Both numerical simulation and experiment demonstrate that stretched-pulse and dissipative soliton mode lockings coexist in the near-zero-dispersion region of a fiuoride fiber laser.With fine dispersion management,the shortest pulse of 95 fs was obtained from the stretched-pulse mode-locked Er:ZBLAN fiber laser,with an average power of280 m W and repetition rate of 52 MHz.To the best of our knowledge,this is the shortest pulse to date directly generated from a mid-infrared mode-locked fiuoride fiber laser.展开更多
High-power ultrafast fiber lasers operating at the 2μm wavelength are extremely desirable for material processing,laser surgery,and nonlinear optics.Here we fabricated large-core(LC)double-cladding Tm-doped silica fi...High-power ultrafast fiber lasers operating at the 2μm wavelength are extremely desirable for material processing,laser surgery,and nonlinear optics.Here we fabricated large-core(LC)double-cladding Tm-doped silica fiber via the sol-gel method.The sol-gel-fabricated Tm-doped silica(SGTS)fiber had a large core diameter of 30μm with a high refractive index homogeneity(Δn=2×10^(-4)).With the newly developed LC SGTS fiber as the gain fiber,high-power mode-locking was realized.By using a semiconductor saturable absorber mirror(SESAM)as a mode locker,the LC SGTS fiber oscillator generated mode-locked pulses with an average output power as high as 1.0 W and a pulse duration of 23.9 ps at the wavelength of 1955.0 nm.Our research results show that the self-developed LC Tm-doped silica fiber via the sol-gel method is a promising gain fiber for generating high-power ultrafast lasers in the 2μm spectral region.展开更多
3–5-μm mid-infrared(MIR)ultrafast laser sources have garnered significant attention due to their critical applications in spectroscopy,environmental monitoring,and imaging.However,4–5-μm compact fiber laser source...3–5-μm mid-infrared(MIR)ultrafast laser sources have garnered significant attention due to their critical applications in spectroscopy,environmental monitoring,and imaging.However,4–5-μm compact fiber laser sources remain a significant technological challenge due to the lack of MIR fibers with good chemical stability,thermal stability,high nonlinearity,and low loss.Here,we develop fluorotellurite fibers based on 60TeO_(2)-20BaF_(2)-10AlF_(3)-10Y_(2)O_(3)(TBAY)glasses with a wide transmission window,demonstrating tunable Raman soliton and dispersive wave(DW)generation beyond 4µm in centimeter-length fluorotellurite fibers pumped by a 3.54μm femtosecond laser source.Fluorotellurite fibers with a loss of 0.39 dB/m were fabricated using a rod-in-tube method.The high numerical aperture(NA~1.1@3.5μm)of TBAY fibers allows the zero-dispersion wavelength(ZDW)to be tuned over a wide range by varying the core diameter of the fibers.The dispersion-engineered TBAY fibers with a core diameter of 6.5μm enabled 4584 nm Raman soliton generation,while fibers with a core diameter of 3μm enabled 4177 nm DW generation.We conducted detailed experiments to investigate the influence of pump power and fiber length on SSFS and dispersive wave dynamics.Theoretical analysis and numerical simulations based on the generalized nonlinear Schrödinger equation corroborate the experimental results.Our results show that TBAY fibers are promising nonlinear media for constructing compact ultrafast laser sources in the 4-5μm wavelength range.展开更多
基金supported by the National Natural Science Foundation of China(32300133 to SZ.and 32100106 to YR)the China Postdoctoral Science Foundation(2023M730965 to SZ.)+3 种基金the Science and Technology Department of Henan Province(232102311103 to SZ.)the Chinese Academy of Sciences(CAS)Youth Innovation Promotion Association(2023351 to YR)the Hubei Province Natural Science Funds(2023AFA008 and 2023AFB582 to YR)the Open project of the State Key Laboratory of Antiviral Drugs,Henan University(FX3020A030002).
文摘Human enterovirus A71(EV-A71)is a major causative agent of hand,foot and mouth disease(HFMD),which poses a significant public health threat,particularly among young children.Mitochondrial antiviral signaling protein(MAVS)and interferon regulatory factor 3(IRF3)are vital proteins for the induction of type I interferons(IFN-I)and downstream interferon-stimulated genes(ISGs)during EVA71 infection.While posttranslational modifications are known to critically influence viral infection processes,the mechanisms by which EV-A71 exploits host deubiquitinases(DUBs)for immune evasion remain poorly understood.In this study,we demonstrated that EV-A71 infection upregulated ubiquitinspecific protease 5(USP5)expression.Knockdown of USP5 not only inhibited EV-A71 replication but also observably increased the production of IFN-I and ISGs.Furthermore,USP5 also regulated the replication of EV-D68 and CVA16 and the production of IFN-I and ISGs.Mechanistically,USP5 physically interacted with MAVS and IRF3 and reduced the K63-linked polyubiquitination of MAVS and IRF3.Conversely,USP5 knockdown increased the K63-linked polyubiquitination of MAVS and IRF3,thereby accelerating the phosphorylation of IRF3 and increasing IFN-I production during EV-A71 infection.Furthermore,pharmacological inhibition of USP5 with the small-molecule inhibitor PR-619 significantly potentiated the antiviral effects of IFN against EV-A71.Collectively,our findings reveal a previously unrecognized role of USP5 in facilitating EV-A71 immune evasion by dampening MAVSand IRF3-mediated antiviral signaling.These insights provide a novel therapeutic avenue for combating EV-A71 infection through targeted modulation of the USP5-IRF3 axis.
文摘With the widespread adoption of encrypted Domain Name System(DNS)technologies such as DNS over Hyper Text Transfer Protocol Secure(HTTPS),traditional port and protocol-based traffic analysis methods have become ineffective.Although encrypted DNS enhances user privacy protection,it also provides concealed communication channels for malicious software,compelling detection technologies to shift towards statistical featurebased and machine learning approaches.However,these methods still face challenges in real-time performance and privacy protection.This paper proposes a real-time identification technology for encrypted DNS traffic with privacy protection.Firstly,a hierarchical architecture of cloud-edge-end collaboration is designed,incorporating task offloading strategies to balance privacy protection and identification efficiency.Secondly,a privacy-preserving federated learning mechanismbased on Federated Robust Aggregation(FedRA)is proposed,utilizingMedoid aggregation and differential privacy techniques to ensure data privacy and enhance identification accuracy.Finally,an edge offloading strategy based on a dynamic priority scheduling algorithm(DPSA)is designed to alleviate terminal burden and reduce latency.Simulation results demonstrate that the proposed technology significantly improves the accuracy and realtime performance of encrypted DNS traffic identification while protecting privacy,making it suitable for various network environments.
文摘There exist a large number of composed documents in universities in the teaching process. Most of them are required to check the similarity for validation. A kind of similarity computation system is constructed for composed documents with images and text information. Firstly, each document is split and outputs two parts as images and text information. Then, these documents are compared by computing the similarities of images and text contents independently. Through Hadoop system, the text contents are easily and quickly separated. Experimental results show that the proposed system is efficient and practical.
基金supported by the National Natural Science Foundation of China(Nos.61675130,91850203,and 11721091)the National Postdoctoral Program for Innovative Talents(No.BX20170149)。
文摘We demonstrated a femtosecond mode-locked Er:Zr F4-Ba F2-La F3-Al F3-Na F(Er:ZBLAN)fiber laser at 2.8μm based on the nonlinear polarization rotation technique.The laser generated an average output power of 317 m W with a repetition rate of 107 MHz and pulse duration as short as 131 fs.To the best of our knowledge,this is the shortest pulse generated directly from a mid-infrared mode-locked Er:ZBLAN fiber laser to date.Numerical simulation and experimental results confirm that reducing the gain fiber length is an effective way to shorten the mode-locked pulse duration in the Er:ZBLAN fiber laser.The work takes an important step towards sub-100-fs mid-infrared pulse generation from mode-locked Er:ZBLAN fiber lasers.
基金National Basic Research Program of China(2013CBA01505)National Natural Science Foundation of China(NSFC)(11721091,61675130)+1 种基金National Postdoctoral Program for Innovative Talents(BX20170149)China Postdoctoral Science Foundation(2017M620150)
文摘In past years, rare-earth-doped fluoride fiber lasers(FFLs) have developed rapidly in the mid-infrared(mid-IR)region. However, due to the lack of fiber optic devices and challenge of fluoride fiber splicing, most mid-IR FFLs have been demonstrated with free-space optic elements, limiting the advantages of all-fiber lasers for flexible delivery, stability, and compactness. Here, we report, to the best of our knowledge, the first pulsed all-fiber FFL in the mid-IR region. By taking advantage of the integration of black phosphorus flake, stable Q-switched and mode-locked pulses were obtained at 2.8 μm wavelength. We believe that this all-fiber design will promote the application of pulsed FFL in the mid-IR region.
基金the National Natural Science Foundation of China(Grant Nos.61675130,91850203,and 11721091)the National Postdoctoral Program for Innovative Talents(Grant No.BX20170149).
文摘The mode-locked fluoride fiber laser(MLFFL)is an exciting platform for directly generating ultrashort pulses in the mid-infrared(mid-IR).However,owing to difficulty in managing the dispersion in fluoride fiber lasers,MLFFLs are restricted to the soliton regime,hindering pulse-energy scaling.We overcame the problem of dispersion management by utilizing the huge normal dispersion generated near the absorption edge of an infrared-bandgap semiconductor and promoted MLFFL from soliton to breathing-pulse mode-locking.In the breathing-pulse regime,the accumulated nonlinear phase shift can be significantly reduced in the cavity,and the pulse-energy-limitation effect is mitigated.The breathing-pulse MLFFL directly produced a pulse energy of 9.3 nJ and pulse duration of 215 fs,with a record peak power of 43.3 kW at 2.8μm.Our work paves the way for the pulse-energy and peak-power scaling of mid-IR fluoride fiber lasers,enabling a wide range of applications.
基金the National Natural Science Foundation of China(Nos.61675130,62075126 and 91850203)。
文摘Dissipative solitons have been realized in mode-locked fiber lasers in the theoretical framework of the Ginzburg±Landau equation and have significantly improved the pulse energy and peak power levels of such lasers.It is interesting to explore whether dissipative solitons exist in optical parametric oscillators in the framework of three-wave coupling equations in order to substantially increase the performance of optical parametric oscillators.Here,we demonstrate a temporalfiltering dissipative soliton in a synchronously pumped optical parametric oscillator.The temporal-gain filtering of the pump pulse combined with strong cascading nonlinearity and dispersion in the optical parametric oscillator enables the generation of a broad spectrum with a nearly linear chirp;consequently,a significantly compressed pulse and high peak power can be realized after dechirping outside the cavity.Furthermore,we realized,for the first time,dissipative solitons in an optical system with a negative nonlinear phase shift and anomalous dispersion,extending the parameter region of dissipative solitons.The findings may open a new research block for dissipative solitons and provide new opportunities for mid-infrared ultrafast science.
基金partially supported by the National Natural Science Foundation of China(Nos.62075126 and 62005161)the Chenguang Program。
文摘We report on a grating-free fiber chirped pulse amplifier(CPA)at 2.8μm for the first time.The CPA system adopted Er:ZBLAN fiber with large anomalous dispersion as the stretcher and germanium(Ge)rods as the compressor with a compact structure.High-energy picosecond pulses of 2.07μJ were generated at the repetition rate of 100 kHz.Using highly dispersive Ge rods,the amplified pulses were compressed to 408 fs with a pulse energy of 0.57μJ,resulting in a peak power of approximately 1.4 MW.A spectral broadening phenomenon in the main amplifier was observed,which was caused by the special gain shape of the Er:ZBLAN fiber amplifier in operation and confirmed by our numerical simulation.This compact fiber CPA system at 2.8μm will be practical and meaningful for application fields.
基金This work was partially supported by the National Natural Science Foundation of China(Nos.62075126 and 62005161)the Fundamental Research Funds for the Central Universities.
文摘Spatiotemporal mode-locking creates great opportunity for pulse energy scaling and nonlinear optics research in fiber.Until now,spatiotemporal mode-locking has only been realized in normal-dispersion dissipative soliton and similariton fiber lasers.In this paper,we demonstrated the first experimental realization of a spatiotemporally mode-locked soliton laser in mid-infrared fluoride fiber with anomalous dispersion.The mode-locked fluoride fiber oscillator directly generated a record pulse energy of 16.1 nJ and peak power of 74.6 kW at 2.8µm wavelength.This work extends the spatiotemporal mode-locking to soliton fiber lasers and should have a wide interest for the laser community.
基金supported by the National Key Research and Development Program of China(No.2023YFB3507404)the National Natural Science Foundation of China(Nos.62005161,62075126 and 62325506)+1 种基金the Innovation Program of Shanghai Municipal Education Commission(No.2023ZKZD19)the Fundamental Research Funds for the Central Universities。
文摘We demonstrate the sub-100 fs pulse generation from a dispersion-managed mode-locked Er:ZBLAN fiber laser at2.8μm.Both numerical simulation and experiment demonstrate that stretched-pulse and dissipative soliton mode lockings coexist in the near-zero-dispersion region of a fiuoride fiber laser.With fine dispersion management,the shortest pulse of 95 fs was obtained from the stretched-pulse mode-locked Er:ZBLAN fiber laser,with an average power of280 m W and repetition rate of 52 MHz.To the best of our knowledge,this is the shortest pulse to date directly generated from a mid-infrared mode-locked fiuoride fiber laser.
基金partially supported by the National Basic Research Program of China(No.2013CBA01505)the Shanghai Excellent Academic Leader Project(No.15XD1502100)the National Natural Science Foundation of China(Nos.61675130 and 11421064)
文摘High-power ultrafast fiber lasers operating at the 2μm wavelength are extremely desirable for material processing,laser surgery,and nonlinear optics.Here we fabricated large-core(LC)double-cladding Tm-doped silica fiber via the sol-gel method.The sol-gel-fabricated Tm-doped silica(SGTS)fiber had a large core diameter of 30μm with a high refractive index homogeneity(Δn=2×10^(-4)).With the newly developed LC SGTS fiber as the gain fiber,high-power mode-locking was realized.By using a semiconductor saturable absorber mirror(SESAM)as a mode locker,the LC SGTS fiber oscillator generated mode-locked pulses with an average output power as high as 1.0 W and a pulse duration of 23.9 ps at the wavelength of 1955.0 nm.Our research results show that the self-developed LC Tm-doped silica fiber via the sol-gel method is a promising gain fiber for generating high-power ultrafast lasers in the 2μm spectral region.
基金supported by National Natural Science Foundation of China(62090062,62225502,62090060,62090063,62105079,62325506)Heilongjiang Provincial Natural Science Foundation of China(LH2022F018)+3 种基金National Key Research and Development Program of China(2020YFA0607602,2021YFB3500901)111 Project(B13015)Fundamental Research Funds for the Central Universities(3072021CF2514,3072021CF2533)the Innovation Program of Shanghai Municipal Education Commission(No.2023ZKZD19).
文摘3–5-μm mid-infrared(MIR)ultrafast laser sources have garnered significant attention due to their critical applications in spectroscopy,environmental monitoring,and imaging.However,4–5-μm compact fiber laser sources remain a significant technological challenge due to the lack of MIR fibers with good chemical stability,thermal stability,high nonlinearity,and low loss.Here,we develop fluorotellurite fibers based on 60TeO_(2)-20BaF_(2)-10AlF_(3)-10Y_(2)O_(3)(TBAY)glasses with a wide transmission window,demonstrating tunable Raman soliton and dispersive wave(DW)generation beyond 4µm in centimeter-length fluorotellurite fibers pumped by a 3.54μm femtosecond laser source.Fluorotellurite fibers with a loss of 0.39 dB/m were fabricated using a rod-in-tube method.The high numerical aperture(NA~1.1@3.5μm)of TBAY fibers allows the zero-dispersion wavelength(ZDW)to be tuned over a wide range by varying the core diameter of the fibers.The dispersion-engineered TBAY fibers with a core diameter of 6.5μm enabled 4584 nm Raman soliton generation,while fibers with a core diameter of 3μm enabled 4177 nm DW generation.We conducted detailed experiments to investigate the influence of pump power and fiber length on SSFS and dispersive wave dynamics.Theoretical analysis and numerical simulations based on the generalized nonlinear Schrödinger equation corroborate the experimental results.Our results show that TBAY fibers are promising nonlinear media for constructing compact ultrafast laser sources in the 4-5μm wavelength range.
