We successfully demonstrate 32-Gbaud Probabilistically Shaped 4096-ary Quadrature Amplitude Modulation(PS-4096QAM)TeraHertz(THz)signal wired transmission at 325 GHz over the 1-m Hollow-Core Fiber(HCF)in a photon-assis...We successfully demonstrate 32-Gbaud Probabilistically Shaped 4096-ary Quadrature Amplitude Modulation(PS-4096QAM)TeraHertz(THz)signal wired transmission at 325 GHz over the 1-m Hollow-Core Fiber(HCF)in a photon-assisted THz-wave communication system.By employing advanced Digital Signal Processing(DSP)and the PS technique,the 352-Gbit/s line rate(288-Gbit/s net rate)delivery with a net Spectral Efficiency(SE)of 9 bit/s/Hz is realized in the experiment,satisfying the 0.86-Normalized Generalized Mutual Information(NGMI)Low-Density Parity-Check(LDPC)threshold.展开更多
We report broadband all-fiber optical phase modulation based on the photo-thermal effect in a gas-filled hollow-core fiber.The phase modulation dynamics are studied by multi-physics simulation.A phase modulator is fab...We report broadband all-fiber optical phase modulation based on the photo-thermal effect in a gas-filled hollow-core fiber.The phase modulation dynamics are studied by multi-physics simulation.A phase modulator is fabricated using a 5.6-cm-long anti-resonant hollow-core fiber with pure acetylene filling.It has a half-wave optical power of 289 mW at 100 kHz and an average insertion loss 0.6 dB over a broad wavelength range from 1450 to 1650 nm.The rise and fall time constants are 3.5 and 3.7μs,respectively,2–3 orders of magnitude better than the previously reported microfiber-based photo-thermal phase modulators.The gas-filled hollow-core waveguide configuration is promising for optical phase modulation from ultraviolet to mid-infrared which is challenging to achieve with solid optical fibers.展开更多
We theoretically study the nonlinear compression of a 20-rnJ, 1030-nm picosecond chirped pulse from the thin-disk amplifier in a krypton gas-filled hollow-core fiber. The chirp from the thin-disk amplifier system has ...We theoretically study the nonlinear compression of a 20-rnJ, 1030-nm picosecond chirped pulse from the thin-disk amplifier in a krypton gas-filled hollow-core fiber. The chirp from the thin-disk amplifier system has little influence on the initial pulse, however, it shows an effect on the nonlinear compression in hollow-core fiber. We use a large diameter hollow waveguide to restrict undesirable nonlinear effects such as ionization; on the other hand, we employ suitable gas pressure and fiber length to promise enough spectral broadening; with 600-μm, 6-bar （1 bar = 105 Pa）, 1.8-m hollow fiber, we obtain 31.5-fs pulse. Moreover, we calculate and discuss the optimal fiber lengths and gas pressures with different initial durations induced by different grating compression angles for reaching a given bandwidth. These results are meaningful for a compression scheme from picoseconds to femtoseconds.展开更多
We theoretically study the nonlinear compression of picosecond pulses with 10-m J of input energy at the 1053-nm center wavelength by using a one-meter-long gas-filled hollow-core fiber（HCF） compressor and consideri...We theoretically study the nonlinear compression of picosecond pulses with 10-m J of input energy at the 1053-nm center wavelength by using a one-meter-long gas-filled hollow-core fiber（HCF） compressor and considering the third-order dispersion（TOD） effect. It is found that when the input pulse is about 1 ps/10 m J, it can be compressed down to less than20 fs with a high transmission efficiency. The gas for optimal compression is krypton gas which is filled in a HCF with a 400-μm inner diameter. When the input pulse duration is increased to 5 ps, it can also be compressed down to less than 100 fs efficiently under proper conditions. The results show that the TOD effect has little impact on picosecond pulse compression and the HCF compressor can be applied on compressing picosecond pulses efficiently with a high compression ratio, which will benefit the research of high-field laser physics.展开更多
We numerically study the self-compression of the optical pulses centered at 1.8-μm in a hollow-core fiber （HCF） filled with argon. It is found that the pulse can be self-compressed to 2 optical cycles when the inpu...We numerically study the self-compression of the optical pulses centered at 1.8-μm in a hollow-core fiber （HCF） filled with argon. It is found that the pulse can be self-compressed to 2 optical cycles when the input pulse energy is 0.2-mJ and the gas pressure is 500-mbar （1 bar=10^5 Pa）. Inducing a proper positive chirp into the input pulse can lead to a shorter temporal duration after self-compression. These results will benefit the generation of energetic few-cycle mid-infrared pulses.展开更多
We study theoretically the spectral intensity evolutions of the femtosecond Gaussian and parabolic pulses with different initial pulse energies and compare the nonlinear compressions of these pulses based on a meter-l...We study theoretically the spectral intensity evolutions of the femtosecond Gaussian and parabolic pulses with different initial pulse energies and compare the nonlinear compressions of these pulses based on a meter-long hollow-core fiber filled with neon for different initial pulse durations. The pulses are first coupled into gas-filled hollow-core fiber for spectrum broadening, then compressed by the optimal chirp compensation. The parabolic pulse possesses a shorter pulse duration, larger peak power, and cleaner wings than Gaussian pulse. The properties are useful for compressing the pulses and thus generating the high-energy, short-duration pulses.展开更多
We perform a numerical study for temporally compressing radially-polarized（RP） infrared pulses in a gas-filled hollow-core fiber（HCF）. The dynamic transmission and nonlinear compression of RP pulses centered at wa...We perform a numerical study for temporally compressing radially-polarized（RP） infrared pulses in a gas-filled hollow-core fiber（HCF）. The dynamic transmission and nonlinear compression of RP pulses centered at wavelengths of0.8 m, 1.8 m, 3.1 m, and 5.0 m in HCFs are simulated. By comparing the propagation of pulses with the same optical cycles and intensity, we find that under proper conditions these pulses can be compressed down to 2–3 cycles. In the transverse direction, the spatiotemporal beam profile ameliorates from 0.8-m to 1.8-m and 3.1-m pulses before the appearance of high-order dispersion. These results show an alternative method of scaling generation for delivering RP infrared pulses in gas-filled HCFs, which can obtain energetic few-cycle pulses, and will be beneficial for relevant researches in the infrared scope.展开更多
We numerically study the propagation dynamics of intense optical pulses in gas-filled hollow-core fibers（HCFs）. The spatiotemporal dynamics of the pulses show a transition from tightly confined to loosely confined c...We numerically study the propagation dynamics of intense optical pulses in gas-filled hollow-core fibers（HCFs）. The spatiotemporal dynamics of the pulses show a transition from tightly confined to loosely confined characteristics as the fiber core is increased, which manifests as a deterioration in the spatiotemporal uniformity of the beam. It is found that using the gas pressure gradient does not enhance the beam quality in large-core HCFs, while inducing a positive chirp in the pulse to lower the peak power can improve the beam quality. This indicates that the self-focusing effect in the HCFs is the main driving force for the propagation dynamics. It also suggests that pulses at longer wavelengths are more suitable for HCFs with large cores because of the lower critical power of self-focusing, which is justified by the numerical simulations. These results will benefit the generation of energetic few-cycle pulses in large-core HCFs.展开更多
We numerically study the pulse compression approaches based on atomic or molecular gases in a hollow-core fiber.From the perspective of self-phase modulation（SPM）, we give the extensive study of the SPM influence on...We numerically study the pulse compression approaches based on atomic or molecular gases in a hollow-core fiber.From the perspective of self-phase modulation（SPM）, we give the extensive study of the SPM influence on a probe pulse with molecular phase modulation（MPM） effect. By comparing the two compression methods, we summarize their advantages and drawbacks to obtain the few-cycle pulses with micro- or millijoule energies. It is also shown that the double pump-probe approach can be used as a tunable dual-color source by adjusting the time delay between pump and probe pulses to proper values.展开更多
A method of fabricating pure germanium dioxide hollow-core fibers has been introduced for the first time. The inner diameter of the fiber is φ0.8mm, with the transmission loss of 1.23dB/m at 10.6μm. The mechanism of...A method of fabricating pure germanium dioxide hollow-core fibers has been introduced for the first time. The inner diameter of the fiber is φ0.8mm, with the transmission loss of 1.23dB/m at 10.6μm. The mechanism of transmitting CO_2 laser by the fiber is analyzed. The transmitting performances are discussed and its application fields are envisaged.展开更多
Over the past half-century, the emergence of technologies such as erbium-doped fiber amplifier(EDFA), wavelength division multiplexing(WDM), coherent transmission and advanced digital signal processing(DSP) has led to...Over the past half-century, the emergence of technologies such as erbium-doped fiber amplifier(EDFA), wavelength division multiplexing(WDM), coherent transmission and advanced digital signal processing(DSP) has led to an exponential increase in the transmission capacity of optical communication networks.展开更多
Fiber gas lasers based on gas-filled hollow-core fibers(HCFs)perfectly combine the advantages of fiber lasers and gas lasers and have obtained fast development in the past years.However,stable and efficient coupling o...Fiber gas lasers based on gas-filled hollow-core fibers(HCFs)perfectly combine the advantages of fiber lasers and gas lasers and have obtained fast development in the past years.However,stable and efficient coupling of high-power pump lasers into the HCFs is one of the key problems to be solved.In this paper,we study the coupling of high-power continuous wave fiber lasers into anti-resonant HCFs through an end-cap.By optimizing the splicing parameters,a maximum laser power of 1167 W was injected into the 1-m-long HCFs,and 1021W was obtained at the output end,giving a total transmission efficiency of〜87.5%.A more than 1 h test showed the stability of such a coupling method.Meanwhile,the laser beam quality was well maintained.This work opens new opportunities for stable and highly efficient coupling of high-power lasers into HCFs,which is significant for its applications in many other fields besides high-power fiber gas lasers,such as high-power laser delivering.展开更多
Continuous operation of fiber gas Raman lasing at the 1135 nm wavelength is experimentally demonstrated with an output power exceeding 26 W.Rotational stimulated Raman scattering(Rot-SRS)is generated in the hydrogen g...Continuous operation of fiber gas Raman lasing at the 1135 nm wavelength is experimentally demonstrated with an output power exceeding 26 W.Rotational stimulated Raman scattering(Rot-SRS)is generated in the hydrogen gas filled 50 m homemade anti-resonant hollow-core fiber(AR-HCF).A single-frequency fiber laser at the 1064 nm wavelength is used as the pump source,and a minimum threshold of 31.5 W is measured where the core diameter of AR-HCF reaches37μm.Up to 40.4%power conversion efficiency of forward Rot-SRS is achieved in the single-pass configuration,corresponding to a quantum efficiency of 43.1%.Over 1 W strong backward Rot-SRS is observed in the experiment,ultimately limiting the further increase of Rot-SRS generation in the forward direction.展开更多
We report all-optical mid-infrared phase and intensity modulators based on the photo-thermal effect in an acetylene-filled anti-resonant hollow-core fiber.Optical absorption of the control beam promotes the gas molecu...We report all-optical mid-infrared phase and intensity modulators based on the photo-thermal effect in an acetylene-filled anti-resonant hollow-core fiber.Optical absorption of the control beam promotes the gas molecules to a higher energy level,which induces localized heating through non-radiative relaxation and modulates the refractive index of the gas material and hence the accumulated phase of the signal beam propagating through the hollow-core fiber.By modulating the intensity of the control beam,the phase of the signal beam is modulated accordingly.By use of a 1.53μm near-infrared control beam,all-optical phase modulation up to 2.2πrad is experimentally demonstrated at the signal wavelength of 3.35μm.With the phase modulator placed in one arm of a Mach-Zehnder interferometer,intensity modulation with on-off ratio of 25 dB is achieved.The gas-filled hollow-core-fiber modulators could operate over an ultra-broad wavelength band from near-to mid-infrared and have promising application in mid-infrared photonic systems.展开更多
The pure-silica hollow-core fiber(HCF) has excellent thermostabilities that can benefit a lot of high-temperature sensing applications.The air-core microstructure of the HCF provides an inherent gas container, which c...The pure-silica hollow-core fiber(HCF) has excellent thermostabilities that can benefit a lot of high-temperature sensing applications.The air-core microstructure of the HCF provides an inherent gas container, which can be a good candidate for gas or gas pressure sensing.This paper reviews our continuous efforts to design, fabricate, and characterize the hightemperature and high-pressure sensors with HCFs, aiming at improving the sensing performances such as dynamic range,sensitivity, and linearity.With the breakthrough advances in novel anti-resonant HCFs, sensing of high temperature and high pressure with HCFs will continuously progress and find increasing applications.展开更多
We report here on a diode-pumped pulsed mid-infrared laser source based on gas-filled hollow-core fibers(HCFs)towards an all-fiber structure by the tapering method. The pump laser is coupled into an acetylene-filled H...We report here on a diode-pumped pulsed mid-infrared laser source based on gas-filled hollow-core fibers(HCFs)towards an all-fiber structure by the tapering method. The pump laser is coupled into an acetylene-filled HCF through a tapered single-mode fiber. By precisely tuning the wavelength of the diode to match different absorption lines of acetylene near 1.5 μm, mid-infrared emission around 3.1–3.2 μm is generated. With 2 m HCFs and3 mbar acetylene gas, a maximum average power of 130 m W is obtained with a laser slope efficiency of ~24%.This work provides a potential scheme for all-fiber mid-infrared fiber gas lasers.展开更多
Highly efficient Cherenkov radiation （CR） is generated by the soliton self-frequency shift （SSFS） in the irregular point of a hollow-core photonic crystal fiber （HC-PCF） in our laboratory. The impacts of pump po...Highly efficient Cherenkov radiation （CR） is generated by the soliton self-frequency shift （SSFS） in the irregular point of a hollow-core photonic crystal fiber （HC-PCF） in our laboratory. The impacts of pump power and wavelength on the CR are investigated, and the corresponding nonlinear processes are discussed. When the average power of the 120 fs pump pulse increases from 500 mW to 700 mW, the Raman soliton shifts from 2210 nm to 2360 nm, the output power of the CR increases by 2.3 times, the maximum output power ratio of the CR at 539 nm to that of the residual pump is calculated to be 24.32：1, the width of the output optical spectrum at the visible wavelength broadens from 35 nm to 62 nm, and the conversion efficiency η of the CR in the experiment can be above 32%.展开更多
In this study, we present speed and displacement measurements of micro-fluid in a hollow-core optical fiber, where an optical interference signal is created by two guided beams reflected at a fixed facet and a moving ...In this study, we present speed and displacement measurements of micro-fluid in a hollow-core optical fiber, where an optical interference signal is created by two guided beams reflected at a fixed facet and a moving fluid end. By counting the number of intensity oscillations of the signal, the movement of the fluid end is successfully traced with high accuracy. Furthermore, we could detect the change in curvature diameters of the fluid end depending on the flow direction by monitoring the visibility of the interference signal.展开更多
Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes ...Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes of plant growth and development,although the functions of SL in fiber development remain largely unknown.Here,we found that the endogenous SLs were significantly higher in fibers at 20 days post-anthesis(DPA).Exogenous SLs significantly increased fiber length and cell wall thickness.Furthermore,we cloned three key SL biosynthetic genes,namely GhD27,GhMAX3,and GhMAX4,which were highly expressed in fibers,and subcellular localization analyses revealed that GhD27,GhMAX3,and GhMAX4 were localized in the chloroplast.The exogenous expression of GhD27,GhMAX3,and GhMAX4 complemented the physiological phenotypes of d27,max3,and max4 mutations in Arabidopsis,respectively.Knockdown of GhD27,GhMAX3,and GhMAX4 in cotton resulted in increased numbers of axillary buds and leaves,reduced fiber length,and significantly reduced fiber thickness.These findings revealed that SLs participate in plant growth,fiber elongation,and secondary cell wall formation in cotton.These results provide new and effective genetic resources for improving cotton fiber yield and plant architecture.展开更多
Ingenious design and fabrication of advanced carbon-based sulfur cathodes are extremely important to the development of high-energy lithium-sulfur batteries,which hold promise as the next-generation power source.Herei...Ingenious design and fabrication of advanced carbon-based sulfur cathodes are extremely important to the development of high-energy lithium-sulfur batteries,which hold promise as the next-generation power source.Herein,for the first time,we report a novel versatile hyphae-mediated biological assembly technology to achieve scale production of hyphae carbon fibers(HCFs)derivatives,in which different components including carbon,metal compounds,and semiconductors can be homogeneously assembled with HCFs to form composite networks.The mechanism of biological adsorption assembly is also proposed.As a representative,reduced graphene oxides(rGOs)decorated with hollow carbon spheres(HCSs)successfully co-assemble with HCFs to form HCSs@rGOs/HCFs hosts for sulfur cathodes.In this unique architecture,not only large accommodation space for sulfur but also restrained volume expansion and fast charge transport paths are realized.Meanwhile,multiscale physical barriers plus chemisorption sites are simultaneously established to anchor soluble lithium polysulfides.Accordingly,the designed HCSs@rGOs/HCFs-S cathodes deliver a high capacity(1189 mA h g^(-1)at 0.1 C)and good high-rate capability(686 mA h g^(-1)at 5 C).Our work provides a new approach for the preparation of high-performance carbon-based electrodes for energy storage devices.展开更多
基金supported by National Key R&D Program of China(2018YFB1800900)National Natural Science Foundation of China(61935005,91938202,61720106015,61835002,61805043,62127802).
文摘We successfully demonstrate 32-Gbaud Probabilistically Shaped 4096-ary Quadrature Amplitude Modulation(PS-4096QAM)TeraHertz(THz)signal wired transmission at 325 GHz over the 1-m Hollow-Core Fiber(HCF)in a photon-assisted THz-wave communication system.By employing advanced Digital Signal Processing(DSP)and the PS technique,the 352-Gbit/s line rate(288-Gbit/s net rate)delivery with a net Spectral Efficiency(SE)of 9 bit/s/Hz is realized in the experiment,satisfying the 0.86-Normalized Generalized Mutual Information(NGMI)Low-Density Parity-Check(LDPC)threshold.
基金We are grateful for financial supports from the National Key Research and Development Program of China(2019YFB2203904)the National Natural Science Foundation of China(U21A20506,62105122,61827820,62005233)+1 种基金the Shenzhen STIC Funding(RCBS20200714114819032)the Local Innovative and Research Teams Project of Guangdong Pear River Talents Program(2019BT02X105).
文摘We report broadband all-fiber optical phase modulation based on the photo-thermal effect in a gas-filled hollow-core fiber.The phase modulation dynamics are studied by multi-physics simulation.A phase modulator is fabricated using a 5.6-cm-long anti-resonant hollow-core fiber with pure acetylene filling.It has a half-wave optical power of 289 mW at 100 kHz and an average insertion loss 0.6 dB over a broad wavelength range from 1450 to 1650 nm.The rise and fall time constants are 3.5 and 3.7μs,respectively,2–3 orders of magnitude better than the previously reported microfiber-based photo-thermal phase modulators.The gas-filled hollow-core waveguide configuration is promising for optical phase modulation from ultraviolet to mid-infrared which is challenging to achieve with solid optical fibers.
基金Project supported by the National Basic Research Program of China(Grant No.2011CB808101)the Funds from the Chinese Academy of Sciences,and the National Natural Science Foundation of China(Grant Nos.11127901,10734080,61221064,60908008,and 61078037)
文摘We theoretically study the nonlinear compression of a 20-rnJ, 1030-nm picosecond chirped pulse from the thin-disk amplifier in a krypton gas-filled hollow-core fiber. The chirp from the thin-disk amplifier system has little influence on the initial pulse, however, it shows an effect on the nonlinear compression in hollow-core fiber. We use a large diameter hollow waveguide to restrict undesirable nonlinear effects such as ionization; on the other hand, we employ suitable gas pressure and fiber length to promise enough spectral broadening; with 600-μm, 6-bar （1 bar = 105 Pa）, 1.8-m hollow fiber, we obtain 31.5-fs pulse. Moreover, we calculate and discuss the optimal fiber lengths and gas pressures with different initial durations induced by different grating compression angles for reaching a given bandwidth. These results are meaningful for a compression scheme from picoseconds to femtoseconds.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11204328,61221064,61078037,11127901,and 11134010)the National Basic Research Program of China(Grant No.2011CB808101)+2 种基金the Commission of Science and Technology of Shanghai,China(Grant No.12dz1100700)the Natural Science Foundation of Shanghai,China(Grant No.13ZR1414800)the International Science and Technology Cooperation Program of China(Grant No.2011DFA11300)
文摘We theoretically study the nonlinear compression of picosecond pulses with 10-m J of input energy at the 1053-nm center wavelength by using a one-meter-long gas-filled hollow-core fiber（HCF） compressor and considering the third-order dispersion（TOD） effect. It is found that when the input pulse is about 1 ps/10 m J, it can be compressed down to less than20 fs with a high transmission efficiency. The gas for optimal compression is krypton gas which is filled in a HCF with a 400-μm inner diameter. When the input pulse duration is increased to 5 ps, it can also be compressed down to less than 100 fs efficiently under proper conditions. The results show that the TOD effect has little impact on picosecond pulse compression and the HCF compressor can be applied on compressing picosecond pulses efficiently with a high compression ratio, which will benefit the research of high-field laser physics.
基金supported by the National Natural Science Foundation of China(Grant Nos.61475169,61521093,and 11127901)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB16)the International Science and Technology Cooperation Program of China(Grant No.2016YFE0119300)
文摘We numerically study the self-compression of the optical pulses centered at 1.8-μm in a hollow-core fiber （HCF） filled with argon. It is found that the pulse can be self-compressed to 2 optical cycles when the input pulse energy is 0.2-mJ and the gas pressure is 500-mbar （1 bar=10^5 Pa）. Inducing a proper positive chirp into the input pulse can lead to a shorter temporal duration after self-compression. These results will benefit the generation of energetic few-cycle mid-infrared pulses.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61221064,61078037,11127901,and 11134010)the National Basic Research Program of China(Grant No.2011CB808101)+2 种基金the Funds from the Commission of Science and Technology of Shanghai,China(Grant No.12dz1100700)the Natural Science Foundation of Shanghai,China(Grant No.13ZR1414800)the International S&T Cooperation Program of China(Grant No.2011DFA11300)
文摘We study theoretically the spectral intensity evolutions of the femtosecond Gaussian and parabolic pulses with different initial pulse energies and compare the nonlinear compressions of these pulses based on a meter-long hollow-core fiber filled with neon for different initial pulse durations. The pulses are first coupled into gas-filled hollow-core fiber for spectrum broadening, then compressed by the optimal chirp compensation. The parabolic pulse possesses a shorter pulse duration, larger peak power, and cleaner wings than Gaussian pulse. The properties are useful for compressing the pulses and thus generating the high-energy, short-duration pulses.
基金Project supported by the National Natural Science Foundation of China(Grant No.61521093)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB16)+1 种基金the International S&T Cooperation Program of China(Grant No.2016YFE0119300)the Program of Shanghai Academic/Technology Research Leader,China(Grant No.18XD1404200)
文摘We perform a numerical study for temporally compressing radially-polarized（RP） infrared pulses in a gas-filled hollow-core fiber（HCF）. The dynamic transmission and nonlinear compression of RP pulses centered at wavelengths of0.8 m, 1.8 m, 3.1 m, and 5.0 m in HCFs are simulated. By comparing the propagation of pulses with the same optical cycles and intensity, we find that under proper conditions these pulses can be compressed down to 2–3 cycles. In the transverse direction, the spatiotemporal beam profile ameliorates from 0.8-m to 1.8-m and 3.1-m pulses before the appearance of high-order dispersion. These results show an alternative method of scaling generation for delivering RP infrared pulses in gas-filled HCFs, which can obtain energetic few-cycle pulses, and will be beneficial for relevant researches in the infrared scope.
文摘We numerically study the propagation dynamics of intense optical pulses in gas-filled hollow-core fibers（HCFs）. The spatiotemporal dynamics of the pulses show a transition from tightly confined to loosely confined characteristics as the fiber core is increased, which manifests as a deterioration in the spatiotemporal uniformity of the beam. It is found that using the gas pressure gradient does not enhance the beam quality in large-core HCFs, while inducing a positive chirp in the pulse to lower the peak power can improve the beam quality. This indicates that the self-focusing effect in the HCFs is the main driving force for the propagation dynamics. It also suggests that pulses at longer wavelengths are more suitable for HCFs with large cores because of the lower critical power of self-focusing, which is justified by the numerical simulations. These results will benefit the generation of energetic few-cycle pulses in large-core HCFs.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11204328,61221064,61078037,11127901,11134010,and 61205208)the National Basic Research Program of China(Grant No.2011CB808101)the Natural Science Foundation of Shanghai,China(Grant No.13ZR1414800)
文摘We numerically study the pulse compression approaches based on atomic or molecular gases in a hollow-core fiber.From the perspective of self-phase modulation（SPM）, we give the extensive study of the SPM influence on a probe pulse with molecular phase modulation（MPM） effect. By comparing the two compression methods, we summarize their advantages and drawbacks to obtain the few-cycle pulses with micro- or millijoule energies. It is also shown that the double pump-probe approach can be used as a tunable dual-color source by adjusting the time delay between pump and probe pulses to proper values.
基金Supported by the High Technology Research and Development Programme of China
文摘A method of fabricating pure germanium dioxide hollow-core fibers has been introduced for the first time. The inner diameter of the fiber is φ0.8mm, with the transmission loss of 1.23dB/m at 10.6μm. The mechanism of transmitting CO_2 laser by the fiber is analyzed. The transmitting performances are discussed and its application fields are envisaged.
文摘Over the past half-century, the emergence of technologies such as erbium-doped fiber amplifier(EDFA), wavelength division multiplexing(WDM), coherent transmission and advanced digital signal processing(DSP) has led to an exponential increase in the transmission capacity of optical communication networks.
基金This work was supported by the Outstanding Youth Science Fund of Hunan Provincial Natural Science Foundation(No.2019JJ20023)National Natural Science Foundation of China(NSFC)(Nos.11974427 and 12004431)+2 种基金State Key Laboratory of Pulsed Power Laser(Nos.SKL2020ZR05 and SKL2021ZR01)Science and Technology Innovation Program of Hunan Province(No.2021RC4027)Postgraduate Scientific Research Innovation Project of Hunan Province(No.CX20200017).
文摘Fiber gas lasers based on gas-filled hollow-core fibers(HCFs)perfectly combine the advantages of fiber lasers and gas lasers and have obtained fast development in the past years.However,stable and efficient coupling of high-power pump lasers into the HCFs is one of the key problems to be solved.In this paper,we study the coupling of high-power continuous wave fiber lasers into anti-resonant HCFs through an end-cap.By optimizing the splicing parameters,a maximum laser power of 1167 W was injected into the 1-m-long HCFs,and 1021W was obtained at the output end,giving a total transmission efficiency of〜87.5%.A more than 1 h test showed the stability of such a coupling method.Meanwhile,the laser beam quality was well maintained.This work opens new opportunities for stable and highly efficient coupling of high-power lasers into HCFs,which is significant for its applications in many other fields besides high-power fiber gas lasers,such as high-power laser delivering.
基金partly supported by the International Science and Technology Cooperation Program(No.2018YFE0115600)National Natural Science Foundation of China(No.61935002)+2 种基金Chinese Academy of Sciences(No.ZDBSLY-JSC020)supported by the CAS Pioneer Hundred Talents ProgramNational Key R&D Program of China(Nos.2020YFB1312802 and 2020YFB1805900)。
文摘Continuous operation of fiber gas Raman lasing at the 1135 nm wavelength is experimentally demonstrated with an output power exceeding 26 W.Rotational stimulated Raman scattering(Rot-SRS)is generated in the hydrogen gas filled 50 m homemade anti-resonant hollow-core fiber(AR-HCF).A single-frequency fiber laser at the 1064 nm wavelength is used as the pump source,and a minimum threshold of 31.5 W is measured where the core diameter of AR-HCF reaches37μm.Up to 40.4%power conversion efficiency of forward Rot-SRS is achieved in the single-pass configuration,corresponding to a quantum efficiency of 43.1%.Over 1 W strong backward Rot-SRS is observed in the experiment,ultimately limiting the further increase of Rot-SRS generation in the forward direction.
基金supported by the National Key Research and Development Program of China(2019YFB2203904)National Natural Science Foundation of China(61827820,62005233)+1 种基金the Shenzhen STIC Funding(RCBS20200714114819032)the Local Innovative and Research Teams Project of Guangdong Pear River Talents Program(2019BT02X105).
文摘We report all-optical mid-infrared phase and intensity modulators based on the photo-thermal effect in an acetylene-filled anti-resonant hollow-core fiber.Optical absorption of the control beam promotes the gas molecules to a higher energy level,which induces localized heating through non-radiative relaxation and modulates the refractive index of the gas material and hence the accumulated phase of the signal beam propagating through the hollow-core fiber.By modulating the intensity of the control beam,the phase of the signal beam is modulated accordingly.By use of a 1.53μm near-infrared control beam,all-optical phase modulation up to 2.2πrad is experimentally demonstrated at the signal wavelength of 3.35μm.With the phase modulator placed in one arm of a Mach-Zehnder interferometer,intensity modulation with on-off ratio of 25 dB is achieved.The gas-filled hollow-core-fiber modulators could operate over an ultra-broad wavelength band from near-to mid-infrared and have promising application in mid-infrared photonic systems.
基金supported by the National Natural Science Foundation of China (NSFC)(Nos.61875128 and 61635007)China Postdoctoral Science Foundation (No.2020M683184)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2021B1515020030)Department of Science and Technology of Guangdong Province (No.2019TQ05X113)Shenzhen Science and Technology Program(No.RCYX20200714114538160)。
文摘The pure-silica hollow-core fiber(HCF) has excellent thermostabilities that can benefit a lot of high-temperature sensing applications.The air-core microstructure of the HCF provides an inherent gas container, which can be a good candidate for gas or gas pressure sensing.This paper reviews our continuous efforts to design, fabricate, and characterize the hightemperature and high-pressure sensors with HCFs, aiming at improving the sensing performances such as dynamic range,sensitivity, and linearity.With the breakthrough advances in novel anti-resonant HCFs, sensing of high temperature and high pressure with HCFs will continuously progress and find increasing applications.
基金supported by the Outstanding Youth Science Fund Project of Hunan Provincial Natural Science Foundation(No.2019JJ20023)the National Natural Science Foundation of China(NSFC)(No.61705266)
文摘We report here on a diode-pumped pulsed mid-infrared laser source based on gas-filled hollow-core fibers(HCFs)towards an all-fiber structure by the tapering method. The pump laser is coupled into an acetylene-filled HCF through a tapered single-mode fiber. By precisely tuning the wavelength of the diode to match different absorption lines of acetylene near 1.5 μm, mid-infrared emission around 3.1–3.2 μm is generated. With 2 m HCFs and3 mbar acetylene gas, a maximum average power of 130 m W is obtained with a laser slope efficiency of ~24%.This work provides a potential scheme for all-fiber mid-infrared fiber gas lasers.
基金Project supported by the National Basic Research Program of China (Grant Nos. 2010CB327605 and 2010CB328300)the Fundamental Research Funds for the Central Universities,China (Grant Nos. 2011RC0309 and 2011RC008)the Specialized Research Fund for the Doctoral Program of Beijing University of Posts and Telecommunications,China (Grant No. CX201023)
文摘Highly efficient Cherenkov radiation （CR） is generated by the soliton self-frequency shift （SSFS） in the irregular point of a hollow-core photonic crystal fiber （HC-PCF） in our laboratory. The impacts of pump power and wavelength on the CR are investigated, and the corresponding nonlinear processes are discussed. When the average power of the 120 fs pump pulse increases from 500 mW to 700 mW, the Raman soliton shifts from 2210 nm to 2360 nm, the output power of the CR increases by 2.3 times, the maximum output power ratio of the CR at 539 nm to that of the residual pump is calculated to be 24.32：1, the width of the output optical spectrum at the visible wavelength broadens from 35 nm to 62 nm, and the conversion efficiency η of the CR in the experiment can be above 32%.
文摘In this study, we present speed and displacement measurements of micro-fluid in a hollow-core optical fiber, where an optical interference signal is created by two guided beams reflected at a fixed facet and a moving fluid end. By counting the number of intensity oscillations of the signal, the movement of the fluid end is successfully traced with high accuracy. Furthermore, we could detect the change in curvature diameters of the fluid end depending on the flow direction by monitoring the visibility of the interference signal.
基金supported by the National Natural Science Foundation of China (32170367 and 32000146)the Fundamental Research Funds for the Central Universities, China (2021TS066 and GK202103063)the Excellent Graduate Training Program of Shaanxi Normal University, China (LHRCCX23181).
文摘Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes of plant growth and development,although the functions of SL in fiber development remain largely unknown.Here,we found that the endogenous SLs were significantly higher in fibers at 20 days post-anthesis(DPA).Exogenous SLs significantly increased fiber length and cell wall thickness.Furthermore,we cloned three key SL biosynthetic genes,namely GhD27,GhMAX3,and GhMAX4,which were highly expressed in fibers,and subcellular localization analyses revealed that GhD27,GhMAX3,and GhMAX4 were localized in the chloroplast.The exogenous expression of GhD27,GhMAX3,and GhMAX4 complemented the physiological phenotypes of d27,max3,and max4 mutations in Arabidopsis,respectively.Knockdown of GhD27,GhMAX3,and GhMAX4 in cotton resulted in increased numbers of axillary buds and leaves,reduced fiber length,and significantly reduced fiber thickness.These findings revealed that SLs participate in plant growth,fiber elongation,and secondary cell wall formation in cotton.These results provide new and effective genetic resources for improving cotton fiber yield and plant architecture.
基金Natural Science Foundation for Distinguished Young Scholars of Zhejiang Province,Grant/Award Number:LR20E020001Foundation of State Key Laboratory of Coal Conversion,Grant/Award Number:J20-21-909+4 种基金Science and Technology Department of Zhejiang Province,Grant/Award Number:2023C01231National Natural Science Foundation of China,Grant/Award Numbers:52372235,52073252,52002052,22379020,U20A20253,21972127,22279116Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment,Grant/Award Number:SKLPEE-KF202206Key Research and Development Project of Science and Technology Department of Sichuan Province,Grant/Award Number:2022YFSY0004Ministry of Education,Grant/Award Number:KFM 202202。
文摘Ingenious design and fabrication of advanced carbon-based sulfur cathodes are extremely important to the development of high-energy lithium-sulfur batteries,which hold promise as the next-generation power source.Herein,for the first time,we report a novel versatile hyphae-mediated biological assembly technology to achieve scale production of hyphae carbon fibers(HCFs)derivatives,in which different components including carbon,metal compounds,and semiconductors can be homogeneously assembled with HCFs to form composite networks.The mechanism of biological adsorption assembly is also proposed.As a representative,reduced graphene oxides(rGOs)decorated with hollow carbon spheres(HCSs)successfully co-assemble with HCFs to form HCSs@rGOs/HCFs hosts for sulfur cathodes.In this unique architecture,not only large accommodation space for sulfur but also restrained volume expansion and fast charge transport paths are realized.Meanwhile,multiscale physical barriers plus chemisorption sites are simultaneously established to anchor soluble lithium polysulfides.Accordingly,the designed HCSs@rGOs/HCFs-S cathodes deliver a high capacity(1189 mA h g^(-1)at 0.1 C)and good high-rate capability(686 mA h g^(-1)at 5 C).Our work provides a new approach for the preparation of high-performance carbon-based electrodes for energy storage devices.
