Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which woul...Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which would be greatly affected by fiber dispersion.In this work,we establish a theoretical model of the entanglement-based DO-QKD system,considering the protocol,physical processes(such as fiber transmission and single-photon detection),and the analysis of security tests.Based on this theoretical model,we investigate the influence of chromatic dispersion introduced by transmission fibers on the performance of DO-QKD.By analyzing the benefits and costs of dispersion compensation,the system performance under G.652 and G.655 optical fibers are shown,respectively.The results show that dispersion compensation is unnecessary for DO-QKD systems in campus networks and even metro networks.Whereas,it is still required in DO-QKD systems with longer fiber transmission distances.展开更多
Reverse design of highly GeO2-doped silica optical fibers with broadband and flat dispersion profiles is proposed using a neural network(NN) combined with a particle swarm optimization(PSO) algorithm.Firstly,the NN mo...Reverse design of highly GeO2-doped silica optical fibers with broadband and flat dispersion profiles is proposed using a neural network(NN) combined with a particle swarm optimization(PSO) algorithm.Firstly,the NN model designed to predict optical fiber dispersion is trained with an appropriate choice of hyperparameters,achieving a root mean square error(RMSE) of 9.47×10-7on the test dataset,with a determination coefficient(R2) of 0.999.Secondly,the NN is combined with the PSO algorithm for the inverse design of dispersion-flattened optical fibers.To expand the search space and avoid particles becoming trapped in local optimal solutions,the PSO algorithm incorporates adaptive inertia weight updating and a simulated annealing algorithm.Finally,by using a suitable fitness function,the designed fibers exhibit flat group velocity dispersion(GVD) profiles at 1 400—2 400 nm,where the GVD fluctuations and minimum absolute GVD values are below 18 ps·nm-1·km-1and 7 ps·nm-1·km-1,respectively.展开更多
This paper examines the longitudinal tensile behavior and failure mechanism of a new unidirectional carbon fiber reinforced aluminum composite through experiments and simulations.A Weibull distribution model was estab...This paper examines the longitudinal tensile behavior and failure mechanism of a new unidirectional carbon fiber reinforced aluminum composite through experiments and simulations.A Weibull distribution model was established to describe the fiber strength dispersion based on single-fiber tensile tests for carbon fibers extracted from the composite.The constitutive models for the matrix and interface were established based on the uniaxial tensile and single-fiber push-out tests,respectively.Then,a 3D micromechanical numerical model,innovatively considering the fiber strength dispersion by use of the weakest link and Weibull distribution theories,was estab-lished to simulate the progressive failure behavior of the composite under longitudinal tension.Due to the dispersion of fiber strength,the weakest link of the fiber first fractures,and stress concentra-tion occurs in the surrounding fibers,interfaces,and matrix.The maximum stress concentration fac-tor for neighboring fibers varies nonlinearly with the distance from the fractured fiber.Both isolated and clustered fractured fibers are present during the progressive failure process of the composite.The expansion of fractured fiber clusters intensifies stress concentration and material degradation which in turn enlarges the fractured fiber clusters,and their mutual action leads to the final collapse of the composite.展开更多
The dispersion properties in the short wavelength region of total internal reflective photonic crystal fiber have been studied by using the models of the equivalent twin waveguide soliton coupling,effective refractive...The dispersion properties in the short wavelength region of total internal reflective photonic crystal fiber have been studied by using the models of the equivalent twin waveguide soliton coupling,effective refractive index,effective normalized frequency and dispersion management solitons.It is shown that the dispersion in the cladding waveguide of the total internal reflective photonic crystal fiber is a positive dispersion,and the dispersion of its core waveguide is a negative dispersion.The method of the compensated probing laser diffraction by the phase hole induced by the stationary pumping laser in the cladding waveguide enables the average dispersion value of the total internal reflective photonic crystal fiber to be close to zero and the zero dispersion point to shift to the short wavelength region.展开更多
Periodic solitons are studied in dispersion decreasing fibers with a cosine profile. The variable-coefficient nonlinear Schrrdinger equation, which can be used to describe the propagation of solitons, is investigated ...Periodic solitons are studied in dispersion decreasing fibers with a cosine profile. The variable-coefficient nonlinear Schrrdinger equation, which can be used to describe the propagation of solitons, is investigated analytically. Analytic soli- ton solutions for this equation are derived with the Hirota＇s bilinear method. Using the soliton solutions, we obtain periodic solitons, and analyze the soliton characteristics. Influences of physical parameters on periodic solitons are discussed. The presented results can be used in optical communication systems and fiber lasers.展开更多
Stripping dispersion hollow fiber liquid membrane system（SDHFLM） containing feed phase adding acetate buffer solution and dispersion solution with HNO_3 solution as the stripping solution and membrane solution of 2-...Stripping dispersion hollow fiber liquid membrane system（SDHFLM） containing feed phase adding acetate buffer solution and dispersion solution with HNO_3 solution as the stripping solution and membrane solution of 2-ethyl hexyl phosphoric acid-mono-2-ethylhexyl ester（PC-88A） dissolved in kerosene,has been studied for the extraction of Sm^（3＋）.Many factors including pH value, volume ratio of membrane solution to stripping solution（OAV） and carrier concentration on Sm^（3＋） extraction were investigated. Experimental results indicate that the optimum extraction conditions of Sm^（3＋） were obtained as that PC-88A concentration was 0.120 mol/L,and OAV was 1.00 in the dispersion phase,and pH value was 4.80 in the feed phase.When initial Sm^（3＋） concentration was 1.20×10^（-4） mol/L,the extraction percentage of Sm^（3＋） was up to 92.8%in 160 min.展开更多
We study localized waves on continuous wave background in an exponential dispersion decreasing fiber with two orthogonal polarization states. We demonstrate that asymmetric W-shaped and M-shaped soliton pulse can be g...We study localized waves on continuous wave background in an exponential dispersion decreasing fiber with two orthogonal polarization states. We demonstrate that asymmetric W-shaped and M-shaped soliton pulse can be generated from a weak modulation on continuous wave background. The numerical simulation results indicate that the generated asymmetric soliton pulses are robust against small noise or perturbation. In particular, the asymmetric degree of the asymmetric soliton pulse can be effectively controlled by changing the relative frequency of the two components. This character can be used to generate other nonlinear localized waves, such as dark-antidark and antidark-dark soliton pulse pair, symmetric W-shaped and M-shaped soliton pulse. Furthermore, we find that the asymmetric soliton pulse possesses an asymmetric discontinuous spectrum.展开更多
We derive analytical bright and dark solitons of the modified nonlinear Schroedinger equations with variable coefficients. Under constraint conditions between system parameters, the optical soliton transmission in the...We derive analytical bright and dark solitons of the modified nonlinear Schroedinger equations with variable coefficients. Under constraint conditions between system parameters, the optical soliton transmission in the dispersiondecreasing fibers can be exactly controlled by proper dispersion management. The analytical description of the interactions between the bright and dark solitons are first obtained.展开更多
Time domain ABCD matrix formalism is a useful model for analyzing the characteristics of actively modelocked fiber laser. Based on this model and given more consideration on the influences of optical fiber dispersion ...Time domain ABCD matrix formalism is a useful model for analyzing the characteristics of actively modelocked fiber laser. Based on this model and given more consideration on the influences of optical fiber dispersion and optical fiber nonlinearity, the laser characteristic of actively modelocked fiber laser is analyzed, and the comparision of the theoretical analysis results with experimental ones is given.展开更多
Degradable industrial packaging foam trays made from cellulose fibers were fabricated using a hot-press baking process.Bleached softwood pulp fibers with a concentration of 30%were dispersed at a high speed under the ...Degradable industrial packaging foam trays made from cellulose fibers were fabricated using a hot-press baking process.Bleached softwood pulp fibers with a concentration of 30%were dispersed at a high speed under the action of a dispersant.The effects of the dispersant dosage of the fibers on the porosity,foam density,and static compression characteristics were discussed.Furthermore,the effects of the reinforcing adhesive including polyvinyl alcohol(PVA),and cassava starch on the physical and mechanical properties of the foam trays were studied,as well as the relationship between these properties and the microstructure of the foam trays.The dispersant enhanced the rheological and blistering properties of the fiber dispersion.As the dispersant dosage increased from 2%to 4%,the foam density gradually increased and the compressive strain performance and residual compressive strain of the foam trays decreased.Under the condition of constant dosage of dispersant,increasing the fiber proportion from 67%to 77%improved the porosity and foam density and slightly reduced the static compression performance.In additioton,the static compression resistance of the foamed materials was improved by increasing the PVA dosage since PVA was beneficial for improving the strength of the foam trays.展开更多
This paper demonstrated the generation of multi-wavelength bound state noise-like pulse(BNLP)in a dispersion-managed composite-filtered fiber laser consisting of nonlinear polarization rotation(NPR)and loop.In the cas...This paper demonstrated the generation of multi-wavelength bound state noise-like pulse(BNLP)in a dispersion-managed composite-filtered fiber laser consisting of nonlinear polarization rotation(NPR)and loop.In the case of BNLP,the generation is caused by the interaction between two noise-like pulses(NLPs)induced by the comb-filtering effect,and bound state level can be artificially controlled in the researches.Our work provides a new method for generating low-coherence pulses and establishes a research idea for the study of the comb-filtering effects.展开更多
In this paper,an efficient 8-channel 32Gbps RoF(Radio over Fiber)system incorporating Bessel Filter(8/32 RoFBF)has been demonstrated to reduce the impact of non-linear transmission effects,specifically Four-Wave Mixin...In this paper,an efficient 8-channel 32Gbps RoF(Radio over Fiber)system incorporating Bessel Filter(8/32 RoFBF)has been demonstrated to reduce the impact of non-linear transmission effects,specifically Four-Wave Mixing(FWM).The simulation results indicate that the proposed 8/32 RoF-BF system provides an optimum result w.r.t.channel spacing(75 GHz),input source power(0 dBm)and number of input channels(8).In comparison with the existing RoF system,the proposed 8/32 RoF-BF system has been validated analytically and it is found that the performance of the proposed system is in close proximity particularly in FWM sideband power reduction of the order of 4 dBm for the 8-channel 32Gbps RoF system.展开更多
The combination of Radio Frequency and Optical Fiber has resulted high capacity transmission at lower costs components and makes Radio over Fiber as a current trend of large broadband communication. In Fiber optics fi...The combination of Radio Frequency and Optical Fiber has resulted high capacity transmission at lower costs components and makes Radio over Fiber as a current trend of large broadband communication. In Fiber optics field, the use of Fiber Bragg Grating (FBG) was been proposed in recent research with different purpose of uses. However, the compensation of dispersion method of Fiber Bragg Grating (FBG) can boost significantly the system performance. This paper investigates the performance capacity improvement of adaptive Radio over Fiber system. The system design was performed using OptiSystem 7.0 software, which 10 Gb/s Non Return to Zero (NRZ) signal was launched into 50 Km Universal Mode Fiber and Fiber Bragg Grating was used as a compensator of dispersion before frequency up conversion. Therefore, the system performances were investigated by comparing the Bit Error Rate (BER) and Q-factors of Positive Intrinsic Negative (PIN) and Ultrafast Avalanche Photodiode (APD) as optical receivers. The Eye diagram analyzer showed acceptable improvement due to use of Fiber Bragg Grating as a compensator of dispersion.展开更多
Hydroxypropyl methylcellulose （HPMC） and amphoteric polyacrylamide （ACPAM） were respectively used to prepare engineered cementitious composite （ECC） which exhibits strain-hardening behavior under uniaxial tensio...Hydroxypropyl methylcellulose （HPMC） and amphoteric polyacrylamide （ACPAM） were respectively used to prepare engineered cementitious composite （ECC） which exhibits strain-hardening behavior under uniaxial tension. The connections between cement paste structure and the performance of the composite in fresh and hardened state were investigated, aiming at achieving the desirable workability at a given solids concentration. The experimental results of viscosity and miCrostructure of cement pastes show that the intimate connections between flocculation groups lead to the growing increase in viscosity. The results of deformability and fiber dispersion demonstrate that fiber dispersion coefficient is a comprehensive index which can reflect the performance of deformability as well as uniformity. And the desirable fresh mixture can be achieved by optimizing the viscosity of cement paste. At last, the ductile strain-hardening performance of the ECC prepared with HPMC or ACPAM was investigated through uniaxial tensile test.展开更多
Statistical properties of the erbium-doped random fiber laser(ERFL)play an important role in studying its physical attributes and advancing profound applications.Thus,there is an obvious need for thorough characteriza...Statistical properties of the erbium-doped random fiber laser(ERFL)play an important role in studying its physical attributes and advancing profound applications.Thus,there is an obvious need for thorough characterization and effective tailoring.Here,we investigate the full-bandwidth time-domain statistical properties of ERFL and achieve its tailoring through the aspect of fiber dispersion.Particularly,a narrowband ERFL is delicately designed to guarantee full-bandwidth measurement.The intensity probability density function(PDF)employed to analyze time-domain characteristics exhibits an inward deviation from the exponential distribution,indicating that correlations exist among different wavelength components.Furthermore,the effect of fiber dispersion on the temporal characteristics of ERFL is explored.The results demonstrate that dispersion accumulation breaks correlations among wavelength components,making its time-domain characteristics closer to the amplified spontaneous emission source.Conversely,dispersion compensation makes the PDF distribution converge further,leading to a more stable temporal output compared to the ERFL seed source.This work reveals the intrinsic time-domain dynamics of ERFL and provides new insights into tailoring demand-oriented temporal characteristics.展开更多
A novel microstructure fiber （MF） structure is proposed for broadband dispersion compensation. Through manipulating the four air-hole parameters and the pitch, the broad band dispersion compensation MF can be effici...A novel microstructure fiber （MF） structure is proposed for broadband dispersion compensation. Through manipulating the four air-hole parameters and the pitch, the broad band dispersion compensation MF can be efficiently designed. The newly designed MF could compensate （to within 0.8%） the dispersion of 101 times of its length of standard single mode fiber over the entire 100-nm band centered on 1550 nm. The proposed design has been simulated through the finite difference beam propagation method, and the corresponding design procedures are also presented. OCIS codes： 060.2310, 060.2280.展开更多
In this paper, we simulate the effect of Polarization Mode Dispersion( PMD ) on 40 Gb/s dispersion compensation transmission system by resolving the coupled nonlinear Schrodinger equation, and calculate the perf...In this paper, we simulate the effect of Polarization Mode Dispersion( PMD ) on 40 Gb/s dispersion compensation transmission system by resolving the coupled nonlinear Schrodinger equation, and calculate the performance of system with different duty cycle order and chirp of the super Gaussian pulse. The results show that the performance of the system changes with these parameters, and there is a group of optimum parameters for the optimum performance of the system.展开更多
The separation of Sm（III） through stripping dispersion hollow fiber liquid membrane system （SDHFLM） containing feed phase adding acetate buffer solution and dispersion solution with HC1 solution as the stripping s...The separation of Sm（III） through stripping dispersion hollow fiber liquid membrane system （SDHFLM） containing feed phase adding acetate buffer solution and dispersion solution with HC1 solution as the stripping solution and membrane solution of di（2-ethylhexyl） phosphoric acid （p204） dissolved in kerosene, has been studied. A set of factors were studied, including pH value, initial concentration of Sm（III） and different ionic strength of feed phase, volume ratio of membrane solution and stripping solution （O/W）, HC1 concentration, carrier concentration, different stripping agents of dispersion phase on Sm（III） separation. Experimental results indicate that the optimum separa- tion conditions of Sm（III） were obtained as that HC1 concentration was 4.00 tool/L, p204 concentration was 0.150 mol/L, and volume ratio of membrane solution and stripping solution （O/W） was 1.00 in the dispersion phase, and pH value was 4.60 in the feed phase. Ionic strength had no obvious effect on separation of Sm（III）. When initial Sm（III） concentration was 1.00 × 10^-4 mol/L, the separation rate of Sm（III） was up to 93.5% in 85 min. The kinetic equation was developed in terms of the law of mass diffusion and the theory of interface chemistry. The modeled results were in good agreement with the experiment data.展开更多
The group-delay dispersion of an optical fiber was measured with the time-of-flight method, using fingerprint-like characteristic spectra from a mode-locked fiber laser source. To determine the group-delay dispersion ...The group-delay dispersion of an optical fiber was measured with the time-of-flight method, using fingerprint-like characteristic spectra from a mode-locked fiber laser source. To determine the group-delay dispersion up to the fourth order, least-squares fitting was applied to the overall time waveform mapped on the time axis for the fingerprint-spectral broadband pulses through a long optical fiber. The analysis of all 4003 data points reduced statistical uncertainty, and provided second-, third-, and fourth-order dispersion with uncertainties of 0.02%, 0.4%, and 4%,respectively.展开更多
The properties of ultra-short dense dispersion-managed soliton (DBMS) in optical fiber links are investigated. They show some excellent characters, such as, reducing pulse's breathing extent greatly, facing fewer ...The properties of ultra-short dense dispersion-managed soliton (DBMS) in optical fiber links are investigated. They show some excellent characters, such as, reducing pulse's breathing extent greatly, facing fewer mutual interactions and tolerating larger local dispersion. In general, DBMS is more stable than a conventional dispersion-managed soliton in high-capacity systems. Excessively dense dispersion compensation is more suitable for systems with weak nonlinear effect.展开更多
基金the National Key R&D Program of China under Grants No.2017YFA0303704 and No.2018YFB2200400Natural Science Foundation of Beijing under Grant No.Z180012National Natural Science Foundation of China under Grants No.61875101 and No.91750206.
文摘Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which would be greatly affected by fiber dispersion.In this work,we establish a theoretical model of the entanglement-based DO-QKD system,considering the protocol,physical processes(such as fiber transmission and single-photon detection),and the analysis of security tests.Based on this theoretical model,we investigate the influence of chromatic dispersion introduced by transmission fibers on the performance of DO-QKD.By analyzing the benefits and costs of dispersion compensation,the system performance under G.652 and G.655 optical fibers are shown,respectively.The results show that dispersion compensation is unnecessary for DO-QKD systems in campus networks and even metro networks.Whereas,it is still required in DO-QKD systems with longer fiber transmission distances.
基金supported by the Fundamental Research Funds for the Central Universities (No.2024JBZY021)the National Natural Science Foundation of China (No.61575018)。
文摘Reverse design of highly GeO2-doped silica optical fibers with broadband and flat dispersion profiles is proposed using a neural network(NN) combined with a particle swarm optimization(PSO) algorithm.Firstly,the NN model designed to predict optical fiber dispersion is trained with an appropriate choice of hyperparameters,achieving a root mean square error(RMSE) of 9.47×10-7on the test dataset,with a determination coefficient(R2) of 0.999.Secondly,the NN is combined with the PSO algorithm for the inverse design of dispersion-flattened optical fibers.To expand the search space and avoid particles becoming trapped in local optimal solutions,the PSO algorithm incorporates adaptive inertia weight updating and a simulated annealing algorithm.Finally,by using a suitable fitness function,the designed fibers exhibit flat group velocity dispersion(GVD) profiles at 1 400—2 400 nm,where the GVD fluctuations and minimum absolute GVD values are below 18 ps·nm-1·km-1and 7 ps·nm-1·km-1,respectively.
基金the National Natural Science Foundation of China(No.52165018)the Jiangxi Key Laboratory of Forming and Joining Technology for Aerospace Component,China(No.EL202303270)the Jiangxi Provincial Department of Science and Technology,China(No.20225BCJ22002)
文摘This paper examines the longitudinal tensile behavior and failure mechanism of a new unidirectional carbon fiber reinforced aluminum composite through experiments and simulations.A Weibull distribution model was established to describe the fiber strength dispersion based on single-fiber tensile tests for carbon fibers extracted from the composite.The constitutive models for the matrix and interface were established based on the uniaxial tensile and single-fiber push-out tests,respectively.Then,a 3D micromechanical numerical model,innovatively considering the fiber strength dispersion by use of the weakest link and Weibull distribution theories,was estab-lished to simulate the progressive failure behavior of the composite under longitudinal tension.Due to the dispersion of fiber strength,the weakest link of the fiber first fractures,and stress concentra-tion occurs in the surrounding fibers,interfaces,and matrix.The maximum stress concentration fac-tor for neighboring fibers varies nonlinearly with the distance from the fractured fiber.Both isolated and clustered fractured fibers are present during the progressive failure process of the composite.The expansion of fractured fiber clusters intensifies stress concentration and material degradation which in turn enlarges the fractured fiber clusters,and their mutual action leads to the final collapse of the composite.
文摘The dispersion properties in the short wavelength region of total internal reflective photonic crystal fiber have been studied by using the models of the equivalent twin waveguide soliton coupling,effective refractive index,effective normalized frequency and dispersion management solitons.It is shown that the dispersion in the cladding waveguide of the total internal reflective photonic crystal fiber is a positive dispersion,and the dispersion of its core waveguide is a negative dispersion.The method of the compensated probing laser diffraction by the phase hole induced by the stationary pumping laser in the cladding waveguide enables the average dispersion value of the total internal reflective photonic crystal fiber to be close to zero and the zero dispersion point to shift to the short wavelength region.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61205064,51272202,and 61234006)the Visiting Scholar Funds of the Key Laboratory of Optoelectronic Technology and Systems of Chongqing University(Grant No.0902011812401 5)
文摘Periodic solitons are studied in dispersion decreasing fibers with a cosine profile. The variable-coefficient nonlinear Schrrdinger equation, which can be used to describe the propagation of solitons, is investigated analytically. Analytic soli- ton solutions for this equation are derived with the Hirota＇s bilinear method. Using the soliton solutions, we obtain periodic solitons, and analyze the soliton characteristics. Influences of physical parameters on periodic solitons are discussed. The presented results can be used in optical communication systems and fiber lasers.
基金financially supported by the National Natural Science Foundation of China for Young Scientists(Nos. 51109197 and 51009126)the Action Plan for the Development of Western China of the Chinese Academy of Sciences (No.KZCX2-XB2-13)+1 种基金the Knowledge Innovation Program of the Chinese Academy of Sciences(No.KSCX2-YW-N -003)Research Fund for Excellent Doctoral Thesis of Xi'an University of Technology(Nos.602-210805 and 602-210804)
文摘Stripping dispersion hollow fiber liquid membrane system（SDHFLM） containing feed phase adding acetate buffer solution and dispersion solution with HNO_3 solution as the stripping solution and membrane solution of 2-ethyl hexyl phosphoric acid-mono-2-ethylhexyl ester（PC-88A） dissolved in kerosene,has been studied for the extraction of Sm^（3＋）.Many factors including pH value, volume ratio of membrane solution to stripping solution（OAV） and carrier concentration on Sm^（3＋） extraction were investigated. Experimental results indicate that the optimum extraction conditions of Sm^（3＋） were obtained as that PC-88A concentration was 0.120 mol/L,and OAV was 1.00 in the dispersion phase,and pH value was 4.80 in the feed phase.When initial Sm^（3＋） concentration was 1.20×10^（-4） mol/L,the extraction percentage of Sm^（3＋） was up to 92.8%in 160 min.
基金Project supported by the National Natural Science Foundation of China(Grant No.11475135)the Fund from Shaanxi Province Science Association of Colleges and Universities(Grant No.20160216)Guangxi Provincial Education Department Research Project,China(Grant No.2017KY0776)
文摘We study localized waves on continuous wave background in an exponential dispersion decreasing fiber with two orthogonal polarization states. We demonstrate that asymmetric W-shaped and M-shaped soliton pulse can be generated from a weak modulation on continuous wave background. The numerical simulation results indicate that the generated asymmetric soliton pulses are robust against small noise or perturbation. In particular, the asymmetric degree of the asymmetric soliton pulse can be effectively controlled by changing the relative frequency of the two components. This character can be used to generate other nonlinear localized waves, such as dark-antidark and antidark-dark soliton pulse pair, symmetric W-shaped and M-shaped soliton pulse. Furthermore, we find that the asymmetric soliton pulse possesses an asymmetric discontinuous spectrum.
基金Project supported by the National Natural Science Foundations of China (Grant No. 11005092)the Program for Innovative Research Team of Young Teachers (Grant No. 2009RC01)the Scientific Research and Developed Fund of Zhejiang Agricultural and Forestry University (Grant No. 2009FK42).
文摘We derive analytical bright and dark solitons of the modified nonlinear Schroedinger equations with variable coefficients. Under constraint conditions between system parameters, the optical soliton transmission in the dispersiondecreasing fibers can be exactly controlled by proper dispersion management. The analytical description of the interactions between the bright and dark solitons are first obtained.
文摘Time domain ABCD matrix formalism is a useful model for analyzing the characteristics of actively modelocked fiber laser. Based on this model and given more consideration on the influences of optical fiber dispersion and optical fiber nonlinearity, the laser characteristic of actively modelocked fiber laser is analyzed, and the comparision of the theoretical analysis results with experimental ones is given.
文摘Degradable industrial packaging foam trays made from cellulose fibers were fabricated using a hot-press baking process.Bleached softwood pulp fibers with a concentration of 30%were dispersed at a high speed under the action of a dispersant.The effects of the dispersant dosage of the fibers on the porosity,foam density,and static compression characteristics were discussed.Furthermore,the effects of the reinforcing adhesive including polyvinyl alcohol(PVA),and cassava starch on the physical and mechanical properties of the foam trays were studied,as well as the relationship between these properties and the microstructure of the foam trays.The dispersant enhanced the rheological and blistering properties of the fiber dispersion.As the dispersant dosage increased from 2%to 4%,the foam density gradually increased and the compressive strain performance and residual compressive strain of the foam trays decreased.Under the condition of constant dosage of dispersant,increasing the fiber proportion from 67%to 77%improved the porosity and foam density and slightly reduced the static compression performance.In additioton,the static compression resistance of the foamed materials was improved by increasing the PVA dosage since PVA was beneficial for improving the strength of the foam trays.
基金supported by the Research Fund of Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology(No.2020B1212030010)。
文摘This paper demonstrated the generation of multi-wavelength bound state noise-like pulse(BNLP)in a dispersion-managed composite-filtered fiber laser consisting of nonlinear polarization rotation(NPR)and loop.In the case of BNLP,the generation is caused by the interaction between two noise-like pulses(NLPs)induced by the comb-filtering effect,and bound state level can be artificially controlled in the researches.Our work provides a new method for generating low-coherence pulses and establishes a research idea for the study of the comb-filtering effects.
文摘In this paper,an efficient 8-channel 32Gbps RoF(Radio over Fiber)system incorporating Bessel Filter(8/32 RoFBF)has been demonstrated to reduce the impact of non-linear transmission effects,specifically Four-Wave Mixing(FWM).The simulation results indicate that the proposed 8/32 RoF-BF system provides an optimum result w.r.t.channel spacing(75 GHz),input source power(0 dBm)and number of input channels(8).In comparison with the existing RoF system,the proposed 8/32 RoF-BF system has been validated analytically and it is found that the performance of the proposed system is in close proximity particularly in FWM sideband power reduction of the order of 4 dBm for the 8-channel 32Gbps RoF system.
文摘The combination of Radio Frequency and Optical Fiber has resulted high capacity transmission at lower costs components and makes Radio over Fiber as a current trend of large broadband communication. In Fiber optics field, the use of Fiber Bragg Grating (FBG) was been proposed in recent research with different purpose of uses. However, the compensation of dispersion method of Fiber Bragg Grating (FBG) can boost significantly the system performance. This paper investigates the performance capacity improvement of adaptive Radio over Fiber system. The system design was performed using OptiSystem 7.0 software, which 10 Gb/s Non Return to Zero (NRZ) signal was launched into 50 Km Universal Mode Fiber and Fiber Bragg Grating was used as a compensator of dispersion before frequency up conversion. Therefore, the system performances were investigated by comparing the Bit Error Rate (BER) and Q-factors of Positive Intrinsic Negative (PIN) and Ultrafast Avalanche Photodiode (APD) as optical receivers. The Eye diagram analyzer showed acceptable improvement due to use of Fiber Bragg Grating as a compensator of dispersion.
基金Funded by the National Natural Science Foundation of China(No.50978031)the Special Fund for Basic Scientific Research of Central Colleges(Chang'an University,No.CHD2011TD003,CHD2011ZY002,CHD2011JC018)
文摘Hydroxypropyl methylcellulose （HPMC） and amphoteric polyacrylamide （ACPAM） were respectively used to prepare engineered cementitious composite （ECC） which exhibits strain-hardening behavior under uniaxial tension. The connections between cement paste structure and the performance of the composite in fresh and hardened state were investigated, aiming at achieving the desirable workability at a given solids concentration. The experimental results of viscosity and miCrostructure of cement pastes show that the intimate connections between flocculation groups lead to the growing increase in viscosity. The results of deformability and fiber dispersion demonstrate that fiber dispersion coefficient is a comprehensive index which can reflect the performance of deformability as well as uniformity. And the desirable fresh mixture can be achieved by optimizing the viscosity of cement paste. At last, the ductile strain-hardening performance of the ECC prepared with HPMC or ACPAM was investigated through uniaxial tensile test.
基金supported by the National Natural Science Foundation of China(No.62075030)the Ministry of Science and Technology(No.DL2023167001L)+1 种基金the Sichuan Science and Technology Program(No.2023YFSY0058)the 111 Project(No.B14039)。
文摘Statistical properties of the erbium-doped random fiber laser(ERFL)play an important role in studying its physical attributes and advancing profound applications.Thus,there is an obvious need for thorough characterization and effective tailoring.Here,we investigate the full-bandwidth time-domain statistical properties of ERFL and achieve its tailoring through the aspect of fiber dispersion.Particularly,a narrowband ERFL is delicately designed to guarantee full-bandwidth measurement.The intensity probability density function(PDF)employed to analyze time-domain characteristics exhibits an inward deviation from the exponential distribution,indicating that correlations exist among different wavelength components.Furthermore,the effect of fiber dispersion on the temporal characteristics of ERFL is explored.The results demonstrate that dispersion accumulation breaks correlations among wavelength components,making its time-domain characteristics closer to the amplified spontaneous emission source.Conversely,dispersion compensation makes the PDF distribution converge further,leading to a more stable temporal output compared to the ERFL seed source.This work reveals the intrinsic time-domain dynamics of ERFL and provides new insights into tailoring demand-oriented temporal characteristics.
基金This work was supported by the National Basic Research Program of China (No. 2003CB314900) the Key Grant Project of Chinese Ministry of Education (No. 104046)
文摘A novel microstructure fiber （MF） structure is proposed for broadband dispersion compensation. Through manipulating the four air-hole parameters and the pitch, the broad band dispersion compensation MF can be efficiently designed. The newly designed MF could compensate （to within 0.8%） the dispersion of 101 times of its length of standard single mode fiber over the entire 100-nm band centered on 1550 nm. The proposed design has been simulated through the finite difference beam propagation method, and the corresponding design procedures are also presented. OCIS codes： 060.2310, 060.2280.
文摘In this paper, we simulate the effect of Polarization Mode Dispersion( PMD ) on 40 Gb/s dispersion compensation transmission system by resolving the coupled nonlinear Schrodinger equation, and calculate the performance of system with different duty cycle order and chirp of the super Gaussian pulse. The results show that the performance of the system changes with these parameters, and there is a group of optimum parameters for the optimum performance of the system.
基金Project supported by the National Natural Science Foundation of China （or Young Scientists （Nos. 41001131 and 51009126）, the Action Plan for the Development of Western China of the Chinese Academy of Sciences （No. KZCX2-XB2-13）, the Knowledge Innovation Program of the Chinese Academy of Sciences （No. KSCX2-YW-N-003） and Research Fund for Excellent Doctoral Thesis of Xi＇an University of Technology （Nos. 602-210805 and 602-210804）.
文摘The separation of Sm（III） through stripping dispersion hollow fiber liquid membrane system （SDHFLM） containing feed phase adding acetate buffer solution and dispersion solution with HC1 solution as the stripping solution and membrane solution of di（2-ethylhexyl） phosphoric acid （p204） dissolved in kerosene, has been studied. A set of factors were studied, including pH value, initial concentration of Sm（III） and different ionic strength of feed phase, volume ratio of membrane solution and stripping solution （O/W）, HC1 concentration, carrier concentration, different stripping agents of dispersion phase on Sm（III） separation. Experimental results indicate that the optimum separa- tion conditions of Sm（III） were obtained as that HC1 concentration was 4.00 tool/L, p204 concentration was 0.150 mol/L, and volume ratio of membrane solution and stripping solution （O/W） was 1.00 in the dispersion phase, and pH value was 4.60 in the feed phase. Ionic strength had no obvious effect on separation of Sm（III）. When initial Sm（III） concentration was 1.00 × 10^-4 mol/L, the separation rate of Sm（III） was up to 93.5% in 85 min. The kinetic equation was developed in terms of the law of mass diffusion and the theory of interface chemistry. The modeled results were in good agreement with the experiment data.
基金partly supported by KAKENHI No. 15H03968 and No. 26610081 from JSPS, the Photon Frontier Network Program of MEXT, JST-SENTAN, and JST-CREST in Japanthe European Regional Development Fund+1 种基金the European Social Fundthe state budget of the Czech Republic (project HiLASE: CZ.1.05/2.1.00/01.0027, project Postdok: CZ.1.07/2.3.00/30.0057)
文摘The group-delay dispersion of an optical fiber was measured with the time-of-flight method, using fingerprint-like characteristic spectra from a mode-locked fiber laser source. To determine the group-delay dispersion up to the fourth order, least-squares fitting was applied to the overall time waveform mapped on the time axis for the fingerprint-spectral broadband pulses through a long optical fiber. The analysis of all 4003 data points reduced statistical uncertainty, and provided second-, third-, and fourth-order dispersion with uncertainties of 0.02%, 0.4%, and 4%,respectively.
基金This work was partly supported by the Doctoral Research Fund of Shanxi University and the Youth Science Fund of Shanxi Province.
文摘The properties of ultra-short dense dispersion-managed soliton (DBMS) in optical fiber links are investigated. They show some excellent characters, such as, reducing pulse's breathing extent greatly, facing fewer mutual interactions and tolerating larger local dispersion. In general, DBMS is more stable than a conventional dispersion-managed soliton in high-capacity systems. Excessively dense dispersion compensation is more suitable for systems with weak nonlinear effect.
