The transports of the dynamic biochemical signals in the non-reversing pulsatile flows in the mixing microchannel of a Y-shaped microfluidic device are ana- lyzed. The results show that the mixing micro-channel acts a...The transports of the dynamic biochemical signals in the non-reversing pulsatile flows in the mixing microchannel of a Y-shaped microfluidic device are ana- lyzed. The results show that the mixing micro-channel acts as a low-pass filter, and the biochemical signals are nonlinearly modulated by the pulsatile flows, which depend on the biochemical signal frequency, the flow signal frequency, and the biochemical signal transporting distance. It is concluded that, the transfer characteristics of the dynamic biochemical signals, which are transported in the time-varying flows, should be carefully considered for better loading biochemical signals on the cells cultured on the bottom of the microfluidic channel.展开更多
From Maxwell's equations and Post's formalism, a generalized chiral nonlinear Schr6dinger equation (CNLSE) is obtained for the nonlinear chiral fiber. This equation governs light transmission through a dispersive ...From Maxwell's equations and Post's formalism, a generalized chiral nonlinear Schr6dinger equation (CNLSE) is obtained for the nonlinear chiral fiber. This equation governs light transmission through a dispersive nonlinear chiral fiber with joint action of chirality in linear and nonlinear ways. The generalized CNLSE shows a modu- lation of chirality to the effect of attenuation and nonlinearity compared with the case for a conventional fiber. Simulations based on the split-step beam propagation method reveal the role of nonlinearity with cooperation to chirality playing in the pulse evolution. By adjusting its strength the role of chirality in forming solitons is demonstrated for a given circularly polarized component. The application of nonlinear optical rotation is also discussed in an all-optical switch.展开更多
We construct various novel exact solutions of two coupled dynamical nonlinear Schrōdinger equations. Based on the similarity transformation, we reduce the coupled nonlinear Schrōdinger equations with time-and space-...We construct various novel exact solutions of two coupled dynamical nonlinear Schrōdinger equations. Based on the similarity transformation, we reduce the coupled nonlinear Schrōdinger equations with time-and space-dependent potentials, nonlinearities, and gain or loss to the coupled dynamical nonlinear Schrrdinger equations. Some special types of non-travelling wave solutions, such as periodic, resonant, and quasiperiodically oscillating solitons, are used to exhibit the wave propagations by choosing some arbitrary functions. Our results show that the number of the localized wave of one component is always twice that of the other one. In addition, the stability analysis of the solutions is discussed numerically.展开更多
We present numerical studies on the switching characteristics of a fiber Bragg grating (FBG) with modulation in the third order nonlinear index of refraction along it’s length. The FBG is operating in a continuous wa...We present numerical studies on the switching characteristics of a fiber Bragg grating (FBG) with modulation in the third order nonlinear index of refraction along it’s length. The FBG is operating in a continuous wave regime (CW). This study was done taking into account the possible asymmetry brought by the non harmonic modulation of the nonlinearity, leading to different reflection and transmission characteristics, that depend on the direction of propagation along the modulated nonlinear FBG. This phenomenon may be useful for applications like an optical isolator. It was found that for a set of values of the modulation parameter, the FBG can exhibit multistable states. The numerical studies were obtained starting from the coupled-mode equations solved from the coupled-mode theory and simulated using the fourth-order Runge-Kutta method.展开更多
Optical transmission technologies have gone through several generations of development.Spectral efficiency has significant ly improved,and industry has begun to search for an answer to a basic question:What are the f...Optical transmission technologies have gone through several generations of development.Spectral efficiency has significant ly improved,and industry has begun to search for an answer to a basic question:What are the fundamental linear and nonlin ear signal channel limitations of the Shannon theory when there is no compensation in an optical fiber transmission system?Next-generation technologies should exceed the 100G transmis sion capability of coherent systems in order to approach the Shannon limit.Spectral efficiency first needs to be improved be fore overall transmission capability can be improved.The means to improve spectral efficiency include more complex modulation formats and channel encoding/decoding algorithms,prefiltering with multisymbol detection,optical OFDM and Ny quist WDM multicarrier technologies,and nonlinearity compen sation.With further optimization,these technologies will most likely be incorporated into beyond-100G optical transport sys tems to meet bandwidth demand.展开更多
Both the level of the high-frequency eddy kinetic energy(HF-EKE) and the energy-containing scale in the upstream Kuroshio Extension(KE) undergo a well-defined decadal modulation, which correlates well with the dec...Both the level of the high-frequency eddy kinetic energy(HF-EKE) and the energy-containing scale in the upstream Kuroshio Extension(KE) undergo a well-defined decadal modulation, which correlates well with the decadal KE path variability. The HF-EKE level and the energy-containing scales will increase with unstable KE path and decrease with stable KE path. Also the mesoscale eddies are a little meridionally elongated in the stable state, while they are much zonally elongated in the unstable state. The local baroclinic instability and the barotropic instability associated with the decadal modulation of HF-EKE have been investigated. The results show that the baroclinic instability is stronger in the stable state than that in the unstable state, with a shorter characteristic temporal scale and a larger characteristic spatial scale. Meanwhile, the regional-averaged barotropic conversion rate is larger in the unstable state than that in the stable state. The results also demonstrate that the baroclinic instability is not the dominant mechanism influencing the decadal modulation of the mesoscale eddy field, while the barotropic instability makes a positive contribution to the decadal modulation.展开更多
Saturable absorbers(SAs)covering wavelengths from near-infrared(NIR)to mid-infrared(MIR)band are required for mode-locking and Q-switching lasers in muti-band wavelengths.Here,broadband nonlinear optical property was ...Saturable absorbers(SAs)covering wavelengths from near-infrared(NIR)to mid-infrared(MIR)band are required for mode-locking and Q-switching lasers in muti-band wavelengths.Here,broadband nonlinear optical property was discovered in Cs_(x)WO_(3) nanorods(NRs),which as a novel non-stoichiometric SA for realizing ultrafast fiber lasers is first demonstrated.The Cs_(x)WO_(3) NRs based SA exhibited good mode-locking ability in three key wavelengths from NIR to MIR region,which is a key advantage over the most reported broadband SAs.The given Cs_(x)WO_(3) NRs showed a broadband optical absorption from 800 to 3,200 nm,and excellent SA properties at 1-μm,1.5-μm,and 2-μm optical bands.Employing such SA,the ultrashort pulse lasers with a pulse duration/repetition rate of 530 fs/37.42 MHz at 1,567 nm and 5.6 ps/41.50 MHz at 1,965 nm from Er-and Tm-doped fiber lasers(TDFL)were realized separately.In addition,a stable mode locked operation at 1,030 nm with a repetition rate of 48.80 MHz was also achieved from Yb-doped fiber laser(YDFL).This work not only offers a new and reliable broadband mode locker for ultrafast laser generation,but also broadens the application of Cs_(x)WO_(3) materials in the field of nonlinear fiber optics.展开更多
We propose a novel optical signal regeneration system based on wavelength converters by use of cross gain modulation in cascaded semiconductor optical amplifiers. The nonlinearity in optical input/output characteristi...We propose a novel optical signal regeneration system based on wavelength converters by use of cross gain modulation in cascaded semiconductor optical amplifiers. The nonlinearity in optical input/output characteristics and eye opening using NRZ signal were archived.展开更多
The electrical nonlinearity of silicon modulators based on reversed PN junctions was found to severely limit the linearity of the modulators.This effect,however,was inadvertently neglected in previous studies.Consider...The electrical nonlinearity of silicon modulators based on reversed PN junctions was found to severely limit the linearity of the modulators.This effect,however,was inadvertently neglected in previous studies.Considering the electrical nonlinearity in simulation,a 32.2 dB degradation in the CDR3(i.e.,the suppression ratio between the fundamental signal and intermodulation distortion)of the modulator was observed at a modulation speed of 12 GHz,and the spurious free dynamic range was simultaneously degraded by 17.4 dB.It was also found that the linearity of the silicon modulator could be improved by reducing the series resistance of the PN junction.The frequency dependence of the linearity due to the electrical nonlinearity was also investigated.展开更多
Nonlinear pulse compression has been demonstrated by cross-phase modulation in a dispersion-shifted fiber. The output is obtained from filtering of the broadened optical spectrum and a pulse width reduction from 61 to...Nonlinear pulse compression has been demonstrated by cross-phase modulation in a dispersion-shifted fiber. The output is obtained from filtering of the broadened optical spectrum and a pulse width reduction from 61 to 28 ps is achieved.展开更多
Plasmonic metasurfaces have recently attracted much attention because of their novel characteristics with respect to light polarization and wave front control on deep-subwavelength scales.The development of metasurfac...Plasmonic metasurfaces have recently attracted much attention because of their novel characteristics with respect to light polarization and wave front control on deep-subwavelength scales.The development of metasurfaces with reconfigurable optical responses is opening new opportunities in high-capacity communications,real-time holograms and adaptive optics.Such tunable devices have been developed in the mid-infrared spectral range and operated in light intensity modulation schemes.Here we present a novel optically reconfigurable hybrid metasurface that enables polarization tuning at optical frequencies.The functionality of tuning is realized by switching the coupling conditions between the plasmonic modes and the binary isomeric states of an ethyl red switching layer upon light stimulation.We achieved more than 20°nonlinear changes in the transmitted polarization azimuth using just 4 mW of switching light power.Such design schemes and principles could be easily applied to dynamically adjust the functionalities of other metasurfaces.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.11172060 and11672065)
文摘The transports of the dynamic biochemical signals in the non-reversing pulsatile flows in the mixing microchannel of a Y-shaped microfluidic device are ana- lyzed. The results show that the mixing micro-channel acts as a low-pass filter, and the biochemical signals are nonlinearly modulated by the pulsatile flows, which depend on the biochemical signal frequency, the flow signal frequency, and the biochemical signal transporting distance. It is concluded that, the transfer characteristics of the dynamic biochemical signals, which are transported in the time-varying flows, should be carefully considered for better loading biochemical signals on the cells cultured on the bottom of the microfluidic channel.
基金Supported by the National Natural Science Foundation of China under Grant No 60977032the Program for Innovation Research of Science of Harbin Institute of Technology(PIRS-HIT)under Grant No T201407
文摘From Maxwell's equations and Post's formalism, a generalized chiral nonlinear Schr6dinger equation (CNLSE) is obtained for the nonlinear chiral fiber. This equation governs light transmission through a dispersive nonlinear chiral fiber with joint action of chirality in linear and nonlinear ways. The generalized CNLSE shows a modu- lation of chirality to the effect of attenuation and nonlinearity compared with the case for a conventional fiber. Simulations based on the split-step beam propagation method reveal the role of nonlinearity with cooperation to chirality playing in the pulse evolution. By adjusting its strength the role of chirality in forming solitons is demonstrated for a given circularly polarized component. The application of nonlinear optical rotation is also discussed in an all-optical switch.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11275072,11075055,and 11271211)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120076110024)+3 种基金the Innovative Research Team Program of the National Natural Science Foundation of China(Grant No.61021004)the Shanghai Leading Academic Discipline Project,China(Grant No.B412)the National High Technology Research and Development Program of China(Grant No.2011AA010101)the Shanghai Knowledge Service Platform for Trustworthy Internet of Things,China(Grant No.ZF1213)
文摘We construct various novel exact solutions of two coupled dynamical nonlinear Schrōdinger equations. Based on the similarity transformation, we reduce the coupled nonlinear Schrōdinger equations with time-and space-dependent potentials, nonlinearities, and gain or loss to the coupled dynamical nonlinear Schrrdinger equations. Some special types of non-travelling wave solutions, such as periodic, resonant, and quasiperiodically oscillating solitons, are used to exhibit the wave propagations by choosing some arbitrary functions. Our results show that the number of the localized wave of one component is always twice that of the other one. In addition, the stability analysis of the solutions is discussed numerically.
基金Conselho Nacional de Desenvolvimento Cientifico e Tecnologico CNPq,CAPES and FUNCAP
文摘We present numerical studies on the switching characteristics of a fiber Bragg grating (FBG) with modulation in the third order nonlinear index of refraction along it’s length. The FBG is operating in a continuous wave regime (CW). This study was done taking into account the possible asymmetry brought by the non harmonic modulation of the nonlinearity, leading to different reflection and transmission characteristics, that depend on the direction of propagation along the modulated nonlinear FBG. This phenomenon may be useful for applications like an optical isolator. It was found that for a set of values of the modulation parameter, the FBG can exhibit multistable states. The numerical studies were obtained starting from the coupled-mode equations solved from the coupled-mode theory and simulated using the fourth-order Runge-Kutta method.
基金supported by National High-Tech Research and Development Program of China under Grant No.2013AA010501
文摘Optical transmission technologies have gone through several generations of development.Spectral efficiency has significant ly improved,and industry has begun to search for an answer to a basic question:What are the fundamental linear and nonlin ear signal channel limitations of the Shannon theory when there is no compensation in an optical fiber transmission system?Next-generation technologies should exceed the 100G transmis sion capability of coherent systems in order to approach the Shannon limit.Spectral efficiency first needs to be improved be fore overall transmission capability can be improved.The means to improve spectral efficiency include more complex modulation formats and channel encoding/decoding algorithms,prefiltering with multisymbol detection,optical OFDM and Ny quist WDM multicarrier technologies,and nonlinearity compen sation.With further optimization,these technologies will most likely be incorporated into beyond-100G optical transport sys tems to meet bandwidth demand.
基金The National Natural Science Foundation of China under contract No.41276026the Special Fund for Strategic Pilot Technology Chinese Academy of Sciences under contract No.XDA11020301the Joint Fund between Natural Science Foundation of China and Shandong Province under contract No.U1406401
文摘Both the level of the high-frequency eddy kinetic energy(HF-EKE) and the energy-containing scale in the upstream Kuroshio Extension(KE) undergo a well-defined decadal modulation, which correlates well with the decadal KE path variability. The HF-EKE level and the energy-containing scales will increase with unstable KE path and decrease with stable KE path. Also the mesoscale eddies are a little meridionally elongated in the stable state, while they are much zonally elongated in the unstable state. The local baroclinic instability and the barotropic instability associated with the decadal modulation of HF-EKE have been investigated. The results show that the baroclinic instability is stronger in the stable state than that in the unstable state, with a shorter characteristic temporal scale and a larger characteristic spatial scale. Meanwhile, the regional-averaged barotropic conversion rate is larger in the unstable state than that in the stable state. The results also demonstrate that the baroclinic instability is not the dominant mechanism influencing the decadal modulation of the mesoscale eddy field, while the barotropic instability makes a positive contribution to the decadal modulation.
基金This work was supported by the Specialized Fund for the Doctoral Research of Jilin Engineering Normal University under(No.BSKJ201920)the Science and Technology Research Project of Jilin Province's Education Department(No.JJKH20210175KJ)the Project of Science and Technology Plan of Jilin Province(No.YDZJ202101ZYTS178)。
文摘Saturable absorbers(SAs)covering wavelengths from near-infrared(NIR)to mid-infrared(MIR)band are required for mode-locking and Q-switching lasers in muti-band wavelengths.Here,broadband nonlinear optical property was discovered in Cs_(x)WO_(3) nanorods(NRs),which as a novel non-stoichiometric SA for realizing ultrafast fiber lasers is first demonstrated.The Cs_(x)WO_(3) NRs based SA exhibited good mode-locking ability in three key wavelengths from NIR to MIR region,which is a key advantage over the most reported broadband SAs.The given Cs_(x)WO_(3) NRs showed a broadband optical absorption from 800 to 3,200 nm,and excellent SA properties at 1-μm,1.5-μm,and 2-μm optical bands.Employing such SA,the ultrashort pulse lasers with a pulse duration/repetition rate of 530 fs/37.42 MHz at 1,567 nm and 5.6 ps/41.50 MHz at 1,965 nm from Er-and Tm-doped fiber lasers(TDFL)were realized separately.In addition,a stable mode locked operation at 1,030 nm with a repetition rate of 48.80 MHz was also achieved from Yb-doped fiber laser(YDFL).This work not only offers a new and reliable broadband mode locker for ultrafast laser generation,but also broadens the application of Cs_(x)WO_(3) materials in the field of nonlinear fiber optics.
文摘We propose a novel optical signal regeneration system based on wavelength converters by use of cross gain modulation in cascaded semiconductor optical amplifiers. The nonlinearity in optical input/output characteristics and eye opening using NRZ signal were archived.
基金National Natural Science Foundation of China(NSFC)(61575189,61635011)
文摘The electrical nonlinearity of silicon modulators based on reversed PN junctions was found to severely limit the linearity of the modulators.This effect,however,was inadvertently neglected in previous studies.Considering the electrical nonlinearity in simulation,a 32.2 dB degradation in the CDR3(i.e.,the suppression ratio between the fundamental signal and intermodulation distortion)of the modulator was observed at a modulation speed of 12 GHz,and the spurious free dynamic range was simultaneously degraded by 17.4 dB.It was also found that the linearity of the silicon modulator could be improved by reducing the series resistance of the PN junction.The frequency dependence of the linearity due to the electrical nonlinearity was also investigated.
文摘Nonlinear pulse compression has been demonstrated by cross-phase modulation in a dispersion-shifted fiber. The output is obtained from filtering of the broadened optical spectrum and a pulse width reduction from 61 to 28 ps is achieved.
基金the support from the National Basic Research Program of China(2013CB328702,2010CB934101)the National Natural Science Foundation of China(11304162,11374006)+4 种基金the 111 Project(B07013)PCSIRT(IRT_13R29)SRFDP(20130031120005)the Fundamental Research Funds for the Central Universitiesthe Collaborative Innovation Center of Extreme Optics.
文摘Plasmonic metasurfaces have recently attracted much attention because of their novel characteristics with respect to light polarization and wave front control on deep-subwavelength scales.The development of metasurfaces with reconfigurable optical responses is opening new opportunities in high-capacity communications,real-time holograms and adaptive optics.Such tunable devices have been developed in the mid-infrared spectral range and operated in light intensity modulation schemes.Here we present a novel optically reconfigurable hybrid metasurface that enables polarization tuning at optical frequencies.The functionality of tuning is realized by switching the coupling conditions between the plasmonic modes and the binary isomeric states of an ethyl red switching layer upon light stimulation.We achieved more than 20°nonlinear changes in the transmitted polarization azimuth using just 4 mW of switching light power.Such design schemes and principles could be easily applied to dynamically adjust the functionalities of other metasurfaces.