Basing on the necessary condition for the trapping dielectric particle by the Gaussian beam, the Kerr effect in the tweezers with the nonlinear particle or the nonlinear medium is proposed to concern. The expressions ...Basing on the necessary condition for the trapping dielectric particle by the Gaussian beam, the Kerr effect in the tweezers with the nonlinear particle or the nonlinear medium is proposed to concern. The expressions of the optical forces concerned with the Kerr effect, which affects the refractive index of the medium, are presented. The distribution of the optical forces in the trapping region is simulated and discussed. The results show that the stability of the tweezers depends on the nonlinear coefficient of refractive index, and the optical tweezers could be broken down with a critical value of the nonlinear coefficient of refractive index of the surrounding medium, or with a critical value of the laser intensity, duration of laser pulse, and radius of beam waist. Moreover, these results give us the explanation the stability of the optical tweezers used for the trapped object as biological molecule embedded in the fluid, which is sensitive with Kerr effect.展开更多
Silver phenylacetylide oligomer was found to exhibit prominent third-order nonlinear optical property, with susceptibility chi((3)) of 2.4x10(-14) esu (10(-4) mol/L in 1:1 dimethyl sulfoxide/CHCl3 mixed solution) and ...Silver phenylacetylide oligomer was found to exhibit prominent third-order nonlinear optical property, with susceptibility chi((3)) of 2.4x10(-14) esu (10(-4) mol/L in 1:1 dimethyl sulfoxide/CHCl3 mixed solution) and second-order hyperpolarizability gamma of 5.18x10(-32) esu via heterodyned ultrafast optical Kerr effect measurement. It existed mainly as 1:1 complex oligomers and polymers as characterized by mass spectroscopy and elemental analysis etc.展开更多
With nanovoids buried in Co films, resonant structures were observed in spectra of polar magneto-optical Kerr effect（MOKE）, where both a narrow bandwidth and high intensity were acquired. Through changing the thickn...With nanovoids buried in Co films, resonant structures were observed in spectra of polar magneto-optical Kerr effect（MOKE）, where both a narrow bandwidth and high intensity were acquired. Through changing the thickness of Co films and the lattice of voids, different optical modes were introduced. For a very shallow array of voids, the resonant MOKE was induced by Ag plasma edge resonance, for deeper ones, hybrid plasma modes, such as void plasmons in the voids, surface lattice plasmons between the voids, and the co-action of them, etc. resulted in resonant MOKE. We found that resonant MOKE resulted from the void plasmons resonance which possesses the narrowest bandwidth for the lowest absorption of voids. The simulated electromagnetic field（EF） distribution consolidated different effects of these three optical modes on resonant MOKE modulation. Such resonant polar MOKE possesses high sensitivity, which might pave the way to on-chip MO devices.展开更多
For L10-FePt films with strong perpendicular anisotropy covered by arrays of hexagonal close-packed polystyrene spheres （PSSs）, fine structures are observed in magneto-optical Kerr rotation spectra in the visible sp...For L10-FePt films with strong perpendicular anisotropy covered by arrays of hexagonal close-packed polystyrene spheres （PSSs）, fine structures are observed in magneto-optical Kerr rotation spectra in the visible spectral range. The reflection minima are found to be located at the same wavelengths as the Kerr rotation peaks. The Kerr rotation enhancement is attributed to the excitation of both the surface plasmon polariton in the dielectric PSS/metal interface and the guide waves （guide mode） in the PSS array. The two-dimensional PSSs/SiO2/FePt system exhibiting a tunable magneto-optical Kerr effect and a high perpendicular magnetic anisotropy will be helpful for designing and fabricating magneto-optics devices.展开更多
Optical diode behavior of asymmetric one-dimensional photonic crystal with Kerr defect is numerically investigated using nonlinear transfer matrix method. In the linear case, the intensity and the phase of transmitted...Optical diode behavior of asymmetric one-dimensional photonic crystal with Kerr defect is numerically investigated using nonlinear transfer matrix method. In the linear case, the intensity and the phase of transmitted field are the same for the forward and backward operations. In the nonlinear case, however, the transmitted intensities are much different for the two operations, which display diode characteristic. Physical origin of the anisotropic transmission lies in the different localizations in the defect layer of the two operations.展开更多
The magnetization reversal process of Fe/MgO （001） thin film is investigated by combining transverse and longi- tudinal hysteresis loops. Owing to the competition between domain wall pinning energy and weak uniaxial...The magnetization reversal process of Fe/MgO （001） thin film is investigated by combining transverse and longi- tudinal hysteresis loops. Owing to the competition between domain wall pinning energy and weak uniaxial magnetic anisotropy, the typical magnetization reversal process of Fe ultrathin film can take place via either an ＂l-jump＂ process near the easy axis, or a ＂2-jump＂ process near the hard axis, depending on the applied field orientation. Besides, the hysteresis loop presents strong asymmetry resulting from the variation of the detected light intensity due to the quadratic magneto-optic effect. Furthermore, we modify the detectable light intensity formula and simulate the hysteresis loops of the Kerr signal. The results show that they are in good agreement with the experimental data.展开更多
We report the multi-component optical azimuthons of four-wave mixing （FWM） composed of several modulated vortex beams, the so-called azimuthons, in V-type three-level and two-level atomic systems. We analyze the for...We report the multi-component optical azimuthons of four-wave mixing （FWM） composed of several modulated vortex beams, the so-called azimuthons, in V-type three-level and two-level atomic systems. We analyze the formation mechanisms of the FWM azimuthons theoretically and experimentally. In addition, we illustrate the interactions between the co-propagating azimuthon components. Finally, we also compare the stabilities of azimuthons in V-type three-level and two-level atomic systems.展开更多
Ultrafine PbS particles with different sizes have been prepared in perfluorocarboxylated cation-exchanged films. The variation of PbS particle size was clarified by absorption spectra and TEM graphs. Time-resolved opt...Ultrafine PbS particles with different sizes have been prepared in perfluorocarboxylated cation-exchanged films. The variation of PbS particle size was clarified by absorption spectra and TEM graphs. Time-resolved optical Kerr effects were measured by femtosecond pump-probe techniques. Optical Kerr effect response time was estimated to be less than 165 fs. A third-order optical nonlinearity of χ(3)10-12 esu for PbS particles was obtained and it was found that it increases with the decrease of particle sizes, showing the influence of quantum confined effect on optical nonlinear behaviour of ultrafine particles.展开更多
We theoretically study the effect of Kerr effect on the second-order nonlinearity induced transparency in a double-resonant optical cavity system.We show that in the presence of the Kerr effect,as the strength of the ...We theoretically study the effect of Kerr effect on the second-order nonlinearity induced transparency in a double-resonant optical cavity system.We show that in the presence of the Kerr effect,as the strength of the Kerr effect increases,the absorption curve exhibits an asymmetric-symmetric-asymmetric transition,and the zero absorption point shifts with the increase of the Kerr effect.Furthermore,by changing the strength of the Kerr effect,we can control the width of the transparent window,and the position of the zero-absorption point and meanwhile change the left and right width of the absorption peak.The asymmetry absorption curve can be employed to improve the quality factor of the cavity when the frequency detuning is tuned to be around the right peak.The simple dependence of the zeroabsorption point on the strength of Kerr effect suggests that the strength of Kerr effect can be measured by measuring the position of the zero-absorption point in a possible application.展开更多
文摘Basing on the necessary condition for the trapping dielectric particle by the Gaussian beam, the Kerr effect in the tweezers with the nonlinear particle or the nonlinear medium is proposed to concern. The expressions of the optical forces concerned with the Kerr effect, which affects the refractive index of the medium, are presented. The distribution of the optical forces in the trapping region is simulated and discussed. The results show that the stability of the tweezers depends on the nonlinear coefficient of refractive index, and the optical tweezers could be broken down with a critical value of the nonlinear coefficient of refractive index of the surrounding medium, or with a critical value of the laser intensity, duration of laser pulse, and radius of beam waist. Moreover, these results give us the explanation the stability of the optical tweezers used for the trapped object as biological molecule embedded in the fluid, which is sensitive with Kerr effect.
文摘Silver phenylacetylide oligomer was found to exhibit prominent third-order nonlinear optical property, with susceptibility chi((3)) of 2.4x10(-14) esu (10(-4) mol/L in 1:1 dimethyl sulfoxide/CHCl3 mixed solution) and second-order hyperpolarizability gamma of 5.18x10(-32) esu via heterodyned ultrafast optical Kerr effect measurement. It existed mainly as 1:1 complex oligomers and polymers as characterized by mass spectroscopy and elemental analysis etc.
基金Project supported by the Natural Science Foundation of Shandong Province,China(Grant No.ZR2015AM024)the Doctoral Research Started Funding of Qufu Normal University,China(Grant No.BSQD20130152)
文摘With nanovoids buried in Co films, resonant structures were observed in spectra of polar magneto-optical Kerr effect（MOKE）, where both a narrow bandwidth and high intensity were acquired. Through changing the thickness of Co films and the lattice of voids, different optical modes were introduced. For a very shallow array of voids, the resonant MOKE was induced by Ag plasma edge resonance, for deeper ones, hybrid plasma modes, such as void plasmons in the voids, surface lattice plasmons between the voids, and the co-action of them, etc. resulted in resonant MOKE. We found that resonant MOKE resulted from the void plasmons resonance which possesses the narrowest bandwidth for the lowest absorption of voids. The simulated electromagnetic field（EF） distribution consolidated different effects of these three optical modes on resonant MOKE modulation. Such resonant polar MOKE possesses high sensitivity, which might pave the way to on-chip MO devices.
基金Project supported by the National Natural Science Foundation of China(Grant No.51171129)the Shanghai Committee of Science and Technology,China(Grant No.11JC1412700)
文摘For L10-FePt films with strong perpendicular anisotropy covered by arrays of hexagonal close-packed polystyrene spheres （PSSs）, fine structures are observed in magneto-optical Kerr rotation spectra in the visible spectral range. The reflection minima are found to be located at the same wavelengths as the Kerr rotation peaks. The Kerr rotation enhancement is attributed to the excitation of both the surface plasmon polariton in the dielectric PSS/metal interface and the guide waves （guide mode） in the PSS array. The two-dimensional PSSs/SiO2/FePt system exhibiting a tunable magneto-optical Kerr effect and a high perpendicular magnetic anisotropy will be helpful for designing and fabricating magneto-optics devices.
文摘Optical diode behavior of asymmetric one-dimensional photonic crystal with Kerr defect is numerically investigated using nonlinear transfer matrix method. In the linear case, the intensity and the phase of transmitted field are the same for the forward and backward operations. In the nonlinear case, however, the transmitted intensities are much different for the two operations, which display diode characteristic. Physical origin of the anisotropic transmission lies in the different localizations in the defect layer of the two operations.
基金supported by the National Natural Science Foundation of China(Grant Nos.11274033,11474015,and 61227902)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20131102130005)the Beijing Key Discipline Foundation of Condensed Matter Physics
文摘The magnetization reversal process of Fe/MgO （001） thin film is investigated by combining transverse and longi- tudinal hysteresis loops. Owing to the competition between domain wall pinning energy and weak uniaxial magnetic anisotropy, the typical magnetization reversal process of Fe ultrathin film can take place via either an ＂l-jump＂ process near the easy axis, or a ＂2-jump＂ process near the hard axis, depending on the applied field orientation. Besides, the hysteresis loop presents strong asymmetry resulting from the variation of the detected light intensity due to the quadratic magneto-optic effect. Furthermore, we modify the detectable light intensity formula and simulate the hysteresis loops of the Kerr signal. The results show that they are in good agreement with the experimental data.
基金Project supported by the National Basic Research Program of China(Grant No.2012CB921804)the National Natural Science Foundation of China(Grant Nos.61308015,11104214,61108017,11104216,and 61205112)+2 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant Nos.20110201110006 and 20110201120005)the Fundamental Research Funds for the Central Universities of Ministry of Education of China(Grant Nos.2012jdhz05,2011jdhz07,xjj2011083,xjj2011084,xjj2012080,and xjj2013089)China Postdoctoral Science Foundation(Grant No.2012M521773)
文摘We report the multi-component optical azimuthons of four-wave mixing （FWM） composed of several modulated vortex beams, the so-called azimuthons, in V-type three-level and two-level atomic systems. We analyze the formation mechanisms of the FWM azimuthons theoretically and experimentally. In addition, we illustrate the interactions between the co-propagating azimuthon components. Finally, we also compare the stabilities of azimuthons in V-type three-level and two-level atomic systems.
基金the High Technology Research and Development Programme of China and Academia Sinica.
文摘Ultrafine PbS particles with different sizes have been prepared in perfluorocarboxylated cation-exchanged films. The variation of PbS particle size was clarified by absorption spectra and TEM graphs. Time-resolved optical Kerr effects were measured by femtosecond pump-probe techniques. Optical Kerr effect response time was estimated to be less than 165 fs. A third-order optical nonlinearity of χ(3)10-12 esu for PbS particles was obtained and it was found that it increases with the decrease of particle sizes, showing the influence of quantum confined effect on optical nonlinear behaviour of ultrafine particles.
基金Supported by the Key Scientific Research Plan of Colleges and Universities in Henan Province(23B140006)the National Natural Science Foundation of China(11965017)。
文摘We theoretically study the effect of Kerr effect on the second-order nonlinearity induced transparency in a double-resonant optical cavity system.We show that in the presence of the Kerr effect,as the strength of the Kerr effect increases,the absorption curve exhibits an asymmetric-symmetric-asymmetric transition,and the zero absorption point shifts with the increase of the Kerr effect.Furthermore,by changing the strength of the Kerr effect,we can control the width of the transparent window,and the position of the zero-absorption point and meanwhile change the left and right width of the absorption peak.The asymmetry absorption curve can be employed to improve the quality factor of the cavity when the frequency detuning is tuned to be around the right peak.The simple dependence of the zeroabsorption point on the strength of Kerr effect suggests that the strength of Kerr effect can be measured by measuring the position of the zero-absorption point in a possible application.
