A series of end-capped triply branched dendritic chromophores have been studied by means of density functional theory calculations. It is found that the second order nonlinear optical properties of the end-capped dend...A series of end-capped triply branched dendritic chromophores have been studied by means of density functional theory calculations. It is found that the second order nonlinear optical properties of the end-capped dendrimers are strongly dependent on the mutual orientations of the three chromophores, numbers of caps and the conjugation length of the ehromophores. Large enhancement of the first hyperpolarizability can be obtained when dipole moments of three branches in the dendrimers are highly parallelized.展开更多
Two-photon resonant nondegenerate four-wave mixing （NFWM） with the addition of a coupling field in Ba atomic vapour has been studied. We find that coherence of the atomic level transitions leads to suppression of th...Two-photon resonant nondegenerate four-wave mixing （NFWM） with the addition of a coupling field in Ba atomic vapour has been studied. We find that coherence of the atomic level transitions leads to suppression of the NFWM signal, giving rise to a dip with a linewidth that is linearly proportional to the intensity of the coupling field.展开更多
A novel second-order nonlinear optical chromophore （DCDHF-2-V） was synthesized from 3-Hydroxy-3-methyl-2-butanae, propanedinitrile and 4-diethylaminobenzaldehyde by aldol condensation reaction. Molecular structural ...A novel second-order nonlinear optical chromophore （DCDHF-2-V） was synthesized from 3-Hydroxy-3-methyl-2-butanae, propanedinitrile and 4-diethylaminobenzaldehyde by aldol condensation reaction. Molecular structural characterization was investigated by elemental analysis, FTIR, and 1H-NMR spectra. The melting point obtained from DSC thermogram was almost 251 ℃, and the compound shows a thermal stability up to 270 ℃. Second-order NLO properties of the chromophore were measured by solvatochromic method. From the quantum-mechanical two-level model, it can be obtained that the μgβ value of DCDHF-2-V is 6520×10^-48esu atthe wavelength of 1064 nm.展开更多
THz wave generated by difference-frequency in nonlinear crystal in normal temperature is theoretically studied. The conclifton of phase matching is deduced and an experimental setup is proposed. With this method, THz ...THz wave generated by difference-frequency in nonlinear crystal in normal temperature is theoretically studied. The conclifton of phase matching is deduced and an experimental setup is proposed. With this method, THz wave can be generated without rigorous condition and can work continuously for a long period of time in room temperature.展开更多
The nonlinear optical （NLO） active chromophore was prepared bv a bridging agent, glyeidyl ether （ AGE）, to connect disperse orange 3 （ DO3 ） and （ γ-Methaerylpropyl）-silsesquioxane （MP-SSO）. A freeradical p...The nonlinear optical （NLO） active chromophore was prepared bv a bridging agent, glyeidyl ether （ AGE）, to connect disperse orange 3 （ DO3 ） and （ γ-Methaerylpropyl）-silsesquioxane （MP-SSO）. A freeradical polymerization was performed to fabricate the methacrylate/Silica hybrid NLO films. Different amounts （ 5-25 wt% ） of （γ-methacrylpropyl） -polyhedral oligomeric silsesquioxanes （POSS） were added as the modifier to improve the degree of cross-linking, density and structure of the NLO matrix. As a result, the modified material properties including coating transmittance, glass transition temperature （ Tg ） , absoption spectra before and after poling, Marker stripes, etc. were presented. The hybrid film containing 15 wt% POSS exhibits the highest T, nonresonant second-order nonlinearity （d33 = 92 pro/V） and temporal stability among the others.展开更多
Diffraction limited electron storage ring is considered a promising candidate for future light sources,whose main characteristics are higher brilliance,better transverse coherence and better stability.The challenge of...Diffraction limited electron storage ring is considered a promising candidate for future light sources,whose main characteristics are higher brilliance,better transverse coherence and better stability.The challenge of diffraction limited storage ring design is how to achieve the ultra low beam emittance with acceptable nonlinear performance.Effective linear and nonlinear parameter optimization methods based on Artificial Intelligence were developed for the storage ring physical design.As an example of application,partial physical design of HALS(Hefei Advanced Light Source),which is a diffraction limited VUV and soft X-ray light source,was introduced.Severe emittance growth due to the Intra Beam Scattering effect,which is the main obstacle to achieve ultra low emittance,was estimated quantitatively and possible cures were discussed.It is inspiring that better performance of diffraction limited storage ring can be achieved in principle with careful parameter optimization.展开更多
基金We thank Prof. Yi Luo, Jiirgen Heck, and Hans- Georg Kuball for constructive suggestions. This work was supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry and the Natural Science Foundation of Shandong Province, China （No.Q2008A06）.
文摘A series of end-capped triply branched dendritic chromophores have been studied by means of density functional theory calculations. It is found that the second order nonlinear optical properties of the end-capped dendrimers are strongly dependent on the mutual orientations of the three chromophores, numbers of caps and the conjugation length of the ehromophores. Large enhancement of the first hyperpolarizability can be obtained when dipole moments of three branches in the dendrimers are highly parallelized.
基金Project supported by the National Natural Science foundation of China （Grant Nos 10174096 and 10374113） and the National Program for Basic Research in China （Grant No 001CB309301）.
文摘Two-photon resonant nondegenerate four-wave mixing （NFWM） with the addition of a coupling field in Ba atomic vapour has been studied. We find that coherence of the atomic level transitions leads to suppression of the NFWM signal, giving rise to a dip with a linewidth that is linearly proportional to the intensity of the coupling field.
文摘A novel second-order nonlinear optical chromophore （DCDHF-2-V） was synthesized from 3-Hydroxy-3-methyl-2-butanae, propanedinitrile and 4-diethylaminobenzaldehyde by aldol condensation reaction. Molecular structural characterization was investigated by elemental analysis, FTIR, and 1H-NMR spectra. The melting point obtained from DSC thermogram was almost 251 ℃, and the compound shows a thermal stability up to 270 ℃. Second-order NLO properties of the chromophore were measured by solvatochromic method. From the quantum-mechanical two-level model, it can be obtained that the μgβ value of DCDHF-2-V is 6520×10^-48esu atthe wavelength of 1064 nm.
基金supported by Anhui province Science Foundation(Grant No.2006KJ056B)Science Foundation for youthfulTeachers of Anhui University (Grant No.2006JQ-1036ZD)
文摘THz wave generated by difference-frequency in nonlinear crystal in normal temperature is theoretically studied. The conclifton of phase matching is deduced and an experimental setup is proposed. With this method, THz wave can be generated without rigorous condition and can work continuously for a long period of time in room temperature.
基金Sponsored by the Department of Science and Technology, the Government of Heilongjiang Province (Grant No.ZJG0506-02 and GB04A204).
文摘The nonlinear optical （NLO） active chromophore was prepared bv a bridging agent, glyeidyl ether （ AGE）, to connect disperse orange 3 （ DO3 ） and （ γ-Methaerylpropyl）-silsesquioxane （MP-SSO）. A freeradical polymerization was performed to fabricate the methacrylate/Silica hybrid NLO films. Different amounts （ 5-25 wt% ） of （γ-methacrylpropyl） -polyhedral oligomeric silsesquioxanes （POSS） were added as the modifier to improve the degree of cross-linking, density and structure of the NLO matrix. As a result, the modified material properties including coating transmittance, glass transition temperature （ Tg ） , absoption spectra before and after poling, Marker stripes, etc. were presented. The hybrid film containing 15 wt% POSS exhibits the highest T, nonresonant second-order nonlinearity （d33 = 92 pro/V） and temporal stability among the others.
文摘Diffraction limited electron storage ring is considered a promising candidate for future light sources,whose main characteristics are higher brilliance,better transverse coherence and better stability.The challenge of diffraction limited storage ring design is how to achieve the ultra low beam emittance with acceptable nonlinear performance.Effective linear and nonlinear parameter optimization methods based on Artificial Intelligence were developed for the storage ring physical design.As an example of application,partial physical design of HALS(Hefei Advanced Light Source),which is a diffraction limited VUV and soft X-ray light source,was introduced.Severe emittance growth due to the Intra Beam Scattering effect,which is the main obstacle to achieve ultra low emittance,was estimated quantitatively and possible cures were discussed.It is inspiring that better performance of diffraction limited storage ring can be achieved in principle with careful parameter optimization.
