A series of squarylium cyanine dyes with different substituents were synthesized and the third-order optical nonlinearities of their ground and excited states were investigated by backward degenerate four-wave-mixing....A series of squarylium cyanine dyes with different substituents were synthesized and the third-order optical nonlinearities of their ground and excited states were investigated by backward degenerate four-wave-mixing.For the ground state,the molecular hyperpolarizabilityγg increases with the red-shift of the absorption peakλabmax,of the squaraine with different substituents,whereas for the excited-state molecular hyperpolarizabilityγe,the nonlinear enhancementγe/γg decreases,which may indicate that in the excited state the electron accepting-donating ability of different substituents changes in the reverse order compared with the order in the ground state.展开更多
The ground-and the excited-state nonlinearities of two new copolymers are investigated in nanosecond scale at 1064 nm.It is found that the excited-state susceptibility is dramatically larger than the corresponding gro...The ground-and the excited-state nonlinearities of two new copolymers are investigated in nanosecond scale at 1064 nm.It is found that the excited-state susceptibility is dramatically larger than the corresponding ground-state susceptibility for each sample.The experimental results also give evidence that superlattice structure of the copolymers can enhance,especially for the excited state,the molecular hyperpolarizabilities significantly.This enhancement may be attributed to the confinement effect of the pump-induced carriers.展开更多
We report the measured results of non-resonant nonlinearity by degenerate four-wave mixing for Cu2O nanopartides having central diameter of 9 nm.The value of x^(3) obtained in a 10ns pulse experiment is 8.48×1O^(...We report the measured results of non-resonant nonlinearity by degenerate four-wave mixing for Cu2O nanopartides having central diameter of 9 nm.The value of x^(3) obtained in a 10ns pulse experiment is 8.48×1O^(-10) esu,and the nonlinear response time of the sample is estimated to be in the order of nanosecond.展开更多
Photorefractivity properties of a polymer are investigated by four-wave mixing(FWM)diffraction measurements.The polymer is composed of photoconducting poly(n-vinylcarbazole),photosensitizing 2,4,7-trinitro-9-fluorenon...Photorefractivity properties of a polymer are investigated by four-wave mixing(FWM)diffraction measurements.The polymer is composed of photoconducting poly(n-vinylcarbazole),photosensitizing 2,4,7-trinitro-9-fluorenone,and optically nonlinear 4-(dicyanoviny1)-N.N-diethylaniline.Its FWM diffraction efficiency and response time as a function of,respectively,electric field and writing intensity have been determined.With a 80μm-think film,a diffraction efficiency of 7.4×10^(-4) has been obtained.The response time of the polymer is as short as 400ms at a writing intensity of 0.17W/cm^(2).展开更多
基金the National Natural Science Foundation of China under Grant Nos.19734040,and 69778014.
文摘A series of squarylium cyanine dyes with different substituents were synthesized and the third-order optical nonlinearities of their ground and excited states were investigated by backward degenerate four-wave-mixing.For the ground state,the molecular hyperpolarizabilityγg increases with the red-shift of the absorption peakλabmax,of the squaraine with different substituents,whereas for the excited-state molecular hyperpolarizabilityγe,the nonlinear enhancementγe/γg decreases,which may indicate that in the excited state the electron accepting-donating ability of different substituents changes in the reverse order compared with the order in the ground state.
基金Supported by the National Natural Science Foundation of China under Grant No.19734004。
文摘The ground-and the excited-state nonlinearities of two new copolymers are investigated in nanosecond scale at 1064 nm.It is found that the excited-state susceptibility is dramatically larger than the corresponding ground-state susceptibility for each sample.The experimental results also give evidence that superlattice structure of the copolymers can enhance,especially for the excited state,the molecular hyperpolarizabilities significantly.This enhancement may be attributed to the confinement effect of the pump-induced carriers.
文摘We report the measured results of non-resonant nonlinearity by degenerate four-wave mixing for Cu2O nanopartides having central diameter of 9 nm.The value of x^(3) obtained in a 10ns pulse experiment is 8.48×1O^(-10) esu,and the nonlinear response time of the sample is estimated to be in the order of nanosecond.
基金Supported by the National Natural Science Foundation of China。
文摘Photorefractivity properties of a polymer are investigated by four-wave mixing(FWM)diffraction measurements.The polymer is composed of photoconducting poly(n-vinylcarbazole),photosensitizing 2,4,7-trinitro-9-fluorenone,and optically nonlinear 4-(dicyanoviny1)-N.N-diethylaniline.Its FWM diffraction efficiency and response time as a function of,respectively,electric field and writing intensity have been determined.With a 80μm-think film,a diffraction efficiency of 7.4×10^(-4) has been obtained.The response time of the polymer is as short as 400ms at a writing intensity of 0.17W/cm^(2).
