The third-order optical nonlinearities of [（CH3）4N]Au（dmit）2 （dmit = 4,5-dithiolate-1,3-dithiole-2-thione） at 532 nm and 1064 nm are investigated using the Z-scan technique with pulses of picoseconds duration. T...The third-order optical nonlinearities of [（CH3）4N]Au（dmit）2 （dmit = 4,5-dithiolate-1,3-dithiole-2-thione） at 532 nm and 1064 nm are investigated using the Z-scan technique with pulses of picoseconds duration. The Z-scan spectra reveal a strong nonlinear absorption （reverse saturable absorption） and a negative nonlinear refraction at 532 nm. No nonlinear absorption is observed at 1064 nm. The molecular second-order hyperpolarizability γ for the [（CH3）4N]Au（dmit）2 molecule at 532nm is estimated to be as high as （2.1 ±0.1） × 10^-31 esu, which is nearly three times larger than that at 1064 nm. The mechanism responsible for the difference between the results is analysed. Nonlinear transmission measurements suggest that this material has potential applications in optical limiting.展开更多
The nonlinear optical properties of a phosphate vitreous system [（ZnO）x-（MgO）30-x-（P2O5）70], where x=8, 10, 15, 18, and 20 mol% synthesized through the melt-quenching technique have been investigated by using th...The nonlinear optical properties of a phosphate vitreous system [（ZnO）x-（MgO）30-x-（P2O5）70], where x=8, 10, 15, 18, and 20 mol% synthesized through the melt-quenching technique have been investigated by using the Z-scan technique. In the experiment, a continuous-wave laser with a wavelength of 405 nm was utilized to determine the sign and value of the nonlinear refractive （NLR） index and the absorption coefficient with closed and opened apertures of the Z-scan setup. The NLR index was found to increase with the ZnO concentration in the glass samples by an order of 10-10 cm2·W-1. The real and imaginary parts of the third-order nonlinear susceptibility were calculated by referring to the NLR index （n2） and absorption coefficient （β） of the samples. The value of the third-order nonlinear susceptibility was presented by nonlinear refractive or absorptive behavior of phosphate glasses for proper utilization in nonlinear optical devices. Based on the measurement, the positive sign of the NLR index shows a self-focusing phenomenon. The figures of merit for each sample were calculated to judge the potential of phosphate glasses for application in optical switching.展开更多
Z-scan technique is an effective tool for measuring the optical nonlinearity of the materials. By using this technique the measurement was made for total protein and albumin. The nonlinear refractive index of the tota...Z-scan technique is an effective tool for measuring the optical nonlinearity of the materials. By using this technique the measurement was made for total protein and albumin. The nonlinear refractive index of the total protein and albumin were found to vary linearly with concentration. Hence by calculating the nonlinear refractive index it is possible to measure their concentration in the sample. The values measured thus are found in equivalence with conventional colorimetric method.展开更多
The third-order nonlinear optical properties of two dmit organometallic complexes, [(CH3)4N] [Au(C3S5)2] (MeAu) and [(CH3)4N][Ni(C3S5)2] (Me Ni) in acetone solutions, were characterized us- ing a short pulse Z-scan te...The third-order nonlinear optical properties of two dmit organometallic complexes, [(CH3)4N] [Au(C3S5)2] (MeAu) and [(CH3)4N][Ni(C3S5)2] (Me Ni) in acetone solutions, were characterized us- ing a short pulse Z-scan technique at 1064 nm wavelength. Self-defocusing effects were found in both samples and stronger saturable absorp-tion was observed in MeNi solution comparing with that of MeAu. The origins were analyzed for the differences between the results. Two figures of merit W and T were also calculated to evalu-ate the suitability of two materials for all-optical integrated devices. The results of W=22.84 and T≈0 of MeAu make it an excellent candidate for the all-optical applications.展开更多
In the present work, z-scan technique was used to study the nonlinear properties, represented by nonlinear refractive index and nonlinear absorption coefficient for Coumarin 450 (C450) doped PMMA as a function of conc...In the present work, z-scan technique was used to study the nonlinear properties, represented by nonlinear refractive index and nonlinear absorption coefficient for Coumarin 450 (C450) doped PMMA as a function of concentration for two different solvents. The results show change of the effect from self-focusing to self-defocusing in closed aperture z-can (or change of the effect from two photon absorption to saturable absorption in open aperture z-scan), when the sample dissolved in low viscosity and more polar展开更多
We report results from the investigation of the nonlinear refractive index and nonlinear absorption coefficient of {(1Z)-[4-(Dimethylamino)phenyl]methylene} 4-nitrobenzocarboxy hydrazone mono-hydrate (DMPM4NBCHM) solu...We report results from the investigation of the nonlinear refractive index and nonlinear absorption coefficient of {(1Z)-[4-(Dimethylamino)phenyl]methylene} 4-nitrobenzocarboxy hydrazone mono-hydrate (DMPM4NBCHM) solution using Z-scan technique with a continuous wave (CW) Argon ion laser. The results show that this type of organic material has a large nonlinear absorption and nonlinear refractive index at 488 nm and 514 nm. The origin of the nonlinear effects was discussed. We demonstrate that the light induced nonlinear refractive index variation, leads to limiting effect. The results indicated that DMPM4NBCHM could be promising candidates for application on nonlinear photonic devices and optical limiters.展开更多
An experimental study of the nonlinear changes in refractive index and transmission coefficient of single-crystal ZnSe:Fe2+, fabricated through the Fe-diffusion method, at long-pulse (~300 ns), sub-mJ, 2.94-mm Z-scan ...An experimental study of the nonlinear changes in refractive index and transmission coefficient of single-crystal ZnSe:Fe2+, fabricated through the Fe-diffusion method, at long-pulse (~300 ns), sub-mJ, 2.94-mm Z-scan probing is reported. As well, a theoretical model based on the generalized Avizonis-Grotbeck equations is developed and applied for straightforward fitting of the open- and closed-aperture Z-scans, obtained for ZnSe:Fe2+ with different Fe2+ centers concentrations. The modeling results reveal that the contributions in the absorption and refractive index nonlinearities of ZnSe:Fe2+ are “common” resonant-absorption saturation (the minor part) and pulse-induced heating of the samples (the major part), which are strongly dependent on Fe2+ concentrations. Large values of the index change (>~10-3) and partial resonant-absorption bleaching (limited by ~50%), both produced via the thermal effect mainly, are the features of the ZnSe:Fe2+ samples inherent to this type of excitation.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant Nos 60377016 and 60476020） and the National High Technology Development Program of China （Grant No 2002AA313070）.
文摘The third-order optical nonlinearities of [（CH3）4N]Au（dmit）2 （dmit = 4,5-dithiolate-1,3-dithiole-2-thione） at 532 nm and 1064 nm are investigated using the Z-scan technique with pulses of picoseconds duration. The Z-scan spectra reveal a strong nonlinear absorption （reverse saturable absorption） and a negative nonlinear refraction at 532 nm. No nonlinear absorption is observed at 1064 nm. The molecular second-order hyperpolarizability γ for the [（CH3）4N]Au（dmit）2 molecule at 532nm is estimated to be as high as （2.1 ±0.1） × 10^-31 esu, which is nearly three times larger than that at 1064 nm. The mechanism responsible for the difference between the results is analysed. Nonlinear transmission measurements suggest that this material has potential applications in optical limiting.
基金Project supported by the Ministry of Higher Education(Grant Nos.1-11-08-664FR/F1 and 01-0410-861FR)
文摘The nonlinear optical properties of a phosphate vitreous system [（ZnO）x-（MgO）30-x-（P2O5）70], where x=8, 10, 15, 18, and 20 mol% synthesized through the melt-quenching technique have been investigated by using the Z-scan technique. In the experiment, a continuous-wave laser with a wavelength of 405 nm was utilized to determine the sign and value of the nonlinear refractive （NLR） index and the absorption coefficient with closed and opened apertures of the Z-scan setup. The NLR index was found to increase with the ZnO concentration in the glass samples by an order of 10-10 cm2·W-1. The real and imaginary parts of the third-order nonlinear susceptibility were calculated by referring to the NLR index （n2） and absorption coefficient （β） of the samples. The value of the third-order nonlinear susceptibility was presented by nonlinear refractive or absorptive behavior of phosphate glasses for proper utilization in nonlinear optical devices. Based on the measurement, the positive sign of the NLR index shows a self-focusing phenomenon. The figures of merit for each sample were calculated to judge the potential of phosphate glasses for application in optical switching.
文摘Z-scan technique is an effective tool for measuring the optical nonlinearity of the materials. By using this technique the measurement was made for total protein and albumin. The nonlinear refractive index of the total protein and albumin were found to vary linearly with concentration. Hence by calculating the nonlinear refractive index it is possible to measure their concentration in the sample. The values measured thus are found in equivalence with conventional colorimetric method.
文摘The third-order nonlinear optical properties of two dmit organometallic complexes, [(CH3)4N] [Au(C3S5)2] (MeAu) and [(CH3)4N][Ni(C3S5)2] (Me Ni) in acetone solutions, were characterized us- ing a short pulse Z-scan technique at 1064 nm wavelength. Self-defocusing effects were found in both samples and stronger saturable absorp-tion was observed in MeNi solution comparing with that of MeAu. The origins were analyzed for the differences between the results. Two figures of merit W and T were also calculated to evalu-ate the suitability of two materials for all-optical integrated devices. The results of W=22.84 and T≈0 of MeAu make it an excellent candidate for the all-optical applications.
文摘In the present work, z-scan technique was used to study the nonlinear properties, represented by nonlinear refractive index and nonlinear absorption coefficient for Coumarin 450 (C450) doped PMMA as a function of concentration for two different solvents. The results show change of the effect from self-focusing to self-defocusing in closed aperture z-can (or change of the effect from two photon absorption to saturable absorption in open aperture z-scan), when the sample dissolved in low viscosity and more polar
文摘We report results from the investigation of the nonlinear refractive index and nonlinear absorption coefficient of {(1Z)-[4-(Dimethylamino)phenyl]methylene} 4-nitrobenzocarboxy hydrazone mono-hydrate (DMPM4NBCHM) solution using Z-scan technique with a continuous wave (CW) Argon ion laser. The results show that this type of organic material has a large nonlinear absorption and nonlinear refractive index at 488 nm and 514 nm. The origin of the nonlinear effects was discussed. We demonstrate that the light induced nonlinear refractive index variation, leads to limiting effect. The results indicated that DMPM4NBCHM could be promising candidates for application on nonlinear photonic devices and optical limiters.
文摘An experimental study of the nonlinear changes in refractive index and transmission coefficient of single-crystal ZnSe:Fe2+, fabricated through the Fe-diffusion method, at long-pulse (~300 ns), sub-mJ, 2.94-mm Z-scan probing is reported. As well, a theoretical model based on the generalized Avizonis-Grotbeck equations is developed and applied for straightforward fitting of the open- and closed-aperture Z-scans, obtained for ZnSe:Fe2+ with different Fe2+ centers concentrations. The modeling results reveal that the contributions in the absorption and refractive index nonlinearities of ZnSe:Fe2+ are “common” resonant-absorption saturation (the minor part) and pulse-induced heating of the samples (the major part), which are strongly dependent on Fe2+ concentrations. Large values of the index change (>~10-3) and partial resonant-absorption bleaching (limited by ~50%), both produced via the thermal effect mainly, are the features of the ZnSe:Fe2+ samples inherent to this type of excitation.
基金supported by the National Natural Science Foundation of China(60778037,50772059,11004123)Foundation of National Excellent Doctoral Dissertation of China(200539)+2 种基金Natural Science Foundation of Shandong Province,China(ZR2009GQ007)China Postdoctoral Science Foundation(20100470040)Youth Scientist Fund of Shandong Province,China(BS2011CL025)~~
