Nonlinear properties of two different crude oils from west-south Iran reservoirs have been investigated using the single beam Z-scan technique. The nonlinear refractive indices of the samples were measured by use of d...Nonlinear properties of two different crude oils from west-south Iran reservoirs have been investigated using the single beam Z-scan technique. The nonlinear refractive indices of the samples were measured by use of diode laser in the CW regime and at the wavelength 660 nm. The experiment results showed that the samples have large and negative refractive index nonlinear refraction coefficient. These results showed that the crude oil has significant nonlinear properties and it could be a candidate for photonic and nonlinear optical devices and also this information can be used in petroleum science and oceanology and etc.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
文摘Nonlinear properties of two different crude oils from west-south Iran reservoirs have been investigated using the single beam Z-scan technique. The nonlinear refractive indices of the samples were measured by use of diode laser in the CW regime and at the wavelength 660 nm. The experiment results showed that the samples have large and negative refractive index nonlinear refraction coefficient. These results showed that the crude oil has significant nonlinear properties and it could be a candidate for photonic and nonlinear optical devices and also this information can be used in petroleum science and oceanology and etc.
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.
