The strong-field processes,including preferential ionization and immediate electronic couplings,can result in a certain permanent alignment of cations.Utilizing the permanent alignment together with molecular alignmen...The strong-field processes,including preferential ionization and immediate electronic couplings,can result in a certain permanent alignment of cations.Utilizing the permanent alignment together with molecular alignment to control the polarization of follow-up coherent emissions from ions remains unexplored to date.In the present work,we first demonstrate the permanent alignment effect on N_(2)^(+)lasing by examining its polarization,which is based on a polarization perpendicular configuration with a pump-seed scheme.It is found that the output polarization of N_(2)^(+)lasing can incline toward the pump polarization direction under a weak seed triggering,which is in contrast to the previous polarization measurement and manifests the crucial role of permanent alignment.In addition,at the alignment delay,the polarization of N_(2)^(+)lasing can be varied from linear polarization to elliptical polarization by adjusting the seed intensity.Our analysis indicates that the permanent alignment in essence arises from the anisotropic distribution of magnetic quantum number M,i.e.,the projection of rotational number J on the fixed z-axis.These findings shed light on the physics of N_(2)^(+)lasing and offer various approaches to manipulate the polarization of ionic coherent radiations.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12264003,12074063,and 12064009)the Jiangxi Provincial Natural Science Foundation(No.20232ACB211007)。
文摘The strong-field processes,including preferential ionization and immediate electronic couplings,can result in a certain permanent alignment of cations.Utilizing the permanent alignment together with molecular alignment to control the polarization of follow-up coherent emissions from ions remains unexplored to date.In the present work,we first demonstrate the permanent alignment effect on N_(2)^(+)lasing by examining its polarization,which is based on a polarization perpendicular configuration with a pump-seed scheme.It is found that the output polarization of N_(2)^(+)lasing can incline toward the pump polarization direction under a weak seed triggering,which is in contrast to the previous polarization measurement and manifests the crucial role of permanent alignment.In addition,at the alignment delay,the polarization of N_(2)^(+)lasing can be varied from linear polarization to elliptical polarization by adjusting the seed intensity.Our analysis indicates that the permanent alignment in essence arises from the anisotropic distribution of magnetic quantum number M,i.e.,the projection of rotational number J on the fixed z-axis.These findings shed light on the physics of N_(2)^(+)lasing and offer various approaches to manipulate the polarization of ionic coherent radiations.
