运用基于矩量法(method of moment,MoM)结合基尔霍夫近似(Kirchhoff approximation,KA)的混合算法研究一维带限Weierstrass分形分层介质粗糙面的电磁波透射问题.在混合算法中将上层粗糙面和下层粗糙面分别划分到MoM区域和KA区域,数值计...运用基于矩量法(method of moment,MoM)结合基尔霍夫近似(Kirchhoff approximation,KA)的混合算法研究一维带限Weierstrass分形分层介质粗糙面的电磁波透射问题.在混合算法中将上层粗糙面和下层粗糙面分别划分到MoM区域和KA区域,数值计算得到透射系数随透射波的散射角的变化,讨论粗糙面分维数、高度起伏均方根、底层介质介电常数、中间层介质介电常数和厚度、入射波频率对透射系数的影响,结果表明上层粗糙面参数对透射系数有显著影响,而下层粗糙面参数对透射系数影响较小.展开更多
基于矩量法(method of moment,MOM)及基尔霍夫近似(Kirchhoff approximation,KA)研究了分层粗糙面的电磁散射问题。首先,利用经典MOM求解了上层粗糙面的总场,包括直接入射场及由其激发的直接散射场。然后,将锥形入射波引入到传统KA中,...基于矩量法(method of moment,MOM)及基尔霍夫近似(Kirchhoff approximation,KA)研究了分层粗糙面的电磁散射问题。首先,利用经典MOM求解了上层粗糙面的总场,包括直接入射场及由其激发的直接散射场。然后,将锥形入射波引入到传统KA中,利用其求解了分层粗糙面的透射场。数值计算并讨论了粗糙面高度起伏均方根、相关长度及分层粗糙面间距等参数对分层高斯粗糙面双站散射系数的影响。展开更多
We develop a full quantum theory of transient-state electromagnetically induced transparency (EIT) in thevapor of three-level A-type atoms interacting with probe and coupling lasers. As applications of the full quantu...We develop a full quantum theory of transient-state electromagnetically induced transparency (EIT) in thevapor of three-level A-type atoms interacting with probe and coupling lasers. As applications of the full quantum theory,we show that transient-state EIT medium exhibits normal dispersion and find that group velocities of both coupling andprobe lasers are greatly reduced. It is shown that the group velocity of the probe laser in the transient-state EIT case isequal to that in the adiabatic EIT case and that the coupling laser group velocity in the transient-state EIT is generallyless than that in the adiabatic EIT.展开更多
In this paper, we propose and analyze an optical multi-wave mixing scheme for the generation of coherent light in a five-level atomic system in the context of electromagnetically induced transparency. A detailed semic...In this paper, we propose and analyze an optical multi-wave mixing scheme for the generation of coherent light in a five-level atomic system in the context of electromagnetically induced transparency. A detailed semiclassical study of the propagation of generated mixing and probe fields is demonstrated. The analytical dependence of the generated mixing field on the probe field and the respective detuning is predicted. Such a nonlinear optical process can be used for generating short-wavelength radiation at low pump intensities.展开更多
文摘运用基于矩量法(method of moment,MoM)结合基尔霍夫近似(Kirchhoff approximation,KA)的混合算法研究一维带限Weierstrass分形分层介质粗糙面的电磁波透射问题.在混合算法中将上层粗糙面和下层粗糙面分别划分到MoM区域和KA区域,数值计算得到透射系数随透射波的散射角的变化,讨论粗糙面分维数、高度起伏均方根、底层介质介电常数、中间层介质介电常数和厚度、入射波频率对透射系数的影响,结果表明上层粗糙面参数对透射系数有显著影响,而下层粗糙面参数对透射系数影响较小.
文摘基于矩量法(method of moment,MOM)及基尔霍夫近似(Kirchhoff approximation,KA)研究了分层粗糙面的电磁散射问题。首先,利用经典MOM求解了上层粗糙面的总场,包括直接入射场及由其激发的直接散射场。然后,将锥形入射波引入到传统KA中,利用其求解了分层粗糙面的透射场。数值计算并讨论了粗糙面高度起伏均方根、相关长度及分层粗糙面间距等参数对分层高斯粗糙面双站散射系数的影响。
文摘We develop a full quantum theory of transient-state electromagnetically induced transparency (EIT) in thevapor of three-level A-type atoms interacting with probe and coupling lasers. As applications of the full quantum theory,we show that transient-state EIT medium exhibits normal dispersion and find that group velocities of both coupling andprobe lasers are greatly reduced. It is shown that the group velocity of the probe laser in the transient-state EIT case isequal to that in the adiabatic EIT case and that the coupling laser group velocity in the transient-state EIT is generallyless than that in the adiabatic EIT.
基金The project supported by National Fundamental Research Program of China under Grant No.2001CB309310National Natural Science Foundation of China under Grant Nos.90103026,10125419,and 10121503
文摘In this paper, we propose and analyze an optical multi-wave mixing scheme for the generation of coherent light in a five-level atomic system in the context of electromagnetically induced transparency. A detailed semiclassical study of the propagation of generated mixing and probe fields is demonstrated. The analytical dependence of the generated mixing field on the probe field and the respective detuning is predicted. Such a nonlinear optical process can be used for generating short-wavelength radiation at low pump intensities.
