%0 Journal Article
%T Ultra-narrow electromagnetically induced transparency and inversionless gain in a ladder-four-level system<br>梯型四能级系统中超窄电磁感应透明与无反转增益
%A Li Yong-Fang
%A Sun Jian-Feng
%A <br>李永放
%A 孙建锋
%J 物理学报
%D 2003
%I 
%X In this paper, we study the effects of Rabi frequencies and multi-path radiation on the electromagnetically induced transparency (EIT) and the inversionless gain in a ladder- four-level system driven by two-coherent fields- The Rabi frequencies of the field-driven transition from the upper level to middle levels play an important role for the realization of the ultra-narrow EIT and inversionless gain- Different excitation mechanism can change the position of the EIT- The action of the spontaneous alignment of the dipole moment is investigated- The explanation for the numerical results is presented using the theory of dressed state
%K ladder-four-level system
%K quantum interference effect
%K electromagnetically induced transparency
%K gain without inversion<br>梯型四能级系统，
%K 量子干涉效应，
%K 电磁感应透明，
%K 无反转增益
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=6E709DC38FA1D09A4B578DD0906875B5B44D4D294832BB8E&cid=47EA7CFDDEBB28E0&jid=29DF2CB55EF687E7EFA80DFD4B978260&aid=787D37F4C5F396FC&yid=D43C4A19B2EE3C0A&vid=286FB2D22CF8D013&iid=38B194292C032A66&sid=4002B7787911C73B&eid=AF4A4411BB448A36&journal_id=1000-3290&journal_name=物理学报&referenced_num=1&reference_num=25