Y型四能级中的双电磁感应透明和超窄吸收

Double Electromagnetically Induced Transparency and Ultra-Narrow Line Width in Y-Type Energy Level System

采用密度矩阵方程 ,对双光场耦合的分子Y型四能级系统的粒子数分布和吸收特性进行了计算和分析 ,在此能级系统中得到了双暗态共振和双电磁感应透明 ,并讨论了相应的物理机制。同时 ,我们讨论了Y型四能级两个上能级的自发辐射产生的量子干涉效应对电磁感应透明的影响 ,发现自发辐射干涉相消可以产生超窄线宽和导致探测光的吸收增强 ,自发辐射干涉相长可以展宽谱线和减弱探测光的吸收 ,并运用缀饰态理论对以上计算结果进行分析 。

Using matrix equation, the population distribution and absorption characteristics in the molecular Y-type energy level system with two driving fields are calculated and analyzed. The generation of double dark resonance and double electromagnatically induced transparency in this energy level system is obtained, its physical mechanism is discussed. The effect of the quantum interference of the spontaneous emission on the electromagnetically induced transparency are also discussed. Coherence cancellation of the spontaneous emission can form the ultra-narrow line width and enhance the absorption, whereas the coherence enhancement of the spontaneous emission can form the wide absorption line width and weaken its intensity, above calculated results are analyzed with the dressed state theory and agree with those by the density matrix equation.