不同三能级系统中利用自发相干感应相位光栅研究  

Study of Phase Grating Induced by Spontaneous Coherence in Different Three-Level Systems

作　　者：郭洪菊 冯吉军 GUO Hong-ju;FENG Ji-jun(Shanghai Publishing and Printing College,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Key Laboratory of Modern Optical System,Engineering Research Center of Optical Instrument and System(Ministry of Education),School of Optical-Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学,上海出版印刷高等专科学校,上海200093 [2]上海理工大学,光电信息与计算机工程学院,上海市现代光学系统重点实验室,上海200093

出　　处：《量子光学学报》2022年第2期114-122,共9页Journal of Quantum Optics

基　　金：国家自然科学基金(11774235,61875125);上海市青年科技启明星计划项目(19QA1406100)。

摘　　要：原子相干是控制光与原子相互作用的有效方法。本文对比研究不同三能级原子系统中自发辐射相干对电磁感应相位光栅的影响。结果发现,自发辐射相干可以显著增强一阶衍射效率,但是不同系统一阶衍射增强的程度不相同,与原子相干程度的依赖关系也有区别。对于Lamda和Ladder型系统,一阶衍射效率随自发辐射相干程度的增强而增强,其中Ladder型系统更明显。与此不同,对于V型系统,在自发辐射相干程度相对较小的区域出现一阶衍射效率的增强。Electromagnetically induced transparency has attracted much attention because of its basic characteristics and its potential applications. With the help of the pump field, the detection field can be transmitted transparently in the medium. When the standing wave field is used as the pump field, the electromagnetically induced transparent medium becomes an electromagnetically induced grating. The electromagnetically induced grating effect is widely used in optical path switch, optical storage, quantum Talbot effect, atomic wave interferometry, etc. Its scheme based on electromagnetically induced transparency mainly uses enhanced dispersion to enhance spatial phase modulation, so as to enhance diffraction efficiency. In this paper, spontaneously generated coherence inducing electromagnetically induced phase gratings are studied and compared in different three-level atomic systems:Lamda-type, Ladder-type and V-type. Spontaneously generated coherence refers to the interference between spontaneous emission channels. In Lamda-type and V-type systems, spontaneous emission from a single excited state to two lower near degenerate energy levels or from two near degenerate higher energy levels to the atomic ground state will interfere with each other. Spontaneously generated coherence also probably appears in the Ladder type system in the case of equidistant atomic energy levels. The existence of this coherence depends on whether the two transition dipole moments are orthogonal. The results show that, spontaneously generated coherence can significantly enhance the first-order diffraction efficiency. However the degree of enhancement is different in different systems, and the dependence on the degree of atomic coherence is also different. For Lamda and Ladder type systems,the first-order diffraction efficiency increases with the enhancement of spontaneous emission coherence, especially for the Laddertype system. In contrast, for the V-type system, the first-order diffraction efficiency increases in the region where the coher

关 键 词：电磁感应相位光栅 自发辐射相干 一阶衍射效率 

分 类 号：O437[机械工程—光学工程]