【作者】 张衍亮；

【导师】 王祖赓； 孙真荣；

【作者基本信息】 华东师范大学 ， 光学， 2002， 博士

【摘要】 原子、分子和离子体系中的量子干涉效应是近年来激光物理和量子光学领域的一个研究热点。基于量子干涉效应，产生了许多新的物理现象和效应，如相干布居捕获、无反转激光、电磁感应透明和自发辐射相消等。因而对多能级系统的量子干涉及其相关因素的研究不仅具有重要的学术意义，而且具有较好的应用前景。 本文首先讨论了影响量子干涉的因素。以∧型能级系统为例，研究了多普勒加宽对无反转增益的影响。计算表明：在探测场波长远大于耦合场波长情况下，虽然耦合光的拉比频率远小于多普勒加宽，但是无反转增益依旧存在，而且强于匹配能级的增益。针对实际的实验条件，考虑了一种影响量子干涉的新的因素-四波混频场，研究了四波混频场对双光子探测的∧-型能级体系的EIT的影响，发现四波混频场能够导致双光子探测的EIT线型的不对称，在此基础上，讨论了不同探测场的传播方式对EIT的影响， 针对分子中实际存在的包含有微扰能级的不同多能级系统，我们分别采用缀饰态绘景下的密度矩阵方程和Weisskopf-Wigner近似下的密度矩阵方程详细地讨论了电磁感应透明、自发辐射的干涉相消和相长、双暗态共振和双电磁感应透明现象。分析了微扰能级的间隔和叠加程度、激光功率以及中间能级的失谐对量子干涉效应的影响，实验上观察了包含有一对微扰叠加中间能级的菱形四能级系统中的双光子激发现象，发现微扰能级的相干叠加可增强双光子吸收。理论计算与实验结果符合很好。 本论文还报道了钠原子-分子以及原子-原子之间的碰撞动力学过程对相应辐射线型和强度的影响，并进行了理论分析。理论分析与实验结果一致。此外还研究了掺杂在固体Y₂SiO₅中的pr³⁺的光泵红外受激辐射和能量转移上转换，分别测得了红外受激辐射的阈值能量和发散角，并拟合得出了能量转移速率。更多还原

【Abstract】 The research for quantum interference in atoms, molecules and ions is an interesting topic in the field of laser physics and quantum optics. Many novel physical phenomena such as coherent population trapping, lasing without inversion, electromagnetically induced transparency as well as spontaneous emission cancellation and enhancement based on quantum interference have been discovered. Besides the important academic values, the research for quantum interference in multi-level systems has also promising applications.In the thesis, we theoretically investigate some influential factors for the quantum interference. We study the Doppler broadened effect on the continuous inversionless gain. The calculated results show that the generation of inversionless gain in Doppler-broadened media for a probe field wavelength in much excess of coupling field wavelength is possible, although the coupling field Rabi frequency is significantly less than the Doppler width. We also put forward a new influential factor for the quantum interference -FWM (four-wave mixing) field for the first time, and analyze the effect of four-wave mixing field on the electromagnetically induced transparency. It is found that the FWM field can cause the asymmetry of electromagnetically induce transparency profile. In addition, the effect of different propagating orientations of probe field on the electromagnetically induced transparency is also discussed.In the molecular multi-level system with the perturbed superposition levels, we discuss the electromagnetically induced transparency, spontaneous emission enhancement, double dark resonance and double electromagnetically induced transparency by using the density matrix equation under Weisskopf-Winger approximation and dressed-state density matrix equation. We analyze the influences of the perturbed energy-level space and superposion, laser power and intermediate level offset on quantum interference. Experimentally, in the sodium dimmer rhomb-type four-level system with a pair of perturbed levels, the interferenceenhancement of two-photon absorption caused by coherent superposition of the perturbed levels is experimentally observed. The calculating results agree with the experimental results.We also experimentally observed the effect of sodium atom-molecular collisions and sodium atom-atom collisions on the line-shape and intensity of fluorescence spectra. In addition, the optically pumped infrared stimulated emission and energy transfer up-conversion process are observed in Pr3+: Y2SiO5, and with the threshold energy, temperature dependence and divergence angle for the stimulated radiation are measured.更多还原