We offer a unified approach to several phenomena related to the electromagnetic vacuum of a complex medium made of point electric dipoles. To this aim, we apply the linear response theory to the computation of the polarization field propagator and study the spectrum of vacuum fluctuations. The physical distinction among the local density of states which enter the spectra of light propagation, total dipole emission, coherent emission, total vacuum energy and Schwinger-bulk energy is made clear. Analytical expressions for the spectrum of dipole emission and for the vacuum energy are derived. Their respective relations with the spectrum of external light and with the Schwinger-bulk energy are found. The light spectrum and the Schwinger-bulk energy are determined by the Dyson propagator. The emission spectrum and the total vacuum energy are determined by the polarization propagator. An exact relationship of proportionality between both propagators is found in terms of local field factors. A study of the nature of stimulated emission from a single dipole is carried out. Regarding coherent emission, it contains two components. A direct one which is transferred radiatively and directly from the emitter into the medium and whose spectrum is that of external light. And an indirect one which is radiated by induced dipoles. The induction is mediated by one (and only one) local field factor. Regarding the vacuum energy, we find that in addition to the Schwinger-bulk energy the vacuum energy of an effective medium contains local field contributions proportional to the resonant frequency and to the spectral line-width.
Towards an understanding of dipole-dipole interactions in nonlocal media
Centre of Excellence ENSEMBLE3（ENSEMBLE3卓越中心）；Wilczek Quantum Center, Shanghai Institute for Advanced Studies（复旦大学高等研究院物理学院）；University of Science and Technology of China（中国科学技术大学）；Department of Energy and Process Engineering（能源与过程工程系）；Chemical and Biological Systems Simulation Lab, Centre of New Technologies, University of Warsaw（华沙大学新技术中心化学与生物系统模拟实验室）
Speckle-based feedback control of optical dipole trap axial waist position
Russian Quantum Center（俄罗斯量子中心）；Moscow Institute of Physics and Technology（莫斯科物理技术学院）；National Research Nuclear University MEPhI（国立核研究大学MEPhI）；PN Lebedev Institute RAS（P.N.列别捷夫物理研究所）
Vacuum-induced interference in light scattering by multilevel atomic chains
University of Innsbruck（因斯布鲁克大学）；Saarland University（萨尔兰大学）；Center for Quantum Technologies (QuTe), Saarland University（萨尔兰大学量子技术中心）；Università degli Studi di Milano（米兰大学）
