Green's tensors for photonic crystal (PC) slabs are numerically solved by the coupled-dipole approximation (CDA) technique. The obtained components of Green's tensors satisfy discontinuous or continuous conditions at interfaces of scatterers. This shows that the CDA technique is very applicable to studying the properties of PC slabs. Green's tensors exhibit obviously periodic oscillation with the increase of the number of scatterers; furthermore, the effect of each scatterer on Green's tensors displays a localization feature in the sample containing one row of scatterers; on the contrary, this localized effect disappears in the sample consisting of multiple rows of scatterers.

The lifetime distribution functions of the spontaneous emission (SE) of the excited atoms embedded in two-dimensional (2D) photonic crystals (PCs) with square lattice, consisting of square air rods in dielectric medium with different filling factors, are calculated by using the plane wave expansion method. The numerical results show that the SE in the 2D PCs cannot be prohibited completely but it can be inhibited intensively by the pseudo-PBG of the PCs. In the pseudoband edges, the SE is accelerated obviously. The reduced average lifetime of the excited atoms and the extension of the reduced lifetime distribution in the 2D PCs both are the same as those in the 3D PCs in the order of magnitude. Our results provide an available way to control the behavior of the SE by changing the structures of the 2D PCs.

We present a general model study of surface-enhanced resonant Raman scattering and fluorescence focusing on the interplay between electromagnetic effects and the molecular dynamics. Our modelmolecule is placed close to two Ag nanoparticles, and has two electronic levels. A Franck-Condon mechanism provides electron-vibration coupling. Using realistic parameter values for the molecule we find that an electromagnetic enhancement by 10 orders of magnitude can yield Raman crosssections σR of the order 10−14 cm2. We also discuss the dependence of σR on incident laser intensity.

对非均匀电磁系统中原子的Lamb移位导出一个普适的理论公式，发现对Lamb移位的主要贡献来自实光子的吸收和再辐射过程，这打破了自1947年以来一直被人们所认同的传统概念，即在均匀空间中，Lamb移位主要来自虚光子的吸收和再辐射过程。对光子晶体，文章作者预言了巨Lamb移位效应。对原子集合，进一步发现依赖位置的Lamb移位将使一个能级扩展成一个能带，就像原子气体中依赖速度的多普勒效应一样。

Decay kinetic properties of a two-level atom near the band edges of photonic crystals (PCs) with absolute gaps are studied based on the Green's function expression for the evolution operator. The local coupling strength between the photons and an atom is evaluated by an exact numerical method. It is found that the decay behavior of an excited atom can be fundamentally changed by the variation of the atomic position: Weisskopf-Wigner and non-Weisskopf-Wigner decay phenomena occur at different atomic positions in the PCs as a result of a significant difference in the local coupling strength. Our finding implies that it is possible to engineer the luminescence spectrum by controlling the atomic position.