Study On The Spontaneous Emission In A Two-Dimensional Arbitraryinhomogeneous Environment

Spontaneous emission research has been a hot topic in the field of quantum optics.Spontaneous emission control plays an important role in the design of various optical components and devices,such as nano-antennas,hyperbolic metamaterials,light-emitting diodes,lasers and solar cells.Suppressing the unwanted spontaneous emission and increasing the required power will drive emerging optical designs with new capabilities.How to modulate spontaneous emission is very important for the exploration and development of new quantum optical technologies.Purcell firstly demonstrated in 1946 that the spontaneous emission of a quantum emitter is not intrinsic to the atom itself,which can be altered by the nanostructured environment surrounding the quantum emitter.Subsequent use of metal nanoparticle structures and photonic crystal cavity control the spontaneous emission of tuned atoms.According to the theory of vacuum fluctuations in electromagnetic fields,atoms or molecules in the inhomogeneous medium radiate photons spontaneously.Therefore,different metal nanostructures have a modulation effect on spontaneous emission,namely the change in the density of states through changing the electromagnetic environment around the atoms.Thus controlling spontaneous emission.This article focuses on the control of spontaneous emission by metallic nanostructures.The size of the spontaneous emissivity and the location of the peak in the metallic structure are determined by the parameters and the structure of the metallic material itself.It is difficult to achieve the position adjustment and the further enhancement.In this paper,the monolayer graphene films are introduced into the spontaneous emission of atoms in the metal structure,and the spontaneous emissivity of the atoms is controlled by the special photoelectric properties of graphene.The green function representation of state density and spontaneous emissivity are deduced,also the numerical simulation of the finite difference method in frequency domain is given.The theoretical results of the research can provide reference for the fabrication and optimization of new nanodevices and optoelectronic devices.The main research work of this paper is as follows:1.The basic theories of spontaneous emission and spontaneous emission control are briefly described,including the development of spontaneous emission research,the principle of spontaneous emission and several ways of modulating spontaneous emission.The Green's function expression of two-dimensional spontaneous emissivity is deduced.2.The basic principle of the FDFD method is introduced and compared with other algorithms.In dealing with the frequency domain problem,there is a big advantage in the FDFD problem in compared with the FDTD.The FDFD method was introduced into the study of spontaneous emission.The Helmholtz equation of spontaneous emission is treated by FDFD method.The spontaneous emissivity of different metallic materials and graphene-containing metallic structures is calculated by the dielectric constant.3.Calculate different photonic crystal matrix inhibition of spontaneous emission.As well as the introduction of single-layer graphene in the metal nanostructures.The use of graphene special photoelectric properties is to regulate the spontaneous emission of atoms.