Fluorescence spectrum due to surface plasmon polariton emission in a three level atom Jabir Hakami, Ali Kamli * , M. Al-Amri Department of Physics, King Khalid University, Abha 61314, P.O. Box 9003, Saudi Arabia Received 19 February 2007; received in revised form 21 May 2007; accepted 11 July 2007 Abstract The dynamics of a V-type three level atom positioned inside a metallic slab sandwiched between two asymmetric infinite dielectrics is studied. The surface plasmon polaritons supported by this structure are calculated, quantized and their dispersions are found to exhibit plasmonic band gaps which in turn modify the spontaneous transition rates and the fluorescence spectrum. Interesting features arise from the variations of the decay rate and spectrum with the mode frequency and electron density including local field effects. Ó 2007 Elsevier B.V. All rights reserved. 1. Introduction In his seminal work [1], Ritchie predicted the existence of sustainable electromagnetic modes at the interface of metal non-metal system. These modes were termed by Stern and Ferrel [2] as surface plasmons. Since then there has been a sizable body of the literature on such modes both on the theoretical and experimental sides [3–6]. Sur- face plasmon polaritons are collective charge excitations at an interface of metal/non-metal. Such modes can be interpreted as EM waves localized near the interface; they are confined to the in-plane interface joining the two media. They are purely TM modes and characterized by a field amplitude that decays away from both sides of the interface. Because of this confinement they have many technological applications. Recently, plasmon polaritons have been suggested [6] to generate strong atom field cou- pling and also as a possible source of single photons which are very essential in the new emerging field of quantum information processing. Furthermore and as we show in this work, plasmon polaritons show band gap regions sim- ilar to, but distinct in origin from photonic band gaps and this makes them important for cavity quantum electrody- namics (QED) processes and for controlling spontaneous emission, the source of decoherence in many processes that take place inside materials. Because of these effects these modes are expected to be of many technological advanta- ges in quantum computing, information processing and CQED problems. Motivated by this we study in this work the coupling of plasmon modes to a three level V-type atom and explore the effects of plasmonic gap and other various parameters on the spontaneous emission spectrum due to such modes. The intensive research on cavity quantum electrodynamics (CQED) [7–10] has unambiguously estab- lished the fact that the spontaneous emission and its spec- trum of a point dipole emitter can be modified from its free space case by suitably tailoring the environment surround- ing the dipole emitter. Much research has been carried out on the modification of the spontaneous emission rate and its spectrum and its practical consequences for dipoles immersed in various media and cavity structures of differ- ent shapes and sizes. The metallic slab has been the subject of investigation by many authors with emphasis on the surface plasmon polaritons that exist at the metal nonmetal interface. Little work, however, has been done on the dynamics of multilevel atoms in the presence of surface plasmon polaritons. Moreover, most of previous studies on photonic crystals have ignored the local field correction 0030-4018/$ - see front matter Ó 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.optcom.2007.07.024 * Corresponding author. Tel.: +966 505 75 6443; fax: +966 7 229 0165. E-mail address: aakamli@kku.edu.sa (A. Kamli). www.elsevier.com/locate/optcom Optics Communications 279 (2007) 112–119