IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) e-ISSN: 2278-2834,p- ISSN: 2278-8735.Volume 12, Issue 2, Ver. I (Mar.-Apr. 2017), PP 08-19 www.iosrjournals.org DOI: 10.9790/2834-1202010819 www.iosrjournals.org 8 | Page Surface Plasmon Modes of Dielectric-Metal-Dielectric Waveguides and Applications Shivani Sital 1 , EnakshiKhular Sharma 2 1,2 (Department of Electronic Science, University of Delhi South Campus, India) Abstract: The dielectric-metal-dielectric plasmonic waveguide structures find applications in integrated optics and fiber polarizers and sensors. Surface plasmon waves guided by thin metal film have been intensively studied over the last two decades. However, most studies have been confined to relatively low index dielectrics. With growing interest in silicon photonics and other semiconductors dielectric of relatively higher dielectric constant we carried out a detailed study of the modes supported by a metal filmbetween dielectrics of relatively higher dielectric constant. The study clearly shows that both modes, the“antisymmetric” (  ) short range and “symmetric” (  ) long range bound modes can exist only when the contrast between the indices is low. For high contrast the symmetric mode transforms into a leaky mode.For completeness we also includethe antisymmetric leaky (  ) mode and symmetric leaky (  ) mode in our study, although they are not important for guided wave structures. We have also included “leaky modes” in the bound mode domain as solution of the boundary value problem as reported in some early studies. We have also considered some applications of the DMD waveguides with an emphasis on identifying the participating mode in each application. Keywords: Surface plasmon modes, dielectric-metal-dielectric waveguide, bound modes, leaky modes, sensors I. INTRODUCTION It is well known that the interface of the medium with a real negative dielectric constant and positive dielectric constant can support a guided surface TM mode. In a typical metal, the dielectric constant can be written as   = −  −   [1,2], i.e., in addition to negative real part there is an imaginary part in the dielectric constant which manifests itself as loss. Hence, a semi-infinite metal dielectric interface [shown in Fig.1(a)] supports a lossy TM surface wave also known as a surface plasmon wave. Similarly, a thick metal slab with semi-infinite dielectric on either side [as shown in Fig.1(b)] can support such surface plasmon modes on either interface. However, for thin metal films these modes get coupled and the film can support one or two lossy bound surface plasmon TM modes depending on the metal thickness and dielectric constants of the two dielectric media. Fig.1 (a) Surface TM mode supported by a metal-dielectric interface. Surface modes supported by the dielectric-metal-dielectric (DMD) waveguide on (b) a thick metal slab, c) thin metal film. Such dielectric-metal-dielectricplasmonic waveguide structures find applications in integrated optic and fiber polarizers [3-7] and sensors [8]. Surface plasmon waves guided by thin metal films on the dielectrics have been intensively studied over the last two decades [9,10]. However, most studies have been confined to relatively low index dielectrics. With growing interest in silicon photonics and other semiconductor dielectrics of relatively