SPP Propagation Using FDTD Method

Abstract

Now a days Surface Plasmon Polariton (SPP) has become a very attractive field of study for its extraordinary confinement of light at optical frequencies and its ability to overcome the diffraction limit. It is a very useful tool for the miniaturization of photonic devices. Keeping that in mind we have tried to discuss some of the basic ideas related to the SPP propagation. At first from various computational techniques FDTD has been taken for presenting the distribution of the electric and the magnetic field. With the help of FDTD 1-dimensional and 2-dimensinal simulations we get an idea how the signal behave within the dielectric at different frequencies. Next simulations related to SPP propagation are performed by forming the interface between metal and dielectric. Both the single and double interfaces are investigated with the help of Gaussian pulse signal. Lorentz model and Lorentz drude model are used for material modeling. Our aim was to enhance the power of the propagating signal. To do that grating has been considered. It is the periodic arrangement of different medium so that the propagating signal can be obstructed to couple with the main signal to enhance the power. We have tried to implement the grating structure with the help some numerical calculations taken from the published research papers. In our whole research work mainly two dielectrics (AlGaAs & GLS) have been used. For different metallic strip thickness transmission power has been shown. Lastly a comparison between the two dielectrics has been presented in terms of their transmission and loss properties.