Study on Incident Angle of Light at Which Surface Plasmon Polaritons Excited

Surface Plasmon Polariton (SPP) travels along the interface between a metal and a dielectric or metal and air. SPPs propagate along the interface until their energy is absorbed by the metal or scattered in other directions. These electromagnetic excitations, or surface waves, are confined to the interface and highly sensitive to changes in the surrounding environment, making them valuable for sensing, photonics, and nanotechnology applications.

In this paper, various types of metamaterials are artificially engineered by combining two different materials, a metal and a dielectric. The procedure of the experiment is as follows:

(1) Choose the ㅈavelength of the incident ray(e.g. 600nm). (2) Select dielectric metal. (3) Select nonmetal. (4) Find approximate values of refractive index (n) and extinction coefficient (k) for both metals and nonmetals at specific wavelengths. (5) Find the relative permittivity of metal and nonmetal.  (6) Find the incident angle in which the surface Plasmon polariton occurs.  (7) Find the effective index.  (8) Calculate the theoretical values of the incident angle.

This study aims to identify an example of a metamaterial where surface plasmon polaritons (SPPs) can be excited when a beam of light is directed at a specific angle. 

The incident angle of light at which surface plasmon polaritons (SPPs) are excited is calculated for each unit using dispersion relation. Results show that the angle is specific to the material properties of the unit(metal and dielectric)  and the wavelength of the light used in the experiment.