No abstract

No abstract

We study the electromagnetic surface waves localized at an interface separating a homogeneous dielectric medium and a semi-infinite one-dimensional photonic crystal made of alternative left-handed metamaterial and right-handed material. An analytical direct matching procedure within the Kronig-Penney model was applied to analyze the dispersion properties of the localized surface states. We show that the presence of metamaterial in the photonic crystal structure can support the surface waves with a backward energy flow and allows a flexible control of dispersion properties of the surface modes. The surface states can be either forward or backward waves depending on the physical parameters of the photonic crystal, physical parameters of the cap layer, the position of the surface plane, and incident angle of the incoming beam.

In biosensors research, much effort has been made to achieve high sensitivity to detect lower concentrations of analyte in a solution by testing different kinds of materials. In this paper, we present a biosensor based on Bloch surface waves made of photonic crystal (PhC) including graphene nanolayers under the Kretschmann configuration. The band structures, surface modes, reflectivity, and sensitivity of the PhC biosensor are calculated by the transfer matrix method and results are compared with those of the structure without graphene layers. Our investigations show that the angular sensitivity of the biosensor considerably increases in the presence of the graphene layers. Moreover, we study the effect of the number of the graphene layers placed on the surface of the biosensor on the performance of our proposed biosensor. The results reveal that the sensitivity of the biosensor is enhanced by increasing the number of graphene layers on the surface due to the π-stacking interactions between graphene's honeycomb cells and the carbon rings in biomolecules. Furthermore, our results show that the phase sensitivity is higher than the angular sensitivity, which can promote the accuracy of the calculations.

No abstract

No abstract

No abstract

No abstract