Influence of surface termination on inverse Goos-Hänchen shift of negatively refractive photonic crystals
The effect of surface termination on the inverse Goos Hanchen (GH) shift of two dimensional (2D) negatively refractive photonic crystal (NRPhC) containing air holes arranged in hexagonal lattice in a dielectric background is investigated for TM polarization. Results show that the magnitude of the inverse GH shift of 2DNRPhC strongly depends on surface termination even for an incident beam with a fixed frequency and incidence angle. Further study by calculating the dispersion of surface mode of 2D-NRPhC as a function of surface termination reveals that 2DNRPhC presents large inverse Goos Hanchen shift at those terminations where surface mode is excited, that is, large inverse Goos-Hanchen shift originates from backward surface mode of 2DNRPhC. In addition, the coupling coefficient of incident field into the field of surface mode as a function of surface termination is studied and demonstrates above results. This paper provides technical information regarding the combination of various functional photonic elements in the design of integrated optical circuits.