Bloch modes at the surface of a photonic crystal interacting with a waveguide

We theoretically studied the influence of an infinite set of waveguides on the evanescent field of Bloch waves at the surface of a one-dimensional photonic crystal (PC) excited by a TE Gaussian beam undergoing total internal reflection. The set of waveguides is regarded as a periodic inhomogeneous medium with period a. Numerical results are presented for the case in which a is greater than λ, which is the wavelength used to excite the surface mode. When the waveguide tip is very close to the surface of the PC, a fraction of the surface wave is reflected by the tip, producing an interference pattern that can be observed in the near field. In this case, the system simulates scanning tunneling optical microscopy in 2D geometry, and an image of the field distribution of the surface mode is obtained by quantifying the flux energy throughout the waveguide.