Interplay between Tamm-like and Shockley-like surface states in photonic crystals

The goal of this paper is to demonstrate that surface states in a defect chain embedded in a host photonic crystal can be viewed as an interplay between the Tamm-like and Shockley-like states. The defect chain with alternating strong and weak bonds is analyzed using an empirical tight-binding model and the finite difference time domain technique. We investigate how the spectrum of the structures changes with different termination of the chain. It is shown that under certain conditions the Tamm and Shockley states can coexist or can transform from one to the other. These important features allow for controlling the surface states in photonic crystals in frequency, location, and strength.