Tamm states of one-dimensional photonic crystal based on surface defect

Based on the Bloch theory of periodic structure, the Tamm states of semi-infinite one-dimensional photonic crystal with surface defect (the defect Tamm states) were studied through analytical and numerical methods. The forming condition and field properties of the defect Tamm states was obtained. The properties of the defect Tamm states and the Tamm states without defect was also compared. For TB wave, the frequency range of defect Tamm state is enlarged to both high frequency and low frequency; for TM wave, the frequency range of defect Tamm state is only enlarged to high frequency, but is narrowed in low frequency. For large refraction index of defect material, the dispersion curve of Tamm state is close to a straight line and the group velocity is close to that light velocity in the single defect layer. The frequency of the defect Tamm state can be adjusted into our needed range by changing the refraction index or thickness of the defect layer.