Exploring Photonic Crystals: Band Structure and Topological Interface States

The physical mechanisms supporting the existence of topological interface modes in photonic structures, formed with concatenation two finite, N-period, one-dimensional crystals, are investigated. It is shown that these originate from a specific configuration bands and bandgaps origin band structure concatenated structure. Our analysis reveals characteristics such depend on structural parameters, including number, N, unit cells, determine properties corresponding resonant transmission peak. was width maximum value peaks decrease N. These results not only provide new insight into nature modes, but also can be used to control manipulate peak properties, as values, full at half (FWHM), Q-factor, which special interest fields optical sensing, filters, etc.