Highly controlled Bloch wave propagation in surfaces with broken symmetry

OpenAlex · English

We propose and demonstrate reduced symmetry photonic surfaces providing highly controlled Bloch wave propagation. The backward and dual directional propagations have been observed in the proposed low-symmetric periodic structures without variation in the unit-cell filling factor. Frequency-domain analyses present group indices up to negative/positive -237/+96 as strong indicators of the observed directional controlled surface waves driven by the orientation angle in the range of 20°-90°. Further verification of the index-based propagation direction has been achieved through detailed time-domain analyses and microwave experiments. Smart management of the propagation direction in low-symmetric surfaces has great potential for next-generation photonic applications.