Large capacity terahertz tag using photonic crystal slabs

The Internet of Everything (IoE) has attracted a great deal of interest. To realize the IoE concept, information tags which directly attach to objects are one of the keys to date. However, in terms of security or their uniqueness issues, today's information tags are still not satisfactory. Here, we propose the use of large capacity terahertz (THz) tags; by utilizing both frequency and spatial domains. This approach is expected to reduce our security concerns towards future IoE applications. In place of usual small capacity THz tag techniques, we introduced a new approach by large capacity THz tags using two dimensional (2D) photonic-crystal slabs in a matrix. As a result, we successfully demonstrated a THz tag of 48 bits/cm² at 600-GHz band. In conclusion, we anticipate that this work will contribute to the further development of the capacity enhancement of the THz tag: over 128 bits/cm² suitable for various IoE applications.