摘要：SummaryLogic gates are important components in integrated photonic circuitry. Here, a series of logic gates to achieve fundamental logic operations based on linear interference in spoof surface plasmon polariton waveguides are demonstrated at terahertz frequencies. A metasurface-based plasmonic source is adopted to couple free-space terahertz radiation into surface waves, followed by a funnel-shaped metasurface to efficiently couple the surface waves to the waveguides built on a domino structure. A single Mach-Zehnder waveguide interferometer can work as logic gates for four logic functions: AND, NOT, OR, and XOR. By cascading two such interferometers, NAND and NOR operations can also be achieved. Experimental investigations are supported by numerical simulations, and good agreement is obtained. The logic gates have compact sizes and high intensity contrasts for the output “1” and “0” states. More complicated functions can be envisioned and will be of great value for future terahertz integrated computing.Graphical AbstractDisplay OmittedHighlights•Six major plasmonic logic gates are designed by the linear interference approach•The logic gates are fabricated with other waveguide components on the same platform•The logic gates are characterized using scanning near-field terahertz microscopy•The logic gates are compact and have high-intensity contrasts for the output statesCircuit Systems; Photonics; Metamaterials
