Plasmonic integrated circuits

Waveguide structure for propagating a surface plasmon polariton,comprising an inter- metal plasmonic waveguide (1). The waveguide structure has two metal strip like structures (2, 3)positioned parallel to each other and an isolating material structure (4) positioned between the two metal strip like structures(2, 3). The two metal strip like structures (2, 3) are positioned at a fixed distance (d) from each other. The inter-metal plasmonic waveguide (1) is provided in a single layer of a CMOS processed substrate (5). Several waveguide structures (1) may be combined with a crystal like structure (6) to build logic gates, such as a switch having a gate, source and drain terminal (1G, 1S, D). Using three dimensional designs spanning several layers in a CMOS processed substrate (5) very complex yet compact logic circuits maybe designed.