Amplification of spoof localized surface plasmons on active plasmonic metamaterials

The amplification of spoof localized surface plasmon (LSP) modes has been explored and experimentally demonstrated for the first time by using a kind of active plasmonic metamaterial, which is composed of grooved ring structures with a sub-wavelength amplifier chip as well as the corresponding bias circuit. We have investigated and explained the physical mechanisms of the manipulation of spoof LSP modes in the grooved ring structures with the presence of the bias circuit, where both the integer modes and the half integer order modes can be supported simultaneously. Experimental results at the microwave frequencies show great agreements with the simulation results. It is believed that the active plasmonic metamaterials can find more applications for the purpose of sensing and integrated circuits in microwave and terahertz frequencies.