Nanoplasmonic optical switch based on Ga-Si₃N₄-Ga waveguide

In this paper, we propose an optical switch based on a metal-insulator-metal plasmonic waveguide with Si3N4 core sandwiched between two gallium (Ga) metal layers. Combining the unique structural phase transition property of gallium, within a total length of only 400 nm, an extinction ratio as high as 7.68 dB can be achieved in the proposed nanoplasmonic structure. The phase transition may be achieved by changing the temperature of the waveguide or by external light excitation.