Designing ultra-compact high efficiency electro-optical plasmonic switches by using of nanocavity reflectors

An ultra-compact plasmonic electro-optical (EO) switch based on a silver-insulator-silver bus waveguide coupled to two nanocavity reflectors and two drop cavities is introduced. All cavities are filled with 4-dimethylamino-N-methyl-4-stilbazolium tosylate as an EO material. Finite difference time domain (FDTD) method and coupledmode-theory (CMT) approaches are used to numerically and theoretically investigate the properties of the device. Results reveal that the proposed device can work properly as 1 x 1 and 1 x 2 switches. By inserting nanocavity reflectors, one can improve the performance of the switches. Results are shown for switches with single and double nanocavity reflectors operating at 984 nm and 1560 nm, respectively. A transmission of 0.83 (0.77) and modulation depth of 31.41 dB (17.72 dB) at the wavelength of 1560 nm (984 nm) could be obtained. The proposed device has potential nanophotonic applications due to simple geometry and compactness. (C) 2017 Elsevier B.V. All rights reserved.