Active absorption modulation by employing strong coupling between magnetic plasmons and borophene surface plasmons in the telecommunication band

Abstract

The tunable and highly confined plasmon in 2D materials paves the way for designing 2D materials capable of manipulating light on a subwavelength scale, making them suitable for the design of optical modulators in ultracompact sizes. Herein, a continuously adjustable modulator in the telecommunication band is theoretically presented by the strong coupling between the magnetic plasmons (MPs) and borophene surface plasmons (BSPs). A remarkable Rabi splitting is observed and the coupling process is theoretically investigated by the model of two coupled oscillators. Results show that the splitting energy is determined by the coupling strength, which can be modulated by adjusting the distance between the borophene monolayer and silver grating. Moreover, by manipulating the electron density of the borophene to drive both two modes coupled or decoupled, the absorption can be continuously adjustable almost from 0 to 1 at 1544 nm, and the maximum modulation depth can be up to 94.8%. This work may provide a method to enhance light–matter interactions by the coupled multi-modes and design borophene-based plasmonic modulator.