Unidirectional plasmonic propagation of a metal-insulator-metal splitter with a multimode cavity

Abstract

A T-shaped metal-insulator-metal structure with a multimode cavity is investigated in a communication region. An s-mode (TM 0 ) propagates from the incoming arm and is coupled into an s-mode and an a-mode (TM 1 ). After propagating along the multimode cavity, the two modes are scattered into s-modes in the two outgoing arms, respectively. Our structure is able to achieve a unidirectional propagation of s-modes in the two outgoing arms under specified parameters (the position of the incoming arm and the length of the multimode cavity). The unidirectional plasmonic propagation phenomenon originates from two mechanisms. One is on account of different linear combinations of the s-modes and a-modes. The other is based on a self-imaging effect of multimode interference. Numerical simulations based on the finite element method verify our design method.

Magnetically controllable multimode interference in topological photonic crystals

“…Conventionally, multimode interference is realized by modifying the size of waveguides [34][35][36][37][38] , including their width or length, or controlling the refractive indices of the system with electrooptic effect 39,40 . However, back reflection loss 41 is a key problem that leads to performance limitations of traditional multimode interference devices.…”

Polarization-independent reflection grating in second-order Littrow for high laser resolving power

“…Gratings are found to have polarization-dependent properties when periods are comparable to the wavelength of the incident light. The power beam splitter, which can distribute the energy of incident light evenly to multiple output directions, is called a multi-port beam splitter [1][2][3][4][5]. These beam splitters are very common optical elements that can be used in couplers [6][7][8][9], quantum teleportation [10], polarizers [11][12][13][14] and polarization detection systems [15,16].…”