Ultra-compact and broadband tunable mid-infrared multimode interference splitter based on graphene plasmonic waveguide

TL;DR

This paper introduces a highly compact, broadband, and tunable mid-infrared MMI splitter based on graphene plasmonic waveguides, with potential for integrated photonic applications.

Contribution

It presents a novel ultra-compact, tunable MMI splitter design in the mid-infrared using graphene plasmonics, achieving a small footprint and broad wavelength tunability.

Findings

Device size is only 0.56μm*1.2μm.

Tunable from 7μm to 9μm wavelength range.

Device fabrication is feasible on-chip.

Abstract

We propose and design an ultra-compact and broadband tunable multimode interference (MMI) splitter in mid-infrared based on graphene plasmonic waveguides. The size of the device is only 0.56{\mu}m*1.2{\mu}m, which corresponds to device area of only about 0.014{\lambda}^2, where {\lambda} is the vacuum wavelength. And the center wavelength of the device can be tuned in a broad band from 7{\mu}m to 9{\mu}m with the Fermi level of graphene varied from 0.5eV to 1eV. Furthermore, the device is easy to be fabricated on chip.