Constructing a nanoscale optical polarizer with a graphene stack

TL;DR

This paper theoretically demonstrates that a stack of graphene layers with constrained carrier velocity can act as a nanoscale optical polarizer by selectively absorbing polarized light, enabling integrated polarization control in future devices.

Contribution

It introduces a novel method to create nanoscale optical polarizers using graphene stacks with constrained carrier velocities, a concept not previously explored.

Findings

Graphene stacks can exhibit polarization-dependent light absorption.

A fraction 2πα of light polarized along carrier motion is absorbed.

The proposed design enables controllable optical polarization at the nanoscale.

Abstract

Two-dimensional graphene layers exhibit many fascinating properties which have sparkled into applied research with the aim to build innovative electronic devices. Here, we theoretically demonstrate that, when the carriers velocity is constrained along one direction, a monoatomic graphene layer exhibits dichroism. A fraction $2\pi\alpha$ of the light polarized along the carriers motion is absorbed, while light polarized perpendicularly to that direction is not absorbed. A stack of two-dimensional graphene layers whose carriers velocity is constrained along one direction (such as a stack subjected to a suitable gate voltage) is thus able to polarize light up to the wished degree by selective absorption. These findings pave the way for built-in controllable optical polarizers in upcoming graphene nanoscale devices.